Sunday 22 December 2013

Scans from Prints on Textured Paper

Why on earth did we do that? That, in this instance, being printing on textured paper like 'white fine lustre'. The texture, so popular in the 1950s, destroyed detail in the print and brings a groan to anybody scanning a print from that era. We did all we could to avoid grain in the negative and then added graininess at the printing stage.

Scans of 1950s prints on textured paper are often highly unsatisfactory. I scanned all the old photographs from two families, dating back to about 1860. Not surprisingly, the least satisfactory were those on textured paper from the time I started in photography. Many were my own prints.

For some time I searched for a solution reasoning that noise-suppressing software should enable a regular pattern to be at least toned down. Then I came across a report that Neat Image was the answer. So I downloaded the free trial version. I was so impressed that I paid for it immediately and dealt with all the scans of prints that I had. Mine is the Mac version that plugs into Aperture. Of course, it cannot restore what is not there and if overdone (the automatic setting worked fine for me) detail is smoothed over and lost.

These are before and after extracts from scans of prints on textured paper:


Before
After
Before
After

In the 1950s the various paper manufacturers had a wide range of textured papers. This is a Kodak advertisement from 1959 that shows the Bromesko (a very popular chloro-bromide paper):



Most of our photographs, particularly in the smaller sizes of paper, would have looked much better on white smooth glossy paper. So why did we not print on that all or most of the time. The current fashion was partly the reason. 'Proper' photographers used 'arty' textured paper. The second reason was that glossy paper had to be glazed by hand. By the late 1950s I had two chromium-plated steel glazing plates which fitted on a print dryer. These plates had to be cleaned, otherwise the dried prints would stick to the plate. After washing the prints were immersed for a few seconds in 'Glazing Solution'. The active constituent of this solution was ox gall; yes, the contents of the gall bladder of cattle killed in abattoirs (or slaughter-houses as they were then known). It is still used by artists as a paper wetting agent.

The wet print was then flattened onto the 8 x 10 inch glazing plate using either a flat rubber squeegee or a rubber roller, making sure that all the air was removed from between the print and the plate. Then the plate was held on the heated drying surface by a canvas cover until the dried print separated from the plate. After that palaver you had a glazed print. Badly glazed prints with air bubbles or specks of dirt looked horrible and had to be resoaked. Unglazed glossy paper had a dull but not quite matt. appearance. Commercial developing and printing houses had automatic, rotary glazers and drying drums.

So, it is perhaps not so surprising that textured papers were popular even when the quality of the final image was compromised.

Neat Image is at:
http://www.neatimage.com

Thursday 7 November 2013

Unitol Developer: Gone But Not Forgotten

All sorts of things turn up in boxes of old photographic equipment. Over the past year I have been buying daylight-loading developing tanks for my other blog/website which is intended to be a resource centre for present-day users of these tanks as well as a source of information on their history.


In an Essex 35 tank that arrived I found a cardboard calculator for Unitol developer. Unitol was made by the Johnsons of Hendon Ltd. It was introduced in late 1950. The BJ Alamanac included Unitol in its 1951 edition:

The essential new feature of "Unitol" is that, unlike most fine-grain developers, it may be diluted within wide limits so that it becomes possible to use it with the utmost economy – and simplicity – by following the slogan "One ounce; one film; use once; then discard". It is reckoned that one ounce of the concentrated solution is necessary for the proper development of one film, and that it is by then exhausted for practical purposes…Quite apart from this convenience, however, "Unitol" is a fine-grain developer of the highest grade…A most convenient calculator and film group chart has been prepared for use with "Unitol". Sold at the nominal price of 4d, it enables the time of development for any dilution, at any temperature, of any film to be immediately calculated by the rotation of a disc.

"Unitol" was extremely popular, at least in UK. I am pretty certain that the main active developing agent was Meritol. All the clues (sold in liquid form, not compatible with Johnsons 142 retarder, half-a-stop loss) suggest Meritol, and, as far as I am aware, the formula of the commercial mix has never been published. Meritol was Johnsons own patented agent. Another clue is that the Johnson advertisement in the same edition of the BJ Alamanac states, After long research Johnsons are now able to present a concentrated liquid fine grain developer. Meritol itself was patented in 1937 (applications made in 1936). Two patents (GB466625 and GB466626) cover the chemical synthesis and the formulation of a developer (essentially Johnson's Superfine Grain). Meritol was invented by Frank Clement Starnes, who worked for Johnsons. Starnes had died in 1945, aged 62, and I wonder whether his death, together with getting the company running properly after the war, was responsible for that statement, After long research.

Meritol was formed from paraphenylenediamine and pyrocatchin (pyrocatechol, catechol), each a developing agent. The additive product is a new compound with different properties from each of its constituents. Claims that the two components can be used instead of Meritol are not, therefore, accurate. Research on Meritol continued. I even found a paper in a chemical journal from 1989 that shows the distinct structure of Meritol.


Finding the Unitol Calculator (which would now of course be launched as an app) was a reminder of that 1950s mantra: Ilford Film; Kodak Paper; Johnsons Developer. It has to be said though that D76/ID11 caused wavering with the last part.

Johnsons of Hendon advertisement in BJPA 1951
The Unitol Calculator:

Centre was pushed out to form the
central disc of the calculator



Finally, the headings of the Starnes patents that covered Meritol:



Monday 28 October 2013

Minolta Autocord. Second Impressions


I put a roll of FP4+ film through the Autocord last week to see how it handled compared with the Rolleicord (and Rolleiflex since it has a lever wind).


First though I replaced the piece of felt on the inside of the door and a circle of leatherette that was missing from the upper spool holder. Milly’s Cameras (order from the eBay site) supplied the materials very quickly indeed. Compared to the Rollei, the back fitting to achieve light tightness is pretty crude.

Arrow shows the replacement felt
I didn’t find the handling so convenient as the Rolleicord. Focusing involves moving one hand (and sometimes two) under the lens board in order to move the lever from side to side. I really found the lack of a concentric depth-of-field scale a hassle. Situated around the lever drive with tiny knobs to move an inner wheel, I gave up on it and used my iPhone depth-of-field app instead. I also found that the position of the shutter did not feel quite right.

Depth of Field Scale
In using a TLR I usually use the magnifier and hold it at eye level with my forehead resting on the hood rather than low down like a box camera. But as I did so the magnifier moved out of the way and so I had to keep my eye a distance from the magnifier. This doesn’t happen to me with the Rolleicord or with any Rolleiflex I have owned.

Magnifier in viewing position
I do like the solid metal lens cap and, once I got used to it, the way it attaches to the bayonet fitting of the viewing lens.


In terms of handling the Rolleicord wins easily. However, when it came to the results, the lens on the Autocord did live up to its reputation. I found it the equal of the Tessar in terms of sharpness. It seemed to have more contrast than the Tessar but I would really need to do a side-by-side comparison to be sure.

This Autocord has certainly lasted well; the mechanisms seem robust and the lens looks and behaves as good as new. I will give it another try soon with infra-red film. I wonder for what wavelength the infra-red focus point was set.


Friday 18 October 2013

Rondinax, Rondix, Essex, Kent: New Blog and Resource Site for Daylight-Loading Developing Tanks

I have just launched a new blog/website on daylight-loading developing tanks. It includes links to videos which show how easy it is to use these tanks for developing 120 and 35 mm film, downloads of instruction manuals, tips on buying and something of their history. It is still a work in progress and more material is being added.

For those wanting to develop films without a darkroom as well as experienced users, I hope readers of this blog will enjoy the new one.

It is at:

http://rondinax.wordpress.com


Magazine Bias to Canon and Adobe?

In successive weeks, Amateur Photographer has been accused of favouring Canon over Nikon and Adobe Photoshop (the full fat version) over other editing software. The former was stoutly denied by the editor but I am surprised to see the letter now. A couple of years ago there was a clear bias towards Canon, subtly and not so subtly, in AP – to the point at which several family, friends and former colleagues (all very satisfied Nikon owners) would e-mail 'did you see that in AP' stories to laugh about.

The writer of the letter stated quite rightly that Canon for a short time held the lead in DSLR technology in terms of the performance of the sensors fitted. A number of professionals swapped to Canon at that time. Canon marketing was also clever. The distinctive colour of their long lenses shows what sports photographers are using and the generally sheep-like amateur camera buyers did what sheep do – they followed. Two high-profile professional wildlife photographers I know are provided with top of the range telephotos on long-term loan. Their cameras and lenses are noticed and copied. The distinctive colour helps again of course. Since then, of course, Nikon have come back with a vengeance in the DSLR stakes.

The obvious bias towards Canon in UK photographic magazines shifted most noticeably after the Olympics. The photographs of Usain Bolt with that Nikon must have been worth a fortune in marketing terms. Interestingly, the photographers who infest Wimbledon were sporting a greater proportion of black-and-gold lenses last year (an interesting diversion from the tennis and on the same level as looking for the binocular brands on BBC's Springwatch).

Both Canon and Nikon obviously make (or assemble) excellent cameras and the competition between them has generated rapid progress over the past 10 years.

The writer on Photoshop made the point that there are other software suppliers while Mac Aperture users (the premium end of the computer market) do not even get considered. We all know that the professional graphics package is the full version of Photoshop but that it comes at a very high price with a new selling strategy that stinks. Software specific articles in magazines are a pain because non-users are paying for content that is often completely irrelevant. If I were the editor, I would advocate a problem-based approach and then deal in outline the steps that would be needed in a variety of software packages. Generic advice on such controls as levels, curves etc that are common to lots of packages would also be useful.

Even though some of the more obvious bias in AP has gone, I must support the two letter writers. Some of the recommendations and comments have been outrageous over the years, not just by AP but by many magazines. Even when pictorial and graphic evidence was presented to the contrary and there for all to see, one brand was favoured in comparison articles.


Wednesday 9 October 2013

Digiscope or Superzoom Bridge Camera for Birding?


A correspondent who sells secondhand optical equipment for birding on eBay tells me that the prices of digiscoping adapters for major brand telescopes are falling. He thinks the rise of the Superzoom ‘Bridge’ cameras I have discussed in this blog is the reason. The extra focal length gained by using a scope (see my Post of 19 August 2012) is now of marginal advantage when we can get the 35 mm equivalent of 1200 mm focal length from a superzoom. Add the large number of pixels captured and the fact that there is image stabilisation in the superzoom, then I can see why the digiscoping may become a thing of the past fairly quickly.

It is obviously much quicker to point a superzoom camera at a bird than it is to mount the scope on a tripod, aim and focus the scope, attach the camera by whatever attachment you have and then press the shutter.

Another correspondent says he has just had a rare bird accepted from a photograph at 1000 mm equivalent with his Nikon P510 handheld.

Over the next few weeks I will eventually get round to comparing my two systems (Nikon P50 Superzoom vs Leica Televid and Panasonic Lumix on adapter) side by side at the mouth of the river and in the garden.


Minolta Autocord versus Rolleicord Vb. First Impressions


For current users of 120 film, the Minolta Autocord has an almost cult following that rivals that of the Rolleiflex and Rolleicord. The lens is argued to be the equal of and sometimes better than the Zeiss Tessar in the latter cameras.

Having read the stories, I was keen to compare the two cameras. It is, of course, not fair to compare the performance of two cameras, both 50 years old, picked at random from those on sale. Conditions of storage, amount of wear and servicing could all be different and affect the original design and construction differently. Unfair, yes, but I will do it anyway.

I bought the Autocord from a UK seller on eBay. As soon as it arrived I realised it was in excellent condition and identified it as the RG 3rd version of 1963. That same day, I checked the shutter speeds electronically and found they were consistently about ½ stop slow and not worth applying a correction when using films like FP4+.

Please bear in mind that the Minolta Autocord was very different in price from the Rolleicord. In Amateur Photographer of 15 February 1961 I found one advertisement for the Autocord at £53-9-6d. In another advertisement on 14 February 1962, the Autocord was £50-7-10. Rolleicords at that time were about £85.

Please also bear in mind that Japanese cameras were very slow to gain acceptance in Britain in the late 1950s and early 1960s. They were regarded as cheap, unreliable and inferior imitations of German products. The trade was still locked into the British agents of German manufacturers. As one camera shop owner said to me in the late 1950s while looking down his nose at a Japanese TLR, ‘I have to sell these because of the price but I hate having to do so. Real photographers will always use German cameras.’ I do not recall ever seeing an Autocord in a camera shop; Yashica, especially the 4x4 yes, Minolta no.

So, without having used it yet, these are my first impressions.

The Autocord is heavier than the Rolleicord Vb (930 vs 1000 g). In general, the construction of the Autocord is crude compared with the Rolleicord. For example: screw heads are on show (anathema to premier German manufacturers); the opening mechanism is very crude and closure of the back relies on felt seals in places. The hood is non-removable and the sports finder release mechanism somewhat unreliable.

In terms of focusing, I prefer the side wheel of the Rolleicord to the front lever of the Autocord. I also prefer the split-image centre of the Rolleicord screen to the plain ground glass centre of the Autocord. I can see no difference in brightness.

The depth-of-field scale is around the focusing knob of the Rolleicord which makes it easier to use than the one on the Autocord. In the latter it is around the winding crank and the focused distance has to be read off the front scale and then applied to the depth-of-field scale. The Autocord but not the Rolleicord has an infra-red focusing mark.

Setting the shutter speed and aperture I find easier on the Autocord. I hated the exposure value system when it was introduced and I hate it now. Having to unlock a lever to change shutter speed and aperture was, and is, infuriating.

A major difference between the two cameras is the winding crank of the Autocord, thus making it comparable with a Rolleiflex like the T model.  For the type of photography I do with TLR cameras, I actually prefer the winding knob of the Rolleicord but I can see that, in its day, a rapid wind lever would have been an attraction.

The next job is to load a film and try the Autocord in action.

Tuesday 13 August 2013

Exakta Varex Cameras. 3: 2013 Perspective


It was nostalgic fun to have an Exakta (well three, actually) at the eye for a while again after an interlude of nearly 40 years. I bought three bodies which came with a total of five lenses from different eBay sellers.

It is very unfair to extend performance of an old camera to criticism of the manufacturer because so much depends on how it has been treated by its owner or succession of owners. So many cameras of the 1950s and 60s have been handed down to children who then abandoned them in attics, garages and sheds until moving house.

There were five problems with one or more of the bodies.

In all three (one Varex IIb and one IIa) the foam rubber that cushions the mirror had crumbled away or was in the final stages of doing so. That was easily replaced by material supplied by an eBay seller.

Replacement foam above the mirror

In both IIbs but not the IIa the frame counter was not working. It jumped all over the place when the film was advanced. This mechanical failure I am told is a common problem.

The frame counter did not work in the two Varex IIbs

The mirror was beyond use in the IIa. The silvering had deteriorated badly, starting it seems, from chemical reaction as the foam rubber broke up. The mirrors in the IIb were fine with just a little deterioration at the edges near the foam.

The mirror of a Varex IIa showing deterioration of the silvering

The major problem in the IIa but not the IIbs was the state of the shutter curtains. The deterioration of the material is a well-known problem. The curtains were wrinkled and had, when a light was held behind them, what seemed like pin holes. However, pin holes are usually a seller’s description. This is far a more serious condition. The whole (rubber?) material within the curtain is in process of breaking down and the light leaks are extensive, as the following photographs show.

Wrinkled shutter curtain - tell-tale sign of light leakage
Light coming through the shutter curtain

Light coming through the shutter curtain (LED torch in mirror box)
Smooth curtains not leaking light in a Varex IIb

Temporary (paint the curtain) and permanent (do-it-yourself curtain replacement or professional repair) solutions are shown in a number of websites. However, professional repair is an expensive route (£200 plus + VAT, I was quoted) which is why so many Exakta bodies are lying ‘beyond economic repair’.

I also tested the shutters of the two IIbs, both electronically, and with film. I did not test the IIa in view of the light leakage through the curtains.


One of the shutters tapered at 1/500th and 1/1000th sec so could not be used at those speeds without servicing. That shutter sounded better than the one in the second body which fired with a squawk that is said to indicate a lack of oil. The second was fine to use at all speeds. In terms of accuracy, the pattern was the same or similar to that reported in various websites. The higher speeds were slow: the slower speeds were fast.

Taking the IIb with the good shutter, from 1/500 to 1/60 sec (I could not get readings at 1/1000 with my set-up) there was 1 stop overexposure (to the nearest whole stop). From 1/30 to ½ sec timing was within ⅓ stop. At 1 sec there was 1 stop underexposure (i.e. the mean exposure of five firings was 0.54 sec instead of 1 sec).

In the body of the one of the IIb that tapered at high speeds, the variation was somewhat different. I held the sensor in a fixed central position in the film frame so that I was not looking at variation across the frame. 1/250 sec was near enough1/250 sec (mean 1/290). 1/60 and 1/30 sec were slow by one stop. ¼ and ⅛ were pretty well spot on while ½ and 1 sec were within 1/3rd stop of being accurate.

By knowing the accuracy of he shutter I was able to make appropriate corrections when I came to testing the lenses and actually using the better IIb to take a few photographs.

Rumour has it that the mechanical build quality of the IIa was better than the IIb. I cannot comment. All these cameras were in need of servicing. I doubt if any had been serviced since they were manufactured.

All the 50 mm lenses (two f/2.8 Tessars and two f/2 Pancolars) had problems. The pin that engages with the lever on the body had been torn out of one of the Tessars. I can only guess that somebody had inherited the camera and had then tried to change the lenses using brute force. The notched lever on the body was also bent (replacement found on a dead Exa). That lens was a write off and soon on its way to the recycling centre for glass and metal.

The other Tessar had slightly stiff focusing and some cloudiness on an inner element (what is the that cloudiness in chemical terms?) so contrast was low. In use it could still produce a reasonable image in high contrast conditions of bright sunlight.

One of the Pancolar was of the earlier design (without the automatic depth of field indicator lugs)(see 11 June post). Again it was slightly cloudy internally (again - what is that cloudiness?). It gave soft, low contrast results on film. The other Pancolar was of the later design with automatic depth of field indicators. Edge fungus was present but only affecting f/2 aperture. It was slightly cloudy internally and again produced soft, low contrast negatives.

In short the 50 mm lenses were way past their best. The Pancolar had the reputation of being fairly low contrast when new but my original 1960s Pancolar was capable of giving very sharp, punchy transparencies with Kodachrome.

Included with one of the outfits I bought was a 135 mm f/4 Sonnar. I was very impressed with the quality (so is its new owner). No sign of any cloudiness or fungus with just a few specks of something internally. The results on film were excellent - very sharp and excellent contrast. That lens had lasted well.

135 mm f/4 Zeiss Jena Sonnar

This Exakta lens hood fits all the 50 mm and the 135 mm f/4 lenses
Original Ihagee filters are not that common

The cameras did the job I wanted them for (to produce developed 35 mm for another project I will describe later) and have now gone to new owners.
So, after handling and using Exakta cameras again, would I like to turn the clock back and return to 35 mm film photography from full-frame digital? NO. NO. NO. We really have never had it so good. 35 film is in the past and offers no advantages over what we have now other than, for black-and-white, a stored silver image.





Friday 9 August 2013

Zeiss Lenses: A Legend Destroyed


For those of us brought up from the cradle to believe that Zeiss lenses are the ultimate in optical design and quality, the review of a very wide range of f/1.4 50 mm lenses in Amateur Photographer (20 July 2013) destroyed that belief as a myth. At full aperture and even at two stops down, the resolution of the Zeiss Planar T* and the Makro-Planar T* (for Canon and Nikon bodies) was truly awful. Only at f/11 (yes f/11) was the resolution excellent. But who is going to buy an f/1.4 lens to obtain excellence at f/11? The lenses from Canon, Nikon, Pentax, Sigma and Sony were, overall, much better and (with the exception of the Sony Zeiss Planar) much cheaper than the very well-built Zeiss Planars.

No more shall I look at my Nikon lenses and think that Zeiss equivalents are probably even better. But, come to think of it, the evidence has been there for years. Nikon took off in the West because photojournalists covering the Vietnam war found Nikon lenses were incredibly sharp in the centre.

The German camera industry is not faring well in AP reviews this year. First the brickbats for the new Leica M and now quantitative evidence on the poor performance of Zeiss 50 mm lenses. Zeiss, of course, lost their leading position in the binocular/telescope market to Leica and, later, Swarovski.

AP, in giving its verdict, stated: …it is clearly an old optical design that has now been bettered. But then, curiously, that statement is hedged: However, the build quality is great, and for those who shoot street pictures, and manually focus, they are nice lenses. Even more curiously, AP gave these lenses 4 out of 5 stars (no lens scored lower than a 4). By my reckoning, they were 1-star. Judging by the quantitative data, being excellent at f/11 with a high price does not make up for the fact that they were poor lenses compared with all the others. My Nikkors can rest easy.

Sunday 4 August 2013

Cameras for Birding: The ‘Bridge’ Camera Zoom War: Panasonic Lumix FZ72 Joins The Fray


Panasonic have now joined the zoom war in the increasingly popular superzoom ‘bridge’ camera category that is so good for birding.

I have added this camera to the table I prepared for my post of 9 March 2013. These are the key features as far as using the camera for birding are concerned but it would be good to know how it handles noise at high gain (ISO setting) and the chracteristics of its autofocus.


Nikon P520Canon SX50Fuji HS50Sony HX300Panasonic FZ72
Optical Zoom (equiv)24-100024-120024-100024-120020-1200
Max Aperture3-5.93.4-6.52.8-5.62.8-6.32.8-5.9
Sensor Size1/2.31/2.31/21/2.31/2.3
Resolution (Mpixels)18.112.11620.416.1
Output Size (pixels)4896x36124000x30004609x34565184x38884608x3456
StablisationYesYesYesYesYes
OutputJPEGRAW/JPEGRAW/JPEGJPEGRAW/JPEG
VideoFull HDFull HDFull HDFull HDFull HD
Weight g550595758623562


I haven’t seen a review of this new camera yet but how the market has changed in little over a year: from only a Nikon to a five superzooms from all the main manufacturers. Given the reputation of the Lumix series, I suspect this new one will provide the others with stiff competition.

Thursday 1 August 2013

Video: Camcorder, Compact or DSLR? It all depends on the depth of field you want


The useful article The Definitive Camera Guide in the new magazine, Digital FilmMaker, together with a discussion in Amateur Photographer on whether to buy separate video and still cameras, prompted me to remind myself, in the headlong rush to use full-frame and APS-sized cameras for video, why a small sensor, as found in most amateur, 'prosumer' and some professional camcorders, is preferable for the type of video photography that I do – travel, wildlife and documentary. Film makers which I define as those setting out to make a movie with actors or a staged documentary, appear to be fixated on getting a film-like appearance. Since the appearance of film can be more easily achieved with the depth of field range of a larger sensor (as with 35 mm cine cameras) some follow the fashion and use a large-sensored DSLR. The fact that we see in such videos endless focus shifts that the dramatic effect is expected and therefore ruined is neither here nor there. Such is the world of arty film making.

For travel, wildlife, family and documentary videos there is one great disadvantage in using a DSLR for video. The depth of field is simply too shallow. I have seen some awful efforts. Even if the camera can be focused, the slightest movements lead to the autofocus hunting to regain focus; objects slightly in front or slightly behind the point of focus that are needed to be sharp to provide context are fuzzy. DSLR video is fine for controlled shooting. The many rigs now available can be used; focus can be pulled manually after rehearsing the shot.

Camcorders are not thought cool any more. But they do work and work very well, especially those in the prosumer ranges of the major manufacturers (even though the gimmicks, like the projectors now added by Sony for example are a real pain and very silly). The quality of the full HD video is superb. I have sold wildlife footage from my Sony camcorder.

So what is the advantage of using a small sensor for video? For stills, the bigger the sensor the better, particularly for the prevention of noise. The advantages of a smaller sensor in terms of depth of field are very great for travel and wildlife. In general, with the same final image size, depth of field increases inversely to the size of the format. That is because for the same picture size, a shorter focal length lens can be used with the smaller format. Shorter focal length equals greater depth of filed. Even though the circle of confusion has to be reduced as the format size decreases, the depth of field is still increased.

The first graph illustrates the point. I compare five formats: 1. Full-frame 35 mm; 2. APS (I know the various sensors vary in size a bit but I have taken one for comparison); 4/3 format as used on many modern non-DSLR cameras; 2/3 sensor as used on many professional camcorders; 1/2.88 sensor as used on many amateur, prosumer and some professional camcorders. I calculated for each the equivalent focal length of the lens and, using the circle of confusion appropriate to each format, read off the hyperfocal distance at f/11 and f/4. The graph shows the near point of acceptable focus (i.e. half the hyperfocal distance), the far point of course being infinity.




The difference in depth of field is clear and dramatic. At a small aperture and at focal lengths shorter than the equivalent of about 50 mm, it is difficult to be out of focus using a camera with a small sensor.

I used the same data to calculate the depth of field with the camera focused at 3 metres, again at f/11 and f/4.



It can be seen clearly why footage from a small-sensored iPhone (1/3.2 – similar to 1/2.88) often produces better results in casual photography than a DSLR.

These calculations were all for the equivalent of a 50 mm lens. At 200 mm the effects are even more marked. Imagine a subject moving (e.g. a child playing or a group of otters) in the frame of full-frame DSLR where the depth of field is only a total of 14 cm at f/11 compared with a camcorder with a depth-of field of 100 cm.

Shallower depth of field can be obtained with a small sensor (even if not to the extent possible with a large sensor) by using neutral-density filters (built-in in some professional camcorders) or a polarising filter.

Sunday 28 July 2013

Leica M: A Crushing Review in AP


Leica must be smarting. The review of the new Leica M Typ 240 in Amateur Photographer (6 July) must be one of the worst pannings ever seen in this magazine. Just a few snippets from the final paragraphs are sufficient to indicate the reviewer was less than impressed:
...but these features have handling snags that smack of a product that hasn’t been thought through properly......the sensor doesn’t record as much detail and sharpness as competitor cameras...is something of a sideways step from the M9, rather than the step up…
All that for £5100 body only.
Then, the next week (13 July) AP had a letter from a disgruntled Leica purchaser who had bought an M8 in December 2010. After 29 months (5 months after the guarantee had expired) the camera failed but Leica were reported as saying that they could not repair it because they did not have the parts but for £2700 would supply a new camera. That correspondence is still running.

Having had a Leica M3 and an M6 with a range of lenses, I always wondered if I would regret selling them when a digital M eventually appeared. The only feature I miss (other than the optical quality of some of the lenses) is the direct vision viewfinder (only with the 28-50 mm lenses, however). Very rarely did the M3 or M6 seem the ideal camera for the type of photographs I was taking at the time.
Since I sold all my Leica equipment I have only handled two digital Ms, an M8 and an M9 both belonging to fellow travellers. Both occasions were nostalgiafests but I talked for a while to the young owner of the M9. He also carried a Canon DSLR and admitted that he was hardly using the Leica. He felt he had to take some photographs with it because he had paid so much to get it. However, he said that he found it far more tricky to use than his  DSLR, both in terms of focusing (he had not been brought up with rangefinders) and exposure.

Will damning reviews in AP and the like have any effect on Leica sales or future policy. I doubt it. There are plenty of wealthy red dot buyers in the world. However, I suspect even more strongly than I did before that Leica are now off the pace when it comes to digital technology.

Leica binoculars and telescopes, fortunately, are still world-class. All members of this family are Leica orientated for birding optics (at least 10 binoculars and scopes between us). We all prefer the handling of the Leicas compared with Swarovski.

Tuesday 16 July 2013

Exakta Varex Cameras. 2: 1960s Perspective


I mentioned in a previous post (2 July) an Exakta Varex IIb I had from 1966 to 1978. I also said that in its day, the Exakta was the 35 mm SLR. By way of illustration, this is an advertisement from Amateur Photographer (25 November 1964):


In the front pages of advertisements — the main selling pages for new and high-end second-hand cameras — Exakta advertisements from retailers loom large. By contrast, I can only find one mention of a Nikon F: a single line listing one second-hand.

To some extent, this pushing of Exakta and ignoring of Nikon reflects the social trends in photography in the late 1950s and early 1960s. As Japanese cameras began to appear in Britain in the late 1950s, there was an intense snobbishness about them. How on earth could the Japanese produce cameras of a quality equal to that achieved by the Germans? However, at the same time, East Germany was dominant in the ‘good value’ market from the late 1950s. We had seen and owned the Zeiss Jena Werra and the Praktica models were now being promoted.

West German cameras led by Zeiss Ikon and Leica, of course, were far more expensive when apparently comparing like with like, than those manufactured East Germany. I suspect the dominant position East German cameras came to occupy in the British camera market was achieved not only by lower manufacturing costs but by retailers being offered higher margins by the importer. So, we had a situation where the rich bought West German and the poor bought East German. However, the Exakta was in a different position in the market. There was no real West German equivalent. The Zeiss Ikon Contaflex was not so versatile and, it seemed, was aimed at the rich amateur taking a limited range of photographs.

So we had Exakta leading the whole German pack when it came to SLRs and not yet being exposed to the competition from Japan. The competition already existed but the market was not being exploited by the agents of the Japanese companies in Britain. It would be years until the Japanese manufacturers set up their own marketing companies in U.K. and replaced their British agents.

The standard choices on offer in the Dolland & Newcombe advertisement reflect the need, then and now, in Britain at any rate, to show a low headline cost. In this case the Varex IIb was offered with the awful Domiplan lens, for example, while the f/2 Pancolar was listed with the body and reflex finder, not the pentaprism. The headline price of these kits varied from £71 to £82. The ideal combination of body, pentaprism and f/2 Pancolar is not listed. Looking at the price list that kit would have been approximately £100. That is the combination I bought in Hong Kong in 1966 but without the purchase tax then applied in Britain and the cut-throat competition, the Hong Kong Price was between £30 and £40.

So what sort of camera would you get for the same money in 2013? There are several ways to calculate what £100 represents today. In terms of the increase in the retail price index, the Varex IIb combination would cost £1663 today. Because pay has risen faster than prices since 1964 (as wealth has been created) this index provides an underestimate of the equivalent price paid. Whatever the exact figure, we can say that, roughly, that top of the range Exakta was equivalent at least to a Nikon D600 with a zoom lens in terms of 2013 prices. Photography really was expensive in the 1950s and 60s. And that 1960s camera delivered just the three controls: shutter speed, aperture and focus. There was no exposure metering, no autofocus and no instant-return mirror. We really have never had it so good — whatever the luddites who infest the letters pages of the photographic magazines may believe.

Tuesday 2 July 2013

Lens Depth of Field Scales. 2. Intrapolation and the Infinity Mark


A slight complication of reading a depth-of-field scale is that the focusing scale on a lens is not linear. In other words, equal distances on the focusing scale are not equal distances between the camera and the subject. There is a greater distance between, say, the marks for 2 and 3 metres than between those for 3 and 4, and so on. The corresponding position on the focusing ring of the aperture mark on the depth of field scale has to be estimated by intrapolation because there is not room on the focusing ring for marks at, say, every metre, as the subject distance increases.

The pitch of the thread on the focusing ring, the greater circular distance the ring has to be turned to change the point of focus. With a fine thread more marks can be shown. Even with a lens with a long travel (i.e. a good depth-of-field scale), estimates have to be made between, say, 10 and 15 feet with allowance made for the fact that the distance on the focusing ring will be greater for 10-11 feet, than for each succeeding foot up to 14-15 feet. Beginners unaccustomed to non-linearity have to be made to realise that a point midway between the 10 and 15 foot marks is not 12.5 feet.

The reason that the focusing scale is non-linear is not because there is a circular dial. It is simply because of the laws of physics. The graph shows the lens-film distance as the focused subject is moved from 1 to 100 metres from the camera. In the nearest 10 metres, the lens is moved more than 2 mm but the movement is less than a further 0.5 mm in shifting the focus between 10 and 100 metres for a 50 mm lens.

Lens-film (sensor) distance at different subject distances for a 50 mm lens

At long subject distances, the change in the lens-film distance is so small that virtually anywhere within reason could be chosen as a point of maximum travel for the focusing ring. At long ranges an ∞ mark is not really necessary especially for short and medium focal lengths. The focal length (i.e. when the lens is 50 mm from the film) could be the position of the ∞ mark, since the blue line in the graph hits the focal length when the subject is at ∞. But what is infinity? With a depth-of-field scale an ∞ mark is necessary and its position can easily be set by the lens manufacturer, either at the focal length or near to it.

One way of looking at the ∞ mark is to consider it from the point of view of the depth of field scale. Depending on the circle of confusion (see previous post) the lens is focused on a subject at the at the hyperfocal distance. Then the scale can be marked at the near point of acceptable focus at a particular aperture. The measured distance on the scale between the near point and the hyperfocal distance can then be applied to the opposite side of the scale to indicate the point on the focusing scale to which the ∞ mark can be marked on the focusing ring. In other words the ∞ mark is needed for the depth-of-field scale but its position can be calculated in the first place from the calculated depth-of-field for a lens of a particular focal length at a particular aperture.

Out of interest, I measured as accurately as I could the position of the focusing marks on an old Pancolar 50 mm lens, transformed the values so that I could get a linear relationship to subject distance and then extrapolated the line to estimate what distance the ∞ mark was set at. Infinity was set at approximately 255 feet (78 metres). How far the actual setting is from the 50 mm focal length that could be set as being at infinity I do not know.


Sunday 30 June 2013

Lens Depth of Field Scales. 1. Hyperfocal Focusing and Circles of Confusion


I know it is difficult to incorporate depth-of-field scales in modern zooms but even on modern prime lenses (like my Nikon f1.4 50 mm) they are rudimentary to the point of uselessness). And I miss them. One of the great advantages of a proper depth-of field-scale is the rapid setting of the hyperfocal distance without having to remember what the hyperfocal distance is. All you have to do — and it seems that very few photographers know this — is decide what the near point of acceptable focus is (by focusing on that point and reading the focus scale), swing the focus ring so that the ∞ mark lines up with a particular aperture (e.g. f/8) on the depth-of-field scale, then look at the other side of the scale to see if at that aperture the near point shown on the focus ring is within the range of acceptable focus. If it is, then set that aperture for exposure. If it is not then move the ∞ mark to larger aperture number (i.e. smaller stop, e.g. f/11) and try again until the near point is within the range. The whole process is so rapid that it is easier to do than describe.

These photographs of the focus ring and depth-of-field scales of an f/2 50 mm Pancolar lens illustrate the point. In each case the ∞ mark on the focusing ring is swung to the point indicated by the aperture (f/8 in one photograph, f/11 in the other). It can then be seen easily that the range of acceptable focus is from about 12 feet (about 3.5 metres) to infinity at f/8. The focus mark is at the hyperfocal distance but you didn’t need to remember that or look it up in tables or even in a depth-of-field app to get there.

Similarly, in the second photograph, using f/11, the depth-of-field extends from about 8 feet or 2.5 metes to ∞.


Here, the aperture is f/8 (lower ring). the focus (upper ring) is swung so that
the ∞ mark is opposite f/8 on the depth-of-field scale (middle). The point of
acceptable near focus can be read from the focusing ring at the f/8 mark on
the depth-of-field scale. The point of focus (orange arrow) is at the
hyperfocal distance.

Same as above, this time using f/11

Now, the interesting point is that you will not get the same result using a modern depth-of-field calculator for a full-frame 35 mm lens. Instead of 12’ to ∞ at f/8 we get 17’ to ∞, and instead of 8’ to ∞ at f/11 we see 12’ to ∞ on a calculator. The explanation is simple. The depth-of-field scale markings on an individual lens depend on the value taken for the circle of confusion used by different manufacturers at different times. For the Pancolar made by Carl Zeiss Jena in the 1960s shown in the illustrations above, the circle of confusion was taken as 1/20 mm (i.e. 0.05 mm). This is what Werner Wurst had to say in the 9th edition of his Exakta Manual (2nd English edition, 1966):

...a circle of confusion of 1/20 mm is still recognized as sharp for the 24 x 36 mm format. The tolerances of unsharpness in which the depth of field scales of the EXAKTA Varex lenses made in Jena and Görlitz are based are derived from these data. However, other optical manufacturers reject as unsharp anything larger than 1/25 mm [0.04 mm]. In actual practice these variations can be ignored; however, bigger variations in either direction can no longer be tolerated. Thus, the assumption of a still smaller circle of confusion (e.g. 1/30 mm [0.03 mm] would unduly restrict our possibilities during focusing while larger diameters (e.g. 1/10 mm [0.1 mm] will be immediately be recognised as unsharpness.

It is interesting that the current practice is to use 0.03 mm for the full-frame (24 x 36 mm) format. Thus, depth-of-field is taken to be shallower than was once regarded as perfectly acceptable by a major lens manufacturer. Whether we can discern a difference is another matter.

What we can do is to compare the reading for near acceptable focus and hyperfocal distance obtained with a depth-of-field scale on an old lens with those values calculated using an iPhone app and the like. By using different circles of confusion in the calculation, it is easy to determine what value was being used by a particular lens/camera maker at the time of manufacture. You can then decide — provided you are using the lens with a sensor of the same format for which it was designed — whether to stick with the depth-of-field scale on the lens or move to a smaller circle of confusion and a shallower calculated depth of field.

Thursday 20 June 2013

Ilford Advocate: Why Ivory?


The article on the Ilford/Kennedy Instruments Monobar camera in Amateur Photographer earlier in the year reminded me of a question that had niggled me for years. Why was the body of the Ilford Advocate ivory in colour?

In its day the Advocate was not a popular purchase or seen by most amateur photographers in Britain as an object of desire. In the early 1950s it could be seen in chemists’ shop windows (pharmacies) amongst the display of Ilford film. But the objects of desire were not this British-designed and built 35 mm but German black leatherette and chrome, even when imports of the latter were restricted to cheap models in the aftermath of the war and protection of the £ sterling currency.

The Advocate was relatively expensive and the colour really did put people off. Serious cameras were black — full stop. Somewhere Ilford marketing had failed. The bright, sunny Ilford displays with their bright white (well ivory) camera had not worked and the cameras were eventually sold off at sale prices.

I read in the AP article that the Advocate was designed and built by Kennedy Instruments. A good deal of laboratory equipment in the 1950s and 1960s was stove-enamelled in ivory. Therefore, I wondered if Kennedy Instruments were scientific instrument makers who then manufactured the Advocate. To satisfy my curiosity I bought the book, Faces, People and Places. The Cameras of Ilford Ltd 1899-2005, by Andrew Holliman from the author*. It appears that Kennedy Instruments (partly from 1949 and then totally owned by Ilford) were not instrument makers in the laboratory sense but came from automative engineering to camera design and construction (including cameras for the Keartons in the 1930s and for aerial reconnaissance).

The ivory finish of the body was, it appears, chosen deliberately. Holliman writes:
   The most distinctive feature of the Ilford Advocate, especially against other cameras in any collection, is the ivory enamel finish. However, other colours were considered. Various methods mostly of different paint finish were assessed in an attempt to give the camera a black and chrome appearance but they came to nothing.
   At one time several bodies were produced in six different enamel colours, Red, Green, Blue, Brown, Yellow and Black, and presented to the Ilford Board for consideration. These were rejected by the board.
Holliman also describes the problems Kennedy Instruments had in trying to get lenses in sufficient quantities from British manufacturers. Dallmeyer could supply with consistency and ‘quite high quality’ but not quantity. Wray had problems with quality control leading to many of their efforts being rejected. Ross also could not supply a suitable lens. The price of the Advocate remained high because economies of scale could not be achieved.

The high prices achieved for these cameras in sales, even of wrecks on eBay, to present-day collectors is a result of marketing and manufacturing failure. Successful cameras are not that rare.

By contrast, consider the later Ilford Sportsman, made in Germany by Dacora. I was surprised to learn that Ilford at one time held over 50% of the UK 35 mm market with the Sportsman series and that this level of sales is thought to have helped them (with the little stickers in the film compartment) to capture the major share of the 35 mm film market. The cost to Ilford of the original Sportsman was less than £3 which was less than the cost of the lens for the Advocate. Dacora were not at the premium end of the German manufacturers but for the British mass market of the 1960s a low headline price held (and sadly still holds) sway.

Finally, looking at the Ilford/Kennedy Monobar in Holliman’s book, I cannot help but think what a superb technical camera it would be with a 24 x 36 mm digital sensor instead of the film holder.



*Andrew Holliman’s book (ISBN 0-9655342-1-2) was published in 2006. It can be obtained from him through his website:
http://www.electricstrings.com/ilford.htm