Photography has entertained, informed and infuriated me for 70 years. However, I am not a photographer. I use video and still photography to record and illustrate my observations of the natural world. In this blog I also comment on optical equipment used for viewing wildlife and on the changes in photography from the 1950s to the present day
I do not know which genius of industrial designer puts an unlockable adjustment wheel in just the position where it is inevitably going to get moved. Well whoever designed the viewfinder of the Sony AX-700 camcorder did just that. Not only does it take great care to pull the viewfinder to its open position, the wheel is so positioned that it catches on the sides of camera bags, on straps and on clothing. Much foul language is emitted when all I can see is a grossly out-of-focus image in the viewfinder. Three times in six days of use it happened to me recently.
I thought about trying to lock the wheel in place with sticky tape—as some users do—but sticky tape often comes adrift, especially in hot places, and if somebody else uses the camera then they have to adjust the dioptre setting to suit their eyes. Not only is the adjustment wheel unlockable, but it is also uncalibrated, so there is no way of knowing it has moved out of position or how far it needs to move to restore the setting.
I decided that instead of trying to tape the wheel in position I would put a mark on both body and wheel where I found optimum focus. This I did with a 0.7 mm white paint marker. Provided the paint sticks (so far so good) I can at least return the wheel quickly if it does get moved or if somebody else uses it. I could also use a different light colour on another position of the wheel to suit another regular user or even a different eye.
That's the eye (dioptre) adjustment wheel which gets moved accidentally
...and that's the index mark I have added across body and wheel
That’s very odd, I thought. I must have left the viewfinder pulled out. Several times I have found long clips of video on my Sony FRDR AX-700 camcorder. Only when I found comment in a forum on the annoyances and idiosyncrasies of this camera, did I realise what I had been doing. On all other camcorders I have had, returning both the LCD monitor and the viewfinder to the closed position turns the machine off, even if the camera is still recording. Indeed I have used that method to stop recording and turn the camcorder off since pressing the on/off recording button inevitably causes a small movement in the clip. And that is what happens according to the main text of the instruction manual (either monitor or viewfinder open, power on; both closed, power off). But it doesn’t. In in small note under the main text describing powering on and off is written: When recording movies or when connected to another device via USB, the camcorder does not turn off even if the LCD monitor is closed and the viewfinder is returned to its original position.
So, if still recording intentionally or accidentally (see below) the camcorder cannot be turned off by the usual means. It carries on recording. It must be that some bright spark at Sony thought this would be a good idea to save battery life during long recordings with the camcorder mounted on a tripod with no need for the monitor or viewfinder to be used. The problem then gets worse because even if, with the monitor and viewfinder closed, you find it still recording, one might have thought that stopping recording would then turn the machine off completely. But no, the camera stays turned on. To turn if off the monitor or viewfinder has to be opened and then closed.
This problem of stopping recording and turning the camcorder off is exacerbated by another highly annoying ergonomic failure. To the operator, the only indication of whether or not the camera is recording video is a tiny indicator in the top right of the monitor and viewfinder. The tiny letters change from STBY in green to REC in red. That’s OK—if not exactly a signal loud and clear—indoors or in moderate outdoor light. However, in bright sunlight, the monitor is difficult to see (even with it brightness turned up). Turning to the viewfinder in bright sunlight is like staring into the Black Hole of Calcutta and it takes some time for the eye to accommodate to the dim indicator lights (the brightness of which cannot be controlled). Because a definite press is needed on the button to switch recording on and off it is difficult to confirm what the camcorder is actually doing. Hence it is possible to both miss shots and to to leave the camera recording accidentally.
Screen and viewfinder information in Standby and Recording modes. Easy to see indoors and on dull days but try the viewfinder in bright sunshine and it's a different story. And pity those who are red-green colourblind
I have written before of how I regard this camera as my curate’s egg. I can only repeat my conclusion:
This camcorder then is typical Sony: some brilliant features let down by poor ergonomics, poor user interface and poor documentation.
Unfortunately, this 2018 model (the manual is dated 2017) has not thus far been replaced. With camcorders being out of fashion I am not surprised but the the AX-700 still being sold by Sony for a high price (£1,800) relative to its features. I am sorry to say that Sony has not seen it fit to update the firmware for four years when there are so many features that could be improved. The AX-700 is not a great advertisement for Sony ergonomics or for its care of what customers experience.
I bought another old Gitzo tripod a few months ago (a chap even in these days of in-camera stabilisation can never have too many tripods). It came with an off-centre Gitzo head (G1375M) which had an old-fashioned screw fitting to the camera. It must have been made after 2002 because it has the modern Gitzo logo.
Those major manufacturers Gitzo and Manfrotto make excellent tripods and heads but the constantly changing multiplicity of plates and closure mechanisms drove me to despair, to not a little annoyance and to the occasional literal wrap on the knuckles from those infernal spring-loaded devices that release the operating lever at great speed in the direction of flesh and bone. I came to prefer the Arca Swiss system and standard width of 38 mm for the plates that Chinese and other manufacturers adhere to. My various cameras now fit all my tripod heads without having to change the plate.
Although rather excessive in weight these early off-centre Gitzo heads work very well (I once had one of the same design (G1376) which had a proprietary quick release system. They can achieve all sorts of angles and they lock with little or no drift. I decided to hang on to the G1375M head but to convert it to take Arca Swiss style plates. Some people have been doing that for years with clamps made in the U.S.A. but prices were high. The entry of Chinese manufacturers selling under a plethora of brand names brought much lower prices for these simple devices.
I bought an Andoer CL-70N Quick Release Clamp (i.e 70 mm long) because instead of just using the single screw on the Gitzo head to hold it in place and on which it might work loose, I could fix it more securely by using two bolts screwed into the clamp. I keep a few steel ¼-20 UNC bolts, washers and nuts (i.e. for the standard camera tripod socket) on hand. I had to shorten the bolts to a thread length of 17 mm. I used Loctite Thread Locker as I tightened the bolts. From the various types of clamp available I see that only with the 70 mm models can two bolts be used; there is only one, central socket in those 50 mm long. I can of course use Arca Swiss style camera plates of all sizes in the clamp.
Total cost: £27.99 plus two bolts and a drop or two of glue.
Although I have two infrared-converted Nikon DSLRs, I sometimes am out and about only with my iPhone and see a shot that would look good in infrared black-and-white. There are numerous reports phone cameras of phone cameras being used with a 720 nm cut-off filter held in front of the lens. The best guide I have found is that by Rick Shea, described here and here. However, he was unable to use the ultra wide lens/camera on an iPhone. That’s because there are problems with the design of any attachment used to hold the infrared filter.
During the winter I was determined to see if I could get usable infrared photographs from the ultra wide lens (equivalent to a focal length of 13 mm in a full-frame 35 mm camera), since it offers pictorial possibilities many people do not have in their range of lenses for their DSLR or mirrorless IR-converted camera.
iPhone 11 Pro with 720 nm filter. Wide (26mm equivalent) Lens/Camera
Having produced attachments that work, I would not want the reader to think that a iPhone is in any way a substitute for an IR-converted camera. There are problems that are inherent in the way the cameras operate, in using the standard Camera app, in the size of the sensor and with lens hotspots:
Using the Apple Camera app, it would be logical to think that the standard settings of 0.5x, 1x and 2x would engage each of the three lenses (respectively 13, 26 and 52 mm focal length in 35 mm equivalents. By holding a finger over the lenses to see which one is producing the image, 1x and 2x magnifications are both produced by the 26 mm lens. Only above x2 (and then not consistently at higher digital magnifications) did the 52 mm lens come into play. I have therefore abandoned the Apple’s standard Camera app for infrared. Instead I use the camera function of Adobe Lightroom. There, selecting UW (13 mm), W (26 mm) or T (52 mm) does actually engage the respective cameras. I will use UW, W and T to denote the three cameras below. Incidentally, I have the file format set to DNG. However when on UW, DNG is not available and the format reverts to jpg.
There is some sort of algorithm operating in the iPhone 11 Pro that interlinks the three separate cameras. If one camera is obstructed there can be times when the UW will not focus or get the correct exposure.
The presence of a 720 nm filter needs an increase in exposure of approximately 12 stops or E.V.s. With the fixed wide aperture of the three lenses (f/2.4, f/1.8 and f/2.0) and optical image stabilisation for W and T, the phone can be hand held for subjects in sunlight. However there is no stabilisation with UW and some form of support may be necessary depending on the exposure and how steady you are in holding a phone camera.
All the lenses have an infrared hotspot. Ways of dealing with them by making presets for Adobe Lightroom or Photoshop are described by Rick Shea.
The phone has a tiny sensor. That couple with the 12-stop increase in exposure will tend to produce a noisy image. I have define Topaz DeNoise AI excellent in dealing with infrared images from the iPhone.
Forget any notion of obtaining faux-colour infrared images. Yes, it can be done but the colour range that can be achieved is not worth the effort.
Filter Holder Requirements
In view of the above I set out to cover all three lenses with a 720 nm IR filter. My first attempt using the clip-on filter mounts that hold a 37 mm filter was completely unsuccessful. I realised there were two problems to overcome, that had not been envisaged when these clip-on plastic mounts were produced for a single phone lens. Although I removed all of the thin plastic plate from the inside of the filter ring, I could not find a position for the clip which allowed all three cameras to be covered by a filter at the same time. There was vignetting from the filter ring either in the UW and/or the W image according to where the clip was positioned. In short I could not find a position where a 37 mm filter could ever work with all the lenses of the iPhone 11 Pro. This problem is, of course, caused by the extremely wide fields of view of the UW and W lenses arranged as they are on the rectangular camera plate of the phone. With diagonal fields of view of 118° and 80° it is only too easy for the filter mount to come into the side or corner of the frame.
A second problem was that in moving the clip around light could get enter the space between the filter and the lens and reflect back into the lens, causing characteristic light marks on the image. To that end the light within the phone’s camera cluster must be turned off.
The effect of light leaking between the IR filter and the phone
Therefore, it is clear that any attachment has to be simple enough to be used by any of the three lenses without physical adjustment and has to prevent light entering behind the infrared filter.
With it not being possible to use a 37 mm filter, the next common larger size is 52 mm—and I had a 52 mm 720 nm filter to hand. There was no problem finding a position in which a 52 mm filter could be used without vignetting. However, the phone itself is not wide enough and needs a plate into which the cluster of cameras will fit and of sufficient width to hold a circular filter mount.
Filter Holder Construction #1
My first attempt to make a filter attachment is shown below. It was made from 1.0 mm styrene sheet and bars. The width of the plate is that required for a 52 mm filter holder to be fitted. The supporting bars allow a close fit to the phone and the lengths have to avoid the buttons on the sides. I first made the olate (cutting out the round-cornered rectangle was the most difficult bit). Then I bought a metal 55-52 mm Step-Down Ring. The 55 thread on the outside extended from half-way down the ring while the 52 mm thread inside went the whole way through. Therefore to get a broad flat surface I cut off the part of the ring with the 55 mm outside thread using a cutting disc. When smoothed down, I stuck it to the styrene plate with cyanoacrylate superglue. To reinforce the joint and to make sure light was excluded I ran black Sugru around the edge. Before gluing the ring in place, I checked its intended position in order to make sure there was no vignetting from any of the cameras..
To be used this plate has to be held tightly to the phone in order, again, to prevent light reaching the back of the filter. The large, soft-sprung clip shown in the photograph is the best I have found so far. The spring has to be gentle in strength because one side presses on the glass front of the phone.
After a spray of matt black paint I found this style worked fine. The attachment, filter and clip would fit in the pocket. Anything similar could easily be built using a 3D-printer.
The use of this filter holder is not confined to an IR filter. Standard 52 mm Polarising and neutral density filters could be used for ‘normal’ photography and video.
The Step-DOWN Ring used to hold the 52 mm IR Filter
Filter Holder Construction #2
With the design of the iPhone lens cluster, a circular filter is not ideal. A rectangular one would be easier to deal with. I therefore made a similar plate to #1 for taking a rectangular piece of filter material. That could be narrower. However, finding a piece of rectangular 720 nm filter material is another matter. I was not keen to buy a large circular filter and cut it down on the chance I could do so without breaking the glass sandwich. Industrial quantities were out of the question but I did find somebody on eBay selling what seemed to be 720 nm plastic material of the sort used in electronic infrared controllers. I soon cut a piece down and sealed it to the plastic plate. Unfortunately, while the initial cut off may be around 720 nm, the supplied spectrum showed there was a dip in transmission at some longer wavelengths and the attachment was unusable. That was a pity because for a purely infrared filter attachment of small size the approach seems ideal. If anybody can get hold of material used to make photographic 720 nm IR filters, or has a go in cutting down a large circular filter, then making such a small attachment would be worthwhile. Incidentally, I have found no other cut off filter, other than 720 nm, works with the iPhone. Lower wavelengths let too much ordinary light in; higher wavelengths so little that the camera tries to take a photograph of the inside of the filter. Again though, that design with suitable filter material could be made by 3D-printing.
Filter Holder Construction #3
The last design uses a SmallRig cage (2776) and therefore avoids having to have a clip to hold a filter holder in place. I realised that I could use a filter mount (Kinqwon Flycoo 52 mm Filter Adapter for GoPro Hero 10/Hero 9 Black) since the rectangular lens bulge of the GoPro is similar in size to the lens plate of the iPhone. I found that the height above the plate of the cage caused vignetting. I therefore cut the back of the filter attachment leaving the rectangular opening surrounded by a 52 mm filter mount. That was glued to the rubber covering of the lens plate. However, there were holes where light could enter around the edges. I therefore sealed the whole thing with black Sugru. That arrangement works perfectly most of the time. However, sometimes when the phone is inserted in the cage there can be a very small light leak between the phone and the plate of the cage (to the right of the logo in the photograph below). I insert a piece of 1mm styrene card into that gap. I suppose I could glue card to the inside of the plate but the quick fix works fine.
With the changing of models and phone sizes, there is of course no permanent solution to producing a filter mount for iPhones. Already the iPhone 11 Pro is two models behind. For those who do not want to have to make a holder like #1 and #2 every time they change their phone, then the cage option with some sort of filter holder of the type that fits a modern GoPros may be the way to go. There must surely be a commercial opening here for iPhone filter mounts that cover all the cameras and not just attach to the cage to cover one (W) as at present.
Finally, I have been surprised about the quality of the infrared black-and-white photographs from the IPhone, but more on that topic in a later post. Suffice it to say at this stage that the UW (13 mm equivalent) lens/camera produces some very strange images with periperal area of mush - just as if some noise reduction process has gone crazy locally. There creative possibilities since anthing towards the centre of the frame is not affected. All-in-all impressive black-and-white IR photographs emerge from the W and T cameras.
Those of us who use a camcorder to take wildlife videos while travelling are often in a dilemma. A very small sensor can produce excess noise in low light while the image is subject to diffraction at all or just about all lens apertures; such cameras are though light in weight. A large-sensored (APS or full-frame) camera, by contrast, is much less liable to noise and diffraction but with a long lens is both heavy and bulky. To some extent the 1-inch sensor is a good compromise in terms of noise, diffraction and weight but choice in the market is very limited with new models appearing only very rarely. Those available have a useful if limited lens zoom range. Thus my Sony FDR-AX700, with which I have a continuing love-hate relationship, has an optical zoom range, in 35 mm equivalents, of 29-348 mm, which in some circumstances is not wide enough or long enough.
The option to use Sony’s ‘clear image zoom’ provides additional focal length at the long end, with a zoom range of 18x, i.e. 29-522 mm when using 4K. I really cannot see the stated small difference in resolution between optical and ‘clear image zoom’ when I shoot in 4K, edit in and output from a 1080 timeline in FCPX and then watch the video on a normal sitting-room sized 1920 x 1080 television.
I always shoot in 4K and edit on a 1080 timelines, giving me the option of cropping without loss of resolution up to 2x. That scaling effectively doubles the maximum focal length of the lens, in this case to 696 mm (optical zoom) and 1048 mm (clear image zoom).
Sometimes, though I need a greater focal length and have been working with two lens extenders, both of which will fit directly on to the filter thread of the AX700. Lens extenders in general have a terrible reputation with cheap and nasty versions available since the 1960s. However, Olympus made a tele-extender (‘Tele Extension Lens Pro’ TCON-14B) for its E-10 and E-20 cameras which went on sale in 2000-2001. That one multiplies the focal length by 1.4. They now sell for very little; I paid £13 for one in mint condition. Reviews from the time praised its high quality but the tests were made on a 4 MP camera. The TCON-14B is very heavy (465 g).
Raynox are highly praised for their converters—the Raynox DCR-2025Pro seemed ideal for my purpose. I have been deterred from buying one by the UK retail price—in excess of £220 and from some suppliers much higher. When I saw one advertised at £115 I ordered it. This one multiplies the focal length by 2.2, providing a very respectable increase in maximum focal length of the AX700 to 766 mm (35 mm equivalent) with optical zoom and to 1148 mm with clear image zoom. Multiply those figures by 2 for maximum cropping of 4K video in a 1080 timeline and we have 1532 (optical zoom) and 2296 (clear image zoom). With those sorts of focal lengths you really could not ask for more.
Raynox DCR-2025Pro mounted on the Sony AX700
The choice between optical zoom and clear image zoom isn’t just one of a small, imperceptible to my eyes when used in the field, difference in resolution. One of the annoying features of the AX700 is that some features that are available in optical zoom disappear when using clear image zoom. I find the central focus area option very useful subjects like perched birds or small mammals. However, the option for that is not available in the clear-image zoom range of x12 (348 mm) to x18 (522 mm). Therefore, it will sometimes be better to use manual focus with peaking.
Apart from the problem of heat distortion in the air between camera and subject that cannot be avoided with any very long lens, there are disadvantages of using a teleconverter. The first is having to operate at full zoom or very nearly full zoom; with any wider angle there is severe vignetting reaching the point of a central circular image. The second is having to screw it in position and then remove it when not needed—a fiddly, two-handed job. A friend lost a Raynox from a canopy hide in a rainforest; it fell while she was trying to screw it into position and was never seen again.
Turning to the Raynox DCR-2025Pro itself. I was delighted to find it is built of light plastic and for such a long and powerful extender weighs only 380 g. Mine came in its original box (I suspect it had never been used at all) and contained a Raynox brochure, dated 2018, which states:
The model Raynox DCR-2025 Pro high definition telephoto lens is made of high index optical glass elements, and it’s designed with new designing concept of two group/four element formula to obtain the maximum resolution power of 260-line/mm at center (MTF30%.
The lens hood (shade) is included as are caps and adapter rings for 43, 52, 55 and 58 mm filter ring lenses. I was confused when looking at the description of this lens by UK dealers since they did not included in their descriptions the fact that it fits a 62 mm lens ring—the AX700 size. In fact 62 mm is the native size with no adapter needed.
The combination of AX-700/Raynox DCR-2025Pro providing such long focal lengths does need a sturdy tripod even without pan/tilt movements while filming. And I soon discovered that shot against the light were a no-no; flare is too great even with the substantial hood on.
I have been testing the AX-700/Raynox DCR-2025Pro a little. To do so I have had the camera on a tripod with stabilisation off. I have put the 4K footage (clear image zoom on) on a 1080 timeline in FCPX and without further processing exported still image tiff files from a single frame. I looked at still images this way because the resolution of in-camera still images is different from that of video and I use this camera for video not stills.
The nest series is a similar illustration for comparison of the two extenders with the maximum focal length of the AX700. Below is added an image from the same position taken with a Panasonic Lumix DC-FZ82 at 1680 mm (35 mm equivalent) from 4K footage on a 1080 timeline. The difference in resolution is very clear but perhaps not surprising given the price difference between the cameras.
I have also tried the Raynox extender in the field. I chose a dull day to prevent the effect of ‘heat shimmer’ affecting the image.
These two series are from two single frames at maximum camera focal length plus the 2.2x extender with clear image zoom on. The top is straight from the timeline; the next at 150% scale (i.e. 1.5x) and the bottom one scaled to 200% (i.e. 2x). Thus the bottom image is the equivalent of using a 2296 mm lens on a full-frame 35 mm camera, i.e. a lens 2.3 metres long in a non-telephoto design). The head shots are cropped stills from the exported tiff files.
When I started the search for a tele-extender I suspected the Olympus version, although only 1.4x would be so optically superior that I would have to abandon the Raynox 2.2x. But no. When length matters the Raynox on the Sony AX-700 reigns supreme. I will be using it in other scenarios and will report if my initial verdict changes.
I previously described how I made a built-in microphone muff for the Sony FDR-AX33 (shown with full details here). I have now made one for my Sony AX-700. The process is a little easier because the curve of the body is not so tight and the self-adhesive Velcro does not lift so easily.
Again I used Velcro Heavy Duty Stick On with the hook half attached to the camcorder and the loop piece attached to faux fur fabric which came from eBay as ‘blue beige wolf’. This time I cut the tough Velcro using a wood chisel for the inner cut out and the outer edges of the hook half and for the inner cut out of the loop piece.
I trimmed the long fake fur to a more reasonable length. Depending on the direction the fur lies it is easy to produce a camcorder with a Trump or end up, like this one, with a Boris Johnson coiffure.
For those wanting to make one, here are the dimensions:
Care must be taken when removing the muff to get a finger nail between the two layers of Velcro and not between the fur and the loop Velcro. I make up several before long trips overseas and with some I make the loop Velcro/fake fur wider than the hook Velcro attached to the camcorder when I know I will be removing the muff frequently since it is easier to get a grip.
I have found these muff to be highly successful in reducing or obliterating wind noise. Using them I do not have to attach an accessory microphone. That makes clambering in and out of vehicles or simply dropping the camcorder in a bag much easier.
I was also told, in relation to microscopes, to be wary of using old lenses since over time the glass deteriorates. For photographic lenses, telescopes and binoculars that problem is seldom mentioned these days. The other problems that befall old lenses such as fungus, dust, separation of elements because of balsam deterioration, and condensation of lubricants as well as mechanical damage to the surfaces all get covered in guides to buying and repairing but actual deterioration of the glass itself is only rarely mentioned. I supposed the writers and repairers are often not dealing with really old lenses, merely ones that are not current models. For users and potential purchasers of old film cameras, particularly those made before the widespread adoption of coated lenses, binoculars, telescopes and microscopes, the problem can be real and insoluble.
The warning about using old lenses for microscopy came in what I can only describe as the most long-winded and boring course (apart from botany) it was my misfortune to attend. Robert Barer* was the new Professor of Anatomy in Sheffield and he gave his now infamous snail-pace course on the use of the microscope he had started at Oxford to those of us who were honours students in zoology. Before deserting most of the sessions, I did pick up that snippet on old lenses. In order to check my memory I bought a copy of his book, Lecture Notes on the Use of the Microscope, first published in 1953. There, he wrote:
Do microscope lenses deteriorate with age?
They may do so. The surfaces of some glasses tend to become cloudy with age, particularly in the presence of moisture. The balsam used to cement lenses together may dry up irregularly, or may retract, leaving an air space. Moulds sometimes grow in the space between lenses. Many old lenses are still perfectly good, but nevertheless caution is advised when purchasing any objective more than about twenty years old.
Since then I have seen a number of lenses affected by what is called ‘glass disease’ in lenses of all sorts. Glass Disease is a major problem in museum collections of glass objects. Its appearance depends on the chemical composition of the glass and the humidity of the surrounding air. It shows first as a cloudiness on the surface of the glass and soon becomes irreversible; the chemistry involved is explained in an article on Wikipedia. Because of the importance of chemical composition, some glasses show relatively rapid deterioration when in high humidity or submerged; others show no deterioration whatsoever.
The nature of glass disease was brought home to me during covid-lockdown. In 1964, my wife, before she achieved that status, spotted on old tip while cycling to work during the summer vacation. Investigating further, she found a number of old medicine bottles and the like. They were left uncleaned with her parents who simply moved the whole lot with them each time they moved house. They emerged when we cleared their house and were transferred to a shed in our garden. Re-emerging as the shed was tidied I was volunteered to clean them up. I have to say with due modesty that I did a very good job. Several, however, had large patches, inside and out, of surface cloudiness. That was resistant to every chemical treatment I could devise, from strong acid to organic solvent. In short they had glass disease and I read that the only way it could be removed was by gentle but prolonged mechanical abrasion.
A long-buried bottle with 'glass disease'
I have, over the years, seen examples of glass disease in microscope lenses, old binoculars and photographic lenses. Since high humidity is needed it is not surprising that fungal growth and glass disease sometimes go together, as in lenses kept without desiccant in the tropics. In the three years before he died my father acquired a large collection of classic cameras. Some of those had cloudy, uncleanable lens surfaces.
Regardless of chemical composition, the coatings applied to modern lenses prevent glass disease. Indeed I was surprised to read that they were invented for that purpose by Lord Raleigh in 1886. Only afterwards did he discover that they decreased the reflectivity and therefore increased the transmittance of light. Some coatings though peeled off in patches or were worn away by zealous cleaning, leaving the surface open to glass disease.
Difficult to see but this 1950s lens has signs of cloudiness on the front surface
The only ‘remedy’ for lenses with glass disease I have seen is to polish them with jewellers’ rouge, a mild abrasive. The effect on the optical properties of the lens was not stated.
I, needless to say, avoid really old or decrepit lenses. They, like many of the cameras they were made for, are simply beyond redemption and are best relegated to the display shelf.
*Although he bored us rigid, we did have great respect and sympathy for him. Word had got out that he was the first to have entered the typhus-ridden Sandbostel Concentration Camp in April 1945; that experience affected him for the rest of his life. He was medical officer in the Guard’s Armoured Division in the advance across Europe. He was awarded the Military Cross for his actions, including rescuing the crews of three burning tanks while under accurate shellfire. Robert Barer (1916-1989) wrote One Young Man and Total War, Portland Press, 1998.
