Sony FDR-AX700 Camcorder. Coping with the viewfinder eye adjustment wheel

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

Sony FDR-AX700 Camcorder. Another annoying feature in a case of ON or OFF

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.

A Robust and Cheap Conversion of a Gitzo G1375 Tripod Head for Arca Swiss Quick Release Plates

 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.

Before - with the fixing bolt removed

After

Infrared photography with an iPhone. DIY IR filter mounts for all three cameras of an iPhone 11 Pro

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:

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.

Like #1, #3 can be used with other 52 mm filters.

The 52 mm filter holder designed for a GoPro

Black Sugru used to fill gaps

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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.