Nikon DP-20 finder for the F4

Recently, as part of a beautiful, practically unused, late model Nikon F4s which (ahem) came my way, I immediately noticed a problem with the DP-20 finder. There was quite a heavy infestation of fungus on at least one of the internal eyepiece surfaces which was so bad it made viewing the lower meter readout difficult, blurring the LCD. I’d already knocked the seller down quite a bit (without knowing about this issue, of course) and so my initial reaction was not to demand a refund. I’ve fixed this kind of thing before – in lenses and more simple finder pieces – so how difficult would it be to eliminate the fungus from this otherwise pristine DP-20 and restore it to minty condition?

Well, as it turns out, quite difficult. But feasible, given care and patience.

This project required some careful planning, given the condition and obvious complexity of the finder. I got hold of the service manual for this finder which, unfortunately, is an x-generation photocopy scanned by an ancient scanner (probably) and so the image quality gives rise to a fair amount of guesswork. I was so determined to get this right that I bought a well-used finder for a cheap price, so that I could practice and note any caveats before working on the “real thing”. At worst, I’d spam it up completely and learn something in the process; at best I’d have a working spare finder that I could use for parts if need be. The practice run went very well in the end; a very grubby, fungus-infested DP-20 (though not nearly as badly affected as the minty one) with decomposing foam seals is now very clean, fungus-free, re-sealed and functioning perfectly, with just a few external scratch marks. I’m keeping it as a spare.

Now much more confident that I could do this, I set to work on the minty one. I’ll describe the steps I took in case this is of use to anyone else who wants to have a go at restoring their own finder. Note that this doesn’t require a complete disassembly but it’s worth mentioning that the finder optics and areas around are quite complex and fragile. With care there should be no need to de-solder any wires, but some patience is required.

The finder optics comprise three separate lenses in front of the prism (not including the screw-in eyepiece on the outside of the casing). The first lens is held in place by two small screws, whereas the second, which is able to travel forwards and backwards, is held in only at the top by the dioptre adjustment mechanism. The third and final lens, before we reach the viewing edge of the prism, is attached to the meter cell unit and is the most difficult to work on. The worst possible area for an infestation of fungus, if we were to try to remove it, would be the back-side of the third lens. Guess where it was in my finder.

Step one, a challenge in itself, is to remove the centre parts of the dioptre dial and meter selector dial without causing too much damage. These plastic discs cover the screws that need to be removed in order to remove the dials. They are held in with glue and are, frankly, a pig to remove because it’s likely that there will be some degree of marking to the outer parts of the dials during removal. To minimise this I covered the outer dials with insulation tape and then gently levered the covers out using a very small screwdriver. Once the screws are exposed both dials can be removed. Take care with the two washers for the meter selector dial: the white plastic one goes against the inside of the dial and the black foam one goes against the case.

After removing the four black screws of the outer case, the top can be lifted away from the body. A little bit of wiggling may be required here. The wires attaching the flash shoe to the main body are quite long and I didn’t need to detach them at all. With the main cover off the first lens can be seen directly, with the two screws holding it in place. 

Take the first lens off and inspect both surfaces; with luck any fungus will be here (this is where it was, mostly, in the “scruffy” finder with a tiny bit also on the front surface of the second lens). If there’s some on the back surface of the second lens then this can be taken out by first loosening the dioptre adjustment unit which sits on top. Notice the two small screws holding this part down (not the larger one; that can stay in place) and loosen them a a bit. Be careful here as the two mercury switches are held by this unit and they are glued to the unit underneath, yet there’s some play to take advantage of. The top adjustment unit may be lifted just enough to wiggle out the second lens, which is held there by the pin of the swinging arm. Again, inspect both surfaces.

If there’s fungus on the front surface of the third lens, it can be treated in-situ. If it’s on the back side, though, then the meter cell housing needs to be taken out. There are two screws holding this in place – a small one and a larger one, but this unit is the most difficult to get out so take extra care here. Remove both screws. Facing the lens, first lift the left side and then lift the right side a little. It may not appear to want to move much but persevere here, gently lifting either side and twisting slightly, firstly at the top, outwards, and then push up, swinging out at the base. Watch for wires snagging and gently lift them out of the way so that the lens/cell unit can swing outwards. Don’t pull it too far out. To clean the back side of this lens it will be best to turn the whole lot upside-down and move the unit out far enough to get at the surface, but no more. 

DP-20 insides
Lens no. 3 of the eyepiece group – clean and clear. Nearly half of the inside surface was covered in fungus.
DP-20 eyepiece lens group holder- side view
Side view. Notice one of the mercury switches and wires going into one of the meter cells in the lower left of the picture.

Once clean, re-assemble everything in reverse and look for any wires that may have become detached. I had just one such casualty – the black wire of one of the mercury switches – which was a simple fix with a soldering iron.

Neither the fungus in scruffy nor that in minty had etched the glass coatings at all and so I was able to remove it completely, using my usual method. There’s no secret to this, although people tend to have their preferences as to which tools and compounds to use. I have cleaned fungus from photographic optics for a few years and I’ve never had any return, using simple, easily obtainable isopropanol, cotton buds, cocktail sticks and certain brands of optical cleaning wipes which are, specifically, impregnated with alcohol. It’s the cocktail stick wrapped in an optical wipe which really does the trick, with gentle rubbing over the affected area. If necessary, the area can be finished off with an optical-grade microfibre cloth. Perhaps stronger chemicals, such as hydrogen peroxide, may be required for very well-established fungus but I’ve yet to encounter any.

Nikon DE-1 finder for F2

In 1972 Nikon brought out the F2 to replace their groundbreaking F. Like its forerunner, the F2 was designed to be modular which meant that the finder could be exchanged, depending on intended size and function (this continued up to and including the F5 of 1996; in 2004 the F6 was introduced with a fixed prism finder). Without going into a long history, the F2 had various finders available over its production run until 1980, most of which had built-in exposure meters and lens aperture coupling. But there was one finder which had neither meter nor coupling to the lens: the DE-1. The F2 is often referred to as the F2A, F2 Photomic, F2AS, etc., depending on the finder fitted, but with the DE-1 fitted it’s simply a plain old F2. In this form the F2 is at its smallest, since there’s no bulky mechanism around the finder prism to to hold and drive the meter coupling. The price to be paid, of course, is a lack of exposure meter, meaning that an external meter would need to be used if personal experience and maybe the “sunny 16” rule wouldn’t suffice.

These days, DE-1 finders are expensive, since they are relatively rare – especially in very good condition. Some time ago I saw one on ebay marked as cosmetically almost mint (always taken with a handful of salt) but with a damaged prism inside. The damage was described as a “blob” which I questioned with the seller and decided that the prism silver coating had to be damaged. I bought it, because it was reasonably cheap in comparison.

What I received was intriguing. The finder top plate was almost mint – and for me to say that means that it’s almost flawless. I’d say the top plate alone is worth what I paid, so I figured I may as well see if I could service the rest, with nothing to lose; if it turned out to be useless, I could buy a bashed-up one and simply replace the top plate with this one. What I found was a strange mixture of old and new.

After removing the top leatherette to gain access to the four screws which enable removal of the top plate, it was clear that one of these screws was not an original. With the top plate off, the prism itself was loose and rattled slightly. Sure enough, there was silver coating damage – probably just age-related – which had been painted over with back enamel (in conversation at the time with Sover Wong, who repairs and services F2s and whose work I can thoroughly recommend, he suggested it may be the prism from an old F finder, as opposed to an F2 one). All the internal foam had turned to sticky goo and so the whole thing needed to be cleaned. I dismantled everything and carefully cleaned it all, including the eyepiece, before replacing all internal foams, re-seating the prism and replacing the top plate with an additional foam to prevent dust entering the eyepiece.

The underside of the finder was more of a surprise. Early DE-1 finders lacked the rubber gaskets around the base to help prevent dust getting in under the finder. These are fixed into place on later finders with plates and screws. My finder had rubber gaskets which had clearly been cut (crudely) from genuine gaskets and fixed to the insides with glue, since there was no provision to fix them in any other way to what was clearly an older finder made to look like a newer one! The glue wasn’t good so they were starting to come away. What’s more, a piece of the internal base metal had been sawn off, the reason for which I still don’t understand. Had I paid more for this finder I’d have been really annoyed at being fleeced in this way, but decided instead to make the best of what I had considering that perfect top plate. I cleaned-up what was left of the gaskets and stuck them back on with strong double-sided tape. I added foam the underside in a similar way to how pre-gasket finders have protective foam and, finally, the leatherette went back on to the top plate using contact adhesive.

A couple of days ago I noticed that the glue from the double-sided tape had decomposed and the gaskets were coming off again, so I did a better job this time using contact adhesive. I took the opportunity to check inside again and re-stick the leatherette on the top plate. Although it doesn’t stand out, the prism itself is damaged right along the centre of the view and so I may consider eventually replacing it in the unlikely event that I spot a cosmetically rough finder going cheap. What I have now could be an old-style underside, an even older prism, a newer top plate and rubber gaskets ripped from a newer finder and stuck on, to give a “franken” DE-1 which looks pretty good to me!



Nikon Coolpix 5200 battery door fix

Recently my father broke the battery door of his Coolpix 5200. He can be a little heavy-handed at times but I don’t believe it’s an uncommon problem for this door to break (or so I’ve read). The main part of the door is plastic and it’s held on by lugs which slide over corresponding lugs on the body; once the door lugs break – probably too much downward pressure instead of sliding to open/close – the door no longer fastens shut.

He took it into a camera shop and asked them how much it would be to repair: they quoted £60 just to look at it and said he may as well buy a new camera. No surprise there, then. So he stuck a small piece of gaffer tape to the door and affixed to the camera body; a bodge solution which looked horrible and wasn’t even very effective. 

Remembering the shop on a certain well-known auction site which I’d used to get parts to repair my father-in-law’s lens, I wondered if they’d have a replacement door. Sure enough, they did, so I ordered one. 

Recently my father broke the battery door of his Coolpix 5200. He can be a little heavy-handed at times but I don’t believe it’s an uncommon problem for this door to break (or so I’ve read). The main part of the door is plastic and it’s held on by lugs which slide over corresponding lugs on the body; once the door lugs break – probably too much downward pressure instead of sliding to open/close – the door no longer fastens shut.

He took it into a camera shop and asked them how much it would be to repair: they quoted £60 just to look at it and said he may as well buy a new camera. No surprise there, then. So he stuck a small piece of gaffer tape to the door and affixed to the camera body; a bodge solution which looked horrible and wasn’t even very effective.

Remembering the shop on a certain well-known auction site which I’d used to get parts to repair my father-in-law’s lens (see earlier post), I wondered if they’d have a replacement door. Sure enough, they did, so I ordered one. It cost me just £14 to get it shipped from the U.S. The shop is called Procamerarepair.

They dispatched pretty much immediately but it took a week or two to arrive. No problem, as it arrived in time for a meet-up with my parents and so I was able to replace the plastic door in about two minutes. Good as new! As ordered, the door comes with the metal hinge assembly but this is not required unless the hinge itself is also broken (in which case it would be a slightly more involved repair). He’s happy and I don’t have to think of his camera (which I bought him, incidentally) held together with a bit of gaffer tape.

Nikon lens repair: AF-S DX 18-55 f/3.5-5.6 VR

Here’s the background story: my Father-in-law had his Nikon D60, with 18-55 VR kit lens attached, on his shoulder when he dropped the lens cap. The cap rolled away and was about to disappear out of reach, so he ran to get it. Unfortunately his Nikon slammed against a metal railing, lens first; the lens came away, would not re-attach and there was no knowing how much damage to lens and camera had been caused.

When it came to me I could see that the whole mount was badly warped and that bits of it had broken off. The electronic connector block was hanging out and the surface which is supposed be flat to mate with the camera throat looked like a tiny roller-coaster track. My F-i-l was going to dump the lens but what he really wanted me to check was the camera, to see if it had been damaged by the impact. My first thought, though, was to save the lens from going to landfill.

It helps that I have taken a few of my own Nikkors apart before, for minor servicing/repair, and so I went straight to remove the whole mount assembly. I found the cause of the severe warp: a tiny lug had broken off inside and was lodged underneath the shims that it had previously been holding in place. I determined that I could get by without this lug, since it was too small for a reliable fix and the shims had one remaining lug to hold them in place before the main mount screws secured them. I re-assembled everything as best I could (the electronic connector block was still a bit loose as one of the screw housings had also broken away) and tested the lens. I had to hold it against the camera body, since two of three mount catches were missing, whilst testing AF, aperture and VR. All seemed to work fine – which was good news because that meant the camera was probably OK too. I feel sure that, had the lens mount been the usual metal instead of plastic, there would have been some significant damage or mis-alignment inside the camera. As it was, the mount absorbed the impact, breaking and warping, thereby saving the camera from any serious damage.

OK, so everything worked, but I wasn’t sure where exactly to get a new mount. I looked for similar lenses on a well-known auction site, being sold for parts, but found none. Thankfully I found a company in the U.S. which sells parts for camera repairs and they had the correct mount for about a tenner. So I ordered it and it arrived a couple of days ago.

The repair itself is quite straightforward. The three main screws are removed, as well as three much smaller screws holding the central sleeve in place. There are two more tiny (but different) screws which hold the electronic connector block in place. There will be a number of shims, which will be specific to each lens and they are to adjust the distance between main mount and optics (i.e., sensor to lens distance). The image below shows the lens barrel, the broken mount to the left, the electronic connector block and, in the background, the inner mount sleeve and shims. Click on any image for a larger version.

Two things need to be done before the main mount can be replaced: the sprung aperture guide is removed to be attached to the new mount as is the small connector with sprung pin, shown near the centre of the image above. Now we’re ready to prepare the new mount.

The aperture guide slots into the underside of the mount and the spring is attached:

The sprung pin is attached:

Then the shims are returned. Notice the guide lug at the top right; there should be another on the bottom left next to a screw hole but it’s missing, so the shims can shift around a bit. This gets fiddly when finally putting it all together as the aperture guide needs to be carefully placed on the correct side of the aperture pin in the lens, otherwise the aperture won’t work at all, but getting the correct positioning can move the shims so that screw holes don’t line up.

With the aperture guide in the correct position and the main screws loosely in place, all that remains is for the inner sleeve to return to its rightful place. Care must be taken with the five tiny screws: two of them have slightly larger heads and a finer thread pitch. It is these two which hold the connector block in place, whereas the other three secure the inner sleeve to the main mount.

After tightening all screws (not too tight – this is a plastic mount, after all), a good clean and mount to camera body, all is well. Focus is accurate and VR works as it should. One more saved Nikon lens to add to my count (OK, that makes two in all – but hey).

One final thought: those shims are thin. Some of them are extremely thin. They are of different thicknesses and will have been put together in that combination for this particular lens and its original mount, so it could be argued that they are no longer an accurate set for this lens. Since all my testing shows focus to be spot-on, though, they appear to be good enough.

Windows 7 “XP Mode” finally useful

I’m partly writing this for my own benefit, as I know I’ll forget this at some point and need to re-set it…

OK, so Windows 7 is what Vista should have been, blah blah… I actually quite liked Vista Ultimate x64 but I’ve gained some speed and UI niceties by changing to W7 Ultimate x64. In both, I’ve been using a modified driver for my Nikon CoolScan 5000 which Nikon does not support because the company refuses to release a 64-bit driver for their film scanners. They have effectively given up on film scanning now (the 9000 is the only one currently available but it’s too expensive and probably won’t be around for much longer either) which is a pain because their scanners are good and there’s not a lot else to choose from these days. 32-bit Windows: no problem. 64-bit: forget it? Not quite.

So I figured out how to use a driver on x64 which would drive the 5000 (I love the internet) and it does work. Usually it works well but I’m finding it occasionally crashes, especially if I’m using the post-processing options such as GEM.

One big selling point of Win7 Ultimate (and Business/Enterprise) is their “XP Mode”. This is basically a registered copy of XP SP3 running as a virtual machine under Win7. It allows the connection of USB devices and, even though the VM is running on Win7 x64 in my case, the XP within is 32-bit. Great – I can run the supported scanner driver under XP 32-bit under Win7 64-bit! Damn – the VM is limited to 16-bit colour and, therefore, looks crap.

So I gave up on XP Mode and put up with the occasional crashes until a few days ago, when I came across this:

I knew I could increase the colour depth if I disabled the integration facilities but that would mean no connection of USB devices to the VM, which would be pretty pointless. This link shows how to get around the 16-bit colour limitation to give 24-bit colour whilst retaining integration. It turns out that XP Mode uses the Remote Desktop Protocol (RDP) and this is limited by default to 16-bit colour – presumably in the interests of connection performance. But I’m not connecting to another physical machine here. This link shows that a simple Group Policy edit (GPEdit.msc) to Terminal Services to set the maximum colour depth to 24-bit should do the trick and it certainly does. Suddenly, XP Mode is useful and I can scan within it now with everything looking as it should.

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