KW Pilot 6 Mirror Replacement.

[Mos6502]

Thought I would document a general cleaning and mirror replacement for a KW Pilot 6 SLR.
Recently went digging through a drawer looking for something when I was surprised to find an ancient and very dirty KW Pilot 6 -I had completely forgot that I purchased this several years ago for use as parts. After inspecting it I thought it may be a good candidate for repair and have begun working on it with the aim of getting it back to life. These are very simple cameras with very robust mechanisms, so generally will function reasonably well even if they are in very poor condition. However one thing that most suffer from, and this one suffered very badly from, is a deteriorated mirror.

Replacing the mirror is very easy fortunately. The viewfinder hood has to be removed, there are seven screws holding it on. Three on each side of the hood, and one on the front, in the middle (on later Pilot 6 cameras there are also two screws hidden inside the film chamber). Once these are removed, the hood can be removed from the camera. The ground glass will simply fall out if the camera is turned upside down, so make sure you're working on a soft surface and simply turn the camera over. It may require a few taps on the camera to persuade it out. Under the ground glass is a wire shim for setting the focus of the glass. On mine this was rusted, so I pried it out to clean the corrosion off.

The mirror is held in place by a tab over the front edge, and the rear edge of the mirror has a flat spring pushing it into the front tab. Since corrosion was evident I decided to put a drop of light oil behind the mirror before attempting to move it. After this I took a very small flat screwdriver and inserted it between the front edge of the mirror and its hold. Pulled the mirror back against the spring until the front edge cleared the tab, and then pulled the mirror up and out.

A new mirror has been ordered, and I'm going to experiment with fitting a fresnel screen... so stay tuned if you want to see how this finishes up!

 

[Kai-san]

I fixed the mirror on my 1938 KW Pilot Super 6 some years ago, but I sent the mirror to a company in the UK for resilvering. I've been thinking about getting a new focusing screen from Rick Oleson, but haven't got around to it yet. Looking forward to see what you can do with this one.

 

[Mos6502]

I ended up putting the new screen in a different Pilot 6. The above camera has an f/6.3 lens which I thought might be too slow for the bright screen. So I put the screen into a Pilot 6 with an f/4.5 lens. The screen is meant for a Kiev 88, and purchased from a seller in China on ebay. The Kiev screen measures 55 x 55 mm, the original Pilot ground glass measures 56 x 56 mm. So the fit is not perfect, but close. It may or may not be a problem depending on the specific Pilot 6 the screen goes into, based on what sort of shim the camera has in it. If it has a thick shim, it should be fine as the screen will sit level even though it is slightly smaller than the original.

Bright Screen by Berang Berang, on Flickr

The real question is whether or not the screen has changed the focus (it is thicker than the original ground glass, presumably because of the Fresnel pattern on the bottom of it). This is something I cannot test on the bench easily since the tripod socket is mounted on the film door of the Pilot six, so I could only do a rough check to see if the focus at the film plane matches that of the focus screen. It may have shifted focus three or four inches, but I'll know for sure when I run film through it.

As for brightness, the new screen does provide illumination to the very corners of the viewfinder, even when the magnifier is used which is very good. Brightness in the center is not much different than with the plain ground glass. The "grind" of the new screen is much more coarse than the original, and no doubt with a faster lens this would be good, but with a slow lens it makes it difficult to do fine focusing. Will have to try it and see if I like it.

 

[Mr_Flibble]

If there's a difference in the thickness of the replacement front-side mirror and the original this will also cause a difference in lens-to-GG distance.

 

[Kai-san]

Does the new screen have a ground surface on one side and a fresnel on the other side? If so the ground surface side must face down towards the mirror, because the image is formed on the ground surface.

 

[Mos6502]

The top of the screen is smooth/shiny, so obviously faces up. The question is whether the screen puts the Fresnel lens under, or over, the ground surface, I was unable to tell from looking at it. However looking at comments about installing screens on the Kiev-88, it doesn't appear any shimming is necessary to adjust for installing one of these screens.

The mirror is 1mm thick, same as the original (I've replaced mirrors in several Pilot 6 cameras, without any problem).