Focuing problem with Nikon FEs

David R · Joined: 08 May 2009 Posts: 8 Location: Toronto, Canada

After posting elsewhere and not getting a suitable answer, I've continued doing research as well, now I'm ready to try again. I've noticed a lot more enthusiasm for traditional hardware, and a lot more genuine knowledge here.

The back-story. The 2 cameras I learned to shoot with, are a Nikkormat FT, and a N2000. These two were for a long time fine for my kind photography. The FT developed mechanical reliability issues, the N2000, no depth of field preview. Here in Toronto we have a twice a year camera flea market (http://www.phsc.ca/), dealers, collectors and enthusiasts buy and sell cameras from Brass & Wood to current Digital. I picked up a several other bodies recently, a FE, a FE2 and N6006. Never use N6006, it was really cheap so doesn't matter. The FE2 became my favourite, love the metering.

Anyways started to notice some focus issues. Images just didn't seem as shape as I thought they should be. Eventually isolated the problem down to the FE and the FE2, the issue is around infinity or distance focusing. Usually when I'm out Kayaking I just set the lens at infinity as most objects of interest are further than 50 feet, good enough for wide-angle lens. Well it turns out that on these bodies infinity comes early, depending on the focal length of the lens. By comparison, the FT, N2000 and for that matter the N6006, hit infinity where the lenses are marked as infinity. For those not familiar with these bodies, the FEs have interchangeable focusing screens, while the FT, N2000, and N6006 are factory fixed focusing screens. As the market is a regular event I bought two more bodies another N2000 and a Nikomat FTN, great price for the pair, so its worth it for parts and comparison for this project. They also have correct focusing.

For those wondering what I'm going on about, two pictures, showing the focus differences. The target for these shots was the upper trunk of a tall tree several backyards away, 400 ft give or take 50 ft. The focusing target was backlit at the same time making it easier to focus on as well. I have samples for the other bodies and lens, but these two should suffice.

N2000 20mm

FE2 20mm

I've tried several techniques, a piece of frosted mylar as a focusing screen on the film plane, with x8 loop, a focusing screen from another camera refashioned to fit on the film plane with a x8 loop, a crude collminator setup using another camera with matching lens. All comparing film plane and viewfinder focus. Actual film tests have been made as well. I usually don't enlarge much beyond 8x10 when printing, so that isn't really as big an issue. Larger prints are done via scanning. Scanning is limited to the 2820dpi max of my scanner, and 4000dpi at work. Scanning is where I find the problem is most pronounced.

I've checked the mirrors, but there isn't enough movement on the mirror stop, also there is no adjustment for the hinge point on the mirror. The only thing that resulted was being able to adjust the top to bottom focus in the viewfinder.

I made some measurements (averaged) of the mount to film pressure plate (original 5 bodies). Using a digital caliper that can read depth. I measured from the front of the center of lens mount (bridged) to the moment of contact with the film pressure plate. Interestingly the FT had the greatest scatter, suggesting the springs for the pressure plate are weak. The N2000 faired the best with 3 of 4 readings being the same.

FT – 46.665 mm
N2000 – 46.635 mm
N6006 – 46.725 mm
FE – 46.663 mm
FE2 – 46.665 mm

Many of you will be saying it should be 46.5 mm, and that's what Nikon says. That's the film plane or the depth to the inside set of rails. The difference is for the thickness of the film, measured 0.13 to 0.16 for the films I have. There is also apparently a focus offset of 0.07 mm is built in to the cameras, to correct for film flatness issues, according to some of my research.

Now this is where things get a little more confusing. Comparing the viewfinder and film plane moment of critical focus. The fixed screen cameras reach critical focus on the film plane just a fraction of movement before the viewfinder critical focus. While the interchangeable focusing screen cameras reach critical focus at the same time. I'm assuming the differences in focus moments for the fixed screen cameras is the focus offset.

I was able to check more cameras, 3 FEs and 1 FA, no FE2s at the market this time around. I brought my 20mm lens with me, as it seems to show the error easiest. The interior of this market is actually indoor soccer fields, 1 field by 3 fields. Two of the FEs were slightly off, early infinity. The FA, great price, sadly was decidedly off for focus, like my FEs. The one remaining FE was spot on for focus, and interestingly looked like it just came out of the box.

So I conclude this is something to do with the focusing screen position and the aging of the mechanical mount for the screens. Attempts to fudge focusing screen or film plane position haven't yielded any results.

I'd love to hear of experiences people here at this forum have had with this style of Nikon body. I know this was long, thanks for you patience.

David R

Sevo · Expire: 2012-12-03

Either wrong (other model or third party) focus screens, or somebody readjusted or shimmed the camera bodies to suit some alien focus screen.

In the early nineties, there was a fad for expensive third party ultrabright focusing screens, and these often required readjustment - as they still raise about 1/4 of a camera body when sold independently on ebay while people won't pay any extra for a body with such a screen, they sometimes are pulled from the camera and replaced with some other screen, and many sellers don't know about and would be unable to make the necessary adjustments.

Do you have independently purchased Nikon original screens, and does the error persist with them? If so, have the cameras readjusted.

Sevo

David R · Joined: 08 May 2009 Posts: 8 Location: Toronto, Canada

Sevo thanks

The focusing screens do appear to be genuine Nikon screens. I also have an extra Nikon screen that behaves the same in both cameras. Your suggestion of a third party screen(s), does make sence, as the FE came with a FE2 screen.

Any idea what has been done. Shimming of the cage the screens fit in? Prism height?

I'm not adverse to dismantling the cameras. At this point pulling them apart isn't a loss, as I'm not going to use them as they are. Dismantled the FTN, the black foam did the classic melt down.

My fondness for the FE and FE2, is the metering of the FE2 and light weight bodies. So I'm hoping that I can recover one.

David R

David R · Joined: 08 May 2009 Posts: 8 Location: Toronto, Canada

On a side note.

I did check into repairs and was quoted $125 Cdn to look at the camera.

The mint condition FE of the last flea market had an asking price of $170 Cdn. You can see where this would go.

Considering the other cameras I tested where also questionable, there may also be something else at play as well. Maybe Nikon used some of their black foam as a shim.

David R

spiralcity · Joined: 02 Oct 2008 Posts: 1207 Location: Chicago, U.S.A

David R · Joined: 08 May 2009 Posts: 8 Location: Toronto, Canada

thanks for responding Spiralcity

Oh, I realize cameras age. Black foam being a serious problem. The FTN I bought was a real mess when opened. Gearing can become dirty altering shutter times.

I think I'll tackle the repairs myself for educational value. The FE and FE2 both also have electrical contact issues as well.

I think the purposely modified focus, is the best explaination a this time. At the last flea market the FEs I tested were all pretty good. Within design limits possibly. The FA stands out and the more I think about it, the more I think something was up. The price was really good, maybe to good. The dealer may have already know the camera had a focus issue.

Anyway weather is good and have lots of cameras.

David R