Potential Savings for Nikon F4 Users

<p>Years ago I used a Nikon F4 and F3 and loved them, but moved on and sold them. Several months ago I realized that I really wanted one of them back, and decided on an F4, and after several weeks found one in good shape at a pretty good price. It came with the standard matte/fresnel field focusing "B" screen. I loved these cameras for their versatility and ease in changing focusing screens to meet the occasion. As I use a lot of manual focus lenses as well as AF lenses, I've come to really like a brite-view split image, and I remembered having one with my previous body. So I searched the bin and realized I must have sold all of my F4 screens, but still had a selection of F3 ones, including a split image "K" screen. After some research I found that you could use some F3 screens in an F4 (it's the details nobody mentions which get you though). Anyway I looked online for a K screen for an F4----scarce as hen's teeth and waaaay to expensive when I could find them, but F3 "K" screens were plentiful and not very expensive at all. Back to the drawing board...slipped the F3 one into the F4 body and voila...it worked. Well, not perfectly, I discovered. It didn't matter whether I was using MF or AF lenses....objects at a distance didn't precisely line up in the vf when the camera said they were in focus...they were slightly off, which meant they would be slightly off at other distances as well....so precision focusing went out the window. After a couple of weeks I grabbed my micrometer and measured the focusing screen mountings of the F4 and F3 screens and discovered there was a miniscule difference in depth, and the screen lens itself was held in place in its holder with 4 screws which held a tiny "L" bracket which fit into slots in the top and bottom sides of the lenses. So I exchanged the "B" screen lens of the F4 holder with the K screen from the F3, and put the F4 holder back in the camera body. Slipped on an AF lens and focused on several structures about 4-500 feet away....the vf lineup was right on the button....same when I moved to closer objects. Did the same with a couple of MF lenses which had hard stops at infinity....same results. IT WORKED. So, for anybody out there who has an F4 and wants to use a much less expensive K screen...get one for an F3 and change it into the F4 holder.</p>

<p>I'd heard about the screen compatibility here on photo.net a few years ago and bought an F3 P-screen to put in my F4. I got it for $9.99 and free shipping on eBay. Works great!</p>

<p>F3 screens could also be used in an F2 by filing off the handling tab, or exchanging the frame. There was no need to alter the register.</p>

<p>"Potential Savings for Nikon F4 Users" - After reading this subject line, I thought the suggestion was going to be to get a DSLR and never have to buy expensive film ever again. :-0</p>

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<p>I think you will find that F3 and F4 screens are the same size but optically different enough that focus will be inaccurate with an F3 screen in an F4 or vice versa. I had horrible problems with an F4 P screen in my F3HP, with the screen causing the camera to focus too close, especially on distant objects. Id expect the opposite would happen in an F4 with an F3 screen, the camera will focus behind the intended subject. My advice is make sure you use the proper screen for your camera.</p>

<p>Rodeo Joe - that too! :)<br>

Steven - the F4 screens, in their holders, are thicker than F3 screens...my measurements showed the difference to be 0.23mm - which changes the visual focusing point if one interchanges the screens in their original holders. The "gripper L brackets" in the holder - when a focusing lens (screen) is inserted into the slots for them, will hold the screen at the proper depth for accurate focusing. The depth differential of the holders is the cause of the problem, at least with a K screen. That's why changing the holder is critical to success, and the main point of my comments above.</p>

<p>Steven Keirstad: Incorrect. As long as you put the F3 screen into an F4 frame, focusing will be accurate. The screen may (or may not) be thicker (don't have a micrometer at home), but the ground glass surface will be in precise register.</p>

<p>Actually, I did put an F4 screen in an F3 screen frame, and I still had focusing problems that I never had with a genuine F3 screen. I also recall reading somewhere that Nikon recommends against mixing the screens because of optical differences. However, if it works for you, good. But If I were you, I would check the performance at many distances to be sure it really works properly before shooting anything critical. I ruined some shots I'll never get back, due to an F4 screen in an F3 frame in an F3HP body.</p>