Top half of focus circle black?

[boulderjoe]

I may not have the right terminology, but the top half of the split

focus circle deal on my FA is black, sometimes.

 

When it's black if I turn the camera vertical it works fine, back to

horizontal, back to black.

 

No real trend as to when this happens that I can figure. I have a

35-135 AIS on there when this happens. Any idea how I can stop this?

 

Thanks again,

 

-Joe

[c_o1]

Are the apertures on your other lenses faster? I think a smaller amount of light is causing

that problem.

[michaelging]

It used to happen when you use lenses with a F4 or slower maximum aperture. You can see it on fast lenses when you use the depth of field preview. I do not think there is a cure other than using a faster lens.

[john_tarrant]

Speeds slower that around f/4.0 will cause this blackout making this type of screen difficult to focus using slow lenses. Zoom lenses that have variable aperatures can start of light and then darken as you zoom out.

[david_h._hartman]

If one?s eye is very carefully centered f/4.5 should be OK and with reasonable centering f/4.0 and faster should be fine. It may be different from lens to lens, camera to camera and person to person. I remember an 80~200/4.5 pre-AI required very careful eye alignment with an F2 Photomic. The 80~200/4.0 AIS is no problem for me.

 

It?s not a matter of light levels it?s the split image rangefinder is see the inside of the lens barrel or aperture assembly, retain rings, etc.

 

Move your eye around and maybe you can get both half bright. At least you can probably get both have equal and somewhat dim. There is an "R" screen designed for lenses f/3.5 to f/5.6 for the Nikon F though F5 (maybe F6). You can use a "B" or "E" screen with your FA.

 

Hope this helps,

 

Dave Hartman.

[luis triguez]

Put the camera a bit up or down and your problem is over.

[birdy]

I had this problem with a 50mm lens on an FE when I realized I did not have the lens twisted on fully. When I tightened it until it stopped completely, the problem was resolved.

[rustys pics]

The answer is to change out the focusing screen and get a clear matte or micro prism. I'm

not sure if the FA has interchangeable screens or not, but that's what I did with my FM2n.

Here is a link that gives you step by step instructions:

http://www.mir.com.my/rb/photography/hardwares/classics/nikonfeseries/fefmshared/

html/screenchange.htm

[Michael R Freeman]

Joe,

 

The 35~135 is f/4.5 on the long end, so unless you keep your eye carefully centered on the finder, as Dave indicated, the rangefinder will occasionally black out.

 

You can replace the screen with either a B2 plain matte screen, or an E2 plain matte with grid lines (these are still available new at B&H for $23.50). Or, if you are particularly flush with funds, you can spring for the brand new B3 or E3 screens ($35) for the FM3A, which will also fit the FA, and are a wee bit brighter.

 

Michael

[boulderjoe]

Thanks all for the responses. I'll check the not-all-the-way on thing when I get home.

 

-Joe

[david_h._hartman]

Joe,<br>

<br>

Michael Freeman got it right on the screen designations. The K, B

and E were for the FE and FM2, The type 2 screens are for the FE2,

FA and FM2n. The Type 3 for the FM3a. Also correct, they are all

interchangeable. Some combinations require exposure compensation.

The older, dimmer screens, should be better for super speed

lenses, f/1.2 to f/0.75. That is better for focus on the matte

surface. Id save the old screens (liar, I didnt ;-).<br>

<br>

The K3 screen would be brighter in the matte area but the slop on

the split image rangefinder focus aid will be the same as the K2

and K screens so the rangefinder blackout problem with be the

same for all. If the spit image range finder works well in bright

light it will continue working well in dim light. This is a

matter of geometry.<br>

<br>

The R screen I mentioned for the F through F5 has a lower slop.

This can be seen when viewing the R screens in hand. The F6 doesnt

have an R screen per the 16 page brochure and instruction manual.

Now that I think of it the F4 and F5 do <u>not</u> have an R

screen either. The need is lower in cameras with an electronic

rangefinder so Nikon doesnt make them. I love the F5 as I

can use a EC-B, EC-E or U screen all the time and still have a

central focus aid. I also love the smaller, lighter FM/FE family

bodies.<br>

<br>

Sorry about the poor proofreading. I had to rush out the door. A

friend of a friend needed a little painting done before finish

carpenters added some trim today. The lady is in a wheel chair

and can't reach the top of door frames. Ah, my proofreading sucks

anyway.<br>

<br>

Best,<br>

<br>

Dave.

[boulderjoe]

Thanks for all of the info. With a matte focusing screen is it similar to an AF screen, where you just attempt to get teh whole image sharp as possible?

 

Thanks,

-Joe

[david_h._hartman]

With the matte focus screen you can focus a specific point or

detail of the subject such as the near eye of the subject and let

the rest fall where it many. That specific point focus can be

anywhere on the matte surface. It doesnt need to be in the

center or in the 12mm circle, its anywhere you chose. When

using fast prime lenses wide open at close distance you want to

avoid recomposing to avoid focus errors.<br>

<br>

If the subject moves you can "dance" with the subject

or refocus with the focus ring. Dancing with the subject means if

the subject moves towards you, you move back to keep the distance

between you constant. You can verify your focus on the focus

screen anywhere. In close-up photography you set the image ratio,

exactly or roughly, and move the camera until the point of prime

interest is sharp. A similar idea but you usually use a focus

rail for precise focus.<br>

<br>

Regards,<br>

<br>

Dave Hartman.