Nikon F "Type F" focusing screen.

[Marco Gilardetti]

I have read contradictory, lexically poor and confusing descriptions of the "Type F" focusing screen for the Nikon F, both in literature and over the internet.

Could anyone who owns a "Type F" screen please be so kind to explain what it is actually about? Nikon F screen please, not later models (although Nikon pretends that the screen types are always the same, it seems it isn't so, with the Type F especially).

In particular, I fail to understand the difference between the Type F and the Type J screens. Could someone please expand?

 

[Fin]

Screen type F has a large 12mm microprism spot in the center, Type J has a small microprism spot and a plain 12mm ring. The ring denotes where the meter heads take the light measurement from.

 

[AgX]

Both are ground/fresnel screens with a microprism patch.

Type J is similar to standard screens, but with its microprisms going up to center. Thus ommiting the slit-wegde. A screen with a small (5mm) microprism patch.
Type F is a screen with a huge (12mm) microprism patch.

 

[narsuitus]

Nikon View Screens by Narsuitus, on Flickr

I have all 22 of the Nikon F and F2 view screens.

The Type F Nikon View Screen has a matte/fresnel field with a 12mm diameter microprism focusing spot in the center of the screen.

The Type J Nikon View Screen has a matte/fresnel field with a 4mm diameter microprism focusing spot surrounded by a 12mm diameter concentric reference circle in the center of the screen.

I have tried the screens on most of my lenses. The following evaluations are based on my screens with my lenses.

The Type F and Type J screens are both good for the following lenses:
35mm f/1.4
50mm
85mm f/1.8
105mm f/2.5
105mm f/2.8 macro
180mm f/2.8
400mm f/5.6

The Type J screen is better than the Type F for the following Nikon lenses:
35mm f/2
28mm f/2.8
28mm f/3.5
24mm f/2

The Type F screen is better than Type J for the following Nikon lens:
35-70mm f/2.8
1000mm f/11 mirror

Neither Type J or Type F are good for the following lenses:
18mm f/3.5 Nikon
28mm f/4 Nikon perspective control
55mm f/3.5Nikon macro
28-200 f/3.8 to f/5.6 Tamron
105mm f/4 Nikon macro

Have not yet tried Type F or Type J on the following Nikon lenses:
14mm f/2.8
14-24mm f/2.8
16mm f/2.8 fisheye
18-55mm f/3.5 to f/5.6
20-35mm f/2.8
28-70mm f/2.8
80-200mm f/2.8
500mm f/4

 

[AgX]

The Type F screen is better than Type J for the following Nikon lens:
35-70mm f/2.8
1000mm f/11 mirror

I assume this being due to the the fresnel lenses being different, not the microprisms.

 

[narsuitus]

I assume this being due to the the fresnel lenses being different, not the microprisms.

That is very likely. It has been so long since I performed these tests and I did not keep good records of how each lens was specifically affected.

However, I do remember that in some cases, one screen produced more vignetting than the other. In those cases, the vignetting had nothing to do with the microprisms.

In other cases, one screen darkened the microprisms more than the other screen. In those cases, the microprisms were involved.

In a few cases, not only was the screen darkened, but the microprisms were also darkened, thus making focusing next to impossible.

 

[Marco Gilardetti]

Thanks everyone for your useful input. Since you have the actual Type F screen in your hand, would you please double check that it is actually of the ground+fresnel type? This is where authors make most confusion: some affirm that it is a clear (=transparent) glass with fresnel lens but no ground surface.

 

[AgX]

Another question: when is such huge microprism patch useful? In sports?

(I did not find such screen at any other manufacturer.)

 

[narsuitus]

...would you please double check that it is actually of the ground+fresnel type? This is where authors make most confusion: some affirm that it is a clear (=transparent) glass with fresnel lens but no ground surface.

I just examined my Type F and Type J Nikon F/F2 view screens with a magnifier.

The Type F screen has a matte (ground) surface outside of the 12mm microprism circle. I also saw very fine fresnel lines on the matte (ground) surface.

The Type J also has a matte (ground) surface outside of the 12mm reference line circle. It also has a matte (ground) surface between the 12mm reference line circle and the 4mm microprism inner circle. I saw no evidence of fresnel lines on any of the matte (ground) surfaces.

Neither of my Type F or Type J view screens have clear (transparent) glass.

 

[Vincent Peri]

All the Nikon focusing screen literature I have makes no mention of an "F" screen. I'm guessing you are talking about another brand's "F" screen made for the Nikons.

 

[narsuitus]

Nikon made Type F view screens for their Nikon F, F2, and F4 bodies.

 

[Vincent Peri]

Nikon made Type F view screens for their Nikon F, F2, and F4 bodies.

I checked the "MIR" site, ( See: http://www.mir.com.my/rb/photography/hardwares/classics/michaeliu/cameras/shared/ff2screens.htm ) and they list a type "F" screen, so I was wrong. Sorry if I added any confusion.

 

[Marco Gilardetti]

Thank you very much for checking!

 

[AgX]

Another question: when is such huge microprism patch useful? In sports?

(I did not find such screen at any other manufacturer.)

Bump

 

[Marco Gilardetti]

Agx, there is no specific suggested use in Nikon's and general literature about this focusing glass, or at least I couldn't find any. It's simply made for people that prefer microprisms as a focusing aid and think that a tiny microprism area in the center surrounded by a non-aided plain grounded area is not the best solution. Nikon had in its line the Type J (5mm microprisms circle surrounded by 12mm ground surface) the Type F (12mm microprisms circle) and a set of Type H (microprisms all over the glass) focusing screens. To each his/her own.

I believe that later, although many authors pretend that Nikon has always been faithful to its nomenclature, compatibility and blah blah, the Type F was radically changed and that the Type F glass for the Nikon F4 has basically nothing to do with the Type F glass for the Nikon F, hence the confusion in literature (which, incidentally, resurfaced also here...).

 

[AgX]

My thought was that a patch of 1/2 of image height is quite obtrusive and hampers sight. Thus it only would be useful where the scene is established and easy focusing is of major importance. As in sports.