Anybody know what these numbers mean?

[sparrow6224]

On eBay, a Nikon F2 for sale, look at the last photo and you'll see previous owner had put in the film speed reminder frame on back door a slip of paper with typed numbers associated with f/11, 16, and 22. Anyone know what they mean?

Here's the listing: http://www.ebay.com/itm/Nikon-F2-Ph...028831664?pt=Film_Cameras&hash=item2a2628c1b0

 

[sreed2006]

Down the left side, there are Focal Lengths of 20, 28, 35, 50 and (I assume) 105.

Across the top are f/stops of f/11, f/16 and f/22.

It appears that the numbers in the middle of the chart represent half the distance to the hyperfocal distance for each focal length and aperture combination. That would be the nearest distance still in focus when the lens is set to the hyperfocal distance.

My hyperfocal calculator doesn't exactly agree with the numbers on the chart, but a different Circle of Confusion value (mine is set to 0.00118 inches) might cause the results to be in agreement. I'm too lazy to run the numbers right now, and the numbers on the chart sometimes vary quite a bit from my calculator, so they may represent somethng else entirely.

 

[sparrow6224]

Ah, I see, the hyperfocal distance being, for f/11 say, the distance at which f/11 is at the infinity mark? I'm not clear, if that's so, on why half that distance becomes the near focus point but I'll ponder it a while and no doubt figure it out. Thanks much for the explanation. Part of my problem was the old pica font typewriter which didn't allow room between some of the numbers.....

 

[johannielscom]

hyperfocal distance: Only works with lenses that have an aperture scale along the distance ring. 1) Set the infinity mark to the mark of the chosen aperture. 2) Now, look at the same aperture mark across the scale. 3) The distance at that aperture mark is the closest distance that will be comparatively sharp.

Perfect sharpness of course is achieved at the distance that lines up with the index mark for focusing, sharpness diminishes as you get closer to the distances that correspond with the aperture marks.

Say, aperture is f8.0. Set the infinity mark on the distance scale to the f8.0 mark, on the other end of the scale is also an f8.0 mark and the distance from the closest to the infinity mark will be comparatively sharp. Anything outside will be OOF.

Hyperfocal distance settings are your friend on a rangefinder, if there is no time to focus but the subject falls within the boundaries, you can just snap the picture. The markings disappeared with the arrival of zoom lenses, since they are variable with the set focal length...

 

[Landshark]

It works with any lens but it's much easier with a distance scale on the lens.

 

[sreed2006]

Ah, I see, the hyperfocal distance being, for f/11 say, the distance at which f/11 is at the infinity mark? I'm not clear, if that's so, on why half that distance becomes the near focus point but I'll ponder it a while and no doubt figure it out. Thanks much for the explanation. Part of my problem was the old pica font typewriter which didn't allow room between some of the numbers.....

I think what this person has done makes a really interesting artifact of photography. It wasn't done with a modern word processor and ink-jet printer, that's for sure.

But, for a street-shooter, or photographer who just wants to set the focus once and then know what distances will be acceptably in focus, the table he/she typed up will provide a quick reminder. If you do get that camera, don't discard this paper - it is pretty unique.

After seeing that typewritten table, it got me wondering how in the world all the wonderful engineering was done back in the day when all they had was typewriters and drafting boards. It seems impossible now - but they did it.

 

[sparrow6224]

Sid -- I agree. the typewriter font -- it's a manual typewriter font, by the way, not even electric, I'm pretty sure -- is exactly what attracted me to the camera. Unfortunately I wasn't in a position to bid on it at this moment in my fiscal life.

 

[oftheherd]

There is a good read on focus from our member, Mr. Hicks and his wife at http://www.rogerandfrances.com/photoschool/ps basics focus d-o-f.html which you may find interesting.

If I recall correctly, some of the early Vivitar Series 1 zoom lenses did provide marks for hyperfocal distance, but I may disremember.