I'm a noob and I need help please

[nolan]

I just bought a crown graphic with a xenar 135mm 4.7. The aperture ring is loose and it slides maybe two centimeters past f/32. Here's my noob question:


Is this normal?


Thanks.

-Nolan

[lenser]

Nolan, When you look through the lens (shutter has to be open) while turning the ring, does it go from full open and continue to close down evenly throughout the movement (to the end) of the aperture indicater distance? If so, you are probaly okay although two CM (almost an inch) seems quite extreme. Most of my large format lenses have some travel past the smallest marking, but not that much.

If it is truly loose, that would indicate a problem. There should be a slight resistance as you press against the lever and through the ovement in each direction.

[nolan]

Thanks for the reply. The lens closes down evenly from wide open to fully stopped down, but it continues to close as it passes f32. I guess my question is: is the lens closing smaller than f32 but the f32 marking is accurate, or is the lens at f32 when it is closed as small as it will go (2 cm past f32)? It is very lose, no resistance, so I guess is needs to be fixed.

[lenser]

Nolan,

Without having the lens in hand to test, this is only a guess. But, many shutters are used for more than one focal length lens in the manufacturing process and sometimes. a shutter may be adapted for a set of lens cells that were not original to that shutter. Due to multiple possible combinations, some shutters have been made where the f stop ring operates universally, but a different scale is appropriate to only one focal length and other scales would be used for other focal length cells. That being the case, it is quite reasonable that your f stops are very accurate, but that an extended movement range is present in case that shutter were to have been applied to a different focal length lens that required a longer f stop travel.

The only way I can suggest to test this is to meter a scene and expose for the combination of f stop and shutter speed that is appropriate for the smallest f number. Given the hope that the shutter speed is fairly accurate, if the actual exposed film yields a good negative or transparency, I would think it is safe to believe in the markings.

Then the answer would be yes, it is accurate and you actually could use the un-scaled movement range of the f stop lever, to utilize as even smaller, but unmarked, f stops.

That does not necessarily pose an advantage though. Often, the smallest marked f stops (largest numbers) and beyond will produce inferior image sharpness due to refraction of the light striking the edges of the iris blades.

Quite often the sharpest images will be produced in the f11 or f 16 range even though this will not have the greatest depth of field. Also, many older lenses suffer from a focus shift at the smaller f stops and need to be re-focused on the ground glass while stopped down, to insure the sharpest results.

You might go to Cameraeccentric.com and research this specific lens to see if Seth has anything posted about it's focusing characteristics. Also, in Ansel Adams "Camera and Lens", there is a good discussion of the refraction problem and of the focus shift need to refocus at shooting aperture.

For repairs on this shutter, I highly recommend Carol Miller at Flutotscamerarepair.com. Very reasonable and even with a waiting list, usually not too long a waiting period for your repair. Also KEH.com has a great repair department.

Good luck.

[Brian Ellis]

Thanks for the reply. The lens closes down evenly from wide open to fully stopped down, but it continues to close as it passes f32. I guess my question is: is the lens closing smaller than f32 but the f32 marking is accurate, or is the lens at f32 when it is closed as small as it will go (2 cm past f32)? It is very lose, no resistance, so I guess is needs to be fixed.

I don't know about the looseness. But it's not unusual to be able to go past the marked minimum number (f/32 in your case) and for the aperture to continue to get smaller. I had several Wollensak lenses that did the same thing. My guess is that the f32 marking is accurate and that as you're going past it the aperture is getting smaller, which by itself wouldn't necessarily indicate a problem with the lens.

[nolan]

Thanks for the information guys, i really appreciate it. If it weren't for the internet I would be so lost!

[Kuzano]

Two centimeters is almost a full inch (2.54 cm = 1 inch). It would surprise me if your aperture control goes almost a full inch past f32. Are you sure you don't mean 2 millimeters?

In any event, as mentioned, going past the end of the scale is not uncommon. The scale usually rules. If you want f32, set the point at f32, and each point accordingly.