Turner Reich Triple Convertible

[rich caramadre]

I just picked up a TR conv. lens and have a question about focusing. My question is when shooting the lens with one cell, do I have to refocus after stopping down? Also, I'm aware I will have to use a yellow or orange filter, so if I do refocus do I do it with the filter on, or refocus then apply the filter. Thanks for any help.

Rich

[Kevin Crisp]

They do have focus shift, so yes, check your focus when you stop down to the taking aperture, which should be quite small when using a single element. I've never had the need to use a filter with single elements of convertible lenses, but some swear by them. Quality is highly variable with that lens so good luck with yours.

[Ole Tjugen]

With practice, it's actually possible to learn to focus using the "center part of the image" - i.e. seeing the difference between what will be sharp with the aperture stopped down and the rest of the image. I have never needed to refocus after stopping down, after I discovered the difference in looks.

Some lenses have significant chromatic aberration, and require a filter to be anywhere near sharp. Convertible symmetrical lenses rarely need one, in my experience, except for the old Symmar which could really do with one if edge sharpness is critical!

[rich caramadre]

WOW! My lens arrived today and I just put it on V8 and was really suprised with how crisp the image was at all three focal lengths. I was most interested in the 19" but I must say the 25" was quite impressive. (at least on the GG). It is very sunny today and I was able to focus while stopped down to f45.

[Vaughn]

Have fun with it!

I have a 12-19-28. The 28" really is the limit at infinity with my Zone VI 8x10 -- both standards are on the last half-tooth of the rails! But my Kodak 2D 8x10 can handle it with room to spare.

I suppose I could make a "top hat" extension for the Zone VI, but I do not use the TR that much (I have a 19" and 26" RD Artar to use -- but the TR is in a shutter...)

A filter can be nice to use -- I was using the 28" element at night (taking multiple exposures of the moon coming out of an eclipse). The cold and the moisture froze up the shutter after the fifth exposure -- it stayed open! I had the 28" element on the rear -- I think that is the way one uses single elements.

Vaughn

[Jon Shiu]

Mine says "Use only between -10 degrees and 110 degrees F" on both rims. Why would that be? I was thinking possible separation?

Jon

[Mark Sawyer]

Mine says "Use only between -10 degrees and 110 degrees F" on both rims. Why would that be? I was thinking possible separation?


Maybe so you don't die of frostbite or heat stroke while photographing? :)

[domaz]

Mine says "Use only between -10 degrees and 110 degrees F" on both rims. Why would that be? I was thinking possible separation?

Jon

Would low temperature be a problem with balsam? I can see high temperature but low? Maybe it gets brittle and starts to crack?