changing lensboards - DIY or not?

[daz7]

Hi,
I have purchased one of the lenses (copal shutter) on the wrong lensboard. Can I change the board myself, by simply un-doing the rear element and the shutter's retaining ring with a spanner, or should I send it to the specialist shop?
I have tried to search the internet and got conflicting info.
Some people say that's the DIY work, some say it should not be done at home as the lens may be carefully calibrated to work its best when mounted at the factory.
Also, Schneider's own brochure says to not to move lenses from the mounting board but to send it to their factory.

So, which one is it? Can it be done by myself or not?

 

[4x5Australian]

The statement from Schneider about returning the lens to the factory refers specifically to replacement of the shutter for the Super-Symmar XL Aspheric lenses.

The caution appears on p.11 of its last large format lenses brochure (10811) within a discussion of the new use of aspheric technology in the Super-Symmar XL Aspheric lenses:

"So that its outstanding image quality achieved is not placed at risk, the photographer must observe the following rules:

1. The lens, which at great expense was adjusted at the factory during its installation in the shutter, should never be unscrewed and taken apart unnecessarily in order not to change the very precise distance between the front and rear component which must be maintained, and in order to prevent its being screwed on crooked if both parts are not put back together properly.

2. "If, for some reason, the shutter has to be replaced, this must be done only at the factory, because the tolerances which the shutter has must be replaced by a new precise calibration. For just as a Formula-1 race car tuned for the highest performance responds more sensitively to “sand in the gears” than a tractor, so does the Super-Symmar XL Aspheric react more sensitively to deficient adjustment in connection with installation in the shutter than a more simply constructed lens."

Your existing lens board was not installed by Schneider, but by a previous owner. Now it's necessary for you to change it again. Just do it carefully.

 

[ThdeDude]

"prevent its being screwed on crooked"

This of course applies to all lenses.

I wonder whether there is a recommended tightening torque.

 

[ThdeDude]

"If ... the shutter has to be replaced, this must be done only at the factory"

Apparently also the case for Rodenstock's Digaron lenses

 

[earburner]

I think it boils down to the exact distance between the front node and the rear, I know shims are used to get it spot on to get the sharpest image. I asked my supplier about getting a lens board changed and they said it could be done and quite a cost due to the lens calibration process

 

[daz7]

The lens in question is Super Symmar XL 110mm.
Did anyone change lensboards with super symmars and noticed any image degradation, or is it fine, as long as the shuter and the front element is left intact?
I can certainly look to buy the lensboard adapter, but I hate adapters with passion - they are rearly snug and secure enough to feel good about them.

 

[anyone]

You can of course try it yourself - if the image results are satisfactory, then you succeeded. If not you can pay for calibration. I changed the lens boards for some of my longer analogue lenses and am still happy. You need to be careful to avoid that any possible shims fall out and of course get the lens straight before screwing it into the thread.

 

[Steve Hendrix]

I can't see a reason to not do this, so long as you are careful about maintaining any original elements from the lens mounted to the current board (shims, for example). Typically, the board itself doesn't really come into play. The fastening collar simply secures the front element to the board. The rear element still has to screw into the front the same way it does on any other board. At least for Schneider.I say go for it.


Steve Hendrix/CI

 

[buildbot]

You could also make a tiny mark (with something removable) and then make sure the element is screwed to the exact same spot.
Too bad there are no cheap collimators

 

[ThdeDude]

Two different events may have gotten mixed up here: lens board replacement and shutter replacement.

Schneider talks about shutter replacement and not lens board replacement. (I know that for lens board replacement the rear element has to be unscrewed and screwed on again.)