This might be a no brainer question but is there any reason why a sinaron 75 6.8 WA lens can't be mounted on a flat sinar lensboard. When I bought the lens (s/hand), it came on a protruding board (possibly a DB type board as it looks to have a cutout for a mechanism even though I use it with a Copal 0). This means it is offset by approx 10mm forwards and hence the standards are pushed even closer together to get it to focus. This leaves me very little chance of using tilt & swing movements (several degrees either way at most).

I don't see that there should be a problem remounting it on a flat board but thought I'd check with the experts first before I part with the cash.

Thanks in advance.

-- Andrew Pell (adp88@btinternet.com), July 02, 2001

Answers

Andrew, Usually folks mount such a lens on a recessed lens board rather than a "protruding" one to allow for additional movement flexibility. A flat lens board will work, i.e., you can focus the lens at infinity, but it will limit your movements as the bellows will be thoroughly "scrunched up." With my Toyo field, I have my 75mm 6.8 Grandagon-N (more or less same lens as yours, I think) mounted on a recessed lens board for this reason. If you don't need movements then the flat lens board should work OK, and the controls are easier to get to. But if you need any movements, go with the recessed-even then movements are limited.

Judging from your description of the way the lens is mounted on the "protruding" lens board, could it be that your lens is mounted backwards? Sounds silly, but these things happen....

-- Greg Jones (greg.jones@wgint.com), July 02, 2001.

The protruding board is designed that way to get the rear element clear of the Sinar Auto Shutter or digital shutter mechanism. But since you are using the lens mounted in a Copal shutter, there is no reason a flat board or even a recessed could not be used.

-- Ellis Vener Photography (evphoto@heartstone.com), July 02, 2001.

Thanks for you answers. It seems that the lens was mounted on the only borad the shop had at the time, i.e. the auto shutter one and not flat or recessed. The lens is the same as the grandagon N but is a sinar badged one (sinaron). I'd thought about a sunk mount but wondered how much room I'd have to get my fingers in to operate the shutter etc. There's little enough room with the lens shade on when I use it.

-- Andrew Pell (adp88@btinternet.com), July 03, 2001.

Thanks for your answers. It seems that the lens was mounted on the only board the shop had at the time, i.e. the auto shutter one and not flat or recessed. The lens is the same as the grandagon N but is a sinar badged one (sinaron). I'd thought about a sunk mount but wondered how much room I'd have to get my fingers in to operate the shutter etc. There's little enough room with the lens shade on when I use it. If anyone knows the inner diameter of a sinar recessed board, I could guess how much room I'd have for my fingers.

As for the lens being mounted with the board the wrong way round, it's in a sinar board and they're cast and machined so that they can only be fitted one way.

One thing I've just thought of (without getting too deep into the optics) - is it preferable that the lens is mounted on a flat board so that the centre of the lens is in line with the vertical plane of the standard, i.e. tilt movements are correct? The camera is a p2. If a recessed board is used, would there be a focus shift if the lens was tilted / swung?

-- Andrew Pell (adp88@btinternet.com), July 03, 2001.