How to calibrate aperture on sinar db lens boards

[brighamr]

Hi

I have a few lens element sets that do not have there own shutters but have some sinar db boards which they will fit into
The boards were for different focal lengths so the iris do not corespondent as far as I can work out
I see that there are various adjustments on the back

Dose anybody know the proper way of adjusting them

Thanks

Robin

[erie patsellis]

image2output (iirc) has the service manuals for all the sinar products available for download. the procedure is simple, and very much like calibrating an aperture for a shutter.

[brighamr]

Thanks Erie

With a quick google I was not an
Blue to find anything on image to outputs web site

Do you have a link maybe

Thanks

Robin

[erie patsellis]

http://www.image2output-support.com/sinar/

[Amedeus]

Calculate the aperture from the new lens based on focal length and opening. Use the numbers on the copal scale as a relative offset. Seems to work most of the time for me. YMMV


Hi

I have a few lens element sets that do not have there own shutters but have some sinar db boards which they will fit into
The boards were for different focal lengths so the iris do not corespondent as far as I can work out
I see that there are various adjustments on the back

Dose anybody know the proper way of adjusting them

Thanks

Robin

[Sevo]

It is not really that hard, as you essentially merely adjust the coupler to the numeric display of the shutter, so that you have no scaling issues. In a nutshell, the boards have movable start and end stops and a coupler. Place the board in a sinar shutter, unscrew the stops and coupler. Set the start to the makers specifications for aperture diameter or the fully open aperture measured on the original shutter, set the coupler to display the proper initial aperture value on the shutter scale when at start, set the stop to the permitted end value, lock everything again, and you should be set. IIRC some versions require working in the right sequence as the parts interact adversely and you might need two or three attempts to get it right, but the principle always is the same.