lenses for 4x5

[pierre salomon]

Hello all.
Does anyone have succesfully mounted newer lens cells onto an older Sinar Db board? I have a Sinar F2, I would like to install ( just screw in) newer multicoated lens cells of 240 or 300 mm onto a sinar db board previously used with a Symmar convertible 240/420 mm. The board is Copal 3. Is it technically possible and would it make sense photografically and financially? I am trying to avoid spending some money in purchasing a shutter mounted lens since I already own a Sinar auto shutter. Any reply will be greatly appreciated. Thank you. Pierre

[tor kviljo]

I have done that a few times - having bought inexpensive (a Fujinon and a couple of repro-lenses among others) remounting them on DB or mickey-mouse type Sinar-Norma lens-boards to use on sinar-copal shutters. If You allready have the lens cells of a modern lens (or can buy these cheap) it would be worth it. Just know that shutterless DB lenses goes very cheap - so this have to be to get a user lens for yourself - you would probably loose money if You have to sell it: I would recon that you find cheap allready DB mounted optics easier than collecting the bits & pieces yourself, but if You would like to try, follow the simple guidelines: Measure the total length (end of rim to end of rim) of assembled modern lens in original shutter. Then remove lens cells from shutter/aperture barrel & measure diametre of aperture at a few relevant stops (one should do, but it takes seconds - so check at least 5.6, 11, 22 & the smallest you intend to use, 44 or 64). Measure the diametre of Your sinar Symmar convertible board to check that apertur values are corresponding (with 240 or 300 on a 240 symmar aperture-mechanism, aperture diametres is supposed to be identical at corresponding stops). Remount lens cells on Sinar lens-mount & tighten slightly. Measure overall length from rim to rim: it should be very close (within half a mm) to original length of modern, mounted lens. If total length is slightly less than on original shutter/mount, se if You have missed some shims in original shutters, or shim up using bought or home cut shims (thin copper-foil is easy to cut with scissors). My favourite lens - a 250mm Fujinon, is "home-mounted" in DB shutter this way. This DB shutter were for a 210mm schneider, and with that little difference in FL, aperture scale were vorrect also with new lens. This fujinon mounted in shutter would have set me back at least twice the amount the lens + DB assy costed me.