focus problem ebony 6x9 adaptor

[adrian tyler]

i've been doing a commission using an ebony 45su with the ebony 6x9 reducing back and horseman and arca baby grafloak backs 58xl and 80xl lenses. i've been getting consistent focus problems, focussing *very* carefully with a lupe and stopping down to f16-22, the cromes are consistently soft. is there a known focus issue with the reducing back? the camera in 4x5 configuration is fine...

thanks

[Henry Ambrose]

Isn't some part of the image sharp? At f16-22 something should be in focus.

[darr]

Adrian, I have been using a 4x5 -> 6x9 reduction back in the past with a SV45U and today with a 45SU and Horseman backs (6x7/6x9). I have experience no problems with focus. I would look at the film magazines for film flatness issues.

[adrian tyler]

in certain areas i seem to have got lucky, but nothing seems as sharp as it should be harry, i've been using the hasselblad swc on the same project and the difference is wild. luckily it's a book project so no big prints and the repro house'll be able to save the work ...

[Henry Ambrose]

Adrian,
I'd check the backs as Darr wrote. A thorough test seems in order.
Glad its not so bad that it can't be made to work.

[Narcissist]

I'm picking up a 6x9 reducing back for my RSW45 in 2 weeks. I hope this is an isolated problem :(

[Frank Petronio]

Try shooting some with the focus racked in and out ~1mm to see if somehow they built the back wrong. Not knowing Ebonies at all, could it be there is a shim missing or something keeping you from seating the film backs fully?

See you should have stuck with the Linhof!

[Michael Alpert]

Adrian,

I've used this combination for years without any problems at all. The reducing back is consistently accurate in placement.

Did you rent or do you own the reducing back? I ask because someone may have put the Fresnel lens on backwards or on the wrong side of the ground glass. Or somehow the hinge for the door is not placing the gg in the right place. (It's a pretty simple mechanism, so I don't see what else could be out of alignment.)

The reducing back puts the glass in a different position than the 4x5 back (I think the difference is 6mm), but you must have seen this. Let us know what the problem is and how you solved it. Also, I suggest that you send an email to Ebony. From all reports, they are very good at responding to questions. I bought my camera from Badger Graphic Sales and they are also very good at answering questions about these cameras. I'm sure the other Ebony dealers are also knowledgable.