Graphic 6x9 roll film back

I bought Toyo 45AX and want to use 6x9 roll film back. The Toyo back is very expensive ($599). I believe the Graphic 4x5 to 6x9 roll film back can be used on Toyo 45 AX. Would you please let me know the quality of the the Graphic 6x9 roll film holder. Thanks!

There are several models of the 4x5 to 6x9 graphic backs. The older models are described as knob wind (as opposed to lever advanced) RH8 backs. The older of the models have an opening that is 2-1/4" x 3-1/4". These backs have been known to allow a significant amount of film buckling...some people describe the variation to be as much as 1/16". The newer lever advance backs (and some knob advance backs) haave corrected the problem via the addition of 2 film rollers. You can identify the newer style by opening the back and looking for the 2 ploshed steel guide rollers. As a result of adding the rollers, the opening of the newer style backs is 2-1/4" x 3-1/16". The film flatmness in the early backs is unacceptable with modern emulsions. I base my comments on something I have read from a posting by Tim Takahashi (tim@me.rochester.edu). Hope this helps.

Later roll backs have larger main rollers and don't bend the film as

tightly. This is the principal advantage that I can see. I have never been impressed that the add-on tiny rollers accomplish much. It

may be more to the point to recognize that the entire film carriage floats in the housing and is pressed forward by two steel springs on the opening back, acting on two screw heads. Carefully (!) tighten these springs by bending **only the tips, not the middle** forward and the improvement in flatness is often amazing. Over the last 40 years many of them have fatigued and allow the film carriage to be loose against the guide rails. Look for 1/2" rollers rather than 3/8" rollers. Interestingly, I have an old graflex factory memo that talks about counter and flatness problems in the later, lever wind backs, too.

Cheers, CJH