Graflex.org
Get help with your Graflex questions here

Crown Graphic Rangefinder Calib.
Graflex.org Forum Index -> Speed Graphic Help
AuthorMessage
shootist
Joined: 05 Nov 2002
Posts: 14
PostPosted: Fri Aug 01, 2003 6:17 pm

I have a Crown Graphic with 135mm Optar. The Crown has a side-mounted Kalart rangefinder.
I have adjusted the rangefinder as per the site's instructions and the accuracy is very good. Here's the odd observation...the distance scale on the Crown is the arrow/semi vernier from 6' to inf. The actual distance is correct to the lead edge of the bed rather than to the film plane as is normal for most cameras. I've scribed lines for 5, 4 and 3ft. and again the distance is correct for the lead edge of the bed. Anyone observe this?
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sat Aug 02, 2003 2:26 am

The scale on my side RF Pace is a two piece system, one on the bed with the distances and one on the rails with 3 indicator arrows. The indicators are infinity, the rear most, 100 foot center, unmarked arrow at the bed front. The rail idicators plate is moveable like infinity stops. Turning the focus knob until the rails are fully retracted then foward until they are extended 1/8 inch max., seting infinity, stops, distance indicator, and calibrating RF without futher movement of the rails should result in corect film plane measurements.
From what you described, you have a 6-8 inch discrepancy, meaning that something in your set-up was off 1/128-1/64 inch in initial reference setting.

I checked my Pace, using a tape measure to an object 6 feet from film plane, GG and RF agree but distance scale did not, readjusted distance scale, went outside and checked infinity according to scale and all 3 are now in sync.
Make sure your camera is level and film plane is parallel to the target when calibrating.( if using a brick wall left side of back must be the same distance as the right side of the back and the top and bottom the same distance as well.)

Charles
_________________
While a picture may be worth a thousand words, a quality photograph is worth a million.

<font size=-1>[ This Message was edited by: 45PSS on 2003-08-01 20:12 ]</font>
shootist
Joined: 05 Nov 2002
Posts: 14
PostPosted: Sat Aug 02, 2003 6:17 pm

Charles...Thanks for responding to my inquiry. I've recalibrated the rangefinder with the same results as previously mentioned. I removed the distance scale to locate the part number and it was 30881-5.
I searched the site but could not locate this scale number. It is different than the posted numbers of 30881-7 for the 135mm. This may account for the difference. Anyone familiar with the 30881-5 or know it's calibration?
Thanks again...Tony
alecj
Joined: 09 May 2001
Posts: 853
PostPosted: Sat Aug 02, 2003 8:59 pm

Yes, Tony. The 30881-5 scale is one of the 12 scales made for the 127mm lens. It was listed as a "-14" variation. That is obviously your problem with that combination.

FYI, the 30881-7 scale is just one of 6 scales for the 135mm lens.
All times are GMT