View Full Version : Graflex 1K Optar 135mm f/4.5 Image Circle?

Bart B
29-Jan-2011, 17:49
After shifting my Super Speed Graphic's lens sideways to the limits and checking images on the ground glass, I'm rather pleased with image sharpness beyond it's rated image circle of about 153mm. Especially at f/16 and f/22. Using a 10X loupe, image detail 95mm off center looked as good as the detail 75mm off center.

Anybody done any photos with such offsets with this lens? I'm going to shoot a few sheets and see what is acceptable for me. Hope it turns out to be pretty good.

Maybe the original ground glass is too coarse to resolve image detail at that level. It might be better to do this test again without the ground glass. Just use the loupe to view the aerial image at the film plane.

Mark Sampson
29-Jan-2011, 20:23
The negative, and the print, will tell you more than the groundglass or aerial image will.

Rod Klukas
30-Jan-2011, 10:12
You can never look at an image with higher than approx 5x loupe and have any idea what you are seeing. A loupe or magnifier of 10x is seeing the grind of the glass/fresnel and this interferes with accurate focus. Even 7x is pushing it. So as Mark suggested shoot some film, especially Transparency, and you will get a much better idea. There is always image larger than the quoted image circle. This is the penumbra or soft edge of the image circle. It is there, but usually not useable image area. Some of the manufacturers are conservative in using this in their image circle data and so it appears that their lens covers less, and others use more of this marginable image to make it seem their lens is better. They assume most never push the lens that far anyway, but want the largest circle for bragging rights etc,.

Mark Sampson
31-Jan-2011, 11:32
I used a similar lens, a 127/4.7 Kodak Ektar, on my 4x5 for six years when I first started. It was/is quite sharp, and certainly met my needs until I started shooting architecture. I'd bet that that Optar (likely made by Wollensak) will be a fine performer.

Michael Graves
31-Jan-2011, 13:02
I have a 135 Optar, and it covers 4x5 with small movements. I cannot say this for all of them, but the one have has very abrupt fall off when stopped down. It is fairly easy to see on the ground glass when you run out of image circle.