Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: Zachary Goulko on August 19, 2008, 10:41:13 am
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Hello,
So I recently picked up an Aptus 75, along with a Sinar X and a Hassy H1. On the Sinar I have a 150mm f/5.6 Digital APO Sironar Lens, and on the Hassy the 80mm kit lens.
After doing some in-studio testing with the back on both cameras, it appears that the Hassy images are looking much sharper. Can it be that the Rodenstock Digital lens is not up to par with the Hassy, or if I am just not getting good enough focus after numerous trials? Currently I am using a 10x loupe on the groundglass, with a Phase FlexAdapter. No live preview yet.
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I have noticed the same thing with the Aptus mounted on the AFI and on a Cambo with Schneider Apo Digitar 47mm 90mm and 180mm. I was taught as a youngster that LF lenses that sported an image circle suitable for use with movements was harder to make than a lens used in a fixed position. The larger the circle the lens needs to project the more compromises the lens designers need to make and so lenses can be a bit softer. Anyway that is what I have ascribed this issue to. I still prefer to use the Cambo because the movements are so much fun and the whole experience of using the camera is so pleasant and contemplative.
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I have noticed the same thing with the Aptus mounted on the AFI and on a Cambo with Schneider Apo Digitar 47mm 90mm and 180mm. I was taught as a youngster that LF lenses that sported an image circle suitable for use with movements was harder to make than a lens used in a fixed position. The larger the circle the lens needs to project the more compromises the lens designers need to make and so lenses can be a bit softer. Anyway that is what I have ascribed this issue to. I still prefer to use the Cambo because the movements are so much fun and the whole experience of using the camera is so pleasant and contemplative.
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After doing some more testing, I have come up with the following...
There are a couple of reasons why the 4x5 images were softer:
1) I was testing at f16-f22, which is not the recommended aperture. The sweet spot seems to be f8-f11.
2) I wasn't hitting the critical focus with the loupe. Once Live Preview came into play, which is really great btw, I now can compose and focus right on the screen, and hit critical focus every time. The Rodenstock lens definitely delivers, if not surpasses the Hassy.
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After doing some more testing, I have come up with the following...
There are a couple of reasons why the 4x5 images were softer:
1) I was testing at f16-f22, which is not the recommended aperture. The sweet spot seems to be f8-f11.
2) I wasn't hitting the critical focus with the loupe. Once Live Preview came into play, which is really great btw, I now can compose and focus right on the screen, and hit critical focus every time. The Rodenstock lens definitely delivers, if not surpasses the Hassy.
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My experience has been that Rodenstock Digital and Schneider Digitars are sharper than any medium format lens.