B
BernhardS
Guest
Dear forum members,
a friend pointed me to this forum, telling me this is the best place to get advice on the following.
I am looking for high quality lenses for a cooled camera containing a Kodak KAF-16803 sensor (37mm x 37mm, pixel size 9 mu square). The lenses need to have back focus of at least 55mm from the point of mounting. If part of the lens protrudes into the mount then it should do so by at most 25mm (otherwise I get problems with the filters that go in between lens and CCD).
The sensor is b/w, it does not have a Bayer array. Hence there is no spatial low pass filter in front of the sensor, and thus the requirements on the lenses are somewhat higher than what one might expect from a 9 mu pixel size.
I am interested in lenses with focal lengths roughly in the range of 50mm to 150mm that can give pinpoint star images in astrophotography, across the whole frame, at large apertures, when focussed to infinity. Distortion does not matter, flare is not a major issue, vignetting should ideally be small, but most importantly the other optical errors need to be small (coma, chromatic abberations. field curvature...). The lenses need not have a shutter. Focussing should be possible, but a small focussing range around infinity suffices.
I have so far tried a Mamiya 645 80mm f/1.9. The results in the corners are OK-ish but not really good, unless it's stopped down to f/5.6. I have also tried a Canon EF 200mm f/2 with much better results, although that lens is of course not made for a 37mm x 37mm sensor.
My friend recommended to look into Schneider-Kreuznach digitars und Rodenstock APO sironars.
Starting from this, I looked around on the web and found the following possibilities:
Rodenstock HR Digaron-S (Apo-Sironar digital HR) 100mm f/4 with Focus-Mount, or HR Digaron-W 50 mm f/4 with Focus-Mount
Schneider-Kreuznach Apo-Digitar 4/60
Zeiss Sonnar T* 4/180 ZV
... Distagon T* 4/40 IF CFE
Distagon T* 4/50 ZV
Planar T* 2/110 FE
Planar T* 3,5/100 CFi
Planar® T* 2/110 FE
Makro-Planar T* 4/120 ZV
Distagon T* 3,5/60 CFi
Planar T* 2,8/80 CFE
Distagon T* 2,8/50 FE
HASSELBLAD HC 2.2/100 or HC 3.2/150N
Mamiya 645 A 2,8/200 mm APO or A 2,8/150 mm N
I would be happy for any recommendations, or pointers to test results.
Best regards
Bernhard
a friend pointed me to this forum, telling me this is the best place to get advice on the following.
I am looking for high quality lenses for a cooled camera containing a Kodak KAF-16803 sensor (37mm x 37mm, pixel size 9 mu square). The lenses need to have back focus of at least 55mm from the point of mounting. If part of the lens protrudes into the mount then it should do so by at most 25mm (otherwise I get problems with the filters that go in between lens and CCD).
The sensor is b/w, it does not have a Bayer array. Hence there is no spatial low pass filter in front of the sensor, and thus the requirements on the lenses are somewhat higher than what one might expect from a 9 mu pixel size.
I am interested in lenses with focal lengths roughly in the range of 50mm to 150mm that can give pinpoint star images in astrophotography, across the whole frame, at large apertures, when focussed to infinity. Distortion does not matter, flare is not a major issue, vignetting should ideally be small, but most importantly the other optical errors need to be small (coma, chromatic abberations. field curvature...). The lenses need not have a shutter. Focussing should be possible, but a small focussing range around infinity suffices.
I have so far tried a Mamiya 645 80mm f/1.9. The results in the corners are OK-ish but not really good, unless it's stopped down to f/5.6. I have also tried a Canon EF 200mm f/2 with much better results, although that lens is of course not made for a 37mm x 37mm sensor.
My friend recommended to look into Schneider-Kreuznach digitars und Rodenstock APO sironars.
Starting from this, I looked around on the web and found the following possibilities:
Rodenstock HR Digaron-S (Apo-Sironar digital HR) 100mm f/4 with Focus-Mount, or HR Digaron-W 50 mm f/4 with Focus-Mount
Schneider-Kreuznach Apo-Digitar 4/60
Zeiss Sonnar T* 4/180 ZV
... Distagon T* 4/40 IF CFE
Distagon T* 4/50 ZV
Planar T* 2/110 FE
Planar T* 3,5/100 CFi
Planar® T* 2/110 FE
Makro-Planar T* 4/120 ZV
Distagon T* 3,5/60 CFi
Planar T* 2,8/80 CFE
Distagon T* 2,8/50 FE
HASSELBLAD HC 2.2/100 or HC 3.2/150N
Mamiya 645 A 2,8/200 mm APO or A 2,8/150 mm N
I would be happy for any recommendations, or pointers to test results.
Best regards
Bernhard