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'classic' Canon FL 55mm F/1.2 prime - star images?

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#1 Ron359

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Posted 03 May 2019 - 11:03 AM

Hi,   I've got this 35mm film camera lens and wondering if anyone have used it for wide field astro-pics, film or digital? - How are the star images wide open or stopped down a stop or so - is it worth keeping for DSLR astro-use with an adapter?  TIA.    

 



#2 Joe F Gafford

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Posted 03 May 2019 - 07:43 PM

Film camera lenses usually do not do well with F/stops less than 4 to 5.6 in a DSLR or CCD camera. Unless this is a "digital ready" lens from the late 1990's on, you still have to stop down from the F/1.2. Experiment. I used my Mamiya RZ medium format 50 and 110 mm F/2.8 lenses on my CCD and my old Olympus OM telephotos on my four thirds E-500 with an adapter. F/5.6 is the widest I can get with these lenses without getting the soft Gauss focus. 

 

Joe



#3 Todd N

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Posted 03 May 2019 - 07:57 PM

An adapter may extend an off brand lens beyond the intended back focus and not be able to focus on the night sky. It would work for closer objects like a macro lens but not at infinity.



#4 Joe F Gafford

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Posted 03 May 2019 - 08:21 PM

An example of using a film lens on a CCD

 

Joe


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#5 Achernar

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Posted 25 May 2019 - 09:09 AM

Having used Nikon and Canon lenses that were in the F/1.4 and F/1.2 range, I will say that even among those the results are better at F/2 or F/2.8 than wide open. There were many times where I had used them wide open, and the falloff towards the edges didn't matter because I was using them for photojournalism, not astronomical photography.

 

Taras


Edited by Achernar, 25 May 2019 - 09:09 AM.


#6 Ron359

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Posted 25 May 2019 - 02:01 PM

Having used Nikon and Canon lenses that were in the F/1.4 and F/1.2 range, I will say that even among those the results are better at F/2 or F/2.8 than wide open. There were many times where I had used them wide open, and the falloff towards the edges didn't matter because I was using them for photojournalism, not astronomical photography.

 

Taras

Thanks,  yeah,  I used to have a Nikkor 1.4, 50mm and it was terrible for stars looking like huge seagulls wide open, even on film.  I also tried another 50mm f/2 (I think) and wasn't as bad but not 'good'.   I had no experience with the Canon 1.2, but have sold it since no one else seems to have used it for astro and its difficult to adapt even to a Canon DLSR.  Since they are easy to adapt I have tried several of my old Nikkor lenses on my Canon DSLRs and found a couple of them are very good for astro, so have kept them around.  



#7 Uwe Pilz

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Posted 29 May 2019 - 11:39 PM

I have an japanese 55/1,4 lens. It is quite sharp in the center but has astigmatism at the edges. Of course, I could stop it down. But there is not much sense in it. If I don't want to use f/1.4 I can screw on a Canon 1.8/50 which is way less heavy.




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