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Phase One 55mm 2.8 LS

donaldlavay

New member
Does anyone have experience with this lens? As part of a new P1 IQ160 system I acquired a P1 150 2.8 AF which is tack sharp throughout the center and central edges of the frame, the 80mm 2.8 LS which shows similar image quality and the 55mm 2.8 LS which is totally different story. I have had 3 copies, all showing the same characteristics:
Very poor central sharpness at f2.8 and f4. Satisfactory to excellent central sharpness at f5.6 and up.
Absolutely horrible (and unusable) central edge sharpness at all apertures until f11 when the edges become marginally acceptable. This involves 30% of the frame on the right and 20% on the left and is not meant to include the corners. Noticeable deterioration begin at f16 due to diffraction.
From my perspective, these characteristics make the lens effectively a 1 f stop piece of glass unsuitable for landscapes and group portraiture unless one is willing to perform major cropping. And if such cropping is done, one has to ask why she/he is using a MF rather than D3x or 1DsIII. Moreover, the necessity of using such a small aperture largely negates the advantage of a leaf shutter mechanism.
I have been told by Digital Transitions and Phase One that this is normal for this lens even though they both have stated that the lens performs on par or better than the 80mm LS which it surely does not. Resolving this issue with the manufacturer and vendor is another issue, but in the meantime I need a wide angle in the 35-55mm range. Can anyone make a suggestion based on personal experience?
 

jagsiva

Active member
I got one a few weeks ago. I was initially holding off based on reviews etc., and thought I would go the tech route, but after testing the lens out, I decided to go for it.

Compared to my 80LS, it is very close from 2.8 on. The only weak points relative to the 80LS is slightly more vignetting wide open and some distortion.

With Lens Correction applied for both lenses, I am hard pressed to tell any differences.

Are you sure your 55LS is focussing properly? Try MF with live view just to be sure. Also, check the firmware on the lens (CF98). Mine shows 1.2. I think some of the earlier 55LS had issues, so just check to make sure this is also not the case.

If you have an FTP site, I can upload the RAW files from both lenses for you.

Cheers...
 

donaldlavay

New member
I would very much like to review your images but, unfortunately, my FTP site is down. I will re-post once it is available. Thanks.
 

Jack

Sr. Administrator
Staff member
There was some variability in the early versions of the 55LS, but the more recent versions are generally excellent.

I made this image earlier in the year with it on my first outing with the IQ180, and the fine detail in a large print is stunning:

 
D

DoubleM

Guest
Can anyone make a suggestion based on personal experience?
Hi Donald,
in my experience, center Softness with any Schneider/Mamiya lens (even the older ones) is always a focus problem. Just check it out.

Below you can find a center 1:1 crop with my SK 55/2.8 LS @2.8 - DF - P65+

Best regards
Martin :)
 
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Bill Caulfeild-Browne

Well-known member
My 55 LS is my most used lens. It is wonderfully sharp at all apertures though the far corners are not perfect until about f5.6.

I think you got a bad copy - or several! But I agree you should check focus.

Bill
 

goesbang

Member
Pretty much the same story from me as the others here. My 55 is superb. Tack sharp across the frame from f5.6. I am confident enough with this lens to have been shooting handheld at 1/80sec at f5.6 from a chopper for an architecture client just a couple of days ago. (Images are posted on my FB page).
If I was having the results you describe , I'd be putting the hard word on my dealer. I have always had superb support from my dealer and from Phase themselves.
Cheers,
 

donaldlavay

New member
I acquired the Mamiya 55 2.8 AF new from KEH. My preliminary results comparing it with the 55 2.8 LS on the P1 645 DF are, to my eyes, quite remarkable. Center is reasonably sharp @ 2.8 @ infinity and tack sharp by 5.6. Corner and edge sharpness is more than acceptable at f4 and 5.6 and excellent @ f8. I detect no appreciable CA wide open in the center or corners although I have yet to photograph a really high contrast, brightly illuminated subject. Likewise, while a more thorough analysis of field curvature is pending I detect nothing obvious. The performance over the entirely of the frame on my IQ160 already appears to be vastly superior to the 3 P1 55mm 2.8 LS units I examined; at least as far as my needs are concerned.

I should also note that P1 concluded that 2 of these LS units were performing within specifications. I still fail to understand how they came to that conclusion and seriously question the competence and/or motivation of those involved. To any experienced photographer this would seems ridiculous and the issue is only magnified by the $3724 price differential.
 

rollsman44

Well-known member
How can you tell the NEWER Version of the SK 55/2.8 LS Is there a ser # ? TY
Is the Mamiya 55 2.8 AF better or just as good and with none of these issues?
 
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