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Guess the lens ...
#41
Quote:Lenstip wasn't all that enthusiastic about that lens.
 

Did Lenstip measure the border resolution when it is foucused at the center then the field curvature lead to their low boder resolution?
#42
Quote:Did Lenstip measure the border resolution when it is foucused at the center then the field curvature lead to their low boder resolution?
 

Is it really important? I mean: let's suppose the problem is field curvature & focus point. From an optic point of view, I agree that it's more precise to say "the lens suffers from field curvature" rather than "it's not sharp at borders". But then, on the field, if I want to take a photo with sharp details from center to border, in any case I'll see a problem. In the end, the lens would be not that sharp, independently on which is the exact cause. Right?

stoppingdown.net

 

Sony a6300, Sony a6000, Sony NEX-6, Sony E 10-18mm F4 OSS, Sony Zeiss Vario-Tessar T* E 16-70mm F4 ZA OSS, Sony FE 70-200mm F4 G OSS, Sigma 150-600mm Æ’/5-6.3 DG OS HSM Contemporary, Samyang 12mm Æ’/2, Sigma 30mm F2.8 DN | A, Meyer Gorlitz Trioplan 100mm Æ’/2.8, Samyang 8mm Æ’/3.5 fish-eye II | Zenit Helios 44-2 58mm Æ’/2 
Plus some legacy Nikkor lenses.
#43
Quote:Is it really important? I mean: let's suppose the problem is field curvature & focus point. From an optic point of view, I agree that it's more precise to say "the lens suffers from field curvature" rather than "it's not sharp at borders". But the, on the field, if I want to take a photo with sharp details from center to border, in any case I'll see a problem. In the end, the lens would be not that sharp, independently on which is the exact cause. Right?
Wrong. With field curvature the corners will be sharp, unless you are photographing a flat surface covering the whole image frame. The lens will not be used for that too often, is my guess. With just plain not so sharp corners, the corners will never be very sharp.
#44
Quote:Right?
No, not necessarily. Field curvature is something you might be able to work around in the field. Soft borders are soft borders, no matter what.

-- Markus
Editor
opticallimits.com

#45
Quote:<p style="font-size:12px;">Wrong. With field curvature the corners will be sharp, unless you are photographing a flat surface covering the whole image frame.
 
Well, indeed it's what I was thinking: consider, for instance, architectural photography in which you're shooting at a building facade (ok, such a photo with a shallow DoF sounds a little weird).
 
But I understand the point, the fact that there is at least one case in which it would be critical doesn't mean it would be always critical and so there's the point to know which of the two defects is involved. Point taken.
stoppingdown.net

 

Sony a6300, Sony a6000, Sony NEX-6, Sony E 10-18mm F4 OSS, Sony Zeiss Vario-Tessar T* E 16-70mm F4 ZA OSS, Sony FE 70-200mm F4 G OSS, Sigma 150-600mm Æ’/5-6.3 DG OS HSM Contemporary, Samyang 12mm Æ’/2, Sigma 30mm F2.8 DN | A, Meyer Gorlitz Trioplan 100mm Æ’/2.8, Samyang 8mm Æ’/3.5 fish-eye II | Zenit Helios 44-2 58mm Æ’/2 
Plus some legacy Nikkor lenses.
#46
Quote:No, not necessarily. Field curvature is something you might be able to work around in the field. Soft borders are soft borders, no matter what.


-- Markus
I remember Ken Rockwell's review of Canon 20/2.8 USM (the lens notorious for its atrocious levels of field curvature, as Klaus has also found out). When there was no getting away from this issue, KR has coined the term "intelligent field curvature" and claimed that this is a feature, not a bug. For a dose of good laughs, go here: http://kenrockwell.com/canon/lenses/20mm.htm#intro

#47
Field curvature is a minus no matter what.

However, it shouldn't be pushed out of proportions. The world isn't 2D but 3D and whether it matters depends on the depth-of-field really.

#48
This graph seems a bit different than one you posted in the review. The edges are much closer to the center resolution Sad

 

Hum I quoted the first post with the image but the image didn't seem to carry forward in the quote.

 

Quote::ph34r:
#49
Hmmh, the MTF chart is the one that I also posted here.

The flat field MTF chart is new.

#50
Klaus,

 

 I have a question regarding your experience with the Fuji cameras. ( I am actuallty considering to buy an x-e2  as a general take-everywhere camera due to the high quality of lenses)

 

I have downloaded raw and jpg files (from the x100s, x-e1)  from various sources, processed them in ACR 8.3 and compared them to each other camers what strikes is:

 

1. The developed raw files are not better than the corresponding jpgs (which is Ok  in itself, I suppose)

 

2. It is impossible to increase the sharpening of the Fuji raw files in ACR over the default sharpening of 25 without very ugly and coarse artefact showing up in low contrast areas  (such as foliage) ( btw these artefacts also show up when the jpgs are further sharpened in photoshop with unsharp mask) I have tried  many approaches here  (e.g. used only the detail slider, increased masking, used lumiscence noise reduction, decreased colur noise reduction  etc.), but  never was I able to achieve a comparable degree of sharpness in a fuji raw file than say in canon or sony aps-c raw file (at least not without artefacts).

 

3.  the fuji raw files render by default low contrast areas too sharp and high contrast areas too soft. 

 

4. I  am absolutly unable to obtain the degree of natural looking detail in stones, foliage, leaves and grass than I can from obtain comparable bayer sensor sucha  a sony nex 6, which also uses a 16mP sensor. Fuji detail in landscape images is either soft or full of artefacts. Other subjects, such as people, are fine, however.

 

I am doing something wrong here? I have more than 10 years of experience with raw processing with files from many different cameras. Or is the fuji x-trans sensor just bad in comparism to other offerings? Btw:I also briefly tried silkypix and capture 1 which do not seem to do a better job.

 

Any help is much appreciated!

 

 best wishes

 Jens
  


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