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This is old, but here's one:Even if it is not "standardized testing", I would not mind some links to comparison reviews, in particular of wide-angle lenses...
Indeed it is old.This is old, but here's one:
Pentax 645 FA 35mm Review
Would anybody know a site comparing the MF DLSRs lenses between brands: Mamiya/Schneider for Phase1, Leica S, Hasselblad HC and Pentax?
For HC lenses, there is hasselbladdigitalforum.com, but it does not offer comparisons with other brands.Maybe threads should be created for the most requested lens examples (i.e., SK 28xl images, Pentax 25mm images, HCD28 images, etc.).
Quite on the contrary, many dealers have a full or almost full collection of lenses for rental.I think most dealers do not have a large stock of lenses sitting on their shelves
All those companies except Pentax publish MTF curves.
I was not able to find MTF data for the central shutter lenses made by Schneider Kreuznach for the PhaseOne / Mamiya cameras. Rodenstock and Schneider Kreuznach only publish MTF data for their lenses designed for technical cameras and indeed traced for different values, which makes comparison difficult.Leica, Hasselblad and Zeiss use 10/20/40 lp/mm. Leica usually adds 5 lp/mm, too.
Rodenstock and Schneider use different schemes, it is often 15/30/60 lp/mm.
Indeed.There are some problems with those curves:
1) They usually are calculated at infinity
2) They apply to flat field
3) They don't show out of focus rendition
This is only valid for simple lens designs. Modern wide-angles often behave in the opposite manner, with maximum corner sharpness rejected beyond the focus distance chosen for the centre point.As an example, many lenses have significant field curvature. Field curvature may often work in our favour. Foreground is often peripheral, so a field that curves towards the photographer may bring foreground detail in focus although the camera is focused near infinity.
It does, but I only did these tests for HC or HCD lenses in MF (I did some Minolta, Sony and Nikon lenses in 24x36) and no-one has ever shown any interest in doing the same tests for other brands although:Your tests with landscape shots covering the diagonal should match MTF curves pretty well.
I disagree, as I have had to wait on delivery when a lens was ordered from a distributor/supplier because it was not sitting on a dealer shelf. This was also the case back in my 4x5 days. I found if I was looking for a Rodenstock or SK lens without a specific mount, B&H was the best supplier, if a specific mount was necessary (Alpa, Arca Swiss, etc.) call the dealers and cross your fingers. The dealers I have dealt with in the US do not sell all the brands, so what you are looking for may not be possible if you could talk a dealer into doing it. Then a few years goes by and there is a new lens line-up.Quite on the contrary, many dealers have a full or almost full collection of lenses for rental.
In the real world those MTF charts are just theoretical and don't address the real issue of assembly and calibration - which is abominable for the price paid for Rody's and Schneider Digitars. The biggest culprit for me is lens skewing with one side or top/bottom not in alignment with the other side. One side will focus near and the other side will focus far. Schneider corrected two of my lenses for free but it took a fairly long time and the lenses had to be sent back to Germany. You won't know this problem exists without testing the lens yourself. They are all different..... I corresponded with another forum member who had just purchased a Rody 32mm only to find out that it was horribly out of alignment. My recommendation is to test any Rody/Schneider lens for alignment..... they all have the potential for greatness as long as they are aligned and assembled properly.Hi,
All those companies except Pentax publish MTF curves. When Leica published their curves, they were calculated and not measured.
Leica, Hasselblad and Zeiss use 10/20/40 lp/mm. Leica usually adds 5 lp/mm, too.
Rodenstock and Schneider use different schemes, it is often 15/30/60 lp/mm.
There are some problems with those curves:
1) They usually are calculated at infinity
2) They apply to flat field
3) They don't show out of focus rendition
On the plus side, they are good indication of lens performance under the conditions they are applicable for.
Yes and no... You can expect a smaller dealer like Digital Transitions to carry a full suit of Phase and tech lenses, but no Hass or Leica. They're willing to dig into details, but they can only compare products they have in stock.Quite on the contrary, many dealers have a full or almost full collection of lenses for rental.
Now that I think about it, Lens Rentals carries just about everything under the sun, in multiple copies, and does regular testing of rented lenses to ensure that they're working as they should, so I do wonder why they don't share their findings...I know that dealers do not want to open boxes. I was talking about rentals, who have a large amount of lenses.
Hmm... that's actually pretty clever, I may try it out sometime.Hi,
All you need for Imatest is a bit of black tape. There are some options to Imatest that are using the same basic principles.
You may look at this one: MTF mapper | SourceForge.net
Lens Rentals http://www.lensrentals.com/rent/medium-format/Now that I think about it, Lens Rentals carries just about everything under the sun, in multiple copies, and does regular testing of rented lenses to ensure that they're working as they should, so I do wonder why they don't share their findings...
I could've sworn I've seen them list other camera systems... then, who does carry all the major MF brands?Lens Rentals http://www.lensrentals.com/rent/medium-format/
only list Pentax MF.
They do post comparisons in the blog of 35mm gear which can be fascinating.
So far this is my conclusion too, but besides technique there are other factors that narrow down the range of shooting environments, outdoors you have atmospheric effects that can do a number on your judgement. Get an 80MP back & 150mm+ lens and watch the heat distortion destroy your hopes and dreams.What would be a great project for forum members to do is contribute to threads where individual images shot with specific focal length lenses could be looked at. But as someone that has been shooting large format and medium format professionally and personally for over 30 years, all I can say is, technique can have a lot to do with the results as well as the condition of the lenses themselves. "C'est la vie."