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GFX with shift adapter to Hasselblad V mount?

Boykinally

New member
I’m curious if anyone has adapted a 40mm Hasselblad CFE or similar version to some brand of shift adapter on a GFX? If so, is there any barrel distortion or mustache distortion like I’ve heard the Pentax 35mm has?
 

FloatingLens

Well-known member
In my experience there is a simple residual distortion with the 40 FLE, but it is well controlled optically by comparison. You may want to refer to the Zeiss datasheet on this lens. In the Hasselblad system, there is a correction profile included with the RAW converter.
 

FloatingLens

Well-known member
Find a sample image below. Developed from RAW file without distortion correction in Phocus software:

B_0625.jpg

At least around 5mm of fall involved in taking this picture using Hasselblad CF 4/40 + FlexBody CP + CFV II 50C.
Not taken with a GFX camera, but unnoticeable distortion in my opinion, but YMMV.
I'd expect sensor and ray angle response to be quite similar to the Fuji.
 

mristuccia

Well-known member
The Hasselblad "non IF" 40mm lenses have very small distortion, so they should be ok for your purposes.
The IF version is way more sharp (and expensive) but it also has way more barrel distortion.

Distortions of both lens types can be digitally corrected, but be aware of the fact that the Hasselblad RAW converter (Phocus) to my knowledge cant correct shifted lens, it only correct centered lenses.
You can correct shifted Hasselblad lenses on a TIFF file in Photoshop with the free ALPA lens corrector tool. That's what I do with my 40 IF when I use it shifted on my Cambo technical camera.

Here a test shot I made some time ago with my IF, a Cambo WDS and the CFV-50c Mk1 (11mm vertical shift):

20210801_MARCO_RISTUCCIA_Berlin_01.jpg

Unfortunately I have no experiences with using the V lenses with a GFX body, but if you're considering the GFX 50s, the sensor will be the same as my CFV one, so you should be able to achieve close results.
 
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Ed Hurst

Well-known member
As an aside, can I mention that the distortion you refer to with the Pentax 35mm depends which version you're referring to. The 35mm FA is known for a little moustache distortion. The earlier A doesn't have this so much and, I think, the most recent DFA seems to be the best of them all...
I know your question was about the V mount lenses, but since you're asking this to seek an improvement on the Pentax, wanted to just be clear on that point (y)
 
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rdeloe

Well-known member
As an aside, can I mention that the distortion you refer to with the Pentax 35mm depends which version you're referring to. The 35mm FA is known for a little moustache distortion. The earlier A doesn't have this and, I think, the most recent DFA seems to be the best of them all...
I know your question was about the V mount lenses, but since you're asking this to seek an improvement on the Pentax, wanted to just be clear on that point (y)
Ed, my SMC Pentax-A 645 35/3.5 has moustache distortion on a 33mm x 44mm sensor. It's the second copy of the A that I've owned. Both have it.

It's not what I would call severe, and it tidies up nicely in Lightroom with the correction profile for the FA. A custom profile would probably do better. However, I haven't bothered to make one because I don't normally shoot things where it is apparent (like brick walls...).
 

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rdeloe

Well-known member
Here's a flat-stitched image that shows the moustache more clearly. Remember that with a 33mm x 44mm sensor we're not using the whole image circle. The reason it's reasonable to think the SMC Pentax-A 645 35/3.5 only has some barrel distortion is because we're not seeing the whole image circle.

This image is shifted +/-15mm, which takes us beyond the image circle someone shooting this lens on 645 film would experience. I've marked the position of the 33mm x 44mm frame, and for reference, the dashed lines are where the edge of the design image circle would be (assuming we need a 72mm image circle to tightly cover 645 film). Even within the 72mm image circle, the moustache distortion is now prominent.

Anyway, long story short, there's your moustache. Unfortunately, the Lightroom profile correction is of no value here. A person pursuing the fine art of brick wall panorama photography would have to start getting clever in Photoshop to fix this. Fortunately, most people shooting this lens unshifted on a 33mm x 44mm will only see mild barrel distortion (in scenes with straight lines). People shifting the lens to the edge of the image circle will definitely run into one side of the moustache.

Cheers, Rob

Shifting the Pentax 35.jpg
 

Ed Hurst

Well-known member
Wow! A brilliant illustration of your point - many thanks!

From what I have seen (admittedly through the blinkers of a 33x44mm frame), the 35mm DFA might be more to your taste, but I don't have one to test for you (or indeed any means of shooting outside the usual confines of a 33x44 frame). I am so happy with the 28-45 that I haven't felt the need to obtain the 35 DFA.

Good luck with your endeavours and please do keep us posted :)
 
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