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Planar 40 CFi vs 40 Distagon

vandevantersh said:
And then there is the 38mm Biogon...from the Zeiss chart, the distortion is ~0.25%
Click to expand...

True, and I would love to own one (too expensive for now, given that I have the Contax 35mm), but you must admit that the workflow with a digital back (or film, actually) compared to a Contax 645 is a little... special :)
 
CarstenW said:
By the way, I believe from what I have read that the 40 IF was designed to be corrected in software, which can be done at quite high quality. Perhaps an early precursor to the strategy adopted with the H 28mm?
Click to expand...

Now I just need to learn how to do that......any suggestions on what software works best? I haven't loaded Phocus on my computers yet (I've been using Flexcolor) and I have Photoshop CS3.

Here is a recent Zeiss newsletter which explains in detail how to read MTF curves:

http://tinyurl.com/7yffk6
Click to expand...

Thanks Carsten....this looks really good!

Gary Benson
 
Peak distortion is around 3.5% with the IF, where it's closer to 1.5% with the FLE, so yes, expect to see more distortion with the IF.

Now here's the interesting part--with the IF, they knew they had a lot of distortion, so near the edges (of the 56mm frame), they deliberately flattened the curve. This means that where you can compare the geometry of the image with the edge of the image, the image flattens nicely (no apparent barrel/pincushion distortion!)

So if you're shooting film, you might find that the IF's flat distortion curve near the edges disguises the distortion very nicely. Unfortunately, I don't have any shots with the IF out at 56mm (my sensor is only 48x36mm) so I can't show the performance of the lens out to 56mm.

Hope that's not too confusing...

-Brad

bensonga said:
Looks very good to me. I assume the 40 CFE IF would show more distortion at the edges?

Gary Benson
Click to expand...
 
A wonderful resource, Carsten! I've bookmarked it. Thanks for posting!

-Brad

CarstenW said:
For someone looking for a really wide MF lens with less distortion than the 40 CF IF, the 35/3.5 Distagon for the Contax 645 is another option. Well respected, although I don't know if it is as sharp as the 40. And it requires a different camera. It has distortion of 2.5% max.

By the way, I believe from what I have read that the 40 IF was designed to be corrected in software, which can be done at quite high quality. Perhaps an early precursor to the strategy adopted with the H 28mm?

Here is a recent Zeiss newsletter which explains in detail how to read MTF curves:

http://tinyurl.com/7yffk6
Click to expand...
 
bensonga said:
Now I just need to learn how to do that......any suggestions on what software works best? I haven't loaded Phocus on my computers yet (I've been using Flexcolor) and I have Photoshop CS3.
Click to expand...

That is a really good question. DxO is the prototypical software for doing things like this, but it doesn't appear to support any Hasselblad products, and it doesn't sound from their website as if it is easy, or even possible, to roll your own based on test images.

http://www.dxo.com/intl/photo/dxo_optics_pro

There must be competitors, but I am not terribly aware of them, since distortion normally doesn't bother me. PTLens is another one:

http://epaperpress.com/ptlens/

It is based on a free library, but cost money itself. There appears to be others, like Lens Corrector Pro, but I have not heard anything about them. You can also do some light-duty correction with Photoshop, I believe, but unless the distortion is of a very simple nature (which may or may not be the case with the 40 IF), it might not be satisfactory.
 
vandevantersh said:
And then there is the 38mm Biogon...from the Zeiss chart, the distortion is ~0.25%

Steve
Click to expand...

That is true wide-angle, not a reverse telephoto. Helps a lot with reducing distortion.

But the Biogon is not usable on an SLR, not enough clearance between rear lens element and the film. So you cannot fit a SLR mirror box. Show stopper for me.

Wilko
 
I am glad there is no mirror in the SWC.
Less service dependant and always ready to go.
It is a like a big Leica with decent size negatives to match.
What more do you need?
 
polypal said:
I am glad there is no mirror in the SWC.
Less service dependant and always ready to go.
It is a like a big Leica with decent size negatives to match.
What more do you need?
Click to expand...

The postage-stamp camera can at least focus ;) (without matte screen loupe). But I would really love an SWC. One day... but likely not this year.
 
CarstenW said:
The postage-stamp camera can at least focus ;) (without matte screen loupe). But I would really love an SWC. One day... but likely not this year.
Click to expand...

Hardly needed, focusing an SWC I mean. Just go hyperfocal.

Still, this is one of the these preferences that are very much a matter of personal taste.

Wilko
 
Focus

CarstenW said:
The postage-stamp camera can at least focus ;) (without matte screen loupe). But I would really love an SWC. One day... but likely not this year.
Click to expand...


Who needs focus when at F 5.6 everything from 2m till infinity is razorsharp?
I know hyperfocal is a sin against serious laws of photography but it has given us many excellent pictures.

Paul
 
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