Tthe example in this photo appears to show convergence, not lens distortion. Be more careful of having the film plane parallel to the center of your photo. The reality is that if you want perfect perspective control, you need to use a shift lens or go to a view camera with movements.
I hope the OP does not mind I used a crop of his picture to show the distortion. I superimposed a grid (I had to rotate the image 0.2 deg counterclocwise to align the grid) and you can see that in points A & A' the upper line touches the grid and there is a white space in point B. In the second picture I intentionally resized the crop changing the aspect ratio, to exagerate the vertical dimension, and the distortion becomes more visible.
As I said before it is very small but not unexistant. Check the technical data sheet in the Zeiss web page. The distortion (barrel) is more than 1.5% at the edges. It is not zero, The Planar 100 has almost nothing, the biogon 38 also has much less (but complex).
I see that you bought this outfit new, but you can get a Planar 100mm used. There are always some for sale, and depending upon your budget you can find a really nice one with some patience.
I agree with fdisilvestro, there is some barrel distortion causing curvature of field there. That said, the CF lens is no slouch, the CB lens is even worse, and the 100mm planar is where there is virtually no distortion. I think we all know that the 80mm CT and CF lenses are not the best in the zeiss line up, but unless doing architectural or scientific shots, it's really of no consequence. It would also be an idea to list the aperture at which these images were taken. I find that the 80mm planar does it's best around f8 through f16 and falls off either side of that.
I would immediately sell the lens.
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To me, there appears indeed to be some distortion on that line on top of the picture. But ... that frame, or whatever that is on the left, seems to be pretty straight ... strange. Are you sure that the shelfboard is not bent ?
Do not forget that the 80 mm Planar is not made for this kind of work, that's why Zeiss made the 100 mm (and the S-Planar 120 mm).
But, of course, at this price, and bearing this name, the lens should be 'almost perfect'...
And, just wondering, are you sure that the upper book shelf, in the first picture, is not bented by the weight of the books on it, who are unevenly displayed? Perhaps, the wood is bented due to climatological influence, out of you control and knowledge of course...
What I want to say is, that this kind of 'tests' should be performed with a controlled target and be repeatable, just to be certain.
And, yes this is a personal point of view, I am working with a 80 mm Planar for over 20 years to my full delight, and never wanted use it for this kind of work, the other Planar is much better.
"...If you can not stand the rustle of the leafs, then do not go in to the woods..."
(freely translated quote by Guido Gezelle)
PS: English is only my third language, please do forgive me my sloppy grammar...
This could also be caused by the film not being perfectly flat in the negative carrier - unless you are using a glass carrier most films will bend slightly causing this same effect.
"Are you sure that the shelfboard is not bent ?"
Indeed, this was also my first intention when I saw the example picture.
I think it will need a more serious method to determine lens distortion.
Anyhow, if you aren┤t satisfied, why don┤t you buy a 100mm Planar or 120 Macro Planar.
I highly recommend the old S-Planar 120/5,6, which I own by myself.
By the way, the Zeiss datasheet says that the 80/2,8 Planar (does not matter
whether it is the latest CFE or a version from the 60s) reaches 1% Distortion
at a distance of about 33mm from the center of the picture, the edge of a typical
56mmx56mm Hasselblad frame has a distance of 3,13mm from the center.
So your distortion should be below 1%.
Sorry for the maths, but I was curious about it and numbers don┤t lie ;-)
I don't "know" that.
Originally Posted by Andrew Moxom
What parameters are you using to determine "best"?
The "Blad 80mm f/2.8 Planar has been designed - and is intended to be, a "general" use lens. To attempt to apply it to a more critical application, and express outrage to the tune of, "I can't understand why Zeiss or Hasselblad would ever allow this lens to be produced" ... is ... I hate to say "stupid", but nothing else seems to fit.
I could question a great deal of the conclusion that there is X amount of "distortion", for example:
"Three points (white) are not aligned in an image overlayed by a grid in PhotoShop....:
1. How accurate IS the PhotoShop grid? Are we assuming 1%, 0.5%, 0.001% - or what? Does PhotoShop specify the limits of accuracy?
2. Where did the "white points" originate? Were they artifacts applied to the background with great accuracy
(... how?) and recorded on the negative?
3. There must have been a scan involved. I know for a fact that the scans from my HP 1310(?) exhibit distortion, comparing file images to the original. I can't remeber ever seeing a tolerance applicable to this distortion, yet I would never, absolutey never, rely on a scan from this thing to "test" a lens - for any parameter.
Now, Hasselblad/ Zeiss claim "No more than 1.5% distortion" ... and that is what it seems to be. They have met their claim, done what they were supposed to do. Why is that cause for complaint?
Ed Sukach, FFP.