Pentax 67 sharper than Hasselblad?

[fschifano]

I think the larger Pentax negative may suggest slightly greater sharpness at the same magnification, but the leaf shutter on the 'Blad vs the curtain on the Pentax might obviate the difference rendering the Pentax negative equal to, or less sharp than the 'Blad. I've used a P67 with 55, 105, and 200 mm lenses for about a dozen or so years, and sharpness has never, ever been an issue except for a NYC rooftop shot that kept the shutter open for 45 seconds, and, when enlarged significantly, showed a tiny double image of every specular highlight detail because of the shutter (I used MLU) I think.

With a 45 second exposure, camera movement during the exposure is a definite possibility. Using MLU or not wouldn't make much difference, since these vibrations settle down very quickly. That little bit of vibration doesn't last long enough to make an impression on the film with very long exposure times. On the other hand, it is very likely that something shifted part way through the exposure. A heavy vehicle running on the street below, or the subway rumbling underground, can vibrate a building enough to shift a tripod a tiny amount.

[Joachim_I]

Pardon my ignorance, I've not used either of these systems, but are we comparing a 6x7 Pentax frame with a 4.5x6 crop of a 6x6 Hasselblad? And folks are still expecting the Hasselblad to be sharper?

As far as I understand, Jordan looks at scans not at 16x20 prints or something like that where the Pentax would have a format advantage. The scanned negative of the Pentax is slighly wider, that's all.

Let me contribute only one more thought to this thread: Jordan's experience is another example that the much debated "shutter shake" problem of the Pentax is seriously exaggerated on the internet. I don't know how many photographers decided against the Pentax because of rumours mostly spread by people who never saw any prints or slides produced by this system.

Every Pentax 67 user I met is very happy with this system, myself included. And I don't care if another system produces marginally sharper results. The overall package counts (otherwise I probably would have changed to digital by now; something which is certainly not in my mind). I guess the same applies to Hasselblad users.

[MikeSeb]

I think the Hasselblad name has quantum properties that cause photons to bend more accurately; and photographers to, gape-jawed, get out their checkbooks.

[GraemeMitchell]

I use both these systems extensively. Both are great, obviously, but they're so so different in the nature of how they're designed, and moreover how they want to be shot, that I've never made it as far to even consider comparing their optics.

W/ that, getting geeky, both have lenses that are so sharp they leave nothing to be desired (hassy 120mm makro, pentax 105mm). At all. They also both have lenses in their line ups that while not incredibly sharp, draw so beautifully, it leaves nothing to be desired (hassy 150mm, Pentax 165mm)

[Pumal]

It's the lens and the aperture that matters

[2F/2F]

At the same size of a standard rectangular print size, yes, because the Pentax negatives do not need to be magnified as much, nor do they need to be cropped to fit the paper.

At the same magnification from the negative? Probably not, with most lenses. This means that if you print the entire composition from each to the same width on the paper (the 6 cm side of each frame enlarged to fit the paper), then the magnification will be the same. (You get a smaller image with the Hassy, however, because it shoots a square.)

I can't think of many instances in which I would print something other than a very minor variation of what I composed in the camera, though, so I would say that a correctly working Hassy should produce sharper images at the same print size, if it is not cropped and enlarged more than the Pentax negative.

As for whether you can see the "better" sharpness of the Hassy lenses on the print, who knows? However, it can be measured on a technical level.

One advantage of the Pentax, aside from negative size, is the film flatness, and the fact that you do not need to ensure this with every back, as you do with a camera that uses exchangeable magazines. It could just be that your Hassy backs need service to perform at their best. It is also possible that your insert does not match your back.

This being said, the lenses simply form images of different aesthetic qualities. A raw technical measurement of sharpness is not as important as learning to see these differences.

Another thought: Are your Hassy shots perhaps shot stopped down more than the Pentax shots, to the extreme end of the aperture range (smallest apertures)? If so, you may be seeing the effects of diffraction when you blow it up on your computer screen.

I am also assuming you are using the same film...but maybe I shouldn't assume things.

[Q.G.]

You need to magnify a 6x6 neg only 1.3x (just under that, in fact) to get the same size as a 6x7 neg.
That is not a lot, and though it certainly helps, the difference in image quality has to be rather obvious for a magnification so small to reveal it.

[2F/2F]

You need to magnify a 6x6 neg only 1.3x (just under that, in fact) to get the same size as a 6x7 neg.
That is not a lot, and though it certainly helps, the difference in image quality has to be rather obvious for a magnification so small to reveal it.

Indeed. As I said, it can be measured.....but can it be measured with your eyeballs?

I would argue, based on my experiences, that you will notice a difference in the general aesthetic qualities ("feel") of the images before you will be able to see a difference in sharpness between the two.

[RidingWaves]

Magazine film plane flatness is totally an issue, as if you shot after letting the film sit in a bend.

[Rinthe]

how will you know if your film isn't flat in the hasselblad?