Ken Rockwell reviews canon 50mm f/1.0

[Loswr]

You seem to be saying that as you open the lens up the light from the outer parts somehow only contributes to the OOF areas and does not contribute to all areas??

I may not be getting what you were trying to get across though and perhaps we are talking at cross purposes.

Evidently.

I made that statement as the 'then' part of if an if-then clause. It's clearly false, and the point was that if the 'then' part is false, then the 'if' part is likewise false.

Light falling at extremely oblique angles from a lens with a very wide aperture is detected at progressively reduced efficiency by smaller pixels. That doesn't make the out of focus light at those wide apertures less out of focus.

 

[Pi]

That doesn't make the out of focus light at those wide apertures less out of focus.

It does, a little. The image is convoluted not with a uniform disk (far from the transition region) but with a non-uniform one, with vignetting near the edge. For over-corrected lenses, close to the focus plane, this can actually help to smoothen the bright edge but I would take a sensor with less light loss any day. (Did I forgot to mention DR? )

 

[Loswr]

That doesn't make the out of focus light at those wide apertures less out of focus.

It does, a little. The image is convoluted not with a uniform disk (far from the transition region) but with a non-uniform one, with vignetting near the edge. For over-corrected lenses, close to the focus plane, this can actually help to smoothen the bright edge but I would take a sensor with less light loss any day. (Did I forgot to mention DR? )

The effect of optical vignetting on OOF regions is a different phenomenon than the reduced sensitivity to obliquely angled light. The former applies to film and digital sensors, whereas the latter applies only to digital (and differentially affects sensors based on pixel size) and was the issue under discussion.

 

[Pi]

The effect of optical vignetting on OOF regions is a different phenomenon than the reduced sensitivity to obliquely angled light. The former applies to film and digital sensors, whereas the latter applies only to digital (and differentially affects sensors based on pixel size).

It is the same, if we are talking about the same thing. The OOF highlights in the center do not suffer from vignetting before registered by the sensor. Close to the focus plane, it may have bright edges or darker one, depending on how the lens is corrected but that is something else. Digital sensors would render a uniform disk to one which is darker towards the edge. You can see that in KR's shots but part of this might be due to an under-corrected design. A good test would be to take a few shots with different defocus and compare.

BTW, film is not as ideal as we may think in that regard. Partly reflective surfaces reflect more at oblique angles and even if they do not reflect much, they transmit less unless they are coated. How visible this is on film - I do not know.

Now, if you are talking about the effect of vignetting away from the center - then this is lens and mirror box induced, creates cut highlights, etc.

 

[Loswr]

The effect of optical vignetting on OOF regions is a different phenomenon than the reduced sensitivity to obliquely angled light. The former applies to film and digital sensors, whereas the latter applies only to digital (and differentially affects sensors based on pixel size).

It is the same, if we are talking about the same thing.

We aren't. The effects on intensity and DoF are distinct.

 

[Pi]

The effect of optical vignetting on OOF regions is a different phenomenon than the reduced sensitivity to obliquely angled light. The former applies to film and digital sensors, whereas the latter applies only to digital (and differentially affects sensors based on pixel size).

It is the same, if we are talking about the same thing.

We aren't. The effects on intensity and DoF are distinct.

The bottom line is that the microlens vignetting affects both.

 

[Loswr]

The effect of optical vignetting on OOF regions is a different phenomenon than the reduced sensitivity to obliquely angled light. The former applies to film and digital sensors, whereas the latter applies only to digital (and differentially affects sensors based on pixel size).

It is the same, if we are talking about the same thing.

We aren't. The effects on intensity and DoF are distinct.

The bottom line is that the microlens vignetting affects both.

The bottom line is we disagree. I'll leave it at that.

 

[LetTheRightLensIn]

You seem to be saying that as you open the lens up the light from the outer parts somehow only contributes to the OOF areas and does not contribute to all areas??

I may not be getting what you were trying to get across though and perhaps we are talking at cross purposes.

Evidently.

I made that statement as the 'then' part of if an if-then clause. It's clearly false, and the point was that if the 'then' part is false, then the 'if' part is likewise false.

Light falling at extremely oblique angles from a lens with a very wide aperture is detected at progressively reduced efficiency by smaller pixels. That doesn't make the out of focus light at those wide apertures less out of focus.

Why would it make out of focus light less out of focus?? But if it didn't capture some of that then you do lose just a little blur along with overall brightness across all parts the image in focus or not since the outer stuff arrives everywhere in focus and out of focus.

 

[Dylan777]

I'm not sure what coming down Canon product pipelines, but recent released primes seem to aim at f1.8ish with IS.

I might keep my 50L f1.2 and 85L f1.2 II around until I see f1.2 replacements. IS is helpful, but I still want that bulky red-ring large prime - that shallow DOF

Otherwise - f2 prime on ff mirrorless seems very attractive to me

 

[Pi]

I'm not sure what coming down Canon product pipelines, but recent released primes seem to aim at f1.8ish with IS.

I might keep my 50L f1.2 and 85L f1.2 II around until I see f1.2 replacements. IS is helpful, but I still want that bulky red-ring large prime - that shallow DOF

I do not think that Canon will kill its 50/1.2 with a 50/1.4 IS. They want to keep f/1.2 primes in heir lineup at least for bragging rights. On the other hand, we will see 50LII at some point, I believe.

 

[RGomezPhotos]

I've seen pics taken with the 50mm f1. It's 'interesting' but a total niche lens. A nice toy but I don't see any real practical applications for it. Shoot in the dark? Um, why? I can see a landscape photographer that would want a 15mm f1 or a researcher needing a 400mm f1 for researching the nocturnal patterns of some endangered species... But for everyone else?

In real world usage, the Canon 50mm f1 and Zeis Otus 55mm f1.4 are completely different beasts.

 

[candc]

I've seen pics taken with the 50mm f1. It's 'interesting' but a total niche lens. A nice toy but I don't see any real practical applications for it. Shoot in the dark? Um, why? I can see a landscape photographer that would want a 15mm f1 or a researcher needing a 400mm f1 for researching the nocturnal patterns of some endangered species... But for everyone else?

In real world usage, the Canon 50mm f1 and Zeis Otus 55mm f1.4 are completely different beasts.

yes they are, the otus is all about sharpness, the canon is all about speed and it has autofocus. both are excellent examples of what can be achieved and i like to see that