roby17269 said:

What would be the point though? apart from price maybe?
But TS lenses are niche lenses so I'd assume not too price-sensitive... and they are not exactly walkaround lenses, they are meant to be used with tripod etc. So making them smaller and lighter should not be a priority

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Which is why I stated, "I highly doubt they'd do that."

However, Richard's point is a good one that hadn't occurred to me, mainly because I do usually use shift only in the vertical or horizontal directions. I've been hoping a TS-R lens would have encoded movements mainly because it would enable DxO to develop correction profiles for a shifted lens...but doing so for all possible sensor positions in the image circle (assuming rotation is encoded) likely precludes development of such profiles. So I guess I can stop hoping for encoded movements, since it will add to the cost of the lens without significant benefit (I doubt Canon would offer DLO for those lenses, anyway, but if they do I may have to use DPP for part of my workflow, ugh).

neuroanatomist said:

Incidentally, maybe Gemini did get it wrong. I took a pragmatic approach rather than a mathematical one, made a circle with a diameter of 39.32 units (19.66 x 2) and centered a 24 x 36 unit rectangle on it, then measured the area of the excluded portions of the rectangle vs the whole rectangle (pixel counts of a screenshot, but that would not affect a % measurement). It came out to ~2.07% of the FF sensor area, i.e. worse than Gemini calculated.

View attachment 227494

Still nothing to lose sleep over, IMO, much less prevent me from buying a lens requiring such correction.

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I had ChatGPT make a similar drawing (to scale) and subsequently calculate the percentage of the area of the dark corners and the result is 1.48%.

Edit: ChatGPT calculated the result using integral calculus, i.e. a different method than Gemini.

AlanF said:

I had checked it with ChatGPT, which gave ~1.4%. I wonder what is going on?

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Interesting. I assumed that PowerPoint can correctly draw shapes of the sizes I input, and that PhotoShop could correctly count pixels with the measurement function.

I confirmed the former in PowerPoint using a 43.2 unit diameter circle in which the inscribed, centered 36x24 unit rectangle touched the circumference at the corners exactly as it should.


I confirmed the latter by using FIJI (ImageJ aka NIH Image), which I know with certainty can accurately count pixels and measure areas.


2,343÷112,888 = 0.0208.

Old Man FL/FD said:

Do Zeiss Milvus (and Otus) RF/EF mount lenses have AF?

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The Otus RF lenses are MF. The Milvus are also MF.

neuroanatomist said:

If the movements of a TS-R lens are encoded, it would be possible to use a lens profile to correct for asymmetrical distortion and vignetting. In theory, that means Canon could actually 'cut the corners' of a TS image circle, making it smaller than strictly required. I highly doubt they'd do that, but it would certainly give the optical purists conniptions if it happened.

View attachment 227493

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Purist here

What would be the point though? apart from price maybe?
But TS lenses are niche lenses so I'd assume not too price-sensitive... and they are not exactly walkaround lenses, they are meant to be used with tripod etc. So making them smaller and lighter should not be a priority

Richard CR said:

I napkin'ed mathed it out to around 20cm. i could be mistaken though.

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A MFD of 20cm would be the same MFD as the RF 20mm f1.4 L VCM lens.

shawnc said:

How about if Canon creates a pocket camera, not a phone wannabe or a do-everything super zoom blah blah. Fast lens, fixed or a modest zoom illuminating a real sensor, "1 inch" or "aps" (jeez sensor sizes need to standardize to area or xy dimensions) not a phone-sized toy. Modest 4k video specs, but stills focused on stills. A camera that can go where we take our phones but blow them out of the water with IQ. Ricoh's GRIV seems to fill the niche but at a ridiculous price.

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Canon could have used the M100/M200 body as the basis of a fixed-lens compact camera, but it will apparently never happen.

AlanF said:

I had checked it with ChatGPT, which gave ~1.4%. I wonder what is going on?

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I think the AI isn't able to decide what is misinformation, so if someone posted wrong calculations on a forum...

Gimme 1/500s flash sync w/ EFCS and I will be super happy. It does 1/320s now so not a massive leap. AFAIK, the only thing that will beat that spec is the A9III w/ global shutter.

APS-C, Living the Dream!

AUGS said:

So far, Canon themselves has not officially announced or declared when (or if) this lens will be released. Dates or other information, may be informed or otherwise, but have not come directly from Canon themselves. So any rumored dates and/or details should be taken with a grain of salt. There are many product development steps and any or all of them may lead to a delay.

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It's also apparently looking like an F/5.6 to F/6.3 lens now as per latest information...
instead of F/4, F/4-F/5.6, constant F/5.6.

neuroanatomist said:

Incidentally, maybe Gemini did get it wrong. I took a pragmatic approach rather than a mathematical one, made a circle with a diameter of 39.32 units (19.66 x 2) and centered a 24 x 36 unit rectangle on it, then measured the area of the excluded portions of the rectangle vs the whole rectangle (pixel counts of a screenshot, but that would not affect a % measurement). It came out to ~2.07% of the FF sensor area, i.e. worse than Gemini calculated.

View attachment 227494

Still nothing to lose sleep over, IMO, much less prevent me from buying a lens requiring such correction.

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I had checked it with ChatGPT, which gave ~1.4%. I wonder what is going on?

EricN said:

It may depend on the topic. I've tried using them to help create charts for understanding data regarding controversial topics and they make the kind of mistakes only the worst politicians could make. Which goes back to your "some humans."

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When it's routine calculations they are very good. When there is proper on-line documented information, like say government websites on tax and law, they are fantastically useful. When there is sparse or conflicting information, then they can be dreadful. Amusingly for me, I've done searches for camera info and got referred to my own threads on CR!

David_B said:

I presented some calculations from gemini about image coverage of the smaller circle on the sensor and its answer was 98.5%. ... Did Gemini get it wrong? It's not a trivial calculation to work out the area lit by the smaller image circle.

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Incidentally, maybe Gemini did get it wrong. I took a pragmatic approach rather than a mathematical one, made a circle with a diameter of 39.32 units (19.66 x 2) and centered a 24 x 36 unit rectangle on it, then measured the area of the excluded portions of the rectangle vs the whole rectangle (pixel counts of a screenshot, but that would not affect a % measurement). It came out to ~2.07% of the FF sensor area, i.e. worse than Gemini calculated.



Still nothing to lose sleep over, IMO, much less prevent me from buying a lens requiring such correction.

AlanF said:

Be fair. There are some humans even the worst AI couldn't stoop low enough to match. For calculations like these, Gemini, ChatGPT etc are very reliable.

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It may depend on the topic. I've tried using them to help create charts for understanding data regarding controversial topics and they make the kind of mistakes only the worst politicians could make. Which goes back to your "some humans."

Berowne said:

My fast 50mm Prime for a very affordable price (600€), excellent optical performance but quite slow AF is a second hand Zeiss Milvus 50mm/ f1.4. Only downside is the weight ...

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Do Zeiss Milvus (and Otus) RF/EF mount lenses have AF?

Richard CR said:

depends, you'd have to restrict the movement, you couldn't, for instance, shift in different angles - you could only move up and down, and left and right from center.

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Rotation could be encoded, too, right? The position of the sensor relative to the image circle could then be calculated, and since DLO is (as I understand it) based on calculations from the optical formula of the lens, it should be possible to apply corrections to any orientation. For Canon, at least. I believe that DxO, for example, uses empirical measurements to drive their lens profiles and in that case, developing a profile for such a lens would likely be a prohibitive investment.

justaCanonuser said:

Richard raises in this very interesting comparison of reviews a question that I ask always myself: do I want perfection or "artistic" imperfection?

Being myself scientifically educated (physics) I always love to check sites like Photozone, now OpticalLimits, with thorough lab reviews - that's the sort of "scientific" Dr. Jekyll in me. But when it gets to real life photography, the "artistic sort" Mr. Hyde could be set free, and then I enjoy shooting with gear that isn't technically, in particular optically, perfect - depending on the subject, of course. Its the street & people side of photography in which I often love to get an imperfect, vintage look (not quite Lomography, that's too crappy for my taste). By contrast, when I shoot wildlife or macro, I want technical perfection. Getting to the 45/1.2 here, this would be a nice candidate for the first approach to real life photography, so I can understand well why some reviewers are more enthusiastic than others.

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I like to think that I too have "2 sides of my photographer's soul", so to speak: the more analytical one and the artsier one
But I do not see them in conflict, I see it more as the artsy side leaning on the technical side.

In the specific, I prefer to capture the image in a way that the data is as optimal as possible and I can always tweak the data in an less than optimal ways in post. I have done so with my latest fashion shoot, where a lot of "character" was added afterwards (haven't shared those images here since they were taken with my MF rig). There's plenty of plug-ins to simulate film and lens defects in post (Nik had a great one, not sure it is still there in their latest incarnation).

Having said so, like you I suspect, I've never based my buying decisions on reviews. I treat them as food for thought, not as decision makers.

stillviking said:

This could be the missing lens in the Canon setup for underwater photography. I'm very interested in knowing what the minimum focus distance is.

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I napkin'ed mathed it out to around 20cm. i could be mistaken though.

99cm length is far too big, even for my largest backpack!

neuroanatomist said:

If the movements of a TS-R lens are encoded, it would be possible to use a lens profile to correct for asymmetrical distortion and vignetting. In theory, that means Canon could actually 'cut the corners' of a TS image circle, making it smaller than strictly required. I highly doubt they'd do that, but it would certainly give the optical purists conniptions if it happened.

View attachment 227493

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depends, you'd have to restrict the movement, you couldn't, for instance, shift in different angles - you could only move up and down, and left and right from center.

This could be the missing lens in the Canon setup for underwater photography. I'm very interested in knowing what the minimum focus distance is.

Richard CR said:

I'm not sure a TS-R of 12mm is even possible, if it did, it'd probably look something like the Nikkor 7.5mm, which would be highly amusing to be honest.

Hah. i guessed around the correct number, it'd be 7.8mm, assuming a 10mm shift amount, or a full 66mm image circle diameter.

Click to expand...

If the movements of a TS-R lens are encoded, it would be possible to use a lens profile to correct for asymmetrical distortion and vignetting. In theory, that means Canon could actually 'cut the corners' of a TS image circle, making it smaller than strictly required. I highly doubt they'd do that, but it would certainly give the optical purists conniptions if it happened.

I'll take one

I'm still using the Sigma EF 14mm f/1.8 with an adapter. Since I use it quite often, I’d gladly upgrade and get rid of the adapter.
If Canon releases a 14mm f/1.4 that’s sharp with minimal coma, I'm willing to splurge whatever it takes for that one

I personally don’t miss OIS on this lens (the Sigma), and I wouldn’t mind if Canon released their version without it as well. To be honest, I’m also not too concerned about digital corrections or stretching. Hopefully it doesn’t vignette too much though, because I’m already shooting with these types of lenses at high ISO sometimes, and I don’t want to push corner brightness corrections too far due to noise.

David_B said:

Find a scraggly old tree and take a photo of it. How many straight lines are in that? Put it in your raw image editor of choice, apply a lens profile and compare the before and after. Sure they're different but does one or the other make or break the image?

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I wouldn't think so, no. In your image of that scraggly old tree, do you believe that digital correction to fill in the corners would break the image, relative to optical correction?

David_B said:

You're assuming I shoot straight lines. Sounds like a boring photo to me. I also don't put faces at the edge of the frame if I can help it.

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If all you shoot is landscapes, it likely doesn't matter either way. Straight lines are most often human-made, and if you're taking pictures of humans there are often straight lines in the scene.

David_B said:

I presented some calculations from gemini about image coverage of the smaller circle on the sensor and its answer was 98.5%. On a 45MP that's ~675,000 pixels (1.5%) that aren't usable. For the R1, 1.5% is 360,000. How'd you come up with 11,400 out of 24,000,000? Did Gemini get it wrong? It's not a trivial calculation to work out the area lit by the smaller image circle

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Perhaps I could have made it more clear. Regarding the area of the image, I was referring to the RF 24-105/2.8 Z, as I stated in the post. The 19.96 mm image height value on which you based your calculation is not universal, it's the value in a patent for the wide end of one possible optical formula of a 50-150/2.8 lens (presumably not an L lens, and regardless, if such a lens is produced based on this patent it may not have that image height). Different lenses will have different image heights. As to how I arrived at my value, I empirically measured it in an uncorrected RAW image from the RF 24-105/2.8 Z at 24mm.

One other relevant bit of information is that the amount of mechanical vignetting is dependent on focus distance, it increases as the lens is focused closer. I presume that in their patents, Canon is specifying the image height as focal length is specified, with focus at infinity. In the 24-105/2.8 Z image that I used, the lens was not focused at infinity, but was focused on a reasonably distant subject (~40 m). The mechanical vignetting is noticeably greater with a close subject, for example (these are uncorrected, high ISO images):