28 'cron falls flat

[Jamie Roberts]

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Umm, be aware that the ExpoDisc is NOT a good way to measure vignetting. It vignettes in of itself, in unpredictable ways.

 

This came up when some CornerFix users were getting really bad corrections using the ExpoDisc. After I contacted the ExpoDisc's manufacturers they confirmed that the ExpoDisc vignettes. Not a problem in its intended application, but a problem when used this way.

 

Regards,

 

Sandy

 

Thanks Sandy! I thought the vignette seemed rather extreme for the 28 Cron ASPH, which in my own shots, hardly seems to vignette at all wide open for a fast 28 (which is the same as saying "I like the optical character of the 28 cron wide open".

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[Jamie Roberts]

If you like the factory correction best, you are welcome to it. To each his own and no arguing about taste and geese and ganders and all that. But I don't.

 

{snipped}

 

Lars, well, if you want to look at an artificial vignette (according to Sandy) and call it terrible, then great. And yeah--there's no accounting for taste.

 

But after measuring the corrections as you reported them (and not eyeballing them on a monitor--laptop or not--sheesh guys!), I'm struggling to understand why you'd prefer corrections that are pretty wildly off in terms of colour for the 28. Talk about seeing red (or magenta / cyan in this case).

 

Can you give us a real shot on the M9 with the 28 cron wide open that shows how terrible it is?

 

It's certainly one of my favourites on the M8 and on my M6/M3 as well. While I don't have an M9 yet, I'm expecting one soon, and I can't imagine not using the 28 cron...so I'm pushing on this more than I normally would...

[chris_tribble]

Jaimie - if you underexpose by three stops and take a photo of a grey wall, the 28 vignettes and you see rogue colours in the corners. Fact. Expose correctly and work in the real world and you get shots like this (wide open).

 

Enjoy the M9...

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[Luuk]

Lars,

 

Great timing this thread. I read it just after having look at the results of a rather quick and dirty series I did to kick the virginity out of my brandnew 28cron yesterday. I wasn´t very pleased with the result. It took me corrections of +2EV to +0,5EV(f2-f5,6) to flatten out the images.

 

Compared to my Canon 16-35 zoom and 5D, which produces flat images in every case, this doesn't look a very professional job by Leica and associates.

 

Although this issue can be corrected in C1 pro in PP, I think this asks for a redo of the in-camera software IMHO.

 

Luuk

[KM-25]

and i was thinking only the other day just how magical this lens is on my m9..must be something wrong with me..

 

There is nothing wrong with you, some people are photographers, others are gear testers.

I am betting you are the former...

[jaapv]

The only thing I can say to the OP is that when I try to correct the vignetting in CS4 the first file can give a very good result with just some falloff in the extreme corners, whist the other two are impossible to correct. The first one, for me, is the best.

[jaapv]

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Lars,

 

Great timing this thread. I read it just after having look at the results of a rather quick and dirty series I did to kick the virginity out of my brandnew 28cron yesterday. I wasn´t very pleased with the result. It took me corrections of +2EV to +0,5EV(f2-f5,6) to flatten out the images.

 

Compared to my Canon 16-35 zoom and 5D, which produces flat images in every case, this doesn't look a very professional job by Leica and associates.

 

Although this issue can be corrected in C1 pro in PP, I think this asks for a redo of the in-camera software IMHO.

 

Luuk

If you are having those problems I guess you are having trouble with the spot-meter like character of the M9 exposure meter on wideangle lenses.

[Jamie Roberts]

Jaimie - if you underexpose by three stops and take a photo of a grey wall, the 28 vignettes and you see rogue colours in the corners. Fact. Expose correctly and work in the real world and you get shots like this (wide open).

 

Enjoy the M9...

 

Thanks Chris! I can't wait

[AlanG]

Jaimie - if you underexpose by three stops and take a photo of a grey wall, the 28 vignettes and you see rogue colours in the corners. Fact. Expose correctly and work in the real world and you get shots like this (wide open).

 

Enjoy the M9...

 

You have eliminated almost all shadow detail in this image. Much of it is nearly solid black. So of course you won't see vignetting, grain, fine detail, or any kind of subtle gradation in these areas. (A lot of detail and dynamic range gets lost when you shoot at high ISOs.) If these are the kinds of images you are most interested in, then vignetting will probably help you.

 

Vignetting and color shifts come into play on scenes that have lighter tones and are much more even. When vignetting is removed from a file you will lose the equivalent amount of dynamic range in those areas. And often a little vignetting helps an image. So that is probably why Leica doesn't try to to "correct" the vignetting to produce a perfectly even image.

[Jamie Roberts]

{Snipped}

Vignetting and color shifts come into play on scenes that have lighter tones and are much more even. When vignetting is removed from a file you will lose the equivalent amount of dynamic range in those areas. And often a little vignetting helps an image. So that is probably why Leica doesn't try to to "correct" the vignetting to produce a perfectly even image.

 

Alan, yes, and that's why I mentioned earlier that Leica is probably using a light hand in correcting the 28 cron, to keep it's film character. And yes, for many instances a vignette does help, especially wide open (and it's totally true that Chris's shot would not be affected by a vignette or it's correction ) .

 

As for even-ness, it's easily achieved with this lens in post with film and hardly shows on the cropped M8. I'll wait till I actually have an M9 to comment on how the 28 works for me.

 

(And I just have to say that it's a heckuva lot easier to fix the vignette, if needed, in post than, say, the 16-35L II Canon's all-round mushiness and distortion I'd happily trade off half a stop of DR for corner sharpness and reasonable distortion).

 

However, the other corrections posted here certainly induce colour shifts where there should be uniformity. Which brings us back to the back to the beginning comment: Leica looks like it's doing the right thing by keeping a light hand but uniform colour correction with the 28 Cron.

[AlanG]

(And I just have to say that it's a heckuva lot easier to fix the vignette, if needed, in post than, say, the 16-35L II Canon's all-round mushiness and distortion I'd happily trade off half a stop of DR for corner sharpness and reasonable distortion).

 

 

I generally only find the 16-35 and 24-105 suitable for my work because the DXO raw converter does such a good job of correction on these lenses. But when possible I'll use the 17 TSE which is just an unbelievably incredible lens and the new 24TSE II (which I should receive this week to replace the old one.) These are large and heavy lenses. Any knocks about Canon not being able to make the best wide angle lenses are pretty much eliminated by those two. So Leica and other manufacturers really have their work cut out for them now.

 

While this gear may seem bulky and heavy to a Leica shooter it is quite small and light compared to the LF gear I used to use. I really don't see Leica competing head to head with this. There are numerous trade-offs to Leica's approach of keeping the lenses relatively compact. And I think people just have to accept those trade-offs if they are looking for a smaller lighter system. Just as DSLR shooters can accept the quality trade-off for the convenience and weight savings of using a zoom or two over carrying a bunch of prime lenses.

[jpattison]

They are complimentary, not in opposition, is what you are saying!

 

John

[Jamie Roberts]

{snipped}But when possible I'll use the 17 TSE which is just an unbelievably incredible lens and the new 24TSE II (which I should receive this week to replace the old one.) These are large and heavy lenses. Any knocks about Canon not being able to make the best wide angle lenses are pretty much eliminated by those two. So Leica and other manufacturers really have their work cut out for them now.

{snipped}.

 

Hey Alan, not to hijack the thread too much, it's always all about trade-offs; I've heard the new Canon TSE stuff is excellent. Come to that, I played with the new Nikkor 24 1.4 at WPPI a couple of weeks ago and it also seemed impressive (and I'm glad there's competition around the wide end primes for once )

 

For me, though, I like the tradeoff of portability without trading much (if any) quality that M cameras offer; I'm often shooting 12 hours plus, so having Ms really makes a difference ergonomically. The fact that the M glass is also--on the whole--spectacular, is a plus

[adan]

The corrections assigned to the 21mm pre-ASPH Elamarit are definitely among the strongest corrections Leica applies in the M9.

 

As a user of the 21 pre with red-edge issues, I have been experimenting using "other" corrections, including the ASPH 21 manual setting, and those corrections all result in even more vignetting than the pre-ASPH corrections.

 

So Lars' results don't surprise me.

 

Vignetting with the 28 Summicron has been commented on since its introduction (in film days), both here and in the Photo.net Leica/RF forum. If one looks at Leica's own charts for the lens (easy to find in the technical data .pdfs for each lens on the home site) - compared to the 35 f/2-f/1.4 lenses, it's vignetting curve is more "S"-shaped (it starts vignetting sooner as one moves towards the frame edges) and does not improve as much when stopped down.

 

(E.G. at 15mm out from the center, at f/2.8 the 28 Summicron is passing only 52% much light as at the center, whereas the 35s (even the f/1.4) are passing 72% of the light).

 

Given that, and given Stefan Daniels' comment that Leica's corrections are not intended to change the basic fingerprints of the lenses, but only correct for the additional effects caused by interaction with a digital sensor - again, Lars' results don't surprise me.

[jaapv]

The strange thing is that with the newest firmware the ZM Biogon 21/2.8, coded as pre-asph Elmarit is clean.

[adan]

As I said, Jaap, the 21 Elmarit pre-ASPH setting will correct almost ANY Leica wide lens nicely - except for the 21 pre-ASPH (sigh!) - and maybe the 18 - I haven't tried that combo yet.

 

Actually, it does pretty well with vignetting with the 21 pre - just not the red-left edge.

[jonoslack]

As I said, Jaap, the 21 Elmarit pre-ASPH setting will correct almost ANY Leica wide lens nicely - except for the 21 pre-ASPH (sigh!) - and maybe the 18 - I haven't tried that combo yet.

 

Actually, it does pretty well with vignetting with the 21 pre - just not the red-left edge.

 

HI Andy

I don't have the 21 pre-ASPH, and so I can't try it out (I guess you've tried already anyway), but at the risk of stating the obvious, have you tried the setting for the 28 elmarit asph with your 21? It was the one setting that really sorted my 25mm Zeiss.

[adan]

Setting as 28 f/2.8 ASPH results in more residual vignetting (not as strong a correction as the native 21 pre-ASPH settings or coding) and no change in the red strip down the left side.

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[chris_tribble]

You have eliminated almost all shadow detail in this image. Much of it is nearly solid black. So of course you won't see vignetting, grain, fine detail, or any kind of subtle gradation in these areas. (A lot of detail and dynamic range gets lost when you shoot at high ISOs.) If these are the kinds of images you are most interested in, then vignetting will probably help you.

 

Alan - I didn't eliminate almost all shadow detail, the lighting situation did (though if you pixel peep there's still a surprising amount of materials in the areas that clip to black in a small JPEG.

 

Here's another example. Real world dreadful mixed light during a corporate shoot. No possibility of using flash to balance the lighting - the client wanted a naturalistic documentation of a major international conference. I used the lens fully open and exposed for mid tones. The image does the job needed. NO obvious vignetting, no obvious colour shifts.

 

Honestly, I'm not trying to be awkward on this and fully accept that under extreme test conditions a lens will shoe issues. It's just that in real world settings where a useable image and a satisfied client are what counts, I depend on the 28 to deliver - and it does.

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[jonoslack]

Honestly, I'm not trying to be awkward on this and fully accept that under extreme test conditions a lens will shoe issues. It's just that in real world settings where a useable image and a satisfied client are what counts, I depend on the 28 to deliver - and it does.

 

I quite agree with you Chris. I've been using the 28 'cron since I first got the camera, and although I can also take test pictures which show a lot of vignetting and some colour shifts (and on this basis the first of Lars's shots here is clearly the best for me). I have yet to have a 'real world' photo which needs to be adjusted because of it.