EOS 5D Woes

[jchrisc]

A camera which vignettes is simply not acceptable in any shape or form never mind at this price bracket and the 5D has done no favors to Canon's reputation and I think will make prospective future purchasers of their products more wary of purchasing on reputation only from now on.

BigWill

Will - since you were so concerned, I wrote again to Canon (as I did when I first had the 5D) and I got very much the same reply. I quote the relevant section below, copied directly from Canon's email:

Thank you for your recent query regarding vignetting around the corners of your images, when using extreme aperture settings with your lenses.

This is not a product fault, but an unavoidable limitation of the camera technology when used with lenses set at extreme aperture settings. The Vignetting occurs as the camera's sensor exceeds the lens visible image circle at these extreme aperture settings.

Now, this implies fairly clearly that every 5D has this problem and that one has to live with it if one wants all the other GOOD things that the 5D offers.

As I have said before, if I could see some pictures from a 5D that did not vignette at wide apertures I would have some basis for arguing that my camera is a poor example, but I have yet to see any.

[BigWill]

Well I sincerely hope that Canon are going to print that in large letters stamped on the first page of the user manual with every 5D they sell and maybe even consider stamping it "health warning like" on the outside of the box ...................but somehow I think they will keep their admissions of failure low key and only confide by emial with those like yourself who have the tenacity to seek such information out!

BigWill

[Lounge Lizard]

A quick brief test last evening suggest that body #2 is probably as bad as the first and I feel that what Canon is saying is true - it is a limitation of the camera technology. However, I would take them to task for implying that 'extreme aperture settings' are something to be avoided. In my tests so far, one of the worst performers is the EF50mm/f1.4 lens. This is what Canon say about it in their brochure:

"One of the best lenses you can buy is the EF 50mm f1.8 II. It has a performance approaching that of some of the L-series lenses, yet is the least expensive, smallest and lightest lens in the range. It also has a wide maximum aperture, making it ideal for photography in low light or at night. Even better is the EF 50mm f1.4 USM, a remarkable lens which excels at all light levels." Hardly in keeping with the view they express to Chris.

Taking this a stage further, vignetting is also visible af f8 with most lenses and I'd hardly call that extreme. In fact, it is slap bang in the middle of the usable range of apertures and one where lens resolution is usually at its maximum.

Like Chris, I'd be interested to see pictures from anyone who doesn't see this problem. I, too, will be writing to Canon shortly if my second body doesn't show an appreciable improvement which, I suspect, it won't.

[The Circle Of Confusion]

As the light fall off is worse left to right than top to bottom then I think what you are seeing is micro lens vignetting (MLV). This plagues all digital sensors with micro lenses and gets progressively worse as the sensor gets bigger. Fall-offs of 3 or 4 stops are not uncommon.

Interesting stuff Terry. Reading around I find that Sigma lenses do better on the 5D than Canon's own lenses. Would they be more telecentric I wonder...?

I found the same when I ran tests on some Nikon zooms against equivalent Sigmas (see here: http://www.thecircleofconfusion.com/...y051212-051412 )

Some manufacturers have looked at offsetting the microlenses towards the edge of the sensor. This is workabale but becomes very lens/camera specific. Kodak patented a telecentric converter a while back but I doubt we'll see this in production as it looks impractical to make.

It can be post-processed out (which I suspect is what most cameras in fact do) but personally I found the impact on noise and colour balance to be unacceptable. I recommended that my customer use Sigma lenses or buy a medium format adapter and use something from a 'blad.

[9pins]

Hi,

Can I add that I have just bought (or should I say got seriously in debt for) last weekend, a 5D and even though there are many problems associated with buying this bit of kit, it did not stop me from buying it, as I know it is going to be the best camera I will probably ever own.

I have listed some of the problems below, which I hope puts into context the whole issue of vignetting and which we all have to overcome as we develop our passion for photography, and do without ever batting an eye lid (a Yorkshire saying I believe).

Problem 1 - My old 1.4 GHZ computer was too slow to shift around 78Mb Tiff files of the kind I am now getting from my 5D, so it has had to go and a new Dell system has been put in its place - a costly problem, but not sufficient to stop me from buying the 5D.

Problem two - The CR2 RAW files the 5D produces do not run with CS, so if I wish to continue using PS as main RAW converter, I have to upgrade - another costly problem but not enough to stop me.

Problem three - My Epson P-2000 will not work with the CR2 RAW files, so I have to upgrade the firmware and hope it will start to work again.

Problem four - My old 256Mb CF cards will only hold about 16 pictures from the 5D CR2's, so out I go and buy some new 1Gb cards - costly but again still not enough to put me off.

Problem five - most of my lenses were bought for the cropped sensor 300D (except a 100mm to 400mm zoom), so new lenses need to be bought as I can only take pictures with this one lens at the moment - again this will be costly, but not enough to stop me.

Problem six - I might when I use a wide angle lens fully open with the 5D, have to spend an extra 2 seconds correcting the vignetting as part of my post processing - ?

9pins

[alanS]

"two seconds"

No problem then.

[Lounge Lizard]

Problems 1-5 are consequential and Canon cannot be blamed for those.

Problem 6

Problem six - I might when I use a wide angle lens fully open with the 5D, have to spend an extra 2 seconds correcting the vignetting as part of my post processing - ?

That's a little naive if I may say so. The vignetting is not necessarily symmetrical and may take a lot more than 2 secs to correct and where the corners have darkened by over 4 stops, that's a hell of a lot of darkening to pull back without shifting the noise/colour balance in that corner. If I've got 200 shots taken in the church at a wedding, that's a big overhead. Besides, it's not just wide open - it occurs to a lesser degree at other apertures up to f8.

New cameras, new designs should be improvements on what has gone before - this is a retrograde step that can seriously impact on image quality and workflow times for close to 50% of the images I would take with this camera. It may not be a big deal to you but it will be to others.

[Benchista]

DxO.

[Lounge Lizard]

DxO

And to you too!

Now, if DxO actually provides a satisfactory fix and Canon bundle it with the 5D then I'd find the situation more acceptable.

[TerryS]

"This is not a product fault, but an unavoidable limitation of the camera technology when used with lenses set at extreme aperture settings."

This is undeniably true - optical vignetting, to some degree, is unavoidable with any lens (since a lens has a finite physical length and is also subject to the cos4 law of illumination falloff), and all lens design is a compromise. It is impossible to eliminate all optical defects and aberrations simultaneously, especially whilst trying to keep physical size, weight and cost within reasonable bounds.

Having said that, some of the vignetting I have seen on 5D images is greater than anything I have ever seen with film and this additional falloff is, presumably, due to the design of the CMOS sensor and the lack of telecentricity of the lenses.

"The Vignetting occurs as the camera's sensor exceeds the lens visible image circle at these extreme aperture settings."

Now this statement I do find amazing, and I would be very surprised if it was actually true! A Canon EF lens is designed to be compatible with 35mm film, thus its image circle should be big enough to completely cover a 35mm film negative and, therefore, completely cover a full-frame digital sensor, such as that in the 5D (and 1DsMkII).

The question that needs answering is does the EF 24-105mm f4 USM IS L (at 24mm f4) show the same degree of vignetting when used on a 35mm film SLR as it does when used on the 5D DSLR? Also, does it show the same degree of vignetting when used on the 1DsMkII DSLR? If the answers are yes then, in my opinion, it will mean Canon have under-designed this lens. If the answers are no then the explanation may lie in the relative cheapness (compared to the 1DsMkII) of the 5D's full-frame sensor.

Terry.

PS: I noticed that a short time ago BigWill started a thread on this subject in the 'Lounge' or 'News' forums (forget which) but it promptly vanished! Why was that?

[BigWill]

Hi Terry, my post in the lounge was pulled for reasons explained to me in a private message by forum moderator David Steel which I entirely accept. Let's just leave it at that for discussion on the boards but I can inform you or anyone else of the reasons by private means if you/they are interested?

BigWill

[TerryS]

Hi Terry, my post in the lounge was pulled for reasons explained to me in a private message by forum moderator David Steel which I entirely accept. Let's just leave it at that for discussion on the boards but I can inform you or anyone else of the reasons by private means if you/they are interested?

BigWill

No problem, I was just curious, especially since I was actually writing a reply to your post at the time it was pulled, which was a little unnerving!

One thing I will add - you asked the editor of AP to take note of Canon's explanation, however it is perhaps worth pointing out that in AP's review of the 5D and 24-105mm lens it was explicitly stated that this combination showed no vignetting at 24mm f4!

Terry.

[BigWill]

Hi Terry, my post in the lounge was pulled for reasons explained to me in a private message by forum moderator David Steel which I entirely accept. Let's just leave it at that for discussion on the boards but I can inform you or anyone else of the reasons by private means if you/they are interested?

BigWill

No problem, I was just curious, especially since I was actually writing a reply to your post at the time it was pulled, which was a little unnerving!

One thing I will add - you asked the editor of AP to take note of Canon's explanation, however it is perhaps worth pointing out that in AP's review of the 5D and 24-105mm lens it was explicitly stated that this combination showed no vignetting at 24mm f4!

Terry.

.............indeed Terry, but I think we have to either accept that as factual or as a flaw in the testing process. I have no reason to suspect AP's integrity with regard to their testing procedure and it would be very wrong for me or anyone else to suggest otherwise.

BigWill

[TerryS]

One thing I will add - you asked the editor of AP to take note of Canon's explanation, however it is perhaps worth pointing out that in AP's review of the 5D and 24-105mm lens it was explicitly stated that this combination showed no vignetting at 24mm f4!

Terry.

.............indeed Terry, but I think we have to either accept that as factual or as a flaw in the testing process. I have no reason to suspect AP's integrity with regard to their testing procedure and it would be very wrong for me or anyone else to suggest otherwise.

BigWill

Agreed BigWill, however it just makes this whole issue ever more perplexing. I am greatly looking forward to seeing the results of the tests that David is planning with his 5D and Canon film SLR and Les with his 1DsMkII. Let's hope that these tests shed some light on the matter.

Terry.

[El_Sid]

"The Vignetting occurs as the camera's sensor exceeds the lens visible image circle at these extreme aperture settings."

Now this statement I do find amazing, and I would be very surprised if it was actually true! A Canon EF lens is designed to be compatible with 35mm film, thus its image circle should be big enough to completely cover a 35mm film negative and, therefore, completely cover a full-frame digital sensor, such as that in the 5D (and 1DsMkII).

So would I. The vignetting in Davids examples (and those of other members) is clearly a fall off in illumination rather than no illumination at all. I have occasionally taken pictures with my Sigma 18-50 DC lens on a film body (for reasons I won't go into) and have gone too short on the focal length for the 35mm neg. The net result is a sharply defined black corner on the negative regardless of aperture rather than a gradual fall off of the kind David sees.

[BigWill]

Quite so Terry. I have a sneaking suspicion that many eyes are taking serious note of this entire thread!

BigWill

[Stevet]

David,

DXO supports the 5D with 14 lens modules available so far - they include the 17-40L and the 24-105L. You can download a 21-day trial version - see here.

If you do bother yourself to try it, I would be interested in seeing the results!

HTH

[Lounge Lizard]

... this site explains why full-frame sensors are so good. Amongst their many advantages are 'Use of wide-angle lenses' and 'Background blur' (presumably using a 'more extreme aperture' to get this effect ).

[Lounge Lizard]

Just looked at the DxO web site. Yes, the 5D is covered but only in the Elite version.

You mean that I have to spend £199 to fix Canon's vignetting problem?

You jest sir!

[BigWill]

...................the 30D's starting to look good David...............and think of all the change you'd have left to spend on things like...................well there's beer...................and maybe even more................beer!


BigWill