View Full Version : 40D image quality
Julian H
Monday 15th December 2008, 19:25
I just acquired a 40D as an upgrade to my 20D, which i loved. The files I got out of the 20D where relatively noise free at ISO 400 and i was looking forward to an increase in quality from the 40D.
It may be the fact that i haven't got used to the files from the 40D, but I shot some in-flight stuff, gulls etc and was disappointed in that many of them appeared to be soft and when sharpened didn't "pop" like the files from my 20D. I'm using the 400m 5.6 Canon lens for flight with a 1.4 x for non-flight stuff.
Also, I noticed that there seemd to be more noise at 320-400 ISO than I expected compared to the 20D. Is this what others have found?
I shot some gulls wings which seemed to come out Ok, but I still expected them to be sharper.
I need to do some focus tests on the lens, but I don't think that is the problem, since if that were the case, some parts of the image, in front of, or behind, would be razor sharp.
It may be just my expectation may be too high and that i need to change some of my processing to accommodate the larger files? Also, do people find much more noticeable difference in quality when making say 13 x 19 prints from the 40D compared with the 20D?
Any input from anyone else that has upgraded that may have felt the same would be appreciated, especially since it's driving me nuts.
Attached is a Snowy i shot with the 400mm and a 1.4x which, after a lot of processing came out nice, but, relatively speaking I feel it should've been slightly better quality.
Hypothetically speaking, let's say worst case scenario, the camera and lens needed calibrating, what is the process, do the lens and body go in?? What does that normally cost.
Julian
Adey Baker
Monday 15th December 2008, 22:26
I've got both cameras and I sort of agree with what you're seeing with regards to image noise and the lack of a 'wow' factor in the 40D compared to the earlier model. Apart from more intense colours on the 40D, I have to say that the results from both bodies are quite similar - not a bad thing really as the 20D is a very good camera.
Where the 40D scores is in the sum of all the improvements making it a more usable camera - quieter shutter/mirror, larger buffer memory, sensor cleaner, etc. and the battery life seems better providing you don't use the live-view too much.
postcardcv
Monday 15th December 2008, 22:59
My main camera is a 40D (but I've not used a 20D) and personally I feel it handles noise very well (if the 20D is better perhaps I should pick one up). I have printed plenty of images from the 40D (upto 12"x18") at upto ISO800 with no NR applied and they look great. I use it with a 400 f5.6 as my walkabout/flight shot set up and think it's great, I have tried it with a 1.4x tc but found that the quality dropped off badly.
Tannin
Tuesday 16th December 2008, 08:39
I've got both cameras and I sort of agree with what you're seeing with regards to image noise and the lack of a 'wow' factor in the 40D compared to the earlier model. Apart from more intense colours on the 40D, I have to say that the results from both bodies are quite similar - not a bad thing really as the 20D is a very good camera.
Where the 40D scores is in the sum of all the improvements making it a more usable camera - quieter shutter/mirror, larger buffer memory, sensor cleaner, etc. and the battery life seems better providing you don't use the live-view too much.
I second Adey's comments, apart from the "more intense colours" part. At least so far as I can tell, that is a side-effect of the 40D tending to under-expose a little compared to the 20D.If you bring both shots back to the same overall brightness (add a little to the 40D or darken the 20D a fraction) then the colour intensity is the same, or close enough that I've never noticed a difference.
Can't really comment on battery life: never noticed much difference one way or another, but then I rarely hammer the 40Ds or the 50D the way I used to work the old faithful 20D - it's the 1D III that does the lion's share of the birding work now, with the others on light-duty landscape stuff, so they rarely fire enough shots in a weekend to need a battery charge. (The 1D III, of course, has a huge battery that lasts practically forever.)
(PS: I am not saying that the 40D under-exposes! Within broad limits, there is no such thing as "wrong" exposure, it is a matter of opinion and taste. But my 40Ds do produce a slightly darker picture than my 20Ds or my 1D III; the 50D is a little lighter than the 20Ds. All are excellent cameras, you just have to get to know your own gear.)
Julian H
Tuesday 16th December 2008, 19:08
Postcardcv,
I have the same lens. I did some focus tests on it and it seems to be focussing OK, so I feel that the camera doesn't need a calibration, I just don't think I'm getting as sharp shots of BIF as I did with my 20D and that lens. Are you using all the focus points or just the center one in the 40D. I find that if you move the sensor off the bird a little it "hunts" more than the 20D and peculiarly, in vertical mode, I had a hard time getting it to "lock-on".
As far as noise, some images at 400 ISO look awful in the background with artefacts that look bad, something I didn't expect from that ISO. other s look OK.
I know the lens is fine, I guess it's just a matter of field testing it more to feel comfortable with it and it may all be in my mind.
J
Roy C
Tuesday 16th December 2008, 19:52
Postcardcv,
I have the same lens. I did some focus tests on it and it seems to be focussing OK, so I feel that the camera doesn't need a calibration, I just don't think I'm getting as sharp shots of BIF as I did with my 20D and that lens. Are you using all the focus points or just the center one in the 40D. I find that if you move the sensor off the bird a little it "hunts" more than the 20D and peculiarly, in vertical mode, I had a hard time getting it to "lock-on".
As far as noise, some images at 400 ISO look awful in the background with artefacts that look bad, something I didn't expect from that ISO. other s look OK.
I know the lens is fine, I guess it's just a matter of field testing it more to feel comfortable with it and it may all be in my mind.
J
Julien, I have not owned a 20D but had both 350D and 30D prior to getting a 40D. With regards to BIF,the centre focus point on the 40D is a lot more sensitive than the 30D which means that if you lose the target for a split second it will lock right on to the background whereas the 30D was more forgiving and would take longer before it locked on to something else. If you lost the target with the 30D you often had time to recover before you lost the bird. You certainly have to be more precise when tracking BIF with the 40D but I have personally found it a lot better than the 350D and 30D for BIF in AI Servo mode.
Re the noise issue, again I can only compare with the 30D but I find the noise on the 40D to be on par or even less than the 30D. I regularly shoot on ISO 800 with the 40D and providing you nail the expsoure, noise is just not a issue.
postcardcv
Tuesday 16th December 2008, 21:04
As far as noise, some images at 400 ISO look awful in the background with artefacts that look bad, something I didn't expect from that ISO. other s look OK.
I am really surprised at this, I shoot at ISO400 on my 40D a lot of the time (going up if needed) and personally don't think that noise is an issue on it. Perhaps you could post an example shot showing the issue?
Chris Galvin
Tuesday 16th December 2008, 21:53
Julian,
I have just got rid of my 20D after not using it all since I got the 40D last September. In my view the 40D gives me better colours, sharpness and a far greater performance when using the higher ISO settings. When I was in Goa last December I used the 40D in preference to my 1DMKIIn when in forest around the Backwoods Camp as the higher ISO settings are better than the 1DMKIIn
The attached image was taken of Orange-headed Thrush mooching around on the forest floor 40D + EF500mm 1/60 @ 5.6 ISO640
djprest
Tuesday 16th December 2008, 22:58
is it a problem with 'AI' servo ? heard that the 40d is not as good as the 20d and 30d for this.
Roy C
Tuesday 16th December 2008, 23:17
is it a problem with 'AI' servo ? heard that the 40d is not as good as the 20d and 30d for this.
See my post above re the 40D and BIF - IMO the 40D is far better in AI servo than the 30D. As a matter of fact I use AI Servo all the time, even for perched birds. The 40D is a great Camera IMO.
See my web site below, all the bird shots over the past year has been taken with the 40D in AI Servo mode.
jdj
Wednesday 17th December 2008, 02:26
Julian
I use both 20D & 40D and cannot square my experience with yours. My 40D files look lush compared to the 20D. Noise is less evident at ISOs above 400, to the point that I now use 640 as my default on the 40D. (I've read elsewhere from people who like to measure such things that 640 actually has less noise than 400 on the 40D.) And for the first time I happily use 3200 and print up to A3 with nice (rather than just acceptable) results.
I'd give the new camera more of a go if I were you, particularly if you have a long and successful relationship with the 20D -- it can take a while to get used to a new camera's files and how to process them best. I struggled with the 20D for a long time after my beloved 10D.
By the way, are you looking at 100% when studying files for qualities such as noise and sharpness? If so, you are blowing up the image more (10MP vs 8MP) and may see greater apparent noise & softness than when viewing or printing at the same size.
I have also changed my technique with the new camera in a couple of ways:
1) AF. I find the AF faster, but also more sensitive, on the 40D so I have started using the 'pumping' technique with some success. That is, as soon as I start to lose focus even a little I lay off the button and press again when the target is squarely in sight once more. With previous models I tried to keep the focus on the whole time.
2) Exposure. I give the 40D more exposure. Often I over-expose a little and then bring the image back down in post processing.
Good luck, and I hope you get to enjoy your new camera as much as I have mine.
John
jtwood
Wednesday 17th December 2008, 16:34
I have owned the 20D 30D and 40D and do find I have problems with noise at setting over 400iso with the 40D, I have no dought that the 20D managed noise a lot better, There are plenty of good points about the 40D and I do like using it and I get some great results with this camera, but I wish it produced less noise at high iso settings.It is interesting that others find under exposure helps this issue, I must do some tests.
JohnZ
Wednesday 17th December 2008, 17:45
I am surprised that you find that jt. I have posted a piccie that was taken at ISO3200 and, obviously, did some noise reduction on it but only in PSE3. No Neat Image, Noise Ninja, or anything like that. I think that the Exif can be checked due to having seen the light, finally !
Would appreciate your thoughts on it.
jtwood
Wednesday 17th December 2008, 19:27
Hi John you have managed to produce a very reasnoble image with this high iso setting it would be helpfull if you can display your camera setting for this image f number and shutter speed would be interesting. Almost all the images I take above 400 iso have to go through Neat image and this does have a effect on the detail.
JohnZ
Wednesday 17th December 2008, 19:42
Hello again jt the info you asked for is as follows. I had my 400mm lens wide open, f5.6, and the shutter speed was 1/250 sec. The temperature was bloody cold and the bird did not look like it was in any hurry to move which may have helped.
kevindurose
Wednesday 17th December 2008, 20:37
Julian
I use both 20D & 40D and cannot square my experience with yours. My 40D files look lush compared to the 20D. Noise is less evident at ISOs above 400, to the point that I now use 640 as my default on the 40D. (I've read elsewhere from people who like to measure such things that 640 actually has less noise than 400 on the 40D.) And for the first time I happily use 3200 and print up to A3 with nice (rather than just acceptable) results.
I'd give the new camera more of a go if I were you, particularly if you have a long and successful relationship with the 20D -- it can take a while to get used to a new camera's files and how to process them best. I struggled with the 20D for a long time after my beloved 10D.
By the way, are you looking at 100% when studying files for qualities such as noise and sharpness? If so, you are blowing up the image more (10MP vs 8MP) and may see greater apparent noise & softness than when viewing or printing at the same size.
I have also changed my technique with the new camera in a couple of ways:
1) AF. I find the AF faster, but also more sensitive, on the 40D so I have started using the 'pumping' technique with some success. That is, as soon as I start to lose focus even a little I lay off the button and press again when the target is squarely in sight once more. With previous models I tried to keep the focus on the whole time.
2) Exposure. I give the 40D more exposure. Often I over-expose a little and then bring the image back down in post processing.
Good luck, and I hope you get to enjoy your new camera as much as I have mine.
John
John,
you have hit on a very important point here! This is that if you over-expose pictures slightly you the reduce the noise in the picture. This is true because noise is most evident in the dark areas, due to the camera only recieving a small amount of information from the dark areas. When you over expose, the shutter stays open, thus allowing more information to reach the sensor this in turn means less noise. Wow this seems like a great idea. However, how would the noise from one of your slightly over-exposed pics compared to one that was correctly exposed at a slightly lower ISO setting which should have been achievable at the same shutter speed. I have never done any experiments to test this but I suspect that the results would be pretty similar! Because at the end of the day its all down to the amount of information the camera recieves.
A few years ago I took of some little bustards at ISO 1600 (I forgot to reset the camera after photographing an eagle owl!) Well once the picture was brought back in the RAW convertor from a seriously over exposed state I couldn't believe it not a hint of any noise whatsoever despite ISO1600 (20D).
A couple of years ago I met a proffessional photographer who reakoned he prefered to slightly over expose pictures with his 1Ds MKII as this helped to keep the noise down. I'm not sure what other professionals would say, but for us its often not an option with white birds especially in sunlight. But perhaps with a dull bird on a dull background, maybe.
And good to see someone else uses the shutter pumping technique, I use this myself, although mostly on single shot as I dont believe the 40Ds AI servo is up to the job on fast moving birds.
Kev
Roy C
Wednesday 17th December 2008, 21:18
As Kevin as indicated, 'exposing to the right' is the way to go. If you underexpose and push back up in processing it is a sure way to increase noise. It is better to overexpose as long as you do not 'blow' any of the bird - blowing the background is no big problem as it can be toned down if it looks ugly.
jdj
Wednesday 17th December 2008, 21:25
Hi Kevin
I think a slightly over-exposed image pulled back has less noise than even a correctly exposed one. I can't be bothered to try and measure, though, as I am happy with the results I get & that suits me fine.
The gearheads call it exposing to the right. The idea is to give as much exposure as possible without blowing the whites. I don't go that far, just a little over the top, but it is surprising how much detail is available at the top of the histogram (and even beyond).
The main point is to try and avoid underexposure, as correcting in that direction is a noisy road. Even when that happens I don't think of 40D files as noisy compared to 20D in a similar situation.
John
Roy C
Wednesday 17th December 2008, 22:16
Hi Kevin
I think a slightly over-exposed image pulled back has less noise than even a correctly exposed one. I can't be bothered to try and measure, though, as I am happy with the results I get & that suits me fine.
The gearheads call it exposing to the right. The idea is to give as much exposure as possible without blowing the whites. I don't go that far, just a little over the top, but it is surprising how much detail is available at the top of the histogram (and even beyond).
The main point is to try and avoid underexposure, as correcting in that direction is a noisy road. Even when that happens I don't think of 40D files as noisy compared to 20D in a similar situation.
John
LOL so I am a Gearhead am I :-O:-O:-O (see my post above or did you not read it ?)
Clive Watson
Wednesday 17th December 2008, 22:31
I saw an article once that basically said that if you take your histogram and divide it into five equal sections vertically, the pixels are not equally distributed. 50% of the pixels are in the right-hand most section, then 25% in the next, 12.5% in the middle one, 6.25% in the next and just 3.125% in the left hand one. This was used to demonstrate the same point as is being made here; i.e. that it is better to expose to the right (over-expose) and bring the exposure back in post-processing (always with the caveat that you don't go off the edge and blow the highlights). Whether that is directly relatable to the noise issue being discussed here I'm not sure.
I have to admit though, I normally try and expose correctly in the field. Old habits die hard. Partly this is because I'd heard once that if I was ever going to flog my photos to make some money, many agencies will only accept raws and presumably wouldn't be too impressed with a load of overexposed photos!
Mick Johnson
Wednesday 17th December 2008, 22:32
I had the 20d for 21/2 years and have now had the 40d for over a year.
I find the noise about the same as the 20d to be honest, no beter, no worse.
I must say though, that I find the colours much better and more accurate on the 40d.
Colours will vary anyway depending on what lens is used.
djprest
Wednesday 17th December 2008, 23:00
See my post above re the 40D and BIF - IMO the 40D is far better in AI servo than the 30D. As a matter of fact I use AI Servo all the time, even for perched birds. The 40D is a great Camera IMO.
See my web site below, all the bird shots over the past year has been taken with the 40D in AI Servo mode.
i only ever use AI servo for bif,using AI servo for perched birds is a no no for me.
Roy C
Wednesday 17th December 2008, 23:06
i only ever use AI servo for bif,using AI servo for perched birds is a no no for me.
Yes but do you focus with the shutter button or the AF-ON button?. Using the AF-ON button to focus gives you advantages if you use AI servo mode all the time. I think you will find that this method is being adopted by an ever increasing number of people. Many bird photographers (far better than me) advocate this method.
Julian H
Wednesday 17th December 2008, 23:19
Thanks guys for the input.
A few things to address a few points.
1.I did a focus test with a scale at 45 degrees and 5 dollar bill square on to my camera. Shooting wide open with flash it seems that my AF is not back or front focussing so no calibration is in order.o:)
I believe that I may need to get used to the different files and adjust my expectations as necessary. I do believe I had the same issues with my 10D first so it's probably paranoia.
As for BIF, I shot rpators last year and murdered Merlins in flight with the 20d (no mean feat with those devils) and a Swallow-tailed kite (400, 5.6 400 ISO) - the AI SERVO gave me good success most of the time.
2. I think the centre point sensitivity may be something I have to get used to
and adjust my reflexes to try and keep the centre-focus on the bird. The 20D seemed to be more forgiving?
I use the AF-On button tapped once for focus-lock so I can recompose and shoot..holding down the AF-ON gives me AI SERVO again at the touch of a button. Due to the lost focus problem if the centre focus point moves off the bird slightly, vave other found any more success for BIF with using the "ring of fire" - all nine points selected as AF points
3. After ACR processing I saw some artefacts in some areas that had some "mosaicing", looking a little like bacteria under a microscope, obvious when i had applied USM??? Noise is one thing, but this pattern was nasty-looking.
4. The noise I'm looking at may be normal and that I'm just "pixel-peeping" too much!|:S|
As for histogram/exposing to the right, if we're shooting RAW, then I believe the LCD is rather pessimistic about clipping highlights since the image is generated from the embedded JPEG data. If you are shooting JPEG and have in-camera parameters set (Contrast, sharpening etc) this may affect the sensitivity of the LCD to show "blinkies". Eg. you may show clipping on the LCD screen yet find, once opened that the data isn't clipped in the histogram in the Raw converter.
I prefer to expose to the right as much as possible for the reasons mentioned by others above, that the most "tonal info" is captured in the right 2/3 rds of the histogram. It's easier to adjust a slightly light image with all the data using black point/white points in curves, than it is to lighten shadow areas since that will exacerbate noise most of the time.
Thanks for the response and good shooting!
JRH
jdj
Wednesday 17th December 2008, 23:50
Roy: went for a cup of tea between writing and pressing the button so no I didn't see. No offense intended.
Julian: Glorious kite pic. Perhaps your nasty pattern problem means going back to scratch with USM settings. I'm adding slight sharpening in Lightroom (30-40) and not seen anything odd. I agree with your settings advice; I keep contrast at minimum to get closest to seeing when clipping actually occurs, not only is the RAW histogram often not clipped but also there is often more detail to pull back in from beyond the right-hand edge.
I was intrigued by the more or less noise & looked back at a few reviews to find that the consensus was that noise levels are the same between 20D & 40D. Whatever, I don't find noise an issue with current SLRs. My impression from the files is along the lines of Mick's comment rather than noise worries.
Julian H
Thursday 18th December 2008, 17:51
JDJ,
Thanks for the comments..a rarity in my home state, and a bird that performed better than any others I've seen in Florida or Central America..truly exceptional and I managed a few nice shots!
I'll just keep on shooting and playing around and get used to stuff..if there's nothing wrong with the camera focus based on my test shots then it's me, ain't it.
Best to all,
JRH
Clive Watson
Thursday 18th December 2008, 18:55
As for histogram/exposing to the right, if we're shooting RAW, then I believe the LCD is rather pessimistic about clipping highlights since the image is generated from the embedded JPEG data. If you are shooting JPEG and have in-camera parameters set (Contrast, sharpening etc) this may affect the sensitivity of the LCD to show "blinkies". Eg. you may show clipping on the LCD screen yet find, once opened that the data isn't clipped in the histogram in the Raw converter.
You may well be right. I normally find that I can recover highlights even if they are 'blinking'.
I also agree about the noise of the 40D being pretty much the same as the 20D (the only two digital bodies I've ever owned).
I can't comment on the 20D vs. 40D for birds in flight since I've only recently purchased a 400mm f5.6 and I've only ever used it with the 40D. Perhaps I'll have to try a little comparison test.
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