metering issues with 5D MkII

[philip_wilson]

<p>Peter - I have shot film for over 30 years (35mm and MF) and recently committed to digital with a 5DII (I toyed with a rebel for a while). I found the metering took time to get used to - sepite the fact that I was using Velvia and have every pro Canon body from the New F1 onwards. I find that polarizing filters and ND grads produce much more variable effects on a digital body. Before someone writes in this is with circular polarizers - I understand the issue with liner polarizers. I am not sure if the issue is the digital sensor or the algorith used for the evaluative metering on the 5DII. I took a whole bunch of test readings from a grey card with 11 canon bodies under controlled lighting and found all of the 5DII metering results were within a 1/3rd of a stop of the film bodies (some of the older bodies such as the F1N and A1 only meter in 1/2 stops). Thus the reason is either the sensor or the algorithm. I should have taken the tests using a polarizer and grads but did not - I may try this next time I have a spare hour. What I have found is that I like to shoot in RAW, I use AEB a lot more than I used to (usually +/- 2/3 or 1 stop) and try and use manual with a polarizer or ND Grad. I also tend to add =1/3 of a stop to most "correct" exposures to get a velvia like result.</p>

[neill_farmer2]

<p>I too get variations in metering with my XTi, In a burst of continuos shooting there will be one frame +1 while the others are ok. Looking through camera tests I notice that Canons metering modes have algorithm that takes a lot of notice of the central area, different metering mode selections just seem to make this area larger or smaller. This means that the frame doesn't have to move far to include or exclude a bright patch in the metered area. Your white sails and white boat could be having vastly different influences on the exposure setting depending on whether these areas are included or excluded from the metered area.<br>

Doesn't fix the problem but might explain why it happens.</p>

[g dan mitchell]

<p>Philip:</p>

<p>Just an observation... if every response is met with "I have a ton of experience (so don't tell me about basic stuff)" there is a possibility that you and those trying to help may decide that it is better to withold suggestions that might be useful.</p>

<p>I certainly understand that you have a lot of experience with photography, but all of us are capable of having blind spots - I know that I sure do from time to time.</p>

<p>Take care,</p>

<p>Dan</p>

[peterlyons]

<p>Lots of good thinking here. Thanks to everyone for the intelligent responses.</p>

<p>The more I look at my recent shoots, the more I'm inclined to think there's something wrong with the camera itself. Have a look at this. They're two different boats, but the composition is exactly the same, and they're shot within seconds of each other. Both on the 5D MkII with the 24-105, Aperture Priority, evaluative metering (I was calling it pattern because that's what Lightroom calls it), and both with +1/3 stop exposure compensation:</p>

[peterlyons]

<p>Lots of good thinking here. Thanks to everyone for the intelligent responses.</p>

<p>The more I look at my recent shoots, the more I'm inclined to think there's something wrong with the camera itself. Have a look at this. They're two different boats, but the composition is exactly the same, and they're shot within seconds of each other. Both on the 5D MkII with the 24-105, Aperture Priority, evaluative metering (I was calling it pattern because that's what Lightroom calls it), and both with +1/3 stop exposure compensation:</p>

[peterlyons]

<p>underexposed</p><div></div>

[peterlyons]

<p>properly exposed</p><div></div>

[peterlyons]

<p>Dan-</p>

<p>I'm not trying to sound like a know-it-all. Discussions of exposure metering can begin at a pretty basic level, and I was only trying to say that I have a good grasp on this stuff, and am familiar with the scenarios that I've seen fool meters. But clearly this has me stumped, so I'm all ears. If there's something basic that I've missed, I'd love to hear it!</p>

<p>thanks for your input!</p>

<p>Peter</p>

[peter_wang6]

<p>That first image isn't even close to correctly metered. Look at the histogram and there's barely any white. :(</p>

[peterlyons]

<p>Neill, the situtation you're describing with one shot in a series being off a stop from all the others...<br>

THAT sounds bizarre. I'm not sure what would cause that kind of result. It sounds like the kind of variability I get when I accidentally switch to spot metering.<br>

As to the polarizer being the source of trouble... I've heard about issues like this before, but have never seen them in my work. I wonder if there's something with the AF sensor in the 5D MkII that causes it to respond differently to polarizers than the 5D does.</p>

[tien_pham]

<p>From the info you gave:</p>

<p>1. Center point AF.<br />2. Av mode.<br />3. Center-weigh metering.</p>

<p>Look at the 1st pix, AF center point meter system would see the light brown color of the sail. Thus it tells the camera to open up a bit. In the 2nd pix, the AF point see the white cloth of the sail, therefore it tells the camera to close down a little.</p>

<p>Same thing happen in pix 3 and 4, except that in #3, probably it see part of dark color, part of white. In pix #4, it sees the dark color of the shirt.</p>

<p>BTW, do not use the years of experience as a supporting argument in a talk, because it is a fallacy:</p>

<p>1. Does the experience closely relate to the matter at hand? For example, a person with 20 years of indoor photography experience may trip when taking pictures outdoor.</p>

<p>2. E.g., a person takes up a camera everyday in 2 years may be better than another person in 20 years, but one day per year; assuming they have the same IQ.</p>

<p>3. Depending heavily on the IQ (not Image Quality, mind you) of a person, eg., how quick he/she learns and digests a lesson.</p>

<p>And more, but these are the few.</p>

[ken schwarz]

<p>Peter, the camera is working fine. The issue is that you are wishing for <em><strong>consistent</strong> </em> exposure more than <em><strong>correct</strong> </em> exposure. If it's consistency that you want, then you have to use manual exposure in order to keep the exposure fixed from frame to frame. You can meter off a gray card or just take some test shots in manual mode, and once you are satisfied with the settings, leave them alone or if you need to change aperture, shutter speed or ISO, you have to manually (*sigh*) adjust one of the others to compensate.</p>

<p>If you use auto-exposure, the camera will try to pick an exposure that it hopes is what you wanted while preserving some post-processing flexibility. From this perspective, all of the shots you posted look reasonably well-exposed to me. All the camera can do is guess at what should be exposed for mid-tone. It looks like it's always assuming that the center of the frame should be exposed as gray, and letting the top and bottom thirds of the frame to fall where they may, even if they might be black or blown out a bit. Some of your pictures have very wide dynamic range right in the center of the frame--from black to white--and I think the camera did an ok job at picking a compromise exposure that preserves flexibility in post-processing to go up or down to pick your black and white points.</p>

<p>Now, a real complaint you could direct against Canon is their very weak manual mode. It would be genuinely useful if Canon had an "exposure value" mode in which you could choose some combination of shutter speed and aperture and lock it down. Then, when you make an adjustment to one would automatically shift up or down to compensate. Maybe they could associate this behavior with the "*" button in manual mode; pressing it would interlock the aperture and shutter-speed dials until you press it again. They could call it "manual shift mode", but I would call it "Hasselblad mode", since this is the way that the C-type lenses worked.</p>

[ken schwarz]

<p>PS: Re-reading your original post I realize now that you probably know all of this. But do give manual mode a try. I don't know why people think it's more work or takes more time. It's the easiest approach if your lighting is consistent (as it is in your examples).</p>

[mikepeters]

<p>I don't understand why you wouldn't just meter manually. You are in a very consistent light space, shooting in the same direction. What I do in situations like this is take a test shot of something representative that I'll be shooting, check my histo and nail the exposure down. I change it depending on my position, but the results are as consistent as the light, very. I personally have not given up my incident light meters, they are the most consistent. In camera, I find the evaluative pattern to be the least consistent, and the average meter pattern to be the most consistent and easiest to anticipate where it will be fooled if I am going to use auto exposure in a situation. Technology is great, but remember that it is still pretty dumb when it comes to simple things.</p>

[d_beard]

<p>use film</p>

[feanolas1]

<p>Evaluative metering is the most inconsistant metering mode one can choose, because it is the only one that has some "brain"! In this mode, the camera is going to use all the information available, from the different metering points, from the focusing distance and focusing points, etc. and it will try to come up with a good image. This can lead to very different exposures for a very small change in the view.<br>

Exemple: your camera has focused on a white part of the scene and the camera decides that that is what should be the reference, so it will under expose the picture; next frame you slightly recompose and the focus is made on some shadowy part, again this will be recognised as the relevant part to render correctly, and the white part will be blown.<br>

Keep in mind that this is a very simple exemple, the exposure algorithms in the evaluative mode are very complex. Citing the EOS5 manual: "After detecting the main subject position, brightness, background, front and backlighting, etc., the camera sets the proper exposure"<br>

But basically the result is that: the camera decides what IT deems is important in the frame and exposes accordingly.<br>

If you are used to compensate, just use the "center weighted average mode", this should give you a much more consistant exposure.</p>

[tudor_apmadoc]

<p>Again, based on the last 2 photos you showed and my own experience with my 5D and 5D MK II, I would tend to point the finger at the camera.</p>

<p>My recommendation would be to get Canon to check it over. Make sure you send in those last two photos</p>

[edrodgers]

<p>If you want to know if the camera is broken, simply test it. Shoot a gray card. Vary the metering mode. If the frame is filled, each shot will be identical middle gray. If the images don't have histograms that show a centered spike, the meter is off.</p>

<p>Do it with and without a polarizing filter.</p>

<p>It is unlikely that the meter is accurate and the evaluative meter mode is broken. It is quite possible that the evaluation program assumes the sail is a face and is giving it a neutral 18% exposure value.</p>

[stu bolin]

<p>Peter, as an advanced amateur with a love of the subject matter (sailing vessels), I certainly sympathize and share your exposure concerns. I upgraded to the 5DII as soon as I was able to obtain one (two months on the waiting list at my favorite store) and find similar issues with using pattern as well as center-weighted averaging. Prior to going digital with 4 different models of Canon EOS digital equipment from the 10D to my current body. Prior to the digital shift, I used a wide variety of film cameras over a 30+ year period. TTL metering has been a bugaboo with me unless I had no better option. Then I experimented with AA's Zone System which I found solved most of my problems when I could properly evaluate using spot metering of desired midtones (Zone V), which I still prefer over any other method.<br>

As for using polarizing filters, I have tried both circular and linear polarizing filters (PL), with varied success, but always with better exposure values in reflecting surfaces and sky areas. Given all of this, I note the following issues which were not noted in any of the previous discussions I read:<br>

Photos 1&2 show one major difference which I feel may have had an effect on the exposure given the other factors discussed; the angle of the sun on the subject of the image (the boat and sails) would have more of an effect on averaged/pattern exposure than the angle of the sun to the polarizer. Given changed angle of the background to the lens as shown by the diffence in the background, a significant change in the lens sun angle could cause the exposure difference shown given the use of the PL.<br>

Photo 3&4 show a significant change in focal length as well as in the amount of light toned areas (deck and background areas) which could have significant effect on pattern and averaging metered shots. Again, spot metering for a midtone might have enabled more consistant exposure.<br>

Photos 5&6 added on the 16th immediately indicated a difference in 1) the boats are different (sail numbers) and each is on a different angle of heel causing significant differences in the relative tone caused by minimal direct sun on the facing surface of the sail in photo 6, while much of the mainsail in Photo 5 is showing the shaded side of the sail (backlit) in relation to the nearly overhead sun.<br>

Again, I'm only an amatuer, but I personally prefer spot to average or pattern metering.<br>

Thanks for the opportunity to comment.</p>

[simon_hobbs]

<p>My EOS 5D MKII consistently overexposes every daylight outdoor scene by 2/3. I have been shooting canon for 25 years, and have shot probably millions of shots with the EOS 5, 10D, 20D, 40D and never had single cause for complaint.<br>

The 5DII however is simply unusable outdoors. Even if you point it at a large white object, it over exposes that by 2/3. i went through phase of shooting every shot with the 40D, 5DII 0ev, and 5DII -2/3 EV. Guess what? near 100% of 5DII -2/3ev are the same as the 40D 0ev, which is so close to perfect I almost never have to compensate (unless there is a very strong backlight or similar).<br>

I called canon and sent them examples (I have thousands), but they said they had not heard of this problem and offered no help or alternatives.<br>

I shoot weddings part time. Outside, 5DII is unsusable, as it overexposes. the 40D is fantastic, as I can always get perfect shots. Indoors the 5DII is good, but not as consistent as the 40D.<br>

I went though a perod of just leaving the camera in -2/3, but occasionally the camera gets the exposure right, so Im left with a badly underexposed image. The anoyting thing is, I cannot work out when this is going to happen.<br>

I normally use evaluative meetinging, as have to shoot from the hip at weddings and sports events in lots of different conditions.<br>

Anyway,<a href="http://simonhobbs.fotki.com/5d-mkii-problem/"> i posted some early comparison shots </a>and got a lot of pointless replies. Note: fotki incorrectly reports that the metering was spot - if you download the full sized original you will see the correct exif data. look at the levels on these shots, and you will see all the 5D shots are shifted to the right by 2/3, and the 40D are bang in the middle.<br>

I only ever use the center point to focus. Most of the test shots were not recomposed. <br>

I have experimented with focusing on light/dark etc. but it doesnt seem to have much difference.<br>

People tend to say things like "use manual" or "use your light meter". I have not had to do that since the EOS 5 20 years ago, why do I have to go back to manual now? You can keep the 5DII if thats the price i have to pay, the 40D is far far better at meetering - I would go as far to say is for me, its perfect.<br>

P.s. I almost never use a poloriser - I tend to get better results in photoshop using levels and curves. Lightroom is not so good at this though.</p>

[jody_stowitts]

<p>turn off bracketing</p>

[heidi1]

<p>I seem to have the same problem. I just purchased my camera last week, but to get good images I need to leave the camera on -2/3 and they are perfect, but it is a bit annoying as I was used to get perfect readings from my Nikon F100. Not sure what to do.</p>

 

[vanessa_fulcher]

<p>I purchased my 5D MkII in the spring and finally received it about a month ago. I am a Las Vegas Wedding Chapel photographer... meaning some days I shoot 8 weddings... over 1,000 shots a day...outdoors and indoors. Indoors we have 3 chapels. The other photographers and I that shoot Canon have all been shooting with the older 5Ds and with either the 24-70 or 24-105 lenses. We have tested many different settings and finally found that shooting with speedlight 580 exII that we would shoot ISO 640, 60th shutter speed, f4 with internal comp up 1, neutral setting, 4000K... trying to neutralize color, exposure, etc... to get even results between all of us shooting. THEN... I got my new 5D. I knew that it would be different... but I thought for the better! I tried these same settings and they were SOOOO dark one minute and then COMPLETELY overblown the next.... doing the same thing (metering, bouncing flash, etc.) that I have been doing with the old 5D for over a year. That was my first problem. THEN... 3 DAYS INTO USING THIS NEW CAMERA... I leaned in to shoot a limo shot and the entire viewfinder lit up... all 8s, ever meter bar showing, etc... the viewfinder was completely unreadable. At this point I called Canon and then had to send it in for repair. They found that the pcb assembly was faulty. Now I've had the camera back for 2 days and last night I'm in the middle of a shoot and it just won't shoot. The lens is focused, red light blinks, and then NOTHING! I press the shutter button, red light flashes that it's focused and then NOTHING! At first I thought perhaps it was the lens so I changed out lenses and again NOTHING! I had to completely switch out cameras for the rest of the shoot. After the shoot I went back to the new 5D to test it out again and find out what was going on.... then it shot. I AM SOOOOO FRUSTRATED that I have what is supposed to be this great new camera and in the past month I've not even been able to shoot 5 days with it without problems and/or having it in Canon's hands! If anyone has suggestions for what I should do, things I should consider... PLEASE HELP! At least after reading this post I now know that at least I'm not the only one with the metering issues.</p>

 

[marcelo1]

<p>Hello, I'm having problems with the metering, at this point I think is a problem with the algorithm in this camera.<br>

I'm getting lot's of underexposed pictures... even looking at the histogram...</p>

[matt_brown4]

<p>I too have exactly the same problems with my 5DmkII under-exposing 9/10. The frustrating part is that it gets it right sometimes. :)<br>

I've spoken to Canon and they refuse to believe that there would be such a problem with the camera.</p>