pcassity Posted August 21, 2016 Share Posted August 21, 2016 <p><img src="https://flic.kr/s/aHskC9Lzeu" alt="" />I use both of these cameras in my real estate photography business. Recently I have begun to use the 'flat' picture control setting and I have noticed subtle differences between the two once I start editing. So, this morning I decided to do a test. I mounted my 200-500mm Lens on a tripod and made sure all menu controls on both cameras were exactly the same. Also, I made sure that the white balance, aperture, shutter speed and ISO were identical. I also made sure that my focal point was the same in both image. It appears that the D810 has a bit more contrast. What I found peculiar though, was that at the Auto1 white balance setting, the D810 was a bit warmer than the D750. I also noticed that the 750 appeared to have a slightly 'wider' result. I have attached screenshots from both images in Lightroom. I have made no adjustments to either image. Why would one camera focus closer with the same lens and at the same focal length as the other? Why would there be such a significant difference in white balance. These two images were taken withing seconds of each other. Thanks for your input!</p> Link to comment Share on other sites More sharing options...
Two23 Posted August 21, 2016 Share Posted August 21, 2016 <p>Were you shooting in jpg or NEF? That could explain a big difference right there.</p> <p>Kent in SD</p> Link to comment Share on other sites More sharing options...
pcassity Posted August 21, 2016 Author Share Posted August 21, 2016 <p>http://flic.kr/s/aHskC9Lzeu</p> <p>Yes. Both images are raw files. Please copy and paste Flickr link above. (I have never been very good at this!)</p> Link to comment Share on other sites More sharing options...
ShunCheung Posted August 21, 2016 Share Posted August 21, 2016 <p>It is quite common that white balance differs a bit from camera to camera. Unless you shoot JPEG, digital photography is mostly about post processing, not what comes straight from the camera's RAW files. As long as you shoot RAW, white balance on the camera doesn't matter much.</p> <p>Both the D750 and D810 have a 23.9mm x 24mm sensor. I wouldn't expect that much difference in terms of angle of coverage. Could you check with a different lens?</p> Link to comment Share on other sites More sharing options...
pcassity Posted August 21, 2016 Author Share Posted August 21, 2016 <p>Thanks Shun. I added 4 images to the same album. These were shot with my 70-200mm.</p> Link to comment Share on other sites More sharing options...
ellis_vener_photography Posted August 21, 2016 Share Posted August 21, 2016 If you want the color responce of multiple cameras to match you need an Xrite ColorChecker target and either Xrite's ColorChecker Passport or Adobe's DNG Profile editor software and build profiles for each camera. Why are the two cameras different? There are different sensors and different image processors in each of the two model cameras. As to why one camera is focusing at a slightly different point even with the same lens, every camera and every lens is a unique and very complex device lenses are different systems and while within spec, Each and every lens and body combination yields slightly different results. Consider getting a LensAlign II V4 target and FocusTune software package and it with the Autofocus micro-adjust feature of your cameras to calibrate both to optimum autofocus performance Link to comment Share on other sites More sharing options...
pcassity Posted August 21, 2016 Author Share Posted August 21, 2016 <p>Thanks Ellis. As Shun mentioned, the white balance really doesnt make that much difference to me as I shoot entirely in RAW and and do quite a bit of post editing anyway. I was more curious about the angle of view. Especially since I was using the same lens on each camera.</p> Link to comment Share on other sites More sharing options...
Andrew Garrard Posted August 21, 2016 Share Posted August 21, 2016 Thom Hogan reported some Bayer changes in the D810 vs the D800, in raw. It might be software (Nikon do "bake" their raw files, for reasons I'd rather they didn't), but the actual filter formula may also have changed in terms of spectral response. The lack of low pass filter might also change the spectrum slightly. It's hard to sample a full colour spectrum in different ways with just the filters and return something that looks right - which is why Sony did RGBE a long time ago (and there was an interesting paper on multi-spectral sampling at SIGGRAPH this year). I've not tried to reproduce Thom's results, but I believe anyone saying different bodies don't match perfectly. As for the field of view, how far out is it? There are some manufacturing tolerances involved in the optical path, but if it's substantial then that's interesting news. Link to comment Share on other sites More sharing options...
peter_langfelder Posted August 21, 2016 Share Posted August 21, 2016 <p>FWIW, I don't see a change in angle, I see a slight shift - the 750 image seems rotated slightly to the left. In terms of color, you are viewing the images in Lightroom which applies a (presumably different between D750 and D810) camera profile. Thus, even with all controls zeroed out, the processing is different for different camera models. This is in addition to the sensor differences.</p> Link to comment Share on other sites More sharing options...
pcassity Posted August 21, 2016 Author Share Posted August 21, 2016 There was no rotation of the 750. The lens was mounted to the tripod. I simply shot the first image with the 810, removed the camera from the lens, attached the 750 and shot the next image. I insured that the lens and tripod never moved. It was a very cloudy day so I a sure that small variances in available sunlight could change the white balance. The differences in viewing is much more pronounced when viewing at 1:1. Also, I made sure that lens profile in Lightroom was not selected. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted August 21, 2016 Share Posted August 21, 2016 Does the EXIF data of each camera's file report exactly the same focal length? Because it's very easy to move the zoom ring while changing camera bodies. Also, is the size change apparent in other image editors? The 70-200mm zoom "breathes" considerably with focussing. This is another variable that needs to be taken into account. Link to comment Share on other sites More sharing options...
ShunCheung Posted August 21, 2016 Share Posted August 21, 2016 <p>If the test is done correctly, you should have the lens on a tripod. Without changing any settings (including focal length, focusing distance, etc.), just swap camera bodies and capture images to compare. The lens should project the same image circle onto the sensors. If the sensors have the same size, the image coverage should be identical. (A 36MP body will have more pixels, but once I scale them down, they should be the same.) Any focus breathing, etc. should be totally irrelevant in this comparison.</p> <p>I just captured the following images with a 200mm/f4 Macro focused on a 10 Eruo bill. I don't have a D810, such that I am using a D800E instead. Actually I tried a third FX body, and there isn't any difference in terms of angle of coverage. Obviously I had to touch the lens when I swapped camera bodies, and its position might have moved a tiny tiny bit, but it was locked down on a tripod the entire time.</p> <p>At least to me, <a href="/photodb/user?user_id=1136399">Pat Cassity</a>'s images show that the D750 covers slightly more area. That means either the D750 has a slightly larger sensor or his D810 has its sensor edges masked off a bit more. Or the lens was slightly changed between captures. That was why I asked him to check with another lens.</p> <p> </p><div></div> Link to comment Share on other sites More sharing options...
Dieter Schaefer Posted August 22, 2016 Share Posted August 22, 2016 <p>1.2x crop mode activated in the D810?<br> Any setting in LR that could cause the difference between the D810 and D750 images?</p> Link to comment Share on other sites More sharing options...
Andrew Garrard Posted August 22, 2016 Share Posted August 22, 2016 <p>Okay, now I've actually had a chance to look at the images, the D810 image is clearly pointing slightly to the right of the D750 one. There's less of the bush to the left on the D810, but more of the flowers to the right. I guess the tripod head panned about its vertical axis a bit, or it might just be flex in the 200-500 mount (it's a bit of a sail in the wind). It's possible the sensor is offset that far horizontally between cameras, but I doubt it or there would be lens coverage problems. There may also be a size difference, but if so it's small. I really don't think it's 1.2-crop-sized, although good thought, Dieter.<br /> <br /> As for the colour difference, unless that's a change in lighting conditions (it looks a bit like a polariser has been used), I'd guess that may have been at least partly down to exposure. Different sensors have different sensitivities, and they're not perfectly normalised. If you're near saturation, you can get big colour differences out of foliage with small exposure changes.</p> Link to comment Share on other sites More sharing options...
Dieter Schaefer Posted August 22, 2016 Share Posted August 22, 2016 <blockquote> <p>I guess the tripod head panned about its vertical axis a bit</p> </blockquote> <p>But why would the same thing happen again with a different lens? <br> I discard my theory about the 1.2x crop - hadn't realized that the "closer" images where just crops.</p> Link to comment Share on other sites More sharing options...
Andrew Garrard Posted August 22, 2016 Share Posted August 22, 2016 <blockquote>But why would the same thing happen again with a different lens?</blockquote> <p>Oh yes - I'd thought there were only two main images, but now I see the 70-200 and 200-500 distinction. Agreed that it seems to have happened twice - though whether it was by exactly the same amount both times is another matter. My guess would be mere luck, assuming the offset is just similar and not a perfect match (I've not gone that far). If it was a vertical offset I'd say weight and something bending might come into it, and if it was a lens short enough to be mounted by the body I'd put it down to a QR plate, but I think it's clear here that the lens is doing the supporting. Occam's Razor suggests that a coincidental twist of the tripod head (given the leverage involved) seems most likely to me, but if Pat is confident that this is impossible, we could think about other oddness (probably based on either a non-centred sensor or a twisted mount). But anything else suggests quite worrying things about a camera, so I'd hope for the slippy tripod explanation first. I'm certainly quite good at locking down everything but panning, because it usually stays where it is if the tripod is level.</p> Link to comment Share on other sites More sharing options...
ShunCheung Posted August 22, 2016 Share Posted August 22, 2016 <p>It is best not to test with a zoom. With a zoom, you can accidentally touch the zoom ring a bit and introduce errors. That was partly why I used a fixed 200mm macro, which has a tripod collar and works well indoors.</p> Link to comment Share on other sites More sharing options...
pcassity Posted August 22, 2016 Author Share Posted August 22, 2016 <p>Thanks all. I performed the test again this morning. This time taking everyone's comments about the tripod, lens and camera into consideration. I made sure, again that the lens was securely mounted to the tripod. However, this time I used a different tripod and head. Appears that may have been the issue. There is still a somewhat of a 'shift' in images but I feel that is may be as a result of the D810 being slightly larger than the 750, thus sitting slightly higher on the tripod. Thanks to all for you help and comments!</p><div></div> Link to comment Share on other sites More sharing options...
pcassity Posted August 22, 2016 Author Share Posted August 22, 2016 <p>D810</p><div></div> Link to comment Share on other sites More sharing options...
ShunCheung Posted August 22, 2016 Share Posted August 22, 2016 <p>Pat, note what I mentioned above. I used a lens with a tripod collar and mounted that onto the tripod; I merely swapped camera bodies behind the lens and the position of the lens mount, and therefore hopefully the position of the sensor, is the same across the board.</p> Link to comment Share on other sites More sharing options...
pcassity Posted August 22, 2016 Author Share Posted August 22, 2016 <p>Shun, exactly what I did with the images above. So, my concern about the size of the camera is not accurate as it was not sitting on the tripod. </p> Link to comment Share on other sites More sharing options...
rick_jack1 Posted August 22, 2016 Share Posted August 22, 2016 <p>Hi,<br> I own the D750 and love it. I've handled the D810 and I passed it up because of it's size and weight and the extra cost. Though I'm not a first hand user I spend several weeks reviewing them both and speaking with people who own them, While having the extra 12mp of the D810 is nice you really need to be using a tripod and mirror lockup (plus premium gold ring ED optics) to see the difference. I think the D750 has a slight edge with respect to lower noise at high ISO's. But this is probably neglectable. I wish My D750 accepted CF cards and had a "X" flash terminal on the body. But's it movable vies screen, built in wi-fi, and intervalometer make it a joy to use. You can't go wrong with either. I would of gone for the Df if it were 24mp. You can hold out and see what Nikon releases next, I've read rumors of them bumping the D750 to 36mp, the D810 to 54mp and the Df to 20-24mp. But these are just rumors.<br> Just my two cents. </p> Link to comment Share on other sites More sharing options...
Andrew Garrard Posted August 22, 2016 Share Posted August 22, 2016 <p>Thanks for running these again, Pat - I'm reassured that they're more similar now. As you say, there's a little vertical shift, but this time with the D810 making the lens point up slightly - and <i>that</i> I'd expect from the weight difference compared with the D750 causing something between the lens, foot, head, tripod and ground to flex slightly more in the D810 case. (Even really solid ball heads - my Triopo's pretty solid, but I've tested an Arca Z1 too - usually move a bit as you take the weight of a body, which is why I've got a geared head for precise framing - it's not that it's necessarily more solid, it's because it's already tensioned when I'm positioning it.) Or it could be a genuine sensor positioning thing, but I'd hope not!</p> Link to comment Share on other sites More sharing options...
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