I recently purchased the Canon 90D. I haven't been able to use it a lot for bird photography yet, but have managed to get some images with it, and I've also been doing some 'backyard' snaps to try and get a preliminary sense of how it feels. I am providing my first impressions in this post. Over time, I expect to add to these as I get more used to it.

Please note that most of these impressions will compare features to the 80D. Other Canon users may be able to compare features with their current camera bodies given the generic approach Canon seems to have to its menus etc. Those who want broader overviews will find lots of reviews on the web. Also note my observations are restricted to still photography using the viewfinder, at this stage.

The body is almost identical to the 80D in terms of size, shape, overall appearance etc. However there are a couple of interesting differences. Pick up the camera and it becomes immediately obvious that the grip is slightly different. The inside face of the grip (ie that nearest the lens) is deeper - I roughly estimate up to 5mm deeper, achieved by making the front-to-back width of the body slightly less in this area. For long hands like mine this give additional purchase, and my hands are able to fold around the grip a little better. The polycarbonate body also has a slightly rougher 'matt' texture than the 80D.

The top plate is identical. On the back the main difference is that a joystick has been added to the left of the natural thumb resting alignment. This does exactly what the control wheel below does (I understand it is not possible to program the two differently) but it is a more natural position for the thumb (simply shift across, rather than flex down to the wheel). It has quite a stiff action. Time will tell whether this makes a difference; I am left eye dominant which means the joystick falls under my right cheek when using the camera, but that's no different from the control wheel. To accommodate this change the Q button is shifted to the left and the Review button now drops to the bottom of the body next to the Bin button. Neither of these last two changes makes any difference ergonomically in my view.

One good change is that the screen is slightly thinner (in terms of front to back depth - it's the same area in terms of viewing). With the screen inward (my preference) it now rests more flush with the rest of the body rather than sticking out a couple of mm like the 80D. This lets me get my left eye closer to the viewfinder. There is now a small recess at the top of the viewfinder for your finger to assist in pulling it out. The viewfinder itself is unchanged although my initial impressions with the dioptre adjustment is that it is less 'sensitive' than the 80D ie you need more clicks to adjust it.

Focusing is now controlled by a new focus sensor with substantially more pixels than the 80D and with face detection. The viewfinder focus system remains at 45 points (all cross type). I am mainly interested in viewfinder focus, not live view (which I believe has improved substantially over the 80D).
One immediately obvious change in the focus system is that there is a new (fifth) focus mode in the viewfinder, 'Spot Focus' (which is the default when you first start the camera after unboxing); other modes are Single Point (1 point), Zone (9 pt), Large Zone, and Auto Selection Zone, which are the same as the 80D's four modes). Spot focus is shown by a square within a square, in contrast to the Single Point focus mode which is shown (as with the 80D) as a simple square. I understand Spot mode uses an even smaller area than Single Point, but I am not sure how this works in terms of the actual focus sensor. According to Canon this mode enables finer targeting of focus, but the downside is lower sensitivity (more prone to hunting etc). I think a new Spot mode is also available now in live view.

It's too early yet to for me to form a view about focusing. Initial impressions of the Spot mode is that it can be a bit hit and miss, and I am not sure if I will keep it as my base operating mode. I have tried focusing on birds in the foliage and sometimes managed to get the bird spot on, at other times just a bit unfocused. At the other end of the scale, initial impressions with wide area focusing (Auto Selection) with Servo drive are that it is better than the 80D in staying 'on target' using either colour sensing or face sensing. Using the grandkids as test subjects, the active points followed faces fairly while they were playing, and if you use the centre point to focus on a particular point of interest (eg a flower) and shift the camera from side to side the active focus points are pretty sticky, staying on the first point of focus provided it is distinct enough (that is, clearly delineated from the background or adjacent material by colour, brightness or similar).

However, I haven't been able to use the camera with birds in flight, nor with continuous focus tracking of activities or people using the fast burst mode, to check how good it is at keeping the subject in focus as it moves. Reviews such as DPReview found that the camera was a bit hit and miss in this regard, and improves if you use slower burst modes.

Speaking of shutter burst mode, the shutter has changed and the camera is now capable of 11 shots per second. The shutter is also more highly rated (in terms of longevity or number of cycles). The additional speed is quite noticeable; if you are not careful the camera 'purrs' through several frames almost instantaneously when you press the button, before you have a chance to release it. The shutter is also slightly quieter than the 80D. I have found you really need a fast card if you are going to use this for lots of frames on a continuous basis, as the large file size and high speed mean there is a lot of data throughput and everything freezes while bursts of files are being written to card.

The obvious question for everyone is no doubt the image quality. I'm afraid I don't have all that much to report yet that cannot be got from online reviews. There is nothing 'oh wow' evident yet, and I expect differences overall will subtle. My raw software of preference, DxO Photolab, hasn't released its 90D module yet, so I can't compare files in DxO with the 80D. In JPEG or processing in Canon's DPP, the photos seem very good, but then so were the 80D's. The additional file size is noticeable in processing - for example, raw files slow down DPP noticeably for some processes, on my computer. Note that Canon now offers a compressed raw, but I haven't tried to do any comparisons with full raw in terms of picture quality.

The initial impression I had from reviewing files downloaded from review sites was that in the first instance the 90D files seemed slightly soft compared to the 80D, which I put down to slightly less local contrast (perhaps due to different pixel sizes). The same seems evident, using DPP, with files I have shot. However the files sharpen up well with a bit of sharpening adjustment and good detail emerges, and noise is not too evident. There seems to be a tiny touch of feather moire in one or two of the bird shots I have managed - perhaps the low pass filter is a little weaker than on the 80D - but it is not problematic.

I am quite sure that the additional pixels will prove useful, but it's going to take a bit of time for me to get on top of getting the best image quality from the sensor, and seeing how much difference the extra 9 or so megapixels makes compared to the 80D. One thing I'm not going to do is lots of comparative test shots - those interested can download such laboratory images from review sites. Obviously over time I will be posting images to the New Images database, although at BLP image sizes differences are never going to be very evident.

I would be happy to answer specific questions to the extent I am able; just post below.

Simon

Thanks for this Simon. My two main interests or questions about the 90D are whether the extra pixels do, in fact, provide a significant benefit, especially when the camera is coupled with the 100-400mm Mark II. The other one is whether the AI servo AF is an significant improvement on the 80D for flight shots. The latter might be harder to pin down and involve more subjective judgements though. All the same, I'd be very grateful if you'd be able to share experiences in these (and any other) areas. As a current owner of two 80D bodies, I'm quite interested in what the new body has to offer although in no urgent need to buy one.

Cheers
Glenn

Bryan Carnathan over at the Digital Picture has published his eagerly awaited review of the 90D. Highly recommended reading for anyone contemplating buying one of these great little cameras. Read Bryan's review here

Thanks Ian. I had seen the earlier incomplete version so it is good to see the final review.

This review adds some useful chart pictures (noise level and resolution) which demonstrate the benefits of the extra resolution in these test conditions, and also which noise levels are kept under control. DP review showed similar results. In my use in the field I am finding that the sensor is very good and with well exposed images ISO 1600 is very usable for birds. There is good highlight and shadow detail recovery capacity. I haven't done side by side comparisons with the 80D (the reviews can do this much better than I can) but I can say that heavy crops still retain plenty of detail. Overall, so far, I am quite happy with the upgrade in this area and with careful post processing raw files deliver excellent results.

Unfortunately his autofocus report seems to still rely on the same set of car photos that all the reviewers got at the Canon release event. I have no real issue with single point viewfinder autofocus, which I have found to be accurate in either One Shot or Servo mode. Overall, so far, viewfinder focus is solid as you would expect given the long heritage of this model, but I certainly can't point to anything yet which says 'this is so much better than the 80D' and I can't compare to the 7DII having never used it. In contrast, I have done some family photos with the LiveView system, using the setting for face detection. This is very impressive; the camera finds and focuses on faces pretty much the moment you point the camera, and follows them around as people move in the frame. It does this automatically if you select the appropriate setting, without needing to half press the shutter button or select servo autofocus. People who do a lot of people photography and are happy to use the rear screen for composing will find this invaluable. Now, if only Canon could develop some bird face recognition....!

Simon

Some members might find the following MTF graph useful. It shows how the contrast of the MTF varies with aperture in the centre of the field of view for green light. I have indicated the Nyquist frequency for the 90D sensor (156 cycles/mm); this is the highest frequency that can be faithfully recorded by the sensor. Higher frequencies in the optical image will be recorded in the digital image as low frequency aliases and it is the function of the AA-filter to stop this from happening. The AA-filter will also stop most of the moire which would otherwise be observed with high contrast when the frequency of repeating patterns in bird feather detail is close to the Nyquist frequency. Moire frequency is the difference between the spatial frequency in the optical image and the Nyquist frequency. For example, if the Nyquist frequency is 156 cycles/mm and the optical image has a component with 146 cycles/mm, the moire frequency will be 156 - 146 = 10 cycles/mm across the sensor. Aliases and moire are a consequence of discrete sampling (digitizing) of a signal. Note for comparison, the Nyquist frequency of the 80D is 135 cycles/mm.

If I understand this correctly, it suggests that you should stick to f/8 or larger apertures for best results in terms of resolution (I suppose I have to add the 'other things being equal' tag to this comment, of course)?