Canon 70D - Impressions, Discussion, etc.

[hokiealumnus]

Pretty heavy crop on this next one.









So far, based on rather limited use, my interim verdict on the Canon 70D is that it is a superb camera. The only thing at this point that I could possibly want (heh, besides more and better lenses) that the 70D doesn't have is a full frame sensor. That said, for most people - myself included - full frame is completely out of the question. The jump is just too far, not to mention unnecessary, for the vast majority of amateur-to-budding-prosumer users on the market. Thus, for most people, that makes the 70D the perfect camera. It has pro-level controls, superb APS-C performance and handles like a dream.

One thing is for sure - there is absolutely no comparison with my previous T3 (1100D). The 70D runs laps around it, and then some. From that perspective, I couldn't be happier.

[alpha0ne]

I REALLY like # 2 and 7, looks like bokeh using that lens is brilliant, can you supply the focal distance/length etc please

[hokiealumnus]

Thanks! Yes indeed, for a "small"(ish) -not to mention variable- aperture lens, it is capable of some great bokeh if you shoot close and at a longer focal length. Here's the EXIF data:

#2: f/5.6, 1/200 sec, ISO 100, 87 mm, no flash, -.3eV
#7: f/5.6, 1/250 sec, ISO 100, 92 mm, no flash, -.3eV

I'm quite pleased with this lens. If it weren't for the lens creep, which does get annoying on occasion, it would be darn near perfect for my needs. Heck, even with the creep (which only really occurs walking around with the camera facing down at a steep angle) it is a superb price-for-performance; I got it for $274 used.

[hokiealumnus]

Kingston is sending what they call their "Fastest SDHC/SDXC UHS-I Speed Class 3 (U3) Card for 4K and Ultra-HD Video Capture" (link to page) for me to have a look at since I have this camera. I'll of course post file transfer speed numbers but more importantly for photography purposes, we'll get to see how much, if any, effect it has on the 70D's ability to shoot more RAW and RAW+JPEG without filling the buffer. As such, I needed to have some comparison numbers!

These were run with a 16GB Transcend Class 6 SDHC card. Class 6 is rated for a minimum 6MB/s transfer speed, making it just on the edge of acceptable for 1080p video, or so Wikipedia tells me. As this camera uses ALL-I format, that may or may not be a problem. So far it hasn't, but I haven't recorded much ALL-I and have the camera set to IPB to save hard drive space. Regardless of video stuff, this is a DSLR, not a video camera, despite its great abilities when shooting video. So what concerns us for the purposes of this thread is a) FPS and b) buffer performance. I'll save info about the new card for when it gets here, but here is the 70D's FPS and buffer performance with a far less than top of the line SDHC card.

You can see the shooting info in the graph, but for reference f/3.5 is wide open aperture on the EF-S 18-135mm IS at 18mm, so that aperture wouldn't slow it down. Obviously all of these numbers will be reduced somewhat in real-world use, but setting the camera like this and shooting with the lens cap on ensures repeatable performance so that you can obtain proper comparison numbers. I didn't note it in the graph, but the lens was set to manual focus.



As you can see, if you shoot in JPEG only mode, the camera does over its rated 7 FPS even with this kind of card. After 15 seconds of shooting, the camera took a total of 108 JPEG shots. As such, I consider the buffer to be not-fill-able when shooting JPEGs. The chances of anyone actually shooting 15 seconds at 7 FPS seem to be slim, so I didn't feel the need to go further and will consider that conclusive.

Once you get to RAW and especially RAW+JPEG, card speed will matter, potentially a lot. The interface can only transfer so fast of course, and after a certain point card speed will be greater than what the camera can transfer, but with a Class 6 card you're seeing just how limited things can get. At the end of the buffer-fill period, it had taken 18 RAW shots and 9 RAW+JPEG shots. After 15 seconds, those numbers were 25 and 17, respectively. Once the buffer fills, you're looking at RAW FPS of .57 FPS and RAW+JPEG of .44 FPS.

When shooting JPEG only, you can get a Class 6 card and be happy. When shooting RAW even, 18 shots before filling the buffer really isn't that bad. It will catch most of anything for any purpose for most people other than maybe dedicated sports or air show shooters. RAW+JPEG? Not so much.

I'm not sure when the Kingston card will arrive nor when I'll get it done, but these numbers should increase with that card. You'll just have to wait and see how much when the time comes.

[hokiealumnus]

One of the things the 70D is known to be good for is its autofocus system, which is pulled from the 7D before it, minus a couple of modes. A great way to test this is with birds, preferably those in flight (birds in flight, or 'BIF'). Regrettably, the longest lens I possess is 135 mm, and it is a moderately slow f/5.6. That can be slightly alleviated by going to a local lake where people enjoy feeding them (while ignoring the signs saying not to).

The weather recently has been horrid and this was the only day I had to get out. Please allow me to lay out a quick couple of excuses - I'm very new to shooting BIF, having never done it before. Additionally, the lighting was poor - in late afternoon, everything was in shadow where they could be shot and the only good shots were with a bright blue sky in the background.



With that out of the way, the 70D's autofocus performed wonderfully. While few of the shots were keepers, it had nothing to do with the autofocus and everything to do with my lack of skill with this kind of thing. Every focus miss was my fault - when I hit my chosen bird with the center point, it then tracked the bird around every one of the 19 points splendidly. As long as I kept the bird in the frame, it happily tracked around, keeping tack sharp focus the entire time.

With default settings, it was even smart enough to keep the right bird when its friends were unkind enough to fly in the way. There was actually an example of that in my plethora of photos.



100% crop from the 'right' bird.



Even when the seagull turned away, it kept tracking the eye nicely.



100% crop.



In the next post, I'll show a couple of the meager keepers (meager due to my skills, not due to the camera) the day afforded.

[hokiealumnus]

Here are several of the keepers from today. They certainly aren't anything near what I've seen posted about on various forums, so C&C is always welcome...and needed!



100% crop.







100% crop.





100% crop.



These are all JPEG SOOC (straight out of camera). I tried post-processing the RAW files, but my skills at that are even worse than my shooting here.

[hokiealumnus]

As a side note, I do realize there is a blue hue to many of the bird shots. The camera set itself for the giant blue sky behind the little birds...and you can hardly blame it for that. Of course that means the WB needed work, which is why it pays to shoot RAW. I should probably have done them all before posting the bird shots, but the point was to explore the autofocus system itself and I posted it prematurely. Regardless, here is a first try. I'll try to get to the rest of them later this week. I do miss the strikingly blue sky, but the bird definitely looks like it should.

[alpha0ne]

^ Thats a great shot hokiealumnus, I always shoot raw plus jpg fine and only ever fill ~5GB @ most per shoot on my 64GB SD card, silly buying one with so much space as I dont use movie mode

I am really impressed with your shots/lens/tracking

I've also been 'trying' to shoot BIF today ................................but my D5200 using my 18-140 lens is pretty average auto tracking, especially when the subject is moving away

If any are worthy out of ~200 shots I took today I'll post in the picture thread

[hokiealumnus]

Re: Size - it's less about filling the card than it is about HDD space, so I've come up with a solution - when I shoot RAW, I just load them into their own directory, pick out the ones that I'd like to work on and ditch the rest, keeping only either SOOC or PP'ed JPEGs on a permanent basis.

Seagulls are about the easiest birds to track, especially with a guy near me throwing bread out (which he shouldn't have been doing, but it helped me plenty!). They weren't going slow though, so the camera did very well to lock focus and keep it on them like that. BIF is a very tough thing for birds like raptors (hawks, eagles, etc) would be much harder than this. I'd also need a much longer lens!

Anyway, thanks for the kind words. Looking forward to seeing any keepers you got too!

[hokiealumnus]

Someone elsewhere asked about autofocus modes and which I use, etc. Took the time to write up a long post and maybe someone here can benefit from it too.

There are three focus modes to use - One Shot, AI Focus and AI Servo. You can forget AI Focus; it's supposed to be an automatic mode, where it starts off as One Shot, but if your subject moves it switches to AI Servo. It has never done me any favors and here's why...

Situation one: Static subjects - typically single point focus in One Shot mode. In this situation I currently tend to use the center point (which is the most sensitive double-cross type point that can also focus in extremely low light if the need arises), focus and re-frame.

The problem with that is that it will meter for the frame you're focusing and not for your final frame, so this may not be the best option. It works for me when I'm getting snapshots and don't have time to fool with the camera. When I have a couple seconds to do so, I will select the autofocus point I want it to use outside center, that way it's focusing where I want and also metering for the frame I want. This is the best of both worlds and selecting your focus point in this manner will always get the focus and metering you're going for. As I get more used to selecting the point I want, I'll move further and further away from the center-point-and-re-frame model except in low light when that extra sensitivity is needed.

Sometimes I will alternate to the groupings and move the group around rather than the specific single point. I'm still experimenting with which one of these two I like best. The OCD person in me that wants to make sure I get it right specifically on the one point. The lazy person in me wants to use the groups so I have fewer options when selecting where to focus. Both seem to work pretty well.

What I do not do in One Shot is use the 19 point full on auto. It always defaults to the closest item in the frame with enough contrast to focus on. Many times that is ok, but many other times it is not. For instance with good composition, you often want something in the foreground....but you don't want it to be the main focus point. Try telling that to the 19 point autofocus system. For that reason alone it's worth getting to know the smaller grouping and/or single-point options better.

Situation two: Moving subjects - typically all 19 points in AI Servo mode. Here is the reason you want AI Servo instead of AI Focus. When you shoot AI Servo with all 19 points available, you'll see something that isn't present in One Shot - the center focus point is also lit up, inside the full focus bracket. AI Servo is very intelligent. What you do is hit your subject with that center point, and half-press the shutter (or hold AF-ON, if you use back-button focusing). From that point on, your camera is locked onto that subject (in theory; practice is always harder, especially if anything jumps in front of your subject for too long) and will chase it around all of the 19 points, so long as you keep the subject inside the autofocus frame.

This is how you get in-focus bird shots. Pick your bird, half-press with the center point where you want to focus (typically the bird's eyes) and then follow it around with the camera, making sure to keep the focus point somewhere inside the 19 points. It doesn't matter where, as long as you're inside the frame the camera will happily track your chosen subject intelligently and quickly. You will see the different AF points lighting up as the camera sticks with them within the frame. It's actually pretty neat to behold, but not something I can really show since it only occurs looking through the eyepiece.

This will work for sports too - pick your subject, lock on them and keep them in the frame to track them around.

Of course, nothing is perfect - sometimes another bird/person will jump in your frame. If they stay too long, the camera will move its focus point to the person who's in your way. There are several options you can adjust that are quite advanced with regard to how hard it locks focus and how long it stays there in the event something does get in the way. Those options are beyond the scope of a post like this, but they're there in the "C.Fn II: Autofocus" menu; page 362 in the manual.

The behavior of AI Servo is exactly why I do NOT like AI Focus. With AI Focus starting out as One Shot, that center focus point is not lit up. The 19 points act just like Single Shot and will lock on the closest object. Without that center point, you're back to being at the mercy of the camera rather than selecting your own subject.

So the moral of the story with regard to focus modes - know your situation and select your focus mode to fit. It's not hard to move between One Shot and AI Servo. Don't think that AI Focus can properly select between the two, because in trying to be a jack of all (ok, both) trades, it ends up being the master of neither.

Hope this helps.