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Canon 70D - Impressions, Discussion, etc.

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May I humbly suggest you show MB/s speeds as an equivalent of 'time to clear buffer'? I'm curious because that could be a rough estimate of the write speed of the camera. For example, if you're clearing a buffer of 16 photos, at 20MB each, are you hitting 24 MB/s? (With a class 6 card, wow!)

I'm curious because I heard Canon DLSRs have a limited write speed. For example, I read that the 6D maxes out at roughly 40MB/s, so I bought Sandisk Extreme Plus (60MB/s claimed write) rather than the Extreme Pro (90MB/s) cards. I want to guess the 70D has a similar card slot, but it's possible it's different (the 5D3 has a very slow SD slot, 25MB/s range).
 
Sure! I'll have to take some more blanks, check actual file size and do the math. I'll try to do it sometime tomorrow or Friday.
 
Or whenever you get the new card. I figure a blank image should be consistently the same file size, no?

Which makes me curious... If you have a larger file (say, ISO 256,000), will your calcs show a different buffer size/write speed because it might take only 15 photos to fill the buffer because the 16th is too large? :p You don't have to test that out, I'm not too curious about it and rather not kill too many shutter shots on blanks. :chair:
 
Good idea, will note file size with the new card.

As far as crazy high ISOs, they should be about the same size; it's the increased processing that slows FPS speed to a relative crawl.

Heh, your 6D is the ISO king. The 70D tops out at 25,600 but yours can go to 102,500 IIRC.
 
So I was curious and tried a couple. I shot 1/4000 with the body cap on:

ISO 100 - 18,686KB:
IMG_5923.jpg

ISO 25,600 - 24,677KB:
IMG_5926.jpg

ISO 102,400 (H2) - 33,119KB
IMG_5928.jpg

(Yes, I just posted three black pictures :p)

I am amazed that the ISO grain almost doubled the file size. There is very minimal file size variation for the RAW files (about 0.009%), however the jpg does jump around much more (0.297%). I took two photos of RAW + Large fine JPG at ISO 50 (L), 100, 25,600, and 102,400. See the file sizes below:
black.png

PS: I did not cover the eye-piece (I recommend doing so), which might explain the brightness in the lower right corner.
 
That's crazy, I thought there may be some variation, but just noise increasing the file size by that much is well beyond what I would have thought; thanks for sharing that!

I didn't cover the eyepiece specifically, but did cover the whole camera with a pillow as 7 FPS is loud and I was testing with a kiddo that had just fallen asleep downstairs...so happy day - I did something right unintentionally. :p
 
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.

20140216213115-18b57657.jpg


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.

20140216213124-3d8e56a2.jpg


100% crop from the 'right' bird.

20140216213126-0270d9b0.jpg


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

20140216213134-5dc72ea7-la.jpg


100% crop.

20140216213136-4c672fcf.jpg


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.
 
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!

20140216213119-57ed52f2.jpg


100% crop.

20140216213122-a0df0d7b.jpg


20140216213128-f84be87c.jpg


20140216213130-606ed354.jpg


100% crop.

20140216213132-d3283011.jpg


20140216213138-c6539af5.jpg


100% crop.

20140216213140-a7f4a448.jpg


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.
 
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.

20140216235547-d2c40fcc.jpg
 
PP attempt #2. Lost the sky for the most part, but the bird looks decent.

20140217205242-00c8c04e.jpg
 
The BIF shots look great! I cant get anything like that with my 6D unless it's dumb luck.

For the PP, if in Lightroom: go to Develop --> HSL tab (third down?) --> Luminance --> dial Blue slider back a bit. I think it should help bring back the blue sky, unless the color Process/temperature removed blue (I do not fully understand this tweak, I just know it usually works for me).
 
Sorry if this might be off the topic but if anyone needs a VERY decent 64GB SDXC card that won't burn your wallet... I would highly recommend this
PNY Elite Performance 64GB SDXC UHS-1
Model# P-SDX64U1H-GE
I bought it for $33....and Fry's has it for $35...or elsewhere online at similar price range
I've benched 2 weeks ago....and love it for its speed and price. Excellent value!

DSC09790_Package
34ep552.jpg

DSC09816_Kingston_MobileLite_G3_USB_3.0_Adaptor
nltmjp.jpg

2nd-to-4th AsSSD-CrystalDiskMark-ATTO-HDTune
f57pw.jpg

5th-to-8th AIDA64-Speedout-Roadkil-Parkdale
256s66g.jpg
 
Thanks for sharing Sam! UHS is indeed a better option. I have the Kingston card now and am putting it through its paces.

The BIF shots look great! I cant get anything like that with my 6D unless it's dumb luck.

For the PP, if in Lightroom: go to Develop --> HSL tab (third down?) --> Luminance --> dial Blue slider back a bit. I think it should help bring back the blue sky, unless the color Process/temperature removed blue (I do not fully understand this tweak, I just know it usually works for me).
Thanks! (For the compliment and the tip.) The HSL slider is actually why there is any blue at all in the second PP attempt. Without it, everything was straight up white.

While I'm posting, 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. :)
 
SamSaveMax, thanks for sharing the info. I should try bench my cards to see how the numbers compare.

hokie, thanks for the AF write up. I haven't bothered playing with the different AF modes since my 9 point points don't cover a whole lot... BTW going back to the PP bird, what happens if you make the color temp just a little cooler, like by 100k? I'm going to guess it should bring back some blue, but still keeping the bird 'okay'.
 
Ok, I'll give the temp change a try!

AFAIK your camera has the same modes (in fact, even my T3 did), just fewer AF points. It could still be useful to use AI Servo for this kind of thing. The only difference is that it would be a little more difficult to keep the bird/person/other moving object in the focus frame since it takes up less of the viewfinder.
 
I'm a little late to the party and only check for it occasionally, but for anyone interested in Magic Lantern, there appears to be a functioning Alpha! http://www.magiclantern.fm/forum/index.php?topic=14309.0

Obviously it will have issues, being an Alpha and all, but it's progress! I don't necessarily have a need for it right now, but I know some people love the features it ads. Now you can try it. :)
 
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