Ian-T
Veteran
This probably explains why the 7D in the GH-1 vs 7D video looked so....flat with no life where the GH-1 had a lot more contrast.
7D impressions...
- Thread starter SPZ
- Start date
I wish somebody would just do a test already comparing the 5D and 7D and post it online because I just don't get all this "the 5D is sharper and better" nonsense. I shot comparison tests using the same lenses and I can't see any difference in sharpness. Now they were not resolution charts, but none the less they looked identical to the eye side by side.
Stephen Mick
Totally Usable
Did this a while back…
I could tell no difference whatsoever in video quality between the 5DII and 7D. Not in sharpness. Not in contrast. Not in any way whatsoever.
I could tell no difference whatsoever in video quality between the 5DII and 7D. Not in sharpness. Not in contrast. Not in any way whatsoever.
morgan_moore
Major Contributor
I think that some us early 7ders may have got dodgy 7ds
Side to side ing is very hard
What how do you do it - FOV, Look, DOF, what ?
Its the whole package, for instance 5d tend to look great at 5.6 while the 7 needs or wants 2.8 (off a smaller chip requiring more LPI from the lens therefore) so you end up with better lens performance on the 5 in real life situation in a way that a chart wont show - of course real life tests ar not controllable so there is always trouble with non chart testing
Personally Im confused about actual quality (in a chart manner) but am currently getting better field performance from my 5 - that is truth not nonsense
Maybe I have a dodgy 7, maybe the 5 is better in the real world, maybe I havnt sussed the small chip and the right lenses - or maby those lenses dont exist
Not so easy you see..
S
ydgmdlu
Veteran
Thank you guys! Now let's figure why the OP got different results...
Sorry to revive this old thread. Just finished shooting the Macau Grand Prix. Canon borrowed me a colection of very good glass, and, I have to say, after much experimenting and trying to find the "sweet spot" of the 7D, I came with very impressive results. The 7D requires, however to be much more precise on shutter and aperture than a normal video camera. This is the key between a a good picture and a very poor one. Video cameras are way more forgiving. The same can be said with overexposure. The 7D is way less forgiving towards overexposure than to underexposure.
Stay tuned, I'll post some of the GP footage here.
Stay tuned, I'll post some of the GP footage here.
Alright, here it is:
http://www.vimeo.com/7860163
Sorry for the SD encoding, but it was how it was conformed to fit with the beta sp footage in the end.
Some of the racing slow motion was 7D, and some of the preparation shots too. Enjoy.
http://www.vimeo.com/7860163
Sorry for the SD encoding, but it was how it was conformed to fit with the beta sp footage in the end.
Some of the racing slow motion was 7D, and some of the preparation shots too. Enjoy.
Green Hornet
Veteran
The reason the 5D II is better is because:
1) It has a larger sensor, and brings in better color.
2) It allows you to shoot at a larger number f stop for desired DOF
You don't need to shoot wide open to obtain the desired DOF.
You can shoot at f5.6 instead of opening all the way to f2.8
3) At F5.6, your LENS sharpness on an f2.8 lens is WAY sharper.
Shooting with the 7D at f2.8 will in no way look as sharp as f5.6 with the same lens on a 5D II.
(2 stops closed from wide open will almost always be sharper on all lenses)
You have to open up more with the 7D to get the same desired DOF on the 5D closed down.
And that is why the 5D will always offer better sharpness in actual movie footage.
1) It has a larger sensor, and brings in better color.
2) It allows you to shoot at a larger number f stop for desired DOF
You don't need to shoot wide open to obtain the desired DOF.
You can shoot at f5.6 instead of opening all the way to f2.8
3) At F5.6, your LENS sharpness on an f2.8 lens is WAY sharper.
Shooting with the 7D at f2.8 will in no way look as sharp as f5.6 with the same lens on a 5D II.
(2 stops closed from wide open will almost always be sharper on all lenses)
You have to open up more with the 7D to get the same desired DOF on the 5D closed down.
And that is why the 5D will always offer better sharpness in actual movie footage.
Barry_Green
Moderator
This is true. But the 5D or 7D, in video mode, won't "see" that sharpness.
I disagree, and my lens testing has so far shown it. My weakest lens wide-open at f/1.4 still delivers more sharpness than a 7D can resolve.
If you're talking about still photography, I agree 100%. If you're talking about video, it's true that the lens is sharper, but it doesn't matter because the camera can't do anything with that sharpness.
True.
They are 1.5 stops different.
Except that in reality, it simply doesn't. Because all that extra sharpness from the lens is thrown away; the movie mode only uses about 10% of the sensor's capability so 90% of that sharpness is tossed out.
If you compare side by side, as Kholi has done, the results are pretty much indistinguishable.
Why 1.5 stops?
If I am not wrong David Mullen has quoted something like 2-2.5 stops no?
Barry_Green
Moderator
I don't know what David Mullen may have quoted, but the difference in DOF between an APS-C-sized sensor and a Full Frame sensor is 1.5 stops. Stop down the FF camera by 1.5 stops and it'll match the DOF of an APS-C sensor (or 35mm movie film).
I see. Any clue how can we find such values?
Barry_Green
Moderator
Use an online DOF calculator and plug in the various values, or refer to the article I did:
http://www.dvxuser.com/articles/article.php/21
http://www.dvxuser.com/articles/article.php/21
None the less, something that I don't understand. You're always mentioning 1.5 stop of difference.
Why do you say 2 stops (APS-C vs full frame) in the end?
APS-C or 7D - open up 5 1/4 stops
Full frame - open up 6 3/4 stops
APS-C or 7D - open up 4 1/2 stops
Full frame - open up 6 stops
APS-C or 7D - open up 2 3/4 stops
Full frame - open up 4 1/4 stops
For a movie camera or APS-C-sized camera like the Canon 7D, to match to
a full frame - open up 2 stops
??
speedjunkie
Well-known member
I totaly agree with you polit! I am a Complete NEWB at all of this and I own an HVX and love it but I love the 7d More because its practical. This is My very first film/short whatever that i shot on the 7d and edited in AVID. mind you Im not even a DP or Photographer, just a creative mind. http://www.youtube.com/watch?v=YkBH_3aH2TE
Glenn Przyborski
Member
This thread has member comments on the 7D's lack of true HD sharpness and moiré problems. The sad thing is that apparently Canon's new $5,000 flagship camera, the 1D Mk4 suffers from the same problems when shooting video. The camera does however, set new "off the chart" standards for high ISO sensitivity.
Since the CMOS imagers in the 7D and the 1D Mk4 have a "comparable" pixel count, and both cameras were developed at about the same time, I'll bet the video processing circuitry is very, very similar. Both cameras record with H.264 compression at the same data rate.
IMHO there's no excuse why a 16mp - 18mp image can't be properly down sampled to yield 1000+ lines of horizontal resolution at 1080P. Canon has to realize that the HD video capabilities of these new DSLR's is what's generating product excitement and sales... or maybe there's rivalry between the video and still camera divisions of Canon? Stranger things happen in big business...
Since the CMOS imagers in the 7D and the 1D Mk4 have a "comparable" pixel count, and both cameras were developed at about the same time, I'll bet the video processing circuitry is very, very similar. Both cameras record with H.264 compression at the same data rate.
IMHO there's no excuse why a 16mp - 18mp image can't be properly down sampled to yield 1000+ lines of horizontal resolution at 1080P. Canon has to realize that the HD video capabilities of these new DSLR's is what's generating product excitement and sales... or maybe there's rivalry between the video and still camera divisions of Canon? Stranger things happen in big business...
Barry_Green
Moderator
DOH! That's a typo. It should be 1.5. Sorry 'bout that.
Barry_Green
Moderator
There is certainly an excuse as to why they can't do it -- they can't read the chip fast enough to read off the full frame. That chip can only be read at 10 to 11 frames per second.
Now, they could make a chip that you could read off at full video frame rates, of course, but it's gonna cost a whole lot more. It's just like a computer cpU -- if you want an Atom, that costs a lot less than an i7.
This is a still camera, and has a still camera chip. The way they get video out of it is to "cheat" (which, by some estimations, means binning three pixels out of six horizontally, and skipping 2 out of three lines vertically) so that they're only reading about 1/9 of the chip in total, which means they can read it 9x faster, which brings it up to video frame rates.
johnhafner
Active member
5184/3 = 1728 wide
3456/3 = 1152 tall
Pretty close to full HD with the binning. In my experience a good lens matters a lot to get the most out of the 7d. The 5d mkii is much more forgiving about not so great glass with it's larger image circle.
I haven't shot any MTF charts, (I would if I had some) but I've done a lot of pixel peeping and the 7d is capable of resolving 1-2 pixel wide fine details. It works for me.
7d footage here.
http://www.youtube.com/watch?v=w5WejjG1HTg
3456/3 = 1152 tall
Pretty close to full HD with the binning. In my experience a good lens matters a lot to get the most out of the 7d. The 5d mkii is much more forgiving about not so great glass with it's larger image circle.
I haven't shot any MTF charts, (I would if I had some) but I've done a lot of pixel peeping and the 7d is capable of resolving 1-2 pixel wide fine details. It works for me.
7d footage here.
http://www.youtube.com/watch?v=w5WejjG1HTg