5D / 7D - Full Frame vs. 1.6x - Pros and Cons

Barry_Green said:
Okay, math on the 7D: largest image it takes is 5184x3456, so assuming that's the active pixel data on the sensor, that leaves a pixel size of 4.25 microns in each dimension, or 18 square microns.

On the 5D, the largest image it takes is 5616x3744; that leaves a pixel size of 6.4 microns in each dimension, or about 41 square microns.

Lots more imager area, not a lot more pixels, means each individual pixel is over twice as big. Which means, basically, that you can probably expect the 5D to be a bit over a stop more sensitive than the 7D. If all other things are equal.
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From TDP ( http://www.the-digital-picture.com/Reviews/Canon-EOS-7D-Digital-SLR-Camera-Review.aspx )
Model FOVCF Sensor Pixel Size Pixels/Megapixels Viewfinder DLA
Canon EOS 7D 1.6x 22.3 x 14.9mm 4.3µm 5184 x 3456 18.0 1.0x 100% f/6.8
Canon EOS 5D Mark II 1.0x 36.0 x 24.0mm 6.4µm 5616 x 3744 21.1 .71x 98% f/10.3

Your approximations are bang on :)
Thanks for the great explanation. :thumbup:
 
xbourque said:
Barry, have you seen the 7D promo clip from canon with the motorbikes and the rally car (Line of Sight)?

http://web.canon.jp/imaging/eosd/samples/eos7d/

These lo-rez clips don't tell us much about aliasing, but I don't think jello looks outrageous.

-- X
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I have to agree, just a gut shot reaction on the available clips, the skew seems VERY improved, even possibly better than the GH1. 720p alliasaing on the 7D... that's another story :(
If we lived in a 720p world then the GH1 would already be "the perfect storm." I think it's amazing at that resolution.

Hopefully all these questions and more will be answered on Phillip Bloom: International Man of Camera Demos!

EDIT: First Philip Bloom video and the CMOS skew/ jello is better than the 5D but seems about as twitchy as a GH1 with an unstabalized lens.
 
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Barry_Green said:
The fact of the matter is: for a cinema shooter, the 7D is going to deliver the same DOF and the same FOV as a 35mm movie camera. Done. End of story. No need to worry about whether a 50mm "becomes" and 80mm, because it doesn't. Put a 50mm lens on a movie camera, and then take it off and put that lens on the 7D, and you'll have identical results (or near-enough identical that nobody's complaining.)

The only reason a "crop factor" exists is to talk about how the lens field of view compares to that of a 35mm still camera. Has nothing to do with us motion/moving image folks.
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Just to clarify (off the back of reading this thread http://www.cinema5d.com/viewtopic.php?f=64&t=4940 ...

Cine lenses on a 7D will act the same as they do on a movie camera, right?

Does this apply to regular primes too, like Zeiss Contax for example?

Cheers C
 
Columbo said:
Just to clarify (off the back of reading this thread http://www.cinema5d.com/viewtopic.php?f=64&t=4940 ...

Cine lenses on a 7D will act the same as they do on a movie camera, right?

Does this apply to regular primes too, like Zeiss Contax for example?

Cheers C
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In short, yes. If the lens is meant for use on a Super35mm film camera, it will provide almost exactly the same DOF and FOV on the 7D because the capture devices (one being film, the other a sensor) are almost exactly the same size.
 
Michael Olsen said:
In short, yes. If the lens is meant for use on a Super35mm film camera, it will provide almost exactly the same DOF and FOV on the 7D because the capture devices (one being film, the other a sensor) are almost exactly the same size.
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Sweet, thanks Michael.
 
Ian-T said:
Ha...explain that to those who keep saying..."But it's not full frame." :)
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The fact that it's "not full frame" is THE ENTIRE POINT.

It's the same frame as the Red One. Or a 35mm cinema camera. Or an F35. Or a Dalsa Origin. Or a Thomson Viper.
 
Ian-T said:
Ha...explain that to those who keep saying..."But it's not full frame." :)
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Unless I'm missing something here, FF/5D seems to me a strange reference point.

Surely cinema is the gold standard, so that should be the reference point, not full frame.

So that being the case, it'd be more accurate to say a 50mm on a 5D acts like a 28mm or whatever, rather than saying a 28mm on a 7D acts like a 50mm, right?
 
Columbo said:
So that being the case, it'd be more accurate to say a 50mm on a 5D acts like a 28mm or whatever, rather than saying a 28mm on a 7D acts like a 50mm, right?
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Personally I would agree with that, but people like to say that a given lens is a lens, period. Which is right, and avoids confusion.

I think that if you want to communicate a lens and its behavior, you'd speak both the lens info, together with the format.
I.E.: "We shot that on S35, on a 28mm at f/1.3" or "Red One 2:1, on a 28mm at f/1.3" or "HPX170 with a Blade set up for S35, on a 28mm at f/1.3".
 
Interesting thread.
Cinema size sensor yelds easier focus pulling compared to ff still sensor, but then a 28 or 35 still lens yelds much shorter focus throw than a 50.
So, witch lens to choose for a fast "normal" to pull focus more accurately with?
Sigma 30 1.4 I've heard has too stiff a focus ring
Canon 28 1.8 maybe? Or the focus ring isn't dampened enough since it's a more an autofocus?
Nikon 35 2? I have one, unfortunately not a good copy in respect to focus ring
Canon 35 L 1.4?
 
KeithAndrews.TV said:
One thing you have to consider is any full-frame sensor (5D Mark II for instance) will be able to create the same shallow look that the 7D can, just at a higher aperture. No one is saying that you have to shoot at f/2.8 or faster to get a shallow look with a full-frame sensor. In fact you will most likely be shooting at the sweet spot of your full-frame lens and still get the same shallow DOF look the smaller sensor is capable of without having to shoot wide open.

This thread proves the point perfectly. Although the 7D is close to s35mm it is not exact, it's actually a little smaller. I would prefer to have that extra control over my DOF in a shot when I want to use it with the full-frame sensor, as opposed to being limited to what I would get with a crop sensor. Referring to DOF and aperture, you can always add DOF to a shot, but you can't take away what isn't physically possible with a smaller sensor.
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Well, that of course, if you have full and 100% control over your environment. But if you ever have to shoot in low light and can't add more light, which is often the case, you will be forced to shoot with your lens wide open and then, your whole theory goes down the drain while your 1AC goes out the door.

By the way, I don't really understand the point of all these 5D owners about the 7D DOF not being shallow enough etc (not necessarily talking about you). S35 has been fine for filmmaking for decades now. Why do 5D owners think we suddenly need Vista Vision DOF and angle of view? Maybe it's a case of buyer's remorse or bias?
 
Barry_Green said:
S

The GH1 was (and is) the nearly-perfect storm. If it wasn't for the codec occasionally puking, and the unfathomable exclusion of 24pN recording, and no live monitoring, I'd say it's The New DVX. .
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This is exactly how I feel. I bought a 7D and I'm loving it so far, but I keep thinking, man, if I could combine the 7D with a GH1 it would be the best movie camera out there till you are talking high end stuff.
But what could be perfectly possible would be for Panasonic to release a new version of the GH1 with better codec, real 24p ,external monitoring and maybe even a bigger sensor (although I wouldn't hold my breath on that since it would mean a new line of cameras.) I could see that happening more easily than Canon making a camera closer to the GH1, specially a camera without a mirror, which is the biggest attraction in the GH1 for me.
Maybe Panasonic will, or maybe they will not in order to protect their video division. Who knows. I know I would be first in line to pre order one. I almost bought a GH1 actually. What stopped me was really just the nasty codec. The rest I could even live with.
 
Ok guys,
everything seems clear about lenses and sensor but what about post production: shooting with both 5d and 7d. How do I manage to edit my footage? should I consider while shooting with the 5d some cropping?
 
Wow. Okay, lots of information. I am trying to digest it all at the moment.

Something that I noticed wasn't really mentioned was the Dynamic Range. I realise this thread was about full frame vs cropped frame but surely this must have an impact on any decisions to buy either camera.

Maybe Barry or someone can tell me if the size of the pixel increases the DR?
 
All other things being equal, larger pixels will lead to higher dynamic range (and less noise).

But again, that's only true if all other things are equal.
 
Thanks for that. So does that mean that the 5D mkII has higher dynamic range than the 7d? I have read conflicting accounts on this.
 
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