Scarlet, Canon C300, and “Super 35”
Sunday, November 6, 2011 at 11:49PM 
Sensor size isn’t everything, but it’s worth examining how many different definitions of a “Super 35mm” -sized sensor there are when thinking about last week’s camera announcements.
The Scarlet X has a larger sensor than the Canon C300, but you won’t be using it all to make movies. You can only achieve 24 fps at 4K and below—where the window you’re shooting to is actually smaller than the C300’s near exact match to the Super 35 frame width.
Canon’s APS-C HDSLRs, such as the 7D and my new favorite, the inexpensive Rebel T3i, are also very close to to the canonical Super 35 width.
On an Epic, shooting 4.5K WS gets you similarly close to the dictionary definition of “Super 35.” I don’t see this resolution listed among the Scarlet X’s options, although it’s possible that was simply for brevity.
What you’ll probably be shooting on your Scarlet X is 4K HD, where your frame size is noticeably smaller than Super 35. So is it fair to call the Scarlet a “Super 35” camera?
The Scarlet allows overcranking, but only at windowed resolutions, as shown above. As you gain frames per second, you lose resolving power, and the ability to achieve shallow depth of field at a given Angle Of View. Your lenses become effectively more telephoto as your sensor goes Costanza on you.
The Canon C300 on the other hand will force you down to 720p for any frame rate between 30 and 60—but it’s a downsample, not a crop, so your lenses will still behave the same way.
Reader Comments (18)
Hi 5tu!
Thanks for your post.
I have a question about the sensor. Beside the size and pixel resolution:
It's about the Bayer filter.
I've read Canon C300 doesn't use that Bayer filter, but the RED does.
Hence the 4K of the Scarlet, it's not like "film 4K" but lower (?)
It will be interesting to see a side by side test.
Cheers!
The C300 uses a 4K sensor to create its HD image. The pixel layout is such that each channel of R, G and B get a full 1920x1080 record on the sensor (double for green actually). There is a bayer pattern there, but the interpolation is easier since there's no attempt to generate a 4K image from a subset of color sampling.
It's a very nice way to make an HD image, similar to how it was done on the Panavision Genesis camera.
I strongly advocate this kind of supersampling on the sensor, which is why I like the Epic so much. 5K acquisition is very nice for 2K mastering. It does mean, however, that I am wary of pushing an Epic, or a Scarlet I suppose, down to these 2K windowed resolutions. At that kind of crop you're no longer supersampling as much, and the camera does not shine as brightly.
Thanks for this post, that is exactly what I was looking for !
But how do you read from the specs if it is a downsample or a crop ??
Scarlet shoots raw, which precludes downsampling.
So it is the same for HDRx... crop again.
Stu... don't you think that if Canon had developed the right codec and in-camera power to save all of that 4K data, we could be debayering a 4K picture out of that sensor? I don't find the marketing copy about their 4K sensor as touting a sensor virtue but a processing weakness. Or at least someone could teach the marketing department the right terminology. Photosites, subpixels, pixels, whatever, it all sounds the same, right?
When I learned the 20K$ C300 sports a Digic III proccessor and the 6K$ 1D-X has two Digic V and one Digic IV I had to wonder: are they even trying? And that other camera? 4K MJPEG? What a joke.
@Daniel: Your are confusing the names of the Canon processors. The Canon C300 is using a Digic DV III which is a totally different thing than a Digic III.
Thanks Eric, great to know. It didn't sound right at all.
Hi Stu,
Are you sure about this?
"the ability to achieve shallow depth of field at a given Angle Of View. Your lenses become effectively more telephoto as your sensor goes Costanza on you."
I think the DOF at a given aperture is the same
I get the same DOF when using a 50@2.8 at 20cm as a 150@2.8 at 60cm. Both 0.13cm DOF. (http://www.dofmaster.com/dofjs.html)
It might even be an advantage on the long side since you can use 1.4 lenses as tele lens. Like the 85mm 1.4 is on a cropped sensor like 2x85 = 170MM 1.4. Look at that shallow DOF! Also you can work around minimum focus distance by cropping on the sensor and effectively magnifying the image. Good for Macro shots and my main reason for buying 600D with cropzoom for macro.
Disadvantage: It is bad news for the wide angles. Use those on 4k.
@Bart
yes, cropping will make shallow DoF more difficult to get... because you'll change to a wider lens in order to get the same FoV
check my notes on this issue, and some examples, here:
http://www.similaar.com/foto/doftest/doftest.html
also, on those DoF calculator exercises you ran, you're right, but the way you perceive DoF at different focal lengths is not the same:
http://www.similaar.com/foto/tuten/320.html
http://reduser.net/forum/showthread.php?66210-Scarlet-X-Data-Sheet
@Samual,
Clearly explained by the photos. Nice.
Anyway with the cropzoom I can make nice dragonfly head footage from a distance. Where my 90mm and 300mm macro alone can't focus this close and I loose light by using extension tubes/tele converter. I can't figure out if I get a bigger DOF from a distance compared to 1cm distance and make it fly away all the time.
One more thing does a teleconverter work as a more tele or as a cropfactor.
(sorry stu for using this post for this but it can help others)
Bart, you are correct that measured DOF remains constant at different focal lengths, and Samuel is correct that this doesn't stop longer focal lengths from giving the appearance of having less DOF. But in those cases, the sensor size remains constant. When you reduce the sensor size and compensate by shortening your focal length to maintain the same Angle of View (not Field of View, sorry, that's something else), you give up the ability to make shallow DOF. That's the whole reason we love these big sensors.
Stu,
Thanks for the post. I am so tired of cameras that force me to make trade-offs for overcranking.
This is why I ultimately decided on the Lomokino.
It was the only way to be sure.
Win.
Just to point out , the pixel pitch is the same on Red One and Scarlet and Epic. So any 4K flavors that people have been using on the Red One will have the same FOV for a given focal length on Epic/Scarlet as you'd be used to, if you've shot Red before. You just get a slightly wider FOV when shooting 5K. I just hear a lot of people on the forums worried about cropping for 4K. But it's the same 4K that the Red One has been shooting, in terms of sensor size.
Nice to have HDSDI (422) out, would have been even nicer to have 3G-SDI so we could have 444.