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

M

Mirezzi

Well-known member
Okay, so for dummies like me, can somebody explain to me the pros and cons of Full Frame vs. 1.6x (aka. 5D vs. 7D) for video mode?

Here is my understanding so far. With Full Frame / 5D, you get the full focal length of your 35mm lenses. With the 1.6x APS-C sensor / 7D, you are cropped to 1.6x (so a 35mm lens becomes roughly equivalent to 55mm, etc.) - why are people excited about this? It seems to me that losing that much focal length kinda sucks. To get a good wide angle with the 7D, shooters will have to use a 17mm lens just to get something equivalent to a 28mm. That will require a pretty hefty investment in glass, yes?

Thanks in advance for info...
 
You are on the right track

however pulling focus with the big chip is a PITA

the smaller chip has the same size as 35mm cinema so creates a cinematic look

Telephotos obvioulsy drop in price but you are indeed forced into expensive wides - there are some cheapo stigmas lenses in the 12-24 range I beleive

My 400 2.8 is pretty hard to stabilise and requires a costly head too and is very heavy considering its reach on FF is about the same as an EX1 camera

Traditional knowledge suggests that smaller chips are noisier

the frame rate IMO really outwieghs all of that

S
 
Kholi said:
Okay... so those who are unfamiliar will know...

the 7D is pretty much right on with the Sensor Size of say, the RED. And RED is around S35mm size, the same size frame that nearly everything is shot on that you watch in theaters. Full Frame is not the current acquisition standard in Cinematography.

By acuiring images with 7D's image sensor you will be immediately within range of reproducing the same cinematic characteristics that everyone has been striving toward for so many years. Pulling focus @ Stops of 2.8 will be simple for the practiced focus puller. And even wide open at 1.4 it's not too difficult at all.

DOF, Angle of View, Field of View will be plenty good for this stuff. It's a very happy medium between everything, and works very well.
Click to expand...

I pulled this from another thread. I apologize for the redundancy, but it seems like starting a thread to specifically address this issue might be useful.

My understanding now is that Full Frame cinematography isn't orthodox and therefore harder to control vignetting / difficult to pull focus or even maintain focus. Is that an accurate assessment?

I have come from a background of shooting with the Canon XHA1 + Letus Extreme + Nikkor primes. How will that experience compare to the 5D / 7D?
 
If all you're shooting with these cameras are still pictures then sure it would be a disadvantage. But for flim-making or making movies the size of this new sensor is equivalent to standard 35mm FILM. Full frame is a bit too much to pull focus accurately with.
EDIT: Morgan beat me to it.
 
With "full frame", you get 35mm still-camera field of view and depth of field.

With the 7D, you get 35mm movie-camera field of view and depth of field. The 7D's sensor is almost exactly the same size as a 35mm movie camera. So you'll get the same perspective, the same depth of field, the same "feel" as 35mm movies. The 5D doesn't give that, it's too shallow (as compared to movies). The 7D replicates the DOF characteristics of a motion-picture camera perfectly.
 
Awesome, thanks everyone. About my last question, how will shooting with 7D compare to my experience shooting with video camera + letus extreme adaptor + 35mm primes?
 
(so a 35mm lens becomes roughly equivalent to 55mm, etc.)
Click to expand...

It becomes equivalent to a 55mm lens in terms of field of view, but not magnification. Some people (not saying you) have the misconception that the crop makes your lenses 'longer', but it's really just reducing the field of view at the same focal length.

One argument for using the 1.6x chip with full-frame lenses is that it uses the sweet spot of your lens, cropping off the edges and using the sharpest middle area. If you use an APS-C lens then this is not the case.

I shot with a Canon 20D when it first came out, which is a cropped sensor. I really liked it but I was used to shooting film and when I got my first 5D it was so nice to have my full 35mm full-frame back. Now I have the 5D II and it's completely amazing. But if moolah were an issue and/or I already had some APS-C lenses, this 7D looks el fantastico.
 
Last edited:
Barry_Green said:
You'll have the same DOF, just a lot less equipment to accomplish it.
Click to expand...

I see, so video camera + 35mm adaptor + 35mm primes is more comparable to the 7D?

For some reason, I thought it was more comparable to the 5D...meaning, I was under the impression that I was getting "full frame" from my old video camera rig (XHA1 / Letus Extreme).
 
Buck Forester said:
Some people (not saying you) have the misconception that the crop makes your lenses 'longer', but it's really just reducing the field of view at the same focal length.
Click to expand...

You certainly could have said me, because I indeed had that misconception!

So they make specific APS-C lenses where this is not an issue (1.6x crop). I didn't realize that...I'm learning slowly here. Thanks!
 
Mirezzi said:
So they make specific APS-C lenses where this is not an issue (1.6x crop). I didn't realize that...I'm learning slowly here. Thanks!
Click to expand...

Yes, there are specific APS-C lenses (they can't be used on full-frame EOS cameras), but the APS-C cameras will take full-frame lenses (with a reduced field of view). The APS-C lenses, such as the Canon 10-22mm, is really equivelant to a 16-35mm full-frame lens.
 
Mirezzi said:
I see, so video camera + 35mm adaptor + 35mm primes is more comparable to the 7D?
Click to expand...
When properly configured for cinema applications, yes.

For some reason, I thought it was more comparable to the 5D...meaning, I was under the impression that I was getting "full frame" from my old video camera rig (XHA1 / Letus Extreme).
Click to expand...
That's possible. It depends on how far you zoom into the ground glass.
 
Low light

Low light

May I ask about how 7D and 5DII handle low light situations? Does the different sizes of sensor have anything to do with low light capability? I know there are not many 7D clips available yet but I'm very curious.

Thank you.
 
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.
 
Mirezzi said:
Ah, so the 35mm "frame" on the ground glass from companies like Letus, etc. is a 35mm cinema frame or 35mm still photo frame?
Click to expand...
It depends on the adapter. The glass on the Letus Ultimate and on the Brevis are both 35mm still-photo frame (or, at least in the case of the Ultimate, actually even a bit larger).

The glass on the Mini35 is designed to be 35mm cinema frame size.

Don't know about others.
 
Barry_Green said:
It depends on the adapter. The glass on the Letus Ultimate and on the Brevis are both 35mm still-photo frame (or, at least in the case of the Ultimate, actually even a bit larger).

The glass on the Mini35 is designed to be 35mm cinema frame size.

Don't know about others.
Click to expand...

Yep, that's what I was looking for...thanks.

Therefore, since I was always framing the Letus Extreme so that the 35mm frame on the ground glass was virtually edge to edge, I was essentially emulating 35mm full frame photography.

This is all very intriguing to me, sorry if it's rather novice and pedantic. :)
 
kenbaby said:
May I ask about how 7D and 5DII handle low light situations? Does the different sizes of sensor have anything to do with low light capability?
Click to expand...
Size of the sensor, in and of itself, has nothing to do with low light capability directly. But indirectly, it definitely does.

See, the thing that determines (or, better said, greatly influences) low light capability is the size of the individual pixels on the sensor, not the size of the sensor itself. The bigger the pixels, the more sensitive the chip will be.

Bigger sensors traditionally mean bigger pixels, because if the amount of pixels stays the same, then each pixel can be bigger. So a 1920x1080 1/3" camera like the HPX300 doesn't have nearly the same sensitivity as a 1920x1080 2/3" camera. In the 2/3" camera the same number of pixels are spread across a chip that's 4x as large, so each pixel can be 4x larger, and that lets each pixel accumulate that many more electrons, making it more sensitive.

But here's where things go wonky: what if the larger sensor has more pixels? Then each pixel will have to be smaller. So what if you were comparing a 1/3" standard-def chip against a 2/3" high-def chip? They might be the exact same sensitivity in that case. The 1/3" chip might have 1/4 as many pixels as the 2/3" chip, and the 2/3" chip has 4x as much surface area to spread them around on, so -- it nets out that the pixels are the same size, hence the sensitivity is the same.

So just by virtue of the 7D having a smaller chip than the 5D, if the pixel count was the same, that would imply that the 7D would have lower sensitivity. But because the pixel counts are *not* the same, and the 5D has more than the 7D, that means there's a chance that the sensitivity will be closer than the sensor size difference might otherwise imply.

Of course, there are other factors too, including that the 7D is a year more technologically advanced (perhaps) than the 5D, and that might allow it to deliver cleaner imagery at a higher native ISO. Or not. We'll see.

Overall, I am optimistic that the 7D might deliver low-light performance that's comparable or at least near to what the 5D can do.
 
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.
Click to expand...

I can understand that perspective. Depth can be added, but it can't always be taken away?
 
Mirezzi said:
I can understand that perspective. Depth can be added, but it can't always be taken away?
Click to expand...

Exactly. You will reach a stopping point with the 7D where the DOF cannot go any shallower as compared with the 5D Mark II for example. It goes the other way too! The 7D will be able to achieve greater DOF than the 5D Mark II will for a given field of view.
 
You must log in or register to reply here.
Back
Top