I'm sorry, I truly don't understand what you are trying to say here. The DOF gap between the two cameras is probably equivalent to 1/3 of a stop (I didn't work the math). So nearly negligible.

I've never delivered a spot and had it broadcast at 24p. Is this possible? Playback is at 29.97 for ntsc broadcast standards. Can somebody care explain this? I'd like that.

"Math" who cares about math?

For me, i notice that the 7D is easier than the 5D when pulling focus, do to the smaller sensor size.

Only my opinion but - Open up the aperture on both cameras, with the same iso, focal length, etc and the 5D has this beautiful bokeh, but for me, its too much, the DOF can be razor thin. Your subject moves a little and there are moments of softness too - temperamental. It can be nice, but to me it looks like a magazine instead of a movie!

The 7D keeps more of focused blur/bokeh - the DOF isn't so razor sharp and thus more forgiving. We've had shoots where the steady cam remote focus pullers prefered the 7D because of this - i thought it was a little strange of them to request a 7D, till i started using them side by side and came to same conclusion!

So I can appreciate your efforts to do these tests. It really is the best way to make an educated evaluation.

But ...

How did you configure your playback display in the process of your evaluations? I think this is a _real_ important detail if you want to get into any critical analysis. For example if you are watching a 60p computer display then when you say you are watching a 24p clip, in all likelihood you're not. You are seeing 2:3 pulldown 24p displayed at 60p. There are subtle effects caused by this conversion that an overly critical analysis may uncover. Most casual viewers do not notice in my experience but the differences are real - especially when you start talking about stutter (judder).

The best you can do to get to a theatrical display experience is to find a display that does 48p and will run your 24p tests at 2:2 pulldown (thus matching most cinema projectors). Not hardly the most popular display available. The next best would be a 120Hz display that does true 5:5 pulldown. Still this does not exactly match the 48p 2:2 pulldown that true cinema projectors do.

Anyways if nothing else this may highlight the futility in a too harsh of an evaluation of 24p vs 30p or 60p if you cannot reproduce the true cinema experience of 24p displayed at 2:2 pulldown.

I care about the math or at least the physics. Particularly when it offers a simple explanation of why you are posting what you are posting.

DOF is a matter of subject to camera distance, focal length, sensor size, and iris. So you can use a different lens, change your distance to the subject, or iris down. Any of these will mitigate the "razor thin" DOF that you describe. Or you could move to a 2/3" camera and that would get it done also.

Yep, i could move to 2/3 ...or i could move from the 5D to the 7D.

in my experience, pulling focus on the 7D is easier than the 5D - my experience!

All things being equal, the sensor size on the 7d is less than half of the 5d... Thus more dof - Easier to pull focus and more forgiving when talent moves,

Yes, the 7D will make it easier with the smaller sensor... but umm... less than half?

Full Frame is 36x24
7D = 22x15
Half would be 18x12

Not sure how you're defining half...

36mm x 24mm=8.64cm2
22mm x 15mm=3.30cm2

a 20" 16:9 tv is NOT twice as big as a 10". it is 4 times as big

good thing you're not laying tile

LOL!

Ahh, in terms of square area. Yea, I understand the math. And I've laid my fair share of tile too... :)

When a movie shot at 24p is viewed on a tv at home, it looks fine. For some reason, whip pans and fast motion doesn't look bad or distracting. But sometimes, when a videographer shoots and edits a commercial at 24p and airs it, every movement stutters, as if something is very wrong.

Have you seen this? It looks horrible, like the field order is wrong.

No - the difference in DoF between 7D and 5D II is 1 2/3 stops.

By same distance, aperture and focal length the DoF of the 5D will greater - CoC (circel of confussion) on the 5D can be greater because of the gerater chip size.

But to became the same image on the 7D you must use a smaller focal length. So if you shoot on the 5D II with a focal length of 50mm you must use 30mm on the 7D for the same picture. In that case the 7D will have the greater DoF.

In practice if you want have the same DoF on the 5D II with 50mm as on the 7D with 30mm you must close the aperture on the 5D II for 1 2/3 stops.


Daniel von Euw

Yea, after I engaged my brain and realized the gap in sensor size, I got this... I really thought they were much closer

Right.

Im very new to capturing moving images, having come from a completely stills driven background, so please excuse me if i am wrong but i think you are missing a crucial point with the 5DII vs 7D sensor debate.

The 5DII's full frame sensor resolves so much more detail than the 7D's its almost embarrassing ( see images below).

The high ISO capabilities of the 5DII also wipe the floor with the 7D, so i would happily bump up the ISO & the f/ stop by 1 2/3 stops to retain that detail than use the 7D.


@ISO 100http://rolandlim.smugmug.com/photos/...6_L3kfP-XL.jpg @ ISO12800 http://rolandlim.smugmug.com/photos/...37_PLBsH-O.jpg

Robert, welcome to DVinfo.

I think your comment on resolution pertains only to still photography, not video.