All 35 adapters i've seen do this...

Don't take it so personally. I was merely joking.

Maybe I was a tad harsh, for that I apologize to InvisionProductions

But since were here yet again... let me quote the man himself:

I mean sure, its good to have shallow depth of field, but these adapters are WAY overdoing it. For example, shoot some footage with one of these adapters then go watch any real film. The adapters make the DOF so shallow that the entire background is nearly unrecognizable.
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Taubkin,

The key sentence here being:

The adapters make the DOF so shallow that the entire background is nearly unrecognizable.
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The adapters. Not the lens. The adapters.

The lens is the primary factor for DOF, not the adapter. I stand by that. If you wish to back up an uneducated assumption that it's the adapter, by harping on a few of my poorly worded sentences that I typed out in a few seconds so be it.

It's quite simple actually... a 100mm lens is going to have a different DOF than a 20mm. Different lenses = Different DOF.

The adapter doesn't have a focal length, the adapter doesn't have an aperture, the adapter doesn't have a focusing ring.

Tell me, how do you control the DOF with the adapter? I'm curious.
 
Good gravy; i betcha if someone took the lens off the adapter and placed it on its SLR, you will see the DOF is the same.

In fact I will do this tomorrow: I will remove the 50mm Canon FD f1.4 from my own adapter and will dig up a AE1 or T70 at work and put it on.

I do beleive its more the lens than it is the adapter. And if the DOF from the adapter is too much for invision, then go with the stock video lens. To each his own.
 
i think we ALL pretty much know what we're talking about. just misconstruing what others said or using what they ommited against them to prove a point. Personally the main statement that I have a beef with is

"With primes you don't have to get as far away from your subject."

The word "prime" doesn't define a lenses focal lenght or DOF or lack there of. It simply defines that this lens has a fixed focal lenght and does not zoom. So therefore zooms and primes (at the same fstop and focal length [let me not ommit anything here]) have the same DOF.

Atleast from what I know. For all I know Barry's gonna come on here and make me look like an idiot now...lol...but that would be good cus I'd learn something new.
 
mmmkay, hopefully we've all satisfied our "venting" urges... let's be nice to eachother again, ya?
 
Tibby said:
Tell me, how do you control the DOF with the adapter? I'm curious.
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The adapter makers are "controlling" DOF through the adapters because they're using a different frame size. The different frame size changes the field of view. The different field of view requires you to get closer in order to get a comparable shot. It is the fact that you are CLOSER to the subject that is causing the hyper-shallow DOF.

It's all caused by a misunderstanding of what people are trying to accomplish. 35mm movie cameras use a different (and much smaller) frame size than a 35mm still camera does. So when using still-camera lenses, these DIY adapter builders are building their devices around the frame that the still-camera lens projects, which can be up to 36x24mm. That's not what movie cameras do. A movie camera uses a maximum frame size of 24x18mm, or *half* the size of what a still camera does.

If you're using a larger frame size, you would need to get closer to the subject in order to have a comparable subject size. DOF is determined by focal length, aperture, and distance-to-subject. Get closer = shallower DOF.

That's where the error is coming in, and why so many of the DIY adapters are exhibiting DOF that's excessively shallow, as compared to actual movie cameras.
 
Mastermind (sort of a presumptious name for someone writing that they aren't sure what they're talkign about), you're right but not entirely. A prime set at f5.6 will have the same DOF as a zoom at the same focal length at f5.6, but primes typically open up much wider. (Look at the prices for 28-70mm and 70-200mm f2.8 zooms, then consider that canon has a f1.8 50mm prime for 60 dollars.) Primes typically provide better images and less "breathing" but the simplicity of working with a zoom is pretty nice.

As for whether the adapter or the lens is "at fault" for giving you a shallower DOF, I agree that everyone should just agree that it's a stupid question, since one (without the other) wouldn't give you any image at all. Of course 35mm lenses will give you a shallow DOF, even more so than 35mm picture film at the same f-stop. However, most DPs (not all, mind you) shoot around f4 most of the time, so shooting f5.6 on a 35mm adapter (which is not ideal but possible, I believe will give you a PLENTY deep DOF, but you'll need a LOT of light.

Also, the resolution of DV is lower so, technically, it has an inherently deeper DOF than high definition or film, even with the same sensor size.
 
Cool ... thanks for the thread guys, answered some questions I was looking to ask at some point ! Cheers
 
Yes, I know the size of the frame is a factor in DOF. I wasn't arguing that.

The adapters make the DOF so shallow that the entire background is nearly unrecognizable.
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This is where I had my original problem. If you used a different lens would you not achieve different results concerning the "unrecognizable background"?
 
Policar said:
Mastermind (sort of a presumptious name for someone writing that they aren't sure what they're talkign about), .
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what's with all the animosity all of a sudden on this site? RELAX!!! it's just a screen name.......and as I recall i was pretty humble with my response.
Did I not say that Barry will probably come on here an make me look like an idiot BUT ATLEAST I WOULD LEARN SOMETHIING.
A wise man knows his ignorance. A fool thinks he knows everything.

"The dumbest people I know are those who know it all."
-Malcolm Forbes
 
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