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

Andrew Brinkhaus

Andrew Brinkhaus

Veteran
Every time somebody posts a new thread about a m35 or any type of 35 adapter, even the redrock micro, I ALWAYS notice that in the footage, the DOF is WAY TOO shallow. 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. Some footage ive seen cannot even keep the frame in focus (ex. right side is in focus, left is slightly out of focus) How is this supposed to be practical in an actual shoot? Even film cameras have like twice the depth of these adapters...sorry just venting.
 
I watched "From here to Eternity" last night, and fell off my chair.

A great number of shots had an intentional deep depth of field, keeping actors from the immediate forground to people in the back pretty sharp.

In this case deep DOF works because the set design and tones (it was a black and white movie) were low in contrast, and didn't detract from the actors.

But then, for an aspiring no-budget Indie film maker like me, spending money on background work is out of the question, and I'll always be worrying about separating the actor from the background.

Anyways, I think the mini35 folks are just showcasing their products by going a bit extreme. I don't think anyone will go that shallow in a real production.
 
Every time somebody posts a new thread about a m35 or any type of 35 adapter, even the redrock micro, I ALWAYS notice that in the footage, the DOF is WAY TOO shallow. I mean sure, its good to have shallow depth of field, but these adapters are WAY overdoing it.
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Your theory is incorrect... disturbingly so.

It's not the lens adapter it is the lens itself. You wont get that kind of DOF with a 20mm lens.

Most people when they get the adapter they usually throw a 50mm and shoot some tests, just to get an example of how the adapters work. That is mostly what you see.

If they were to shoot on wider lens (i.e. a 20mm) You would not be able to notice much of a difference from the wide end of a video lens.

The adapters project the image from the lens onto the focusing screen inside the adapter, that the video camera then photographs (similar to a telecine process) The adapters themselves have nothing to do with the actual DOF.

The adapters are a way for digital filmakers to use prime lenses (fixed focal length) instead of the traditional zoom that is attached to the end of the camera.

Most films are shot with primes. Why? because you can never get a decent DOF without going all the way to the telephoto end of the lens and standing 50 feet away from you subject.

Some footage ive seen cannot even keep the frame in focus (ex. right side is in focus, left is slightly out of focus) How is this supposed to be practical in an actual shoot?
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Uhh...yeah...the left side is out of focus because the object on the left is probably closer to the camera.

I think you should read up a little more on the subject (and filmaking in general) before you...uhh..."vent". You shouldn't comment on something you don't really understand. You should ask questions before you disregard (i.e. "vent) out of hand.

Please, do yourself a favor and get a book on filmaking, take some classes, or just surf the net so that you can educate yourself before you do an "actual shoot".

...'sigh'
 
Its completely the DP's choice on how much DOF he wants to play with depending on his lens choice its not based on the adapter. Good 1st AC's will know the exact DOF a certain lens will give you at any certain stop. And yes... if you use a 200mm Cooke lens on one of these adapters you will get the same DOF as if you were shooting with it on a 35mm camera. There are lens index's that will prove such.
 
Thanks Chayse, I appreciate the mature comment, as it actually answered what I was looking for. Tibby, trust me, I know more about filmmaking and photography than you'd think. I know how an adapter works and how they are used. Dont belittle me, because quite frankly you know nothing about me and just from reading my post, you wouldnt know the first thing about what I know. A big part of the adapter (the main problem I had in my post) is that the adpaters CAN change the depth of field. Is it not true that the GG can be placed at different lengths from the lense? Also, the thickness of the GG, as well as the amount of "frosting" or "etching" can be changed, thus resulting in different outcomes from the whatever milimeter lens? People like Tibby need to grow up and realize that these forums are for learning, not for destructive criticism.
 
A big part of the adapter (the main problem I had in my post) is that the adpaters CAN change the depth of field
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Certainly some of these designers are implementing their designs in a way that makes for significantly different DOF than one would get with a 35mm movie camera. Still camera lenses are designed for a 36x24mm frame. The movie camera frame is at most 24x18mm, and usually smaller still. If the adapter designers are using a full 36x24mm frame, the results will be (after all is said and done) *much* shallower DOF than would have been achieved by using the movie-sized frame.

Is it not true that the GG can be placed at different lengths from the lense?
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Depends on which lens you mean, of course. You cannot place it at varying distances from the still-camera lens, as doing so would throw off the ability to focus to infinity. But of course you can place it at varying distances from the video camera lens, and that's what's happening, and that's why DIY adapters are getting results substantially different from a mini35.

Another thing that's happening is that the mini35 and other designs do, by nature, encourage shooting wide-open. That substantially reduces the DOF as well, as compared to movie lenses. Movies may frequently be shot at somewhere around f4, or maybe a 2.8-4 split, whereas lens adapters are pretty much all-wide-open, all-the-time.
 
Invision, I think your question is one of the few comments in this thread that actually makes sense. Sorry everyone, but this topic is almost a disservice since it is spreading a lot of bad info.

Points to acknowledge:

#1: They are demoing their product, or are costumers that are getting carried away.
#2: They don't have money or time to shoot some cool locations, and shalow DOF tends to make things look a little better.

My answer to your question: most adapters don't let you work with any lens closed past f4. So basically, they are all shooting all open. That's why DOF is always so shallow.

Invision, no, they can't change the DOF of the lens by moving the image plane, only if they zoom in in a small area of the projected image, but then, the DOF will be even shallower (for an equivalent fild of view).

Tibby, your post is pretty much full of false information. A few examples:

The adapters are a way for digital filmakers to use prime lenses (fixed focal length) instead of the traditional zoom that is attached to the end of the camera.

Most films are shot with primes. Why? because you can never get a decent DOF without going all the way to the telephoto end of the lens and standing 50 feet away from you subject.
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Primes and zooms don't differ a dang thing in DOF. A 50mm prime at 4.0 will have the same DOF as a Zoom lens set to 50mm at 4.0. However, primes often open wider in aperture (wich would grant you shallower DOF), and are sharper. Prime lenses are better quality lenses and cheaper, that is why most films use them in their main basic kit. A lot of films are shot with zooms thees days, it really depends on the DP.

Some shots could have a whole side out of focus, that would be caused by a missalignment of the GG to the lens axis, wich would leave a part of the ground glass closer/further from the optimal distance of the projected image and could lead to a "split diopter" effect where one side of the image is out of focus. Invision's right, that is pretty much useless.

The main goal is that a DOF adaptor is not for everybody nor for every type of situation, but can do wonders if you use it right.
 
I think the mini35 folks are just showcasing their products by going a bit extreme. I don't think anyone will go that shallow in a real production.[/QUOTE]


:thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:
 
InvisionProductions said:
Some footage ive seen cannot even keep the frame in focus (ex. right side is in focus, left is slightly out of focus) How is this supposed to be practical in an actual shoot?
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It can be very effective because.

Having an uneven focal plane gives filmmakers access to a "tilt-shift" style lens for a very low price. Instead of adjusting the lens, you adjust the ground glass inside the adapter. Using this method is actually better than using a tilt-shift lens on a real mini35, because you aren't limited to small aperture lenses. You can use any lens, even the really wide 24mm f/1.4 from Canon! It can be a very cool look.

But, you're right by saying the homemade adapter crowd "discovered" this by mistake because they lack the precision alignment for a flat focal plane.

The homemade film lens adapter absolutely has its' place in the world of creative imaging, much like a Holga, Lomo, or PXL-2000.

Even film cameras have like twice the depth of these adapters...
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Right. I would compare the homemade adapter to the 65mm motion picture format, speaking strictly in terms of apparent depth of field.
 
taubkin said:
Wells, wouldn't you loose backfocus by doing this?
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For the way I am accustomed to thinking of backfocus, it means something a little different.

...But, yes, you are changing tilting the plane, so naturally, the real image does not hit the ground glass at the same point (this isn't easy for me to put into words). I think you could say you lose backfocus, but only on the part of the plane that's tilt/shifted. Which is why it's unique.

Very few photogs are using tilt/shifts. When they do, it's usually for artsy reasons.
 
I see, but everything in the area outside of the image plane would be out of focus, you would not be able to compensate for something in the frame this way as , say, using a split diopter, am I thinking this right? So you can have a hlaf blurry image, but not a full "in focus" image doing this, am I correct?
 
Tibby, your post is pretty much full of false information.
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Hmm.. interesting. I meant the telephoto on the video lens, but you knew that. You've done you good deed for the day, maybe you'll get a prize now boy scout.

My answer to your question: most adapters don't let you work with any lens closed past f4
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Thats funny, I have two adapters and I've gotten lenses down to f5.6 (some occasions f8) and still had a decent picture. You can also get around this by the iris on the camera itself.

Have you even used an adapter? Doesn't sound like it.

I may not have all the terminology correct, but at least I have practical first hand knowledge of what adapters can and cannot do.

On to the topic at hand. Yes the adapter themselves may alter the DOF slightly due to the light being let in, but the lens is the main factor in DOF.

So yeah, I stand by my original point. There's no iris or aperture on the adapters themselves. Putting the blame on the adapter is quite silly.

A lot of films are shot with zooms thees days, it really depends on the DP.
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I haven't met one DP yet that prefers zooms over primes. So I guess that could be construed as false information.
 
Tibby said:
. . . because you can never get a decent DOF without going all the way to the telephoto end of the lens and standing 50 feet away from you subject.
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Not true. Shallower depth of field results when you focus nearest (not 50 feet away from your subject) the lens' shortest focus distance (M.O.D.).
 
I was exaggerating...my point is this: try working in close-ups for the sake of coverage, using only the lens supplied with most camcorders.

Good luck trying to isolate the actor from the background. It's kinda why these adapters were developed.

With primes you don't have to get as far away from your subject.
 
Tibby need to grow up and realize that these forums are for learning, not for destructive criticism
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This from the guy who started the thread to "vent" on adapters in general.

You weren't here to learn anything, your mind was made up.

Is it not true that the GG can be placed at different lengths from the lense
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Huh...I don't recall making that claim. Matter of fact I never said anything remotely resembling that.

Needless to say, I stand by my original point, it's not the adapters that are the main factor for the DOF. Yes, they are there for that purpose, but it's the lens that does it.

Maybe you should actually get an adapter with a few lenses and then comment. Until that day it's all speculation on your part.

After all I thought you were here to "learn" something.
 
Thanks Taubkin and Barry, those are the great posts that keep forums like this up and running smoothly, staying to the point and discussing the actual post. Thats why I always keep coming back to this place, because I know even though there are some real jerks out there, the majority of people are great, and I appreciate that everyday. Thanks Dvxuser!
 
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