DOF against noise

joe 1008

joe 1008

Veteran
Probably the Sony XD cam will have a cleaner image than all the 1/3 HD-cams. But with all those "small" cams you have the option to use a 35mm adapter like the M2 and get a REAL film-look. For my intentions that option is crucial. A 1/2-cam won´t provide a much smaller DOF than a 1/3 cam. Any ideas how to solve this issue? Is there any possibility to fix a low-cost 35mm adapter to a XD cam, or would something like a set of very fast primes give a better result? Do there even exist any primes for 1/2" cams?
 
It shouldn't have anything to do with the chip size once slap a 35MM adaptor on there because they don't work by changing the optics of the camera, they work by changing the optics BEFORE it gets to the camera.

Each of these adaptors has some kind of element that the camera actually focuses on within it and then the camera remains focused on that.

So with my letus 35 its some type of slightly opaque screen which vibrates via battery power, some others use oscillatiing or vicrating ground glass, some have static elements.

So you attach the adaptor, and then you zoom in on the small screen within so that there's no vignetting.

In a way it's like filming a movie screen, infinate focues with ZERO DOF on the movie screen and then whatever the filmmakers used on their cameras in the movie will be the SDOF or lack thereof that you get.

So you zoom in and focus on the ground glass or wahetever inside.
Then you turn off your servos for zoom, turn off auto focus, and some people tape over the focus ring/manual zoom area so they don't bump it.

No you can't zoom or focus whith your actual camera -- all that's static.

So whatever lens you put on the adaptor will now give you depth that depth of feild
50mm 28mm etc.

As far as one for the SonyXD you just need to make sure that the adaptir is threaded to fit your camera and there you go. You may actually get a better image with a 2/3 chip camera than the 1/3 boys because sometimes these adaptors create an effect that's TOO soft. There's so much glass in front of the camera that the crips often not as crisp as it actually would be in film with the shallowest depth of field.

So the chipsize won't matter much, you just need to make sure you get a higher quality adaptor that has as little noise as possible.

you can even use step down or up rings to fit your threads as you are zooming into an area about the size of a match book so there will be no vignetting from stepping down or up.
 
Last edited:
Sorry, maybe I did not express myself clear enough: I know how those 35mm adapters work. I assumed that it would not be a practical solution to plug such an adapter, designed for small cams, onto an already big and long cam like the XD cam. (I´m no sure if it fits at all) So I compared the DOF of 1/2" WIHTOUT ADAPTER with the DOF of the 1/3cams WITH ADAPTER. Regardless that the adapters are softening the image. It´s kind of comparing apples and onions, I know, but it´s becoming an issue when you are going to incline to one of those cams. I mean: You just can´t get it all a once.
My question about fast primes referred to the fact, that they would provide a shallower DOF without adapter. But how big would that effect be with a 1/2" cam? I actually work with a 2/3" cam and it´s pretty difficult to get a soft background. You have to use the whole zoom and open up the iris completely to get that effect.
 
Sorry if I'm still not following you but I think you are asking 3 questions.
A) will it fit on my cam?
B) could I achieve better SDOF without the adaptor by attaching a faster cinema prime lens directly to the camera without the long DV lens that's on there now at all.
C) will the 2/3" make it harder to get shallow depth of feild with the adaptor?

A:
I don't know the cam. It looks like it has a long lens that is perhaps removable.
You can however stick these things on long canon lenses on the XL2 so ... ?
If your lens is threaded for filters and you can support the adaptor with rods all the way out there at the end of that long lens then why not. Again I don't really have any idea though.

B:
Are you saying that cinema prime attached right to the cam with no adaptor or other lens will produce a shallower depth of field than with the adaptor?

Is that even possible to attach cinema primes like that to a DV cam?

You can get the "eyes in focus/ears and nose out of focus" with the adaptor ... so any more SDOF after that would have to be marginal if even possible to achieve at all.

I don't know that the primes would produce more SDOF on their own, because again you are filmming a little screen inside the adaptor and the SDOF party is going on in the adaptor in front of that screen all on its own before your cam films the event on the little screen.

So considerations like making the lens longer by attaching an adaptor would seem to be irrelavent.

The more relevent concerns would seem to deal with noise and quality of using the adaptor vs somehow getting a prime right onto the camera. But the SDOF should be the same because its not making the lens longer by using an adaptor its just putting that little screen there.

C:
are saying you are concerened with the abity of these adaptors to produce shallow deprth of field on a 2/3" camera which inherently produces a more infinate depth of field -- as you say "its hard to get the background soft?"

Again it shouldn't matter. If you pirated a movie by properly focuising on a movie screen and filmimg it, then the infinite depth of filed of either a 1/3 chip camera or a 2/3 chip camera is irrelevant.

I actually work with a 2/3" cam and it´s pretty difficult to get a soft background. You have to use the whole zoom and open up the iris completely to get that effect.
Click to expand...
That's the same with a 1/3" camera. You have to shoot completly zoomed in and iris at f 2.8 to get the background soft without an adaptor

... which is why I keep saying the chip size won't matter WITH an adaptor - its not focusing on the actors eyes which are ten feet away and trying to achieve SDOF over that ten feet, its focusing on the little screen inside and it actuall NEEDS to be doing so in INFINITE focus -- the camer itself need not produce a single solitary bit of SDOF

SO ...

I have no idea if you can get it on there or not.

If you can, however, will make the shallowest depth of field your heart desires. Seems pretty cut and dry to me, but hopefully someone that knows more about this than me will drop by soon.

If you can somehow get primes to work without the adaptor then great as the image quality will be higher, though not necessrily with more shallower DOF. But if this is possible why arent people doing it left and right and why not do it with XL2's as they have removable lenses?
 
Jack, you are right, I was asking different questions. Essentially two:

1) Is there any CHEAP, that means less than 1K, 35mm adapter attachable at this cam? (I know there is, for example an an adapter from P+S for 2/3" cams but it costs about 20k) - by the way: the Sony XD cam has a 1/2" sensor, not a 2/3" sensor - that´s why I´m so concerned, if it was 2/3 I knew with what I was dealing.

2) Are there any primes for 1/2" cams? In my opinion this question makes sense because there are primes for 2/3" cams, from Canon for example. They are faster than zoom-lenses and therefore the DOF is shallower. But I don´t know if that would be useful on a 1/2" cam like the Sony XD cam.

In both cases I have many doubts that there is a viable solution. But there IS one with the 1/3": cheap and viable 35mm adapters. So: Though the image of the Sony XD cam might be sharper and cleaner, an 1/3"cam with 35mm adapter might provide a more filmic look. In the end, my basic question is:

Is there any possibility to get close to that filmic look of an 1/3" cam that is fixed to a 35mm adapter with a 1/2" cam? (regarding question 1 and 2)
 
We are not even sure what the standard lens is for this camera let alone what 35mm lens attachment will work. Of course if you want to shoot something this month or next you may have to get somone to get you a preproduction model adapter to set yourself up
They are promising 2/3 inch to 1/2 adapters for HD lenses but when they will deliver them is unclear. My feeling is that the adapter will cost the same amount as a 35MM adapter for 2/3 inch. More than we would like but affordable if you need it
I think the picture comparison will be very favorable to the XDCAM with adapter compared to 1/3 inch cameras with adapter based on my experieces with PS Technik set ups on 1/3 inch and 2/3 inch cameras.
A 1/3 inch camera with 35MM adapter will certainly have less DOF than the Standard XDCAM lens setup but I would rather handhold the XDCAM. Given the XD cameras ability to do filmic frame rates and manual lens exposures it should be easy to control DOF better than on the 1/3 inch cameras with standard lenses.
When I had some Philips BTS cameras with 1/2 inch chips the optics where much more like the 2/3 inch cameras than they were like the 1/3 inch cameras.
 
Hey Jack: Sorry for driving you crazy with this thread! The question was quite simple but... english is not my native language. Sometimes this is complicating things. :beer::beer::beer:
 
Joe is basically asking the same thing I asked in a Cinemek thread. We need SOMEONE to develop and market a LOW COST 35mm adapter for 1/2" and 2/3" B4-mount (Sony-mount) cameras. Adding a 2/3" lens adapter to the 1/2" XDCAM HD cameras only allows you to mount 2/3" lenses on the camera--this does NOT give you the shallow depth-of-field effect you're looking for--it only "crops" the image and adds a "focal length multiplier" effect when using 2/3" lenses.
 
What we really need is for someone to develop a DIRECTLY-MOUNTABLE relay lens (for maximum focal plane stability and minimum light loss) and 35mm adapter (or even a medium-format lens adapter) for use with full-sized, 1/2" and 2/3" cameras. Note that this solution would NOT require us to even buy a standard video zoom lens if we didn't want to. So therefore, this market would be much more likely to pay substantially more than the sub-$1,000 adapters now on the market for 1/3" cameras (but not nearly as much as the P+S adapters, which are ridiculous).
 
NBCshooter said:
What we really need is for someone to develop a DIRECTLY-MOUNTABLE relay lens (for maximum focal plane stability and minimum light loss) and 35mm adapter (or even a medium-format lens adapter)
Click to expand...
PHAT idear!!! Besides a VERY shallow DOF I supose the adapter-relatet softening would be less because of the bigger surface of the proyection-plate. And 2/3" or even 1/2" would compensate the lightloss much better.

NBCshooter said:
Note that this solution would NOT require us to even buy a standard video zoom lens if we didn't want to. So therefore, this market would be much more likely to pay substantially more than the sub-$1,000 adapters now on the market for 1/3" cameras (but not nearly as much as the P+S adapters, which are ridiculous).
Click to expand...
$$$! Interesting point. $$$!
 
Right on, Joe! Is anyone listening??? Red Rock, Cinemek, anyone? All you savvy DIY-ers? I would pay several thousand dollars (but NOT $20,000!!!) for a product that met this need. I'm dead serious about this.
 
I'm not sure that one of these adapters wouldn't work on a 1/2" camera the same way they do for the 1/3" ones. Seems to me you just need a proper thread size or adapter ring and it would function just fine. I've seen footage from an M2 mounted on a 1/6" crapola DV cam, and besides the fact that the camera has no latitude whatsoever, it gets the same great DOF results as any other camera pointed at the "ground glass" projection.
 
You must log in or register to reply here.
Back
Top