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Primes for digibeta


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#1 Anastasia Loguinova

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Posted 23 September 2005 - 04:42 AM

Hi all,

I have Sony DVW790 and I heard that some primes (like cooke or zeiss for example) can fit it? Is it true and if so what kind of a lens adaptor I should buy?

Thanks,
Anastasia
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#2 Landon D. Parks

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Posted 23 September 2005 - 06:54 AM

well, it depends on the mount the lense uses and the mounting bracker the camera has. If your Camera is 2/3", chances are it has a "B" mount, and primes like Zeiss Superspeed, Ultraprimes) and lenses of that such are PL mount. Of course a PL mount lense wont fit on a B mount camera unless you buy an adapter such as the Pro35 or the other kinds of adapters that just adapt the lenses... Not sure where to buy them, but they do make them.
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#3 Anastasia Loguinova

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Posted 23 September 2005 - 08:50 AM

well, it depends on the mount the lense uses and the mounting bracker the camera has. If your Camera is 2/3", chances are it has a "B" mount, and primes like Zeiss Superspeed, Ultraprimes) and lenses of that such are PL mount. Of course a PL mount lense wont fit on a B mount camera unless you buy an adapter such as the Pro35 or the other kinds of adapters that just adapt the lenses... Not sure where to buy them, but they do make them.

<{POST_SNAPBACK}>


Thanks for your reply. But I'm not sure about is it "B" mount or something else, because in operating manual it is indicated as "special bayonet type" - what the hell is this? As far as I understand in order to find the adapter I should know exactly what to search. (My cam is 2/3).

Anastasia
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#4 Dimitrios Koukas

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Posted 23 September 2005 - 09:15 AM

Thanks for your reply. But I'm not sure about is it "B" mount or something else, because in operating manual it is indicated as "special bayonet type" - what the hell is this? As far as I understand in order to find the adapter I should know exactly what to search. (My cam is 2/3).

Anastasia

<{POST_SNAPBACK}>


Most video cameras have a B mount wich is the special bayonet type.
Also note that there are some digi-primes allready in the market in case that u want to go with this. www.digiprimes.com

Dimitrios Koukas
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#5 Tim J Durham

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Posted 23 September 2005 - 09:23 AM

Hi all,

I have Sony DVW790 and I heard that some primes (like cooke or zeiss for example) can fit it? Is it true and if so what kind of a lens adaptor I should buy?

Thanks,
Anastasia

<{POST_SNAPBACK}>

Yes, Zeiss Digiprimes will fit.

http://www.digiprimes.com/2005/home/
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#6 Jim Murdoch

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Posted 23 September 2005 - 09:07 PM

Hi all,

I have Sony DVW790 and I heard that some primes (like cooke or zeiss for example) can fit it? Is it true and if so what kind of a lens adaptor I should buy?

Thanks,
Anastasia

<{POST_SNAPBACK}>


What sort of "primes" are you talking about? If you mean lenses designed for movie cameras, there's no practical way of adapting them to work on a 3-CCD video camera without a drastic loss of quallity. That's one reason they've developed single-chip HD cameras like the Genesis and the D-20.

The problem lies with the dichroic beam splitter prism in front of the CCDs which separates the image into its red, green and blue components. Because this is quite large in a 2/3" camera, the lens has to be designed to focus the image a long way behind its rear element (about 50mm with 2/3" camera), to leave room for the beam splitter.

Lenses designed for film cameras, on the other hand, only have to allow room for the shutter mirror so they're generally designed to have a shorter focal plane, and so to get one of those to focus on the CCDs of a video camera, the rear element would want to be sitting somewhere in the middle of the prism block!

There are adaptors that are supposed to allow you to use film-type lenses on video cameras, but none of the ones I've seen works particularly well. Apart from depth of field issues, you'll generally find that the zoom than came standard with your camera will give better images than an expensive film lens with an adaptor!

But if you're talking about primes specifically designed for video cameras, you should have no trouble getting ones that fit the DVW970, since it's a pretty "mainstream" Sony camera. Why not check out Cooke or Zeiss's websites?
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#7 Phil Rhodes

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Posted 24 September 2005 - 06:08 AM

Hi,

There seems to be an assumption inherent to this discussion that video zooms are somehow inferior, and I'm not sure it's true, or at least certainly not enough of an issue for all this farting about.

Phil
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#8 Stephen Williams

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Posted 24 September 2005 - 10:31 AM

Hi,

There seems to be an assumption inherent to this discussion that video zooms are somehow inferior, and I'm not sure it's true, or at least certainly not enough of an issue for all this farting about.

Phil

<{POST_SNAPBACK}>



Phil,

The newer HD zooms I saw at IBC are really very good. What I don't like about older and very low cost zooms is breathing and the coloured edges as you pull focus.
I have rented a DVW 700 which was supplied with a lens designed for tube camras! Not a good combination.

Stephen
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#9 Dimitrios Koukas

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Posted 24 September 2005 - 11:01 AM

Phil,

What I don't like about older and very low cost zooms is breathing and the coloured edges as you pull focus.
Stephen

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Indeed ''breathing'' is an issue, and very annoying.I can recall times when the director was saying : Did you zoomed? why?
Dimitrios Koukas
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#10 Stephen Williams

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Posted 24 September 2005 - 11:24 AM

Indeed ''breathing'' is an issue, and very annoying.I can recall times when the director was saying : Did you zoomed? why?
Dimitrios Koukas

<{POST_SNAPBACK}>



Hi,

Even worse when slowly zooming and the direction changes due to the focus!

Stephen
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#11 Phil Rhodes

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Posted 24 September 2005 - 01:10 PM

Hi,

I think you'll find that's a problem only with really, really cheap stuff.

And anyway, you aren't going to be zooming all that much on a drama, are you?

Phil
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#12 Dimitrios Koukas

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Posted 24 September 2005 - 01:59 PM

Hi,

I think you'll find that's a problem only with really, really cheap stuff.

And anyway, you aren't going to be zooming all that much on a drama, are you?

Phil

<{POST_SNAPBACK}>


Phil,
we are talkin about breathing of the lens while focusing and not zooming.
After all, u can make a drama with zoom-in and out in every shot if that's the decision.Who knows...
Not that I do not dislike it.
Dimitrios Koukas
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#13 Anastasia Loguinova

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Posted 26 September 2005 - 03:39 AM

What sort of "primes" are you talking about? If you mean lenses designed for movie cameras, there's no practical way of adapting them to work on a 3-CCD video camera without a drastic loss of quallity. That's one reason they've  developed single-chip HD cameras like the Genesis and the D-20.

The problem lies with  the dichroic beam splitter prism in front of the CCDs which  separates the image into its red, green and blue components. Because this is quite large in a 2/3" camera, the lens has to be designed to focus the image a long way behind its rear element (about 50mm with 2/3" camera), to leave room for the beam splitter.

Lenses designed for film cameras, on the other hand, only have to allow room for the shutter mirror so they're generally designed to have a  shorter focal plane, and so to get one of those to focus on the CCDs of a video camera, the rear element would want to be sitting somewhere in the middle of the prism block!

There are adaptors that are supposed to allow you to use film-type lenses on video cameras, but none of the ones I've seen works particularly well. Apart from depth of field issues, you'll generally find that the zoom than came standard with your camera will give better images than an expensive film lens with an adaptor!

But if you're talking about primes specifically designed for video cameras, you should have no trouble getting ones that fit the DVW970, since it's a pretty "mainstream" Sony camera. Why not check out  Cooke or Zeiss's websites?

<{POST_SNAPBACK}>


Jim, thanks for explanation, because I actually didn't know about that. I've just heard that it was possible... unfortunately it wasn't.
As far as I understand the only way (to improve the image quality in comparison to my broadcast zoom) is to buy a higly expensive DigiPrime?
By the way may be you know is there any great difference in the depth of field between DigiPrimes and standard zooms (canon for ex.)?

Thanks,
Anastasia
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#14 Stephen Williams

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Posted 26 September 2005 - 04:01 AM

By the way may be you know is there any great difference in the depth of field between DigiPrimes and standard zooms (canon for ex.)?

Thanks,
Anastasia

<{POST_SNAPBACK}>



Hi,

At the same F stop, and object size on the CCD the theoretical DOF will remain the same regardless of focal length. With Digiprimes as they are sharper they may seem to have less DOF than a softer lens. You might well be able to turn OFF the detail and have sharp images.

The Digi Primes are unfortunately very expensive.

Stephen
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#15 Anastasia Loguinova

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Posted 26 September 2005 - 06:12 AM

Hi,

At the same  F stop, and object size on the CCD  the theoretical DOF will remain the same regardless of focal length. With Digiprimes as they are sharper they may seem to have less DOF than a softer lens. You might well be able to turn OFF the detail and have sharp images.

The Digi Primes are unfortunately very expensive.

Stephen

<{POST_SNAPBACK}>


The thing is that I prefer soft image with a samall DOF, but as you know its quite difficult to reach it on video. May be one can advise me some hints how to make small DOF on my DVW790.

Anastasia
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#16 Stephen Williams

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Posted 26 September 2005 - 06:29 AM

The thing is that I prefer soft image with a samall DOF, but as you know its quite difficult to reach it on video. May be one can advise me some hints how to make small DOF on my DVW790.

Anastasia

<{POST_SNAPBACK}>



Hi,

Try to shoot wide open. The zoom will probably not keep the same stop end to end, so its easier said than done!
Reduce detail settings, try -10 to -30 range.

Cheers,

Stephen
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#17 Jim Murdoch

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Posted 26 September 2005 - 07:15 AM

Hi,

There seems to be an assumption inherent to this discussion that video zooms are somehow inferior, and I'm not sure it's true, or at least certainly not enough of an issue for all this farting about.

Phil

<{POST_SNAPBACK}>

I think it's fair to say that it's easier and/or cheaper to make a high quality prime lens than it is to make a zoom lens of equal quality.

However I tend to agree that this video primes vs zooms thing is a bit of a wank.
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#18 Jim Murdoch

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Posted 26 September 2005 - 07:31 AM

The thing is that I prefer soft image with a samall DOF, but as you know its quite difficult to reach it on video. May be one can advise me some hints how to make small DOF on my DVW790.

Anastasia

<{POST_SNAPBACK}>

In other words, you want a depth-of-field characteristic like a 35mm film camera, but using a 2/3" CCD camera! You and everybody else! :)

Leaving the iris out of it, the depth of field characteristic is mainly determined by the amount the dimensions of your subject have to be shrunk down to fit it on the imaging device.

The image area of 35mm film approximates the size of the retina of the human eye, which is one reason people find 35mm film the most "natural" capture medium.

Unless you can get actors that are no more than 1 Metre tall (in other words, half the normal size:-) the short answer is that you can't get the same results using a 2/3" sensor! Well, you can; you can shoot it on 35mm film and then "photograph" that with your video camera. Which is more or less what a Telecine chain does.

Why do you think everybody is so keen to produce video cameras with 35mm-sized sensors?
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#19 Jim Murdoch

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Posted 26 September 2005 - 07:43 AM

Phil,

I have rented a DVW 700 which was supplied with a lens designed for tube camras! Not a good combination.

Stephen

<{POST_SNAPBACK}>

Who the hell rented you that?!

Lenses designed for tube cameras were generally designed with less emphasis on chromatic abberation, because that can be corrected by re-centering the pickup tubes.

When CCDs came along, the lens manufacturers had to improve this aspect, because there was no equivalent adjustment for a CCD. So using a tube-type lens on a CCD camera was bound to end in tears!

In general, tube cameras and their lenses were supposed to be supplied as a pair, the camera being adjusted to match the characteristics of that particular lens, and the two not separated after that. But this hardly ever seemed to happen in rental situations.
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#20 Alex Haspel

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Posted 03 October 2005 - 03:44 AM

The thing is that I prefer soft image with a samall DOF, but as you know its quite difficult to reach it on video. May be one can advise me some hints how to make small DOF on my DVW790.

Anastasia


http://www.35digital...on_entries&id=5

Posted Image

i'm not sure if the pro35 adapter has already been mentioned.
it projects a 35mm sized image on a rotating groundglass(to prevent the groundglass structure from beeing visible) from where it is then picked up by the videocamera.
you can use real film lenses and it gives you the depth of field of 35mm.

but it costs you about two stops of light...

Edited by haspel, 03 October 2005 - 03:46 AM.

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