35mm lens on Sony DXC990P camera ?? at DVinfo.net

Stephen Deboo · February 13th, 2007, 02:53 AM

Would it be possible to add a "custom made" C Mount to FD mount" set at the correct focal length, to say one of those lovely Sony DXC990P camera modules then mounting the whole lot upside down on a camera plate. I understand (I think, I am very new to all of this) that the area of the CCD is only 1/2 inch but there would be no GG eating into the imagery and we would be getting clean images falling on the CCD with DOF, again I think.
Would this work ??
Steve

Phil Bloom · February 13th, 2007, 03:03 AM

possibly...but I couldnt see any advantage in doing so...what are you wanting from the combo?

Stephen Deboo · February 13th, 2007, 07:50 AM

Phil,
I was just wondering why cameras are not made to accept a film lens and offer that DOF. Now I know the 35mm lenses require a large imager to get the full potential but I own a Nikon D200 which has a smaller than 35mm area but you can get DX lenses which suit this type of imager. I can get all DOF I want from my lenses
So why cant all the big guns make an affordable camera that could take these DX style lenses and offer a great range as well as a good DOF.
Thats why I ask the question, If I could get a cheap enough C-Mount high res camera and slap a 35mm film lens or a DX lens to cater for the smaller CCD or CMOS device. Would that give me a good enough quality DV output bearing in mind no loss from a GG device and also no light loss.

Phil Bloom · February 13th, 2007, 08:02 AM

i assume you mean you want shallow depth of field.

Surely by buying the SGPro you know the answer to that question otherwise why would you have ordered it?

It's not really to do with the glass, although that is important, it's to do with the imaging sensor. On film its 35mm, on the d200 it's not quite and on most hdv/ dv cameras you wont get larger than just a 1/3rd of an inch and on your v1 it's just a 1/4 of an inch!

Think of the sensor like an aperature. To get shallow DOF you need to have the aperature way open, to get wide dof you keep the aperature closed down, so think of the 35mm frame as like the large aperature and the 1/3rd inch chip as like a small aperture, hence it's bloody hard to achieve it on a 1/3rd inch chip camera without the adaptors...especially the V1, it is next to impossible.

There is some info on how they work across these forums and some on my shootout on my website. You need to read up on the how's and why's. Just go to wikipedia as there is loads of info there, look up mini35 or something similar.

Stephen Deboo · February 13th, 2007, 08:13 AM

Phil,
I do understand you, but the one thing I find hard to fathom is this.
If you had a 1/2 inch camera and you placed a 35mm lens the correct distand in front of the imager I understand that the CCD would be flooded with the whole image produced by the lens. BUT would the part that does fall on the CCD ( a fraction of the frame) would this not be in focus and at the same DOF set by the lens, would you not just see say for arguments sake one persons head and his/her blurred background instead of the two people either side of him/her. Then you would see this on the monitor and adjust accordingly.

Stephen Deboo · February 13th, 2007, 08:16 AM

Phil to answer your part re SGPro, yes I have ordered one and am looking forward to getting it. But the whole rig does not set itself good for close proximity shooting and will not really be that portable. I was just thinking the smaller camera body with a lens attached directly too it would help in those circumstances.
Steve

Ben Winter · February 13th, 2007, 12:22 PM

Quote:

Originally Posted by Stephen Deboo

Phil,
I do understand you, but the one thing I find hard to fathom is this.
If you had a 1/2 inch camera and you placed a 35mm lens the correct distand in front of the imager I understand that the CCD would be flooded with the whole image produced by the lens. BUT would the part that does fall on the CCD ( a fraction of the frame) would this not be in focus and at the same DOF set by the lens, would you not just see say for arguments sake one persons head and his/her blurred background instead of the two people either side of him/her. Then you would see this on the monitor and adjust accordingly.

Yes but because of the cropped image, having a 50mm lens on there will be like having a 300mm lens. so the image would be the same as if you zoomed in a whole lot on the stock lens--the image is there, but.extremely cropped and theefore flat. So okay, you say, I'll just put on a wider angle lens...But bah, now the dof is gone.

Focal length, depth of field end focal plane are all interconnected. Sorry, no cheating this system :)

Bob Hart · February 13th, 2007, 12:42 PM

Depth of field with 50mm set at f2.8 on a 1/3" CCD video camera is the same as 50mm set at f2.8 on a 35mm still-camera.

But ---- the field of view on the 35mm still-camera is wider.

Therefore, if you choose a 35mm still-camera lens which has the same field of view as the videocamera lens, the depth of field on the still camera will be shallower.

Phil Bloom · February 13th, 2007, 05:42 PM

the sgpro on the v1 will be very portable. dont worry. you will be very happy with the results!

Stephen Deboo · February 14th, 2007, 03:03 AM

Yeh Ha, Great news Phil very glad to hear it.

Shame I have to wait until the end of March to get it.

I am sorry about my silly post I actually researched frame sizes last night and WOW what a difference there is between the 1/4 1/3 & 1/2 sensors compared with the full 35mm frame.
Although I did play around with my dx lenses last night and a piece of white card and the clear image from my 12-24 sigma did fit pefectly over one of the ccd areas but I know there is no real DOF with that lens but at least my theory about the DX lens was kind of right.

February 13th, 2007, 02:53 AM	#1
Stephen Deboo Regular Crew Join Date: Feb 2007 Location: Portugal Posts: 27	35mm lens on Sony DXC990P camera ?? Would it be possible to add a "custom made" C Mount to FD mount" set at the correct focal length, to say one of those lovely Sony DXC990P camera modules then mounting the whole lot upside down on a camera plate. I understand (I think, I am very new to all of this) that the area of the CCD is only 1/2 inch but there would be no GG eating into the imagery and we would be getting clean images falling on the CCD with DOF, again I think. Would this work ?? Steve __________________ Canon 5D Mark II, 24-105mm F4L, 50mm F1.4, 16-35mm F2.8L Flash 580EXII Manfrotto 701HDV Tripod. Apple Mac Pro Dual 3Ghz + 4Gig Apple Cinema display 23"

February 13th, 2007, 03:03 AM	#2
Phil Bloom Trustee Join Date: Aug 2006 Location: London UK Posts: 1,939	possibly...but I couldnt see any advantage in doing so...what are you wanting from the combo? __________________ Philip Bloom Cinematographer, Director, Filmmaker www.philipbloom.net

February 13th, 2007, 07:50 AM	#3
Stephen Deboo Regular Crew Join Date: Feb 2007 Location: Portugal Posts: 27	Phil, I was just wondering why cameras are not made to accept a film lens and offer that DOF. Now I know the 35mm lenses require a large imager to get the full potential but I own a Nikon D200 which has a smaller than 35mm area but you can get DX lenses which suit this type of imager. I can get all DOF I want from my lenses So why cant all the big guns make an affordable camera that could take these DX style lenses and offer a great range as well as a good DOF. Thats why I ask the question, If I could get a cheap enough C-Mount high res camera and slap a 35mm film lens or a DX lens to cater for the smaller CCD or CMOS device. Would that give me a good enough quality DV output bearing in mind no loss from a GG device and also no light loss. __________________ Canon 5D Mark II, 24-105mm F4L, 50mm F1.4, 16-35mm F2.8L Flash 580EXII Manfrotto 701HDV Tripod. Apple Mac Pro Dual 3Ghz + 4Gig Apple Cinema display 23"

February 13th, 2007, 08:02 AM	#4
Phil Bloom Trustee Join Date: Aug 2006 Location: London UK Posts: 1,939	i assume you mean you want shallow depth of field. Surely by buying the SGPro you know the answer to that question otherwise why would you have ordered it? It's not really to do with the glass, although that is important, it's to do with the imaging sensor. On film its 35mm, on the d200 it's not quite and on most hdv/ dv cameras you wont get larger than just a 1/3rd of an inch and on your v1 it's just a 1/4 of an inch! Think of the sensor like an aperature. To get shallow DOF you need to have the aperature way open, to get wide dof you keep the aperature closed down, so think of the 35mm frame as like the large aperature and the 1/3rd inch chip as like a small aperture, hence it's bloody hard to achieve it on a 1/3rd inch chip camera without the adaptors...especially the V1, it is next to impossible. There is some info on how they work across these forums and some on my shootout on my website. You need to read up on the how's and why's. Just go to wikipedia as there is loads of info there, look up mini35 or something similar. __________________ Philip Bloom Cinematographer, Director, Filmmaker www.philipbloom.net

February 13th, 2007, 08:13 AM	#5
Stephen Deboo Regular Crew Join Date: Feb 2007 Location: Portugal Posts: 27	Phil, I do understand you, but the one thing I find hard to fathom is this. If you had a 1/2 inch camera and you placed a 35mm lens the correct distand in front of the imager I understand that the CCD would be flooded with the whole image produced by the lens. BUT would the part that does fall on the CCD ( a fraction of the frame) would this not be in focus and at the same DOF set by the lens, would you not just see say for arguments sake one persons head and his/her blurred background instead of the two people either side of him/her. Then you would see this on the monitor and adjust accordingly. __________________ Canon 5D Mark II, 24-105mm F4L, 50mm F1.4, 16-35mm F2.8L Flash 580EXII Manfrotto 701HDV Tripod. Apple Mac Pro Dual 3Ghz + 4Gig Apple Cinema display 23"

February 13th, 2007, 08:16 AM	#6
Stephen Deboo Regular Crew Join Date: Feb 2007 Location: Portugal Posts: 27	Phil to answer your part re SGPro, yes I have ordered one and am looking forward to getting it. But the whole rig does not set itself good for close proximity shooting and will not really be that portable. I was just thinking the smaller camera body with a lens attached directly too it would help in those circumstances. Steve __________________ Canon 5D Mark II, 24-105mm F4L, 50mm F1.4, 16-35mm F2.8L Flash 580EXII Manfrotto 701HDV Tripod. Apple Mac Pro Dual 3Ghz + 4Gig Apple Cinema display 23"

February 13th, 2007, 12:42 PM	#8
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Depth of field with 50mm set at f2.8 on a 1/3" CCD video camera is the same as 50mm set at f2.8 on a 35mm still-camera. But ---- the field of view on the 35mm still-camera is wider. Therefore, if you choose a 35mm still-camera lens which has the same field of view as the videocamera lens, the depth of field on the still camera will be shallower.

February 13th, 2007, 05:42 PM	#9
Phil Bloom Trustee Join Date: Aug 2006 Location: London UK Posts: 1,939	the sgpro on the v1 will be very portable. dont worry. you will be very happy with the results! __________________ Philip Bloom Cinematographer, Director, Filmmaker www.philipbloom.net

February 14th, 2007, 03:03 AM	#10
Stephen Deboo Regular Crew Join Date: Feb 2007 Location: Portugal Posts: 27	Yeh Ha, Great news Phil very glad to hear it. Shame I have to wait until the end of March to get it. I am sorry about my silly post I actually researched frame sizes last night and WOW what a difference there is between the 1/4 1/3 & 1/2 sensors compared with the full 35mm frame. Although I did play around with my dx lenses last night and a piece of white card and the clear image from my 12-24 sigma did fit pefectly over one of the ccd areas but I know there is no real DOF with that lens but at least my theory about the DX lens was kind of right. __________________ Canon 5D Mark II, 24-105mm F4L, 50mm F1.4, 16-35mm F2.8L Flash 580EXII Manfrotto 701HDV Tripod. Apple Mac Pro Dual 3Ghz + 4Gig Apple Cinema display 23"