Surprising Lens Options!!

Dan Vance · July 13th, 2005, 05:19 PM

There is a significant problem with using C-mount 16mm and 35mm lenses on 3-CCD cameras. Lenses for 3-CCD cameras are designed with long exit pupil distances. If the exit pupil distance of the lens is too short, it will result in chromatic aberration because of the camera's prism block. This shows up as loss of color registration toward the edges of the frame.
Since the exit pupil distance is not such an issue with film cameras (or single-CCD cameras), it can be hard to find the spec for the exit pupil distance for a particular lens. A good minimum value for the exit pupil distance is 40mm (for use on 1/3" cameras). (Note that the exit pupil distance is a totally different specification than the back focus distance.)
Depending on the particular lens, the chromatic aberration may not be that noticable in SD, but would probably be an issue in an HD image.

Barry Green · July 13th, 2005, 06:33 PM

That 5.9mm lens you linked to would actually be a bit more telephoto than the JVC's stock lens (which starts at 5.5mm).

Quote:

since the CCD's are about half the size of the original intended imaging surface...

If it was half, that'd be almost okay. But a 1/3" 16x9 chip is about 1/6 the size of a frame of Super16 film. S16 is about 12.4 x 7.5mm, whereas the 1/3" CCD is more like 5.25 x 2.95. S16 has about 93 square millimeters of surface area; the 1/3" CCD has more like 15.5 square millimeters.

So to deliver a certain standard of resolution to such a smaller frame size, the lens would need to be dramatically sharper than it would need to be to deliver that same standard of resolution to the S16 frame.

Additionally, most c-mount lenses weren't nearly of the same optical quality as modern PL-mount motion picture lenses. Many c-mount lenses were more along the lines of "coke bottle" lenses. The Switars are renowned for their sharpness; I'd like to see how one performs on the HD100. For SD it might be fine; I just don't know how it'd hold up to HD standards.

Kevin Dooley · July 13th, 2005, 06:36 PM

Well that explains it. I figured that since 2/3" is roughly equal to 16mm that 1/3" is therefore half... shows what I know...

Yusuf Thakur · October 5th, 2005, 05:10 AM

We got our lens adapter nikon to JVC 100 1/3 bayonet mount a week back, after extensive test I can confirm that its works
fine with Long Lenses, I have mounted a 200-400 Tamron nikon mount lens and shot footage, and its very good. The reason to order this was to film Wildlife. We will try other lenses but the reason to order was for long reach. The adapter was made by Zoerk in Germany. Do a google and you will find the site. A similar adapter is also to be made by Optex they have a website and Photos. When I called them I was told that it will take two three months before its is available, though they announced it at IBC.

Chris Hurd · October 5th, 2005, 07:44 AM

Here's the link to Zoerk, although I could not find this adapter:

http://www.zoerk.com/

Here is the Optex page Yusuf refers to:

http://www.prohd.co.uk/page8/page8.html

Guy Barwood · October 6th, 2005, 03:02 AM

whats the crop factor? I worked it out to be about 7x, or is it more?

Tim Dashwood · October 6th, 2005, 07:07 AM

Quote:

Originally Posted by Guy Barwood

whats the crop factor? I worked it out to be about 7x, or is it more?

Just over 7x if you are comparing 1/3" FOV over focal length to 35mm SLR photography. It is around 4.4X if you are comparing FOV of 35mm motion picture photography.

Yusuf Thakur · October 7th, 2005, 05:12 AM

Zoerk does not advertise this lens adapter, this was the very first one he made for us, Advise if you need one call Zoerk on the phone, he rarely answers to emails. I spoke to him the day I got my camera, and he agreed to make one, but only to mount nikon lenses which was fine. I can post some pictures but you can check link above which is what my camera looks like. The image is not exactly as 35mm, we mounted
are 17mm nikon lens and I would say it the image from the camera was about 30-32mm. The adapter is just a mechanical one, no optics or glass between the nikon lens and the ccd.

Guy Barwood · October 7th, 2005, 05:29 AM

how much did he charge for it?

Yusuf Thakur · October 7th, 2005, 05:31 AM

Euro 280/- plus shipping

Wendy Daniel · October 7th, 2005, 09:55 AM

I also have the fujinon 20xs lens and we were going to buy two more and get converters for them all, just to have all the same lens and 4 more times the zoom power. Two questions: first, will that lens work for HD or should I wait for a true 20Xs HD lens? I did scim through the posts, but I am wondering if there is any new advancements since the camera is now out.

Second, if I kept two of the 16X lens that came with the camera and only used the 20xs lens on one of the cameras, what would be the difference in picture quality? (besides the extra zooming)

Thanks,
Wendy

John Jay · October 7th, 2005, 06:23 PM

Late into this thread but...

anyone remember Canons pro Hi-8 offerings from the early 90s?. In the UK they were known as EX1 and EX2 Hi, in the US maybe called L1 and L2.

Well they were 1/2" CCD cameras and they had an EF converter in the accessory list, which meant they could use Canon SLR primes and zooms.

Now my thinking is; if that old EF converter can be tooled for a JVC mount and if the dimensions are such that the FFD can be accomodated then it should be possible to access all those Canon SLR family lenses or even those rather nice Sigma APO LD that are out there.

Wouldnt that be nice?

John Mitchell · October 8th, 2005, 08:15 AM

Quote:

Originally Posted by Tim Dashwood

Just over 7x if you are comparing 1/3" FOV over focal length to 35mm SLR photography. It is around 4.4X if you are comparing FOV of 35mm motion picture photography.

And it get more complicated if comparing to modern DSLR's which have a built in cropping factor of 1.4 x over traditional 35 mm, therefore about 5x compared to a DSLR like the D70, and remember some lenses are only designed for this FOV.

I'd be interested to hear if the results were good resolution wise, because geometry type problems should almost disappear. Not sure about CA.

Yusuf Thakur · October 8th, 2005, 10:16 AM

Can one post pictures on this forum, I can post some comparitive grabs. We shot the same scene with exactly the same lighting and setup just changed the lens, from standard to nikon with the adapter. The results I guess would be helpfull to those looking at doing this. (Mounting Nikon Lenses)

Michael Maier · October 19th, 2005, 01:32 PM

Yusuf , It would be great to see them. If you can't post, could you email them to me? Thanks.

July 13th, 2005, 06:36 PM	#33
Kevin Dooley Major Player Join Date: Dec 2003 Location: Fort Worth, TX Posts: 414	Well that explains it. I figured that since 2/3" is roughly equal to 16mm that 1/3" is therefore half... shows what I know... __________________ Kevin Dooley Media Director, Pantego Bible Church

October 5th, 2005, 05:10 AM	#34
Yusuf Thakur Regular Crew Join Date: Oct 2005 Location: Dubai, UAE Posts: 68	A Shock for all, Mount Nikon lenses to JVC100 We got our lens adapter nikon to JVC 100 1/3 bayonet mount a week back, after extensive test I can confirm that its works fine with Long Lenses, I have mounted a 200-400 Tamron nikon mount lens and shot footage, and its very good. The reason to order this was to film Wildlife. We will try other lenses but the reason to order was for long reach. The adapter was made by Zoerk in Germany. Do a google and you will find the site. A similar adapter is also to be made by Optex they have a website and Photos. When I called them I was told that it will take two three months before its is available, though they announced it at IBC.

October 5th, 2005, 07:44 AM	#35
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Here's the link to Zoerk, although I could not find this adapter: http://www.zoerk.com/ Here is the Optex page Yusuf refers to: http://www.prohd.co.uk/page8/page8.html __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

October 7th, 2005, 05:12 AM	#38
Yusuf Thakur Regular Crew Join Date: Oct 2005 Location: Dubai, UAE Posts: 68	Nikon Lens Mount Zoerk does not advertise this lens adapter, this was the very first one he made for us, Advise if you need one call Zoerk on the phone, he rarely answers to emails. I spoke to him the day I got my camera, and he agreed to make one, but only to mount nikon lenses which was fine. I can post some pictures but you can check link above which is what my camera looks like. The image is not exactly as 35mm, we mounted are 17mm nikon lens and I would say it the image from the camera was about 30-32mm. The adapter is just a mechanical one, no optics or glass between the nikon lens and the ccd.

October 7th, 2005, 05:31 AM	#40
Yusuf Thakur Regular Crew Join Date: Oct 2005 Location: Dubai, UAE Posts: 68	Euro 280/- plus shipping Euro 280/- plus shipping

July 13th, 2005, 05:19 PM	#31
Dan Vance Built the VanceCam Join Date: Apr 2004 Location: Prescott Valley, AZ Posts: 109	There is a significant problem with using C-mount 16mm and 35mm lenses on 3-CCD cameras. Lenses for 3-CCD cameras are designed with long exit pupil distances. If the exit pupil distance of the lens is too short, it will result in chromatic aberration because of the camera's prism block. This shows up as loss of color registration toward the edges of the frame. Since the exit pupil distance is not such an issue with film cameras (or single-CCD cameras), it can be hard to find the spec for the exit pupil distance for a particular lens. A good minimum value for the exit pupil distance is 40mm (for use on 1/3" cameras). (Note that the exit pupil distance is a totally different specification than the back focus distance.) Depending on the particular lens, the chromatic aberration may not be that noticable in SD, but would probably be an issue in an HD image.

October 6th, 2005, 03:02 AM	#36
Guy Barwood Major Player Join Date: Mar 2005 Posts: 423	whats the crop factor? I worked it out to be about 7x, or is it more?

October 7th, 2005, 05:29 AM	#39
Guy Barwood Major Player Join Date: Mar 2005 Posts: 423	how much did he charge for it?

October 7th, 2005, 09:55 AM	#41
Wendy Daniel New Boot Join Date: Sep 2005 Posts: 5	fujinon 20Xs lens I also have the fujinon 20xs lens and we were going to buy two more and get converters for them all, just to have all the same lens and 4 more times the zoom power. Two questions: first, will that lens work for HD or should I wait for a true 20Xs HD lens? I did scim through the posts, but I am wondering if there is any new advancements since the camera is now out. Second, if I kept two of the 16X lens that came with the camera and only used the 20xs lens on one of the cameras, what would be the difference in picture quality? (besides the extra zooming) Thanks, Wendy

October 7th, 2005, 06:23 PM	#42
John Jay Major Player Join Date: Sep 2002 Location: US & THEM Posts: 827	Late into this thread but... anyone remember Canons pro Hi-8 offerings from the early 90s?. In the UK they were known as EX1 and EX2 Hi, in the US maybe called L1 and L2. Well they were 1/2" CCD cameras and they had an EF converter in the accessory list, which meant they could use Canon SLR primes and zooms. Now my thinking is; if that old EF converter can be tooled for a JVC mount and if the dimensions are such that the FFD can be accomodated then it should be possible to access all those Canon SLR family lenses or even those rather nice Sigma APO LD that are out there. Wouldnt that be nice? __________________ John Jay Beware *PLUGGER-BYTES*

October 8th, 2005, 10:16 AM	#44
Yusuf Thakur Regular Crew Join Date: Oct 2005 Location: Dubai, UAE Posts: 68	Nikon Lens Can one post pictures on this forum, I can post some comparitive grabs. We shot the same scene with exactly the same lighting and setup just changed the lens, from standard to nikon with the adapter. The results I guess would be helpfull to those looking at doing this. (Mounting Nikon Lenses)

October 19th, 2005, 01:32 PM	#45
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	Yusuf , It would be great to see them. If you can't post, could you email them to me? Thanks.