The debate about HD lenses. at DVinfo.net

Stuart Nimmo · February 3rd, 2009, 06:17 PM

I think it's generally agreed that the Fujinon stock lens isn't a great piece of glass; stock lenses seldom are and at the price what can one expect? Other available 1/3 lenses have a very much better reputation of course. However, it's inevitable that anyone owning an expensive broadcast 2/3 SD lens will want to know how it would work on their GY-HD series camera. One technical answer is this:
(The link appears to have been hijacked, but if you close the "tape ad" you do come to:)

HDTV lens design

My immediate reaction to this article is OK, so HD glass is fine tuned specifically for HD camera use, SD glass isn't. Why then are we all so pleased with what Nikon/ Zeiss, Schneider or Cooke / Arri mount lenses will do for us? Many of them were designed and made long before SD video lenses were ever thought of. They were never designed or made for video work let alone 1/3-chip cameras, and yet the results seem to be what we like.

Is the technical fuss about using HDTV glass important, or is it basically spurious? Maybe it's more about what will work and what people like? On that basis (and given the 1.34ish X "magnification" factor), is there another reason why full broadcast quality 2/3 SD video lenses are beyond hope on a 1/3 mount camera?

Brian Standing · February 4th, 2009, 10:11 AM

I would think that SD vs. HD is a more important consideration when you are comparing lenses designed for the same imaging format.

A 1/3" chip will crop out the very center of a 2/3" lens, resulting in the "magnification factor" or "crop factor" you described. The center of any optical system is usually the sharpest, with aberrations often appearing towards the edges of the image. It's very difficult to manufacture a piece of glass with equal sharpness edge to edge, and you often pay a very high premium for such glass.

By throwing away the image generated by the edges of the lens, I would think you could get away with a lower quality 2/3" lens on a 1/3" camera than you could if you were using a 2/3" camera.

I also suspect, but cannot confirm, that some of the SD vs. HD distinction is marketing hype (although I would be willing to believe that HD lenses may be specifically designed to avoid vignetting with a 16x9 sensor.)

Nikon and Zeiss still photography lenses may not have been designed for video, but they were certainly designed for a format that (compared to video) is an extremely high-resolution, high-contrast format: 35mm film. Add to that an even more extreme crop-factor, and these optics are more than adequate to resolve images at HD video resolution. If you are willing to live with their limitations (focal lengths that produce super-telephoto images on 1/3" chips, manual focus, manual iris, etc.) they can produce spectacular images.

Stuart Nimmo · February 4th, 2009, 12:19 PM

Umm, the 2/3 SD lens I'm thinking of is on a 16x9 Digital Betacam, it was made for native 16x9. I thought the same as you Brian about cropping using the sweetest glass, and do wonder about marketing hype. I guess the simple answer is to hire an adapter and check it out, I just felt that others here must have put this apparent option to the test?

I'm lucky enough to have my father's Hasselblad / Zeiss lenses and now have a Hasselblad to PL adapter, I bet those'll be just the thing for really long compression shots, (but think of all that wasted glass).

Robert Rogoz · February 4th, 2009, 12:39 PM

The whole issue SD vs HD lens is marketing hype. It's not glass that is an issue here, but the compression that the signal is going through. Lens manufacturing process has been going on for last 100 of years and is pretty much down to science. Digital technology is relatively new.
It would be like comparing 35mm SLR to 4MP SLR shooting small jpegs.
Personally I think Red is on a right track on this one.

Alex Humphrey · February 4th, 2009, 05:23 PM

With Nikon lenses and filter from various brands, GENERALLY the only real difference of the lens (other than the cheapie nikon DX lenses that really are not that bad, just no exterior aperture ring) is a slightly different coating that is supposedly better for digital imaging instead of film. Probably true, but otherwise not that important. A good skylight filter would do just as well, and you should be using one anyway.

biggest problem with using a good SD lens probably wouldn't go wide enough for general use, that and a good 2/3 lens to buy would be as much as a good 1/3 lens. So if you have a 2/3 laying around it might be quite usable, but not a great idea to go out and buy one for $4,000 to $8,000. I didn't see many 2/3 on Ebay last time that was thinking about finding a cheap 2/3 lens to do just that. There might be more by now though.

Mat Thompson · February 10th, 2009, 09:19 AM

Hi guys.

I've used a current nearly new Canon 2/3rds lens albeit a low end model (About $2.2k us) on the JVC GY HD 110 and all I can say is this was wasn't great. It had some bad abberation, especially towards the long end and wasn't sharp. The standard fuji was definately a stronger performer as far a IQ was concerned. I went through a lot of image testing before I came to my final judgement and sold on the lens. I sure higher end lenses would perform much better but I was surprised this wasn't better considering i was using the 'sweet' area of this lens.

Cheers
Mat

Stuart Nimmo · February 10th, 2009, 05:48 PM

Umm, interesting Mat. It could be a problem, I'll give it a go and let you know.

February 3rd, 2009, 06:17 PM	#1
Stuart Nimmo Regular Crew Join Date: Aug 2006 Location: Paris France Posts: 89	The debate about HD lenses. I think it's generally agreed that the Fujinon stock lens isn't a great piece of glass; stock lenses seldom are and at the price what can one expect? Other available 1/3 lenses have a very much better reputation of course. However, it's inevitable that anyone owning an expensive broadcast 2/3 SD lens will want to know how it would work on their GY-HD series camera. One technical answer is this: (The link appears to have been hijacked, but if you close the "tape ad" you do come to:) HDTV lens design My immediate reaction to this article is OK, so HD glass is fine tuned specifically for HD camera use, SD glass isn't. Why then are we all so pleased with what Nikon/ Zeiss, Schneider or Cooke / Arri mount lenses will do for us? Many of them were designed and made long before SD video lenses were ever thought of. They were never designed or made for video work let alone 1/3-chip cameras, and yet the results seem to be what we like. Is the technical fuss about using HDTV glass important, or is it basically spurious? Maybe it's more about what will work and what people like? On that basis (and given the 1.34ish X "magnification" factor), is there another reason why full broadcast quality 2/3 SD video lenses are beyond hope on a 1/3 mount camera?

February 4th, 2009, 10:11 AM	#2
Brian Standing Major Player Join Date: Dec 2003 Location: Madison, Wisconsin Posts: 621	I would think that SD vs. HD is a more important consideration when you are comparing lenses designed for the same imaging format. A 1/3" chip will crop out the very center of a 2/3" lens, resulting in the "magnification factor" or "crop factor" you described. The center of any optical system is usually the sharpest, with aberrations often appearing towards the edges of the image. It's very difficult to manufacture a piece of glass with equal sharpness edge to edge, and you often pay a very high premium for such glass. By throwing away the image generated by the edges of the lens, I would think you could get away with a lower quality 2/3" lens on a 1/3" camera than you could if you were using a 2/3" camera. I also suspect, but cannot confirm, that some of the SD vs. HD distinction is marketing hype (although I would be willing to believe that HD lenses may be specifically designed to avoid vignetting with a 16x9 sensor.) Nikon and Zeiss still photography lenses may not have been designed for video, but they were certainly designed for a format that (compared to video) is an extremely high-resolution, high-contrast format: 35mm film. Add to that an even more extreme crop-factor, and these optics are more than adequate to resolve images at HD video resolution. If you are willing to live with their limitations (focal lengths that produce super-telephoto images on 1/3" chips, manual focus, manual iris, etc.) they can produce spectacular images. __________________ http://www.prolefeedstudios.com/blog/ Documentary for the masses!

February 4th, 2009, 05:23 PM	#5
Alex Humphrey Major Player Join Date: Mar 2007 Location: california North and South Posts: 642	HD vs SD lenses might be like Film vs Digital lenses With Nikon lenses and filter from various brands, GENERALLY the only real difference of the lens (other than the cheapie nikon DX lenses that really are not that bad, just no exterior aperture ring) is a slightly different coating that is supposedly better for digital imaging instead of film. Probably true, but otherwise not that important. A good skylight filter would do just as well, and you should be using one anyway. biggest problem with using a good SD lens probably wouldn't go wide enough for general use, that and a good 2/3 lens to buy would be as much as a good 1/3 lens. So if you have a 2/3 laying around it might be quite usable, but not a great idea to go out and buy one for $4,000 to $8,000. I didn't see many 2/3 on Ebay last time that was thinking about finding a cheap 2/3 lens to do just that. There might be more by now though.

February 4th, 2009, 12:19 PM	#3
Stuart Nimmo Regular Crew Join Date: Aug 2006 Location: Paris France Posts: 89	Umm, the 2/3 SD lens I'm thinking of is on a 16x9 Digital Betacam, it was made for native 16x9. I thought the same as you Brian about cropping using the sweetest glass, and do wonder about marketing hype. I guess the simple answer is to hire an adapter and check it out, I just felt that others here must have put this apparent option to the test? I'm lucky enough to have my father's Hasselblad / Zeiss lenses and now have a Hasselblad to PL adapter, I bet those'll be just the thing for really long compression shots, (but think of all that wasted glass).

February 4th, 2009, 12:39 PM	#4
Robert Rogoz Major Player Join Date: Sep 2007 Location: Bellingham, WA Posts: 457	The whole issue SD vs HD lens is marketing hype. It's not glass that is an issue here, but the compression that the signal is going through. Lens manufacturing process has been going on for last 100 of years and is pretty much down to science. Digital technology is relatively new. It would be like comparing 35mm SLR to 4MP SLR shooting small jpegs. Personally I think Red is on a right track on this one.

February 10th, 2009, 09:19 AM	#6
Mat Thompson Trustee Join Date: Sep 2006 Location: Kent UK Posts: 1,397	Hi guys. I've used a current nearly new Canon 2/3rds lens albeit a low end model (About $2.2k us) on the JVC GY HD 110 and all I can say is this was wasn't great. It had some bad abberation, especially towards the long end and wasn't sharp. The standard fuji was definately a stronger performer as far a IQ was concerned. I went through a lot of image testing before I came to my final judgement and sold on the lens. I sure higher end lenses would perform much better but I was surprised this wasn't better considering i was using the 'sweet' area of this lens. Cheers Mat

February 10th, 2009, 05:48 PM	#7
Stuart Nimmo Regular Crew Join Date: Aug 2006 Location: Paris France Posts: 89	Umm, interesting Mat. It could be a problem, I'll give it a go and let you know.