SD glass on HD cameras

[SimonMW]

Has anyone here managed to do a decent test regarding the use of good SD glass on an HD camera?

When I used the PDW-700 I used it with a Canon HJ17. It exhibited more issues than I have ever seen with my SD J17. It got me wondering whether there would be any point at all in upgrading to the HJ version if I ever plonked down the cash for a 700. After all, what is the point in selling my current lens at a loss to upgrade to the so-called HD version only to find that it has huge CA and fringing issues, when that is exactly the sort of thing that is supposed to be minimised with HD specific glass?!

Further, both Canon and Fuji has budget HD lens lines available that retail for far less than my standard def J17 ever did (and still does!) Am I to believe that these budget 2/3" HD lenses have a higher quality of glass on them than my more expensive SD lens?

I recently spoke to someone who was going through the same dilemma with his J11. He was told be Canon themselves not to bother upgrading to the HJ11 because both lenses came off the same production line, and the only difference between them was how they were graded in quality. So it would be possible to have an SD lens that pretty much made the HD grade but perhaps fell ever so slightly below it. Now, I don't know how accurate that is, but it would make sense in many respects.

Regardless I am not sure what to do. How much should I buy into the idea that the HD designated lenses are actually really much better than high quality SD glass?

[ClaireTall]

Not sure if you're a member but there has been a big debate on this on the GTC forum (Guild of Television Cameramen) with both sides making comments.

http://tv.groups.yahoo.com/group/gtc_forum/

There are some good links to Canon etc in the thread, sorry don't have time trawl through for you.

Personally for OUR end market, satellite broadcast, tiny bit of terrestrial and DVDs I think a decent SD lens is fine. I've just been checking a dance show we filmed recently from the final DVD and the quality is pin sharp, just used the cameras with the 6pin firewire out through the Sony Anycast and out to a hard drive.

For final HD broadcast use I would agree that only the best will do but it may just a big con.

[infocus]

Further, both Canon and Fuji has budget HD lens lines available that retail for far less than my standard def J17 ever did (and still does!) Am I to believe that these budget 2/3" HD lenses have a higher quality of glass on them than my more expensive SD lens?
It's conceivable - my understanding is that the difference between budget ("professional") ranges and the more expensive ("broadcast") has less to do with resolution and CA etc, more to do with build quality, amount of ramping, etc etc.

"Quality" normally gets used to mean sharpness etc, it can just as well mean more strongly built etc.

[SimonMW]

"Quality" normally gets used to mean sharpness etc, it can just as well mean more strongly built etc.

That's very true. Although I would find it hard to believe that those budget HD lenses have amazing glass on them. I've noticed that the 'breathing' on even the broadcast lenses these days is still absolutely huge. I know there are limits in what can be achieved with a zoom compared to the simplicity of a prime, however I really do get the distinct feeling that lens manufacture these days is more about cost cutting and profits than really giving the customer value for money.

The price of HD lenses doesn't appear to correlate with the quality they are giving, both in build and in glass. Softening away from the centre seems to be a particularly common offender, with many of the lenses almost making it look like a tilt/shift has been used!!

If I am being asked to upgrade my SD lens because HD glass is a lot better and more suited to an HD camera, the least I can expect, especially given the prices involved, is that a base level of expected quality is there.

When a manufacturer tells me that CA has been reduced from the previous model I expect to see less CA, not more! When they say that 'breathing' has been reduced, I expect it to be reduced, not exactly the same as it was previously.

[paultv]

This was a major issue for me with HDCam and HD lenses, chromatic aberration was so awfull and more obvious in HD than SD - really horrid, I remember a shoot with Sony HDCam and a Z1, where in some respects the Z1 looked better.

This is why I opted for an EX1, the CAC (chromatic aberration correction) is really so good
compared to many more expensive cams, I'd always found the XDCam HD 350 quite good in this respect, maybe it has the same system.

Paul

[Alan Roberts]

Yes, the Guild is very interested in it. And, I did tests for BBC News about 4 years ago. The idea then was whether to replace battered lenses for SD cameras with SD or HD, and the tests showed that there was a significant advantage in doing so. In the other direction, using SD lenses on HD will give a softer picture, but with a much higher level of spherical/chromatic/diffraction aberrations.

I've just got back from an exhausting couple of days in Oslo, where we saw PDW700 and HPX2100/3000 in action. The single biggest issue with the pictures was all down to lens aberrations, and tghey're using modern but small HD lenses. Chromatic aberration is a major problem , and only money can solve it.

[SimonMW]

Chromatic aberration is a major problem , and only money can solve it.

I just saw it mentioned elsewhere that the 700 may have CA compensation for certain lenses built into forthcoming firmware. Don't know if it is true or not.

One thing I have thought about though is that although an SD lens may be softer on an HD camera, in the general scheme of things will it make such a difference? For example taking into account operator issues such as perhaps not nailing focus perfectly correctly in the first place, as well as movement in the picture in general.

For example would it be noticable during handheld documentary style camerawork? And also perhaps if we consider how many people dial down the detail settings on HD cameras anyway?

I'm just thinking of things in terms of 'on a budget'. The aim would obviously be to get HD specific glass. But at present I am not sure if it is justifiable, all things considered. At a glance, with all the issues present, as well as the fact that it seems both the SD and HD glass comes off the same line, the HD glass is clearly overpriced. I'd be prepared to spend £20k on glass that has zero CA etc issues. But not one that is full of such problems, as they are at the moment.

Alan, have you been able to compare the budget 2/3" HD glass to broadcast 2/3" SD glass?

[Alan Roberts]

Yes, that was the essence of my last posting.

Even more so, much of the current range of HD lenses is underpriced, not overpriced. Many of the lenses I've seen that are sold as HD, don't do justice to the cameras. It isn't sharpness, that's fairly easy to get right (at one focal length), the problem is the aberrations. Only yesterday, I was looking at a PDW700 that made dramatically poor pictures because of chromatic aberration, coloured fringes many pixels wide. The compromises in cheap lenses are very much more visible in HD than they are in SD.

[SimonMW]

Alan, could you tell me which lens the 700 had on it so that I know to avoid it?!

Looks like in-camera CA correction is the only viable solution. Primes are impractical most of the time, and it seems as if none of the manufacturers actually make a zoom lens, expensive or not, that doesn't suffer heavily from these issues.

[Alan Roberts]

Didn't get the details, but it must have been at least 15:1, and a small front element, the sort of design that's down to a price and not up to a quality. If I can find out, I'll let you know, it was a hectic couple of days, 50 people - 5 cameras, lots of booze. I've only just come out of the hangover.