HD vs SD glass again

[Simon Wyndham]

Okay, debate time again.

I'm considering the PDW-700. However I'm in two minds whether to sell my J17 lens or to keep it. Why?

When I tried the 700 I used it with an HJ17, and to be honest the CA it showed along with other issues made me wonder if there is actually any difference whatsoever between these two lenses other than the name designation!

Furthermore, there are budget lenses such as the KJ20 available. Would a budget KJ20 HD lens actually be better than my broadcast classed J17 SD lens? Given the issues I have seen on other budget HD glass I am not sure that it would be.

Is the fear of use of a good 2/3" SD broadcast lens on a HD camera more FUD than reality? I know Alister did some good comparisons with his 1/2" lenses that showed that his SD lens was more than adequate. But has anyone done the same sort of test (with downloadable results) on good 2/3" cameras?

In fact I was just speaking to someone who spoke to Canon about this once regarding his J11. he was told that there would be absolutely no use upgrading to the HJ11 because they both came off the same production line!

[Alister Chapman]

First off this is a far bigger issue with 1/2 inch cameras than 2/3. The smaller photo sites of the 1/2 cams shows up the resolution difference between SD and HD lenses. 1/2" lenses require a higher MTF than 2/3" lenses.

I did some tests with a 700 and HD and SD lenses. The result was not clear cut. Overall the HD lenses appeared to have a slight edge, but it was a marginal difference that required close scrutiny of the pictures to discern. There have been some discussions over some older pre internal focus lenses. In some cases these have been found to be sharper than some of the more recent lenses.

A lens is a lens. If it is well made and well corrected it should work well. One thing that can make a difference is the use of exotic glass to correct for chromatic aberration. This glass is expensive but compared to the cost of designing and manufacturing a complex zoom lens that cost is small.

At the end of the day I believe that it comes down to the individual lens. Lens manufacture is a black art and even today there will be small variations between the elements made for each lens. Get a lens where all the elements are a good match and you will get good results. I think many of the HD and SD lenses share the same production lines with the lenses with the best optics being sold as HD and the rest as SD. Find a good one from that line at it will probably be just about as good as the more expensive HD lens.

Much the same thing happened when CCD's were first launched. The lens manufacturers were quick to bring out lenses with "CCD" badges on them, apparently "CCD" lenses were some how better than regular lenses.

So the issue is how do you find a good lens?

More important than using an HD lens is knowing the lens you are using and how to get the most from it. Most lenses perform best between F4 ad F8. A good quality SD lens used at it's sweet spot would probably out perform an HD lens that was wide open or at F16.

[Uli Mors]

Hi Simon,

Fujinon shows its new ZA (?) Lenses : A Tele, a normal and a WIDE Lens.

"for SD-Budgets" - I am not sure what the price point is, but perhaps this will be a new alternative...

Second, I saw the Firmware update roadmap for the pdw-700. Sooner next year a firmware upgrade will implement an electronic CA compensation. Dont know more about it (only for dedicated lenses? Automatic Adjustment? ...) , but this will be a nice feature anyway.

ULI

[Steve Phillipps]

Thanks for the ZA info. Usual strange staetments in Fuji's pages, saying things like they're suited to "professional and corporate" uses, so corporate users don't mind a bit of softness and CA? And these "budget" lenses always talk about using the highest quality optics for HD production etc. etc., but if that's the case why are the other tiers so much more expensive.
I think the only way is to try the lenses side by side, and if the difference is huge then fine buy the more expensive one, but if there is a difference but it's small then I wouldn't worry about it, as no viewer is going to looking at 100% frames and side-by-side tests.
I'll be doing some more side-by-side lens tests with a 700 this weekend so will post the results.
Steve

[Alister Chapman]

isn't it sad when you are buying a professional piece of kit and you can no longer be sure of the performance of what you are buying because the manufactures literature is so deliberatly vague. Lens manufactures should have to publish actual performance data with details of achievable resolution, mtf, distortion, dispertion levals. At least the we would really know what to expect. At the moment it is all but impossible to take a lens back if you don't belive it is performing to spec as the spec is so vague. There is no clear definition of what an HD lens is and how it should perform. There is nothing to stop any manufacturer putting an HD badge on any lens they choose. If you then take the lens back saying it's soft they say it's within spec....... But what is the spec? Camera manufacturer publish resolution, codec, compression ratios etc, why can't lens manufactures do the same? The reason has to be marketing, as I don't believe there is really the kinds of differences between so called pro lenses and broadcast lenses that justifies the often massive price difference.

[Steve Phillipps]

Here are 2 frame grabs from PDW700, one with old Canon J14x8.5 the other with Canon HJ22x7.6. Light's crappy (just done it 5 mins ago, will do more soon). Both wide open, 0db gain. Which do you prefer?
Steve

[Simon Wyndham]

At a glance I'm damned if I can tell the difference. Might be worth doing a landscape shot though, then the differences might show.

I'm wondering whether, with all the manufacturer confusion, whether it might be worth putting together a website with some definitive tests and results that potential purchasers can check out. Perhaps it will kick the manufacturers into giving some true specs.

Odd isn't it? It is easy to find good tests of pretty much every stills camera lens around, but virtually nothing when it comes to broadcast and professional video lenses.

Perhaps if we got together and shot some charts etc. I'm quite happy to set up an SQL site that can be updated easily.

[Steve Phillipps]

Problem with having tests is that they'd almost all fail I think!
When HD first started to emerge in a big way there was so much talk about lens selection being SO important. The plan was to use only primes as zooms weren't really really good enough. Then zooms were deemed OK, but obviously only the highest quality and obviously no 2x extenders! Now they've almost all got a 2x, and now we're into several tiers of lenses, and we all know that even the top tier leave a little to be desired, so what does that mean the lowest on the ladder!?
The first HD lens I ever used was a Canon Digital Cinema lens, a 14x7 or something and it was superb (on an original F900), but it's all seemed to go downhill from there. Build and handling are pretty naff too (when you're paying £15k or so!)
It's a very tricky situation, and I think most folks would be (almost) happy to pay big money if there was a chalk and cheese difference but it doesn't seem to be anywhere that clear cut.
Will do some more tests and post.
Steve

[Steve Phillipps]

Here are some more side by sides. Lenses were Canon J14x8.5 and Canon HJ22x7.6. a1,b1 and c1 were with one lens, a2, b2 and c2 were with the others. I CAN tell the difference, what do you think? PDW700, -6db, f5.6.
Steve

[Mike Marriage]

a1,b1 & c1 appear sharper but seems to have worse CA on the clothes pegs shot than lens 2.

How old is the J14?

[Steve Phillipps]

My thoughts exactly Mike, though the CA is not too different I thought. The J14 must be about 10 years old I guess. It's an IF one, not a really old fashioned job.
Steve

[Steve Phillipps]

No, second thoughts, you're right, the CA in 1 is definitely worse.
Steve

[Stewart Menelaws]

Steve - thanks for doing this stuff (and to everyone else doing these things), I am very keen on this camera, unfortunately I have not been able to get my hands on one up here in Fife, and I can't get the time to go to any of the shows.

I agree (from what I can see) that a1,b1, and c1 appear to be sharper - as for CA, I can't make a judgement on that with the monitor I am viewing this on.

Once again, many thanks for what your are doing, it is most informative...

Regards: Stu
www.studioscotland.com

[Steve Phillipps]

For those who are interested, here are a couple of grabs from PDW700 and F355 side by side. Shots 1 and 1b are PDW700 and 2 and 2b from the F355. Quite a bit of difference. Also interesting that the file sizes are so different, even though they are from exactly the same grabbing proccess, presumably just shows how much extra res there is there?
Steve

[Greg Boston]

Originally Posted by Steve Phillipps

Here are 2 frame grabs from PDW700, one with old Canon J14x8.5 the other with Canon HJ22x7.6. Light's crappy (just done it 5 mins ago, will do more soon). Both wide open, 0db gain. Which do you prefer?
Steve

I can't see much difference in the full size images.

Also, because I have experienced CA issues with my HSs (supposedly the cream of the crop) Fujinon lens, I started researching the CA thing. What I learned was CA becomes more of an issue as the lens MTF goes up. I suspect this is why we're starting to see cameras like the Panny and the EX have a CA correction feature incorporated.

i still don't believe I'm getting good HD images from this camera in wide shots, despite closely checking FB adjustment. The one time I had an SD loaner from Fujinon as my HD lens was being replaced, the SD lens seemed to have better saturation of color.

It still seems that if you get a best of the lot SD lens, it will perform quite admirably on the HD cameras. Should I elect to buy the 700, I'm going to take a serious look at going that route. I saw first hand at NAB in Dennis' presentation what the 700 can do with good SD glass on it.

-gb-