DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Sony ENG / EFP Shoulder Mounts (https://www.dvinfo.net/forum/sony-eng-efp-shoulder-mounts/)
-   -   More HD Lens Tests (https://www.dvinfo.net/forum/sony-eng-efp-shoulder-mounts/144334-more-hd-lens-tests.html)

Steve Phillipps October 10th, 2008 03:18 AM

More HD Lens Tests
 
4 Attachment(s)
I've just shot a couple more lens comparisons, this time with news print (which seems to be a preferred method for some).
One of the lenses is a Fujinon HA22x7.8, the other a Canon J14x8.5, both at 40mm, shot first at f4 then at f8.
Thoughts, guesses?!
Steve

David Heath October 10th, 2008 04:20 AM

No idea which is which, but I'd say lens 1 looks sharper.

Mike Marriage October 10th, 2008 04:35 AM

I see little difference! Lens 1 may be slightly sharper.

The J14 isn't exactly new either! How old is it? I wonder how a J17 or my A18 would compare.

Steve Phillipps October 10th, 2008 04:44 AM

Lens 1 is the SD lens. On the landscape shots I did there was a - fairly - noticeable difference but as you both say there's little to choose between them here.
Steve

Stewart Menelaws October 10th, 2008 04:48 AM

From that test and the limitations of the monitor I am looking at these, there is certainly not a lot in it -

Lens 1 does look like it has the edge, but in a moving presentation there would be no perceivable difference.

Come on Steve.... I can't wait to hear the details....

Regard Stu:
www.studioscotland.com

Stewart Menelaws October 10th, 2008 05:04 AM

Beat me to it....

In your opinion, what sort of money are you talking about, for a high quality general purpose decent wide to telephoto SD lens that will give you the best results before you need to move into the HD glass range?

Regard Stu:
www.studioscotland.com

Steve Phillipps October 10th, 2008 05:47 AM

Well, that's the question isn't it! According to this test it's £500 for a secondhand old SD lens. But as you say, perhaps in other situations the difference would show.
I've no experience with the "cheaper" HD lenses, there's a Canon KH20 I think that's about £4k. I've actually only used a few HD lenses, mostly because the rental houses, BBC etc. tend to just use the same ones, so HJ11x4.7, HJ18x28 and HJ40, plus the Fujinon I have here and that's about all I ever get sent out with really.
The more input we can have from users the better I think.
Steve

Alister Chapman October 10th, 2008 06:22 AM

The cheap Canon 2/3" HD lens is the KJ20x8.5. I've used one and it really is nothing special. There is no extender, but at 20x it offers a good zoom range. I found it to be very sharp in the center, falling off a little at the edges. I would rather buy a £4k low cost HD lens than take a gamble on a £4k "good" SD lens.

Steve Phillipps October 10th, 2008 08:13 AM

I'm not sure you'd be wise to do that Alister. Aren't some of these "budget" HD lenses designed to work in conjunction with these CAC functions that are appearing now - basically allowing a crappy lens design to be fixed at shooting rather than editing stage. I wou;dn't be at all surpised to find a fairly recent top range SD lens being better than one of these low-end HD lenses.
Did you find edge sharpness falling off at all apertures or just wide-ish? No 2x extender sounds like a drawback, but to be honest if you're looking at top quality results (which surely is what HD is all about) then you shouldn't be using a 2x anyway. Must say I tried 2x on the F350 on a Canon HJ lens and it really didn't look good - but I assume a lot of this was because it was also going through the 1/2" - 2/3" adapter which also has an optic in it.
Steve

Alister Chapman October 10th, 2008 12:32 PM

Like most lenses the KJ20 worked best between F4 and F8. CA was reasonably controlled, there was some and it was worse towards the edges, certainly as with any lens it will benefit from electronic CA reduction, which the 700 should get in the next firmware release.

I've used top end HD zoom lenses on many cameras, including the 700 and they have all exhibited CA, every single one of them. Even primes exhibit some CA (although a lot less). Some of the CA is caused by the prism in the optical block.

The problem is finding that good SD lens. In every HD/SD lens test I have done the HD lenses have been better than SD lenses. It has never been by much and in most real world situations the difference would often go un-noticed, but they have always been better.

2/3" lenses on 1/2" cameras never work well. The smaller photo sites and shorter prism paths of the 1/2" cameras are not well matched to 2/3" lenses. 2x extenders and HD are not a good combination with any lens or camera, but a 2/3" lens on a 1/2" camera has to be the worst possible combination.

Buying used lenses is a lottery. It only takes a knock on the side of a lens barrel to put the collimation out, this can lead to focus issues that may not immediately be obvious and may only show up at certain focal lengths. I stand by what I said, if I was going to spend £4k I would buy the new HD lens and not take a gamble on an unknown SD lens. Having said that if I found a really good SD lens for £1k then I would quite possibly buy that and then hire in lenses as required.

Tim Polster October 10th, 2008 09:24 PM

Alister, you have a good point, but the HD lens used in the comparison was a ~$20,000 lens, I was shocked to see how little a difference there was.

I would think this story would change if the lenses were wide open or f2, but maybe not.

But still, for the price to be so far apart for generally the same perception is a nod to going the SD lens route.

Steve Phillipps October 11th, 2008 02:47 AM

And it's a fairly old SD lens too, you might expect better from a later generation (I think it's about 15 years old?) Also I did think about wide open performance, that's why I shot at different apertures, the f4 shot was nearer f3.5 so as wide as I'd tend to want to shoot, as to be honest no video lenses apart from Digiprimes and the like are any good wide open.
And I don't think it's down to taking "a gamble on an unknown SD lens" either, as I think the ranges of SD lenses are pretty well known (there was always budget like the YJ, and industry standard like the J series), and the SD lenses I have here both perform about the same (the other is an even older Fujinon 8.5x5.5, good but flare-prone).
I don't know about any of you engineer-types, but I assume that viewing a 100% crop from a still image is going to tell you as much or more than viewing even on a 50" HD TV, so that these tests do mean something?
Steve

Steve Phillipps October 11th, 2008 07:09 AM

2 Attachment(s)
OK, here's a couple more. It's funny, but I can definitely see more of difference on the wide, landscape shots. It's still pretty damn close though.
Which is which this time?
Steve

Tim Polster October 11th, 2008 07:20 AM

I would guess lens #2 is the HD lens.

Greg Boston October 11th, 2008 09:58 AM

In researching the problems I've had with CA in some of my images, I learned that the HIGHER the resolving power a lens has, the more CA becomes an issue. It's a real bear for lens designers to tackle.

So IMHO, CA correction is not something to overcome the handicap of 'crappy' lenses.

-gb-


All times are GMT -6. The time now is 02:56 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network