More HD Lens Tests

[Alister Chapman]

My guess is that lens 1 is the HD lens. Lens 2 is very soft at the edges and in the corners. Bottom left is positively blurred!

It is very difficult to tell with that image as it is pretty low contrast with lots of haze acting as a natural diffuser.

[Alister Chapman]

Further to my post above, I still think lens 1 is the HD lens. I've spent a bit of time looking at the images and the difference is so small that for a while I did start to wonder if Steve was pulling a fast one by posting the same image twice :). However what I see is Lens 1 is certainly sharper at the edges, while lens 2 is soft at the edges getting shaper towards the center where it appears to have very similar sharpness to lens 1.

What I did notice when I got both images up side by side on a big monitor was that lens 1 appears to have quite a bit more contrast than lens 2. The exposure looks similar so I think this is actually the lens. Perhaps lens 2 is an older lens and the coatings are not as fresh or the optics are a little dirty. Also the colours are slightly different between the lenses.

I saw similar differences when comparing 1/2" HD and SD lenses on my F350. The HD lenses had better contrast and the SD lenses tended to be soft at the edges.

Thanks for posting these Steve, they are remarkably similar. If you get a chance on a bright sunny day I'de love to see a similar comparison.

I agree with Greg that CA correction is not something to be passed off as a gimmick or trick, but a useful tool to help improve image quality. There is a whole bunch of processing going on in 3 chip video cameras already to help reduce flare and other optical effects created by the prism block, CAC is just a new tool to help achieve a realistic image. Of course it's only a good tool if it's operation is in effect invisible.

Shall be checking back to hear which is which.

[Steve Phillipps]

Spot on on all counts Alister, I'm very impressed!
I've always noticed that HD lenses seem to win in the contrast stakes on all comparisons I've done (including vs. say Canon 300mm prime), and my cynical side ha always wondered if this is boosted on purpose to increase apparent sharpness to make it HDish?
As you say, they are very close, and if you're nit-picking on 100% crops side-by-side I'd say it's definitely not worth spending the extra £15k!
Steve

[Tim Polster]

Great post.

I purposefully made a quick decision to get a viewer's feel and it shows to me what Steve said about the need to spend the extra money.

If contrast is the main difference then that is not that big of an issue as this can be addressed with camera settings and or software in post.

I thought the higher resolution chips of the PDW-700 would show the weakness of an SD lens more so than a camera like the HPX-500.

Makes the whole game look needlessly expensive.

[Steve Phillipps]

Right, here are some more tests shot on PDW700.
"5" is an old Fujinon 8.5x5.5
"90" is a Tamron 90 macro
"300" is a Canon 300mm f2.8
"HA" is a Fujinon HD lens
"HA90" is the Fujinon HD lens at 90mm
"HA300" is the FUjinon HD lens at 300mm
"J14" is an old Canon J14

Haven't yet had a good look, be interesting to see what you think.

Steve

[Steve Phillipps]

Here's my quick analysis:

Looks to me on the wide shot that the 5.5 Fujinon is actually the best, then the HD lens, then the J14. The 300 prime looks a lot better than HD lens (BUT the HD lens did have to have the 2x extender on to get to 300, but aperture was f5.6 or so, so not as though it was wide open, and if it's made with an extender then it should bloody work!). The 90 macro looks pretty similar to the HD lens to me, tricky one to judge because being a CU the depth of field comes into play and bit of one look sharper than the other, and then vice versa on another part of the image.

All these were mid apertures-ish, between f5.6-f8 ish.
Hmmm!

Steve

[Brian Drysdale]

It would be better to test wide open or even f2.8, any differences will start to show through clearly. At f5.6 to f8 even poorer lenses tend to show up well on tests.

[Steve Phillipps]

When I did my previous tests I did some at f3.5ish, and same at f8ish, and the differences showed in both (ie the poorer lens looked poorer at both apertures and by the same amount). Personally I try to avoid wide open on any lens (except a Leica 105-280 I had a few years back that was sensational wide open), as they all suffer unless you stop down about 1 stop or more, and then crappy again of couse beyond f11ish.
Steve

[Brian Drysdale]

F2.8 is a pretty commonly used stop, you've got that one stop improvement on most zooms. Although, I do like to have a lens that you can actually use wide open, it's handy in low light situations or if you want a shallower DOF.

[Alister Chapman]

Contrast is very important. While you can tweak the camera setting to make the image look more contrasty, if the shadow detail has been lost because the lens is bleeding light into the dark areas you will never get it back.

It could be that in this and the other tests I have seen and done that the comparison has been between fresh HD lenses and older SD lenses. Over time the oils and lubricants used in lenses evaporates and some of the vapor ends up on the lens elements causing some fogging and loss of contrast. Or it could be that the HD lenses are using better coatings or better glass and thus can produce more contrast.

Fogging like this is one of the reasons why I don't like spending lots of money on used lenses.

As you say Steve it is not a £15k difference.

[Steve Phillipps]

You just won't get the performance wide open, all video lenses tend to be soft wide open, some dreadfully so. Also, I think what I and others are looking for here is not whether an SD lens can compete with an HD lens at the extremes and under worst-case conditions, but whether for a fraction of the cost you can get an image of very similar quality when the lens is used sensibly (ie medium apertures, no extender).
Looking again, that Fuji 8.5x5.5 does look a lot better than the HD Fujinon. Same for the 300 Canon (though again not 100% fair as the HD lens had extender on).

Steve

[Brian Drysdale]

The SD wide angle zooms are excellent, so I wouldn't be too surprised that they hold up well against a HD standard zoom.

Medium apertures are OK for day exteriors, but for interiors and night exteriors the wider stops are commonly used, not only on docs, but also on drama work. It's how well the zooms actually do hold up at these wide stops, especially under extreme lighting conditions that's important, using only the medium apertures is extremely limiting creatively. I'd push the lenses further than shooting the day exteriors.

I'd also check for CA, which is an issue even on the HD lenses.

[Steve Phillipps]

In general CA seems to be less of an issue with SD lenses, and certainly is with this wide angle vs the HD lens.
If I get time I'll try to do a couple of wide open tests, but I expect them to have the same relative performance, and for all to look a bit crap! When you're talking about dramas, using wide apertures really does require primes, that's why they've always been favoured for serious creative work, and still are.
Steve

[Steve Phillipps]

OK, here's a couple of print, with the 5.5 SD lens and the HD 22x Fujinon, both wide open. Close I'd say, but DoF again is a problem.
Steve

[Brian Drysdale]

Originally Posted by Steve Phillipps

OK, here's a couple of print, with the 5.5 SD lens and the HD 22x Fujinon, both wide open. Close I'd say, but DoF again is a problem.
Steve

Dramas commonly use zooms, especially the Wide Angles, because of the breathing issue with the other zooms and they tend to be better quality. Of course, primes are also used, but zooms tend to be the workhorses on many dramas, especially for TV. There are some high quality HD zooms intended for drama type work.

:: CARL ZEISS DIGIPRIME & DIGIZOOM LENSES ::
Cooke S4 HD Zoom
Plus the Panavision zooms.

However, the Canon or Fuji are more likely on quite a few productions. Often using f2.8 because stopping down does improve the performance, but you've got a shallower DOF which is desirable (if not a 35mm DOF). It also keeps the heat from the lighting down and has lower power requirements.

Perhaps the test really says that if you want to shoot HD using wide apertures you need better lenses than these particular zooms.

BTW Cooke had a SD zoom video lens for 2/3", an impressive performer.