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Originally Posted by R Harkness /forum/post/21716451
Drexler is not ignoring such examples; the point is they do not meet the criteria Drexler keeps bringing up: Blind Testing.
Did that person do a blind (even better, double-blind) test of the lens? Correct me if I'm wrong, but I don't think you've said that this person performed a blind test.
I'm not sure. I do know that he was zooming and bought a second hand ISCO II just to see what the effect was. He intended to sell it on afterwards because he didn't think it would make a difference but instead found that it did. He was sceptical and thought he'd be selling the lens on. In his case he was biased the other way so would have been looking at a reason to not want to keep it.
Unfortunately people don't tend to do blind testing when the results seem pretty conclusive.
If you don't know what to look for you won't necessarily see the difference. 4:2:0 vs 4:4:4 can be difficult to see for example. Poor scaling, poor contrast/brightness settings are another. There are plenty of others. If you're Joe Public you're likely to not know but most people here can spot stuff like that quite quickly.
I was at an event where a JVC and a Titan 3 chip DLP were on view in separate dedicated rooms, and both were using A lenses. The Titan had less contrast capability than the JVC but I could see the blacks were crushed. I asked the guy hosting the event if that was deliberate to give the impression of more contrast to compete with the JVC but ended up getting balled out, with him talking about below black and completely missing the point. I didn't reply back because, as a guest, I didn't want to have a public argue at such an event. Later, when we were back in the room, he then pointed out that I had spotted that the source player was set at the wrong settings (PC/Video) and changed it back. VoilÃ*, black detail was restored. The point I'm making is that Joe Bloggs probably wouldn't have seen that. Even the guy from the company didn't, so I think from an experience point of view, I'm not exactly clueless.
Just because a double blind test isn't done, doesn't mean the results aren't visible. Sometimes the results are so obvious that blind testing isn't required. I give Art Sonneborns CIH set up with 3 chip DLP as an example and that he can see pixels in his preferred seating position if he zooms, but with a lens he rarely sees them except in very bright scenes (he's at 2 x SH). In a blind test that would be very obvious wouldn't you say?
If there were two identically proportioned cars in front of you, and one was 4 feet tall, and the other 6 feet tall, do you think you might be able to tell which was which, even in a double blind test?
When I used a 720 pj, I had exactly the same problem. I went from a 7ft wide 16:9 screen to an 8ft wide 2.35 screen and I zoomed. If I sat at the same seating distance ratio for scope (3 x SH) I could see pixels/SDE and the image became very chunky looking. I tried defocussing a little but that didn't work, it just made the image softer and look out of focus. I then looked at getting an A lens. The first one (borrowed) was a very basic prism lens and made the image soft. Knowing there were better lenses out there, I then bought a Prismasonic lens with anti CA and coated lenses and a 14 day returns policy should it not work for me. That was much better lens, so I kept it. If it wasn't, I would have got my money back. I did plenty of testing to make sure but the benefits were very obvious - I no longer saw pixels/SDE at 3 x SH. A few months later a used ISCO II came up on this forum and out of interest I bought it, just to compare. I didn't think it would make a difference but with testing, initially using test patterns, it was obviously sharper, and that was unexpected to me at the time. It was harder to tell with moving images but it was still perceptible. I then sold the Prismasonic.
Of course with 1080 and smaller pixels, the need for a lens would be less, but Art still needs a lens or he couldn't sit in the front row of his theatre. I bet he would easily pass a double blind test. You'll have to ask him.
All anecdotal I know, but 1080 vs 817 pixels is a very different physical difference wouldn't you say?
Now, you might say I didn't do blind testing, but the difference between zooming and a lens was so obvious it it wasn't necessary. Between a Prismasonic and an ISCO I agree it would be interesting to do the blind testing with moving images (because test pattern comparisons were obvious), but I think people here would still manage to tell the difference. I wonder if GetGrey (Scott) could do something like that for us?
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Originally Posted by R Harkness /forum/post/21716451
Yes Drexler has mentioned that brightness changes will tend to skew preferences to the brighter image. But that's not the only point he's making.
Well it is, he keeps saying its brightness and placebo, ignores the extra pixels and says it defies physics.
Quote:
Originally Posted by R Harkness /forum/post/21716451
The point Drexler keeps making is that, especially when it comes to a comparison of the E-shift images with/without an A-lens, BARRING brightness advantages (if there is no brightness difference) then theoretically, given the pixel density of a E-shifted image from any normal viewing distance (it's hard to see pixels at all with a nose to the screen!), there is no reason to expect an advantage to making the pixels even smaller via an A-lens.
I'm sceptical because you still have to zoom them 33% larger for CIH. I tend to think that if you zoom something 33% larger, it physically gets bigger. What do you think?
It's also quite possible that e-shift it works very well and it nullifies the use of an A lens but when I hopefully get the kit for my room next year, I'll know for sure.
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Originally Posted by R Harkness /forum/post/21716451
It is entirely rational to be deeply skeptical of such a claim. (I am).
That wasn't his point. The point I'm addressing is that it's not brightness or placebo, it's pixel density.
And I'm always sceptical.
I've seen it said that we can only see something like 200:1 contrast 'at once', but I did some testing to prove otherwise (was a few years back and I posted it here because I wanted to see other peoples input).
The advantage of an A lens is the extra pixels you can use to keep pixel size smaller than zooming would allow. In theory an e-shift image should be able to do without the need for an A lens since it's doing something similar by rapidly shifting the panel to replicate having more pixels which by overlapping appear smaller. Where the sceptic in me comes out is that you still have to make the pixels 33% larger to zoom for CIH, and I'm curious to see how visible that is when zooming. If it is, then an A lens may still be necessary. I've not been able to test that for myself, but it's something I'm curious about.
Not everyone believes marketing hype until they've proved it to themselves. However, by all accounts e-shift seems to work very well indeed. I'd still like to see it and do some testing vs an A lens. Someone here already has but some people don't want to believe him.
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Originally Posted by R Harkness /forum/post/21716451
And at such a point of diminishing returns, if you really want to be careful and rigorous about such a claim, or about finding out if there REALLY is a detectable difference, then blind testing becomes very wise. The fact that brightness is constant between the A-lens and the zoomed image is great, but in no way does that negate the very well known problem of our bias.
I agree that blind testing is sometimes completely necessary, especially when there are no means to test the claim (audio cables, power leads etc). With video it's easier to see differences when you know what to look for, but you must be aware of the placebo effect. As you say, it's a very real issue. Like I said before, I misread a magazine article and almost convinced myself I was seeing what I thought I should be seeing, but I wasn't convinced. After re-reading the article and slapping myself on the forehead (I misread a word), I now make a point of not believing anything until I've seen it for myself. A lenses included.
A Sony rep told us at a demo once how good the scaling was of one of the top end amps that was being used as a video switch (like many do), but I quickly started noticing glitches here and there. If I wasn't sceptical, I'd have believed him and seen what he told me.
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Originally Posted by R Harkness /forum/post/21716451
Keep everything utterly the same in an audio system, but show an audiophile that you are switching the AC cords or switching speakers cables, and many of them will swear they hear an obvious difference in the sound, despite the theoretical impossibility. Then, do it blind-tested with them, and suddenly they can't tell between the two. Placebo. And all the "experience" an audio professional or audio dealer has in the world does not guard against this bias problem - they'll fall to the same problems (as has been shown a number of times).
Yup, seen it so many times now it's funny. Same thing for power leads. I tried those as well but I can't hear a difference.
Many years ago I bought some new speakers for my old cinema room and thought I'd try them in my lounge, temporarily replacing the existing ones. I tried a movie I was used to and thought I was hearing things I'd not heard before. I then tried the old speakers back and found I could hear all those sounds I thought I hadn't heard before. So the new speakers weren't reproducing anything the old speakers weren't, it's just what I thought I would hear. I wonder how many people buy new speakers and swear they hear more detail but don't recheck the old ones.
The trouble with audio is that it's very hard to know what we're hearing is true or not. With video, it's less difficult but still subject to error so we have to make sure, by testing, that we're seeing what we think we're seeing. I agree that blind testing is good if you're not sure.
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Originally Posted by R Harkness /forum/post/21716451
And the placebo/bias effect is hardly confined to audio - it happens everywhere - it's a fact of life.
Absolutely, and something I'm more than aware of from experience.
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Originally Posted by R Harkness /forum/post/21716451
It is great to hear reports from owners trying various things, to be sure. But Drexler's skepticism is, I think, quite warranted and he's not being simply stuffy or recalcitrant for simply pointing out very real problems in how people are going about their comparisons.
One might be tempted to say "Well, great, should we all just stop posting our experiences unless we do nothing but blind testing?"
No. Of course there are many times in which visual differences are going to exist, uncontroversially. Most of the types of visual differences we discuss between products fall well in line with what it expected and possible, given our visual system and the differences in contrast/color/brightness etc of various systems. But when you get into more controversial claims...time to remember our skeptical tools.
Yup, and I'm more sceptical than yourself since you were convinced of the e-shift hype before you'd seen it and were arguing how it would replace A lenses (which it might, but I pointed out to you that it still doesn't get away from the 33% increase in the 1080 pixels that are being shifted). I remember saying to you even then that until we'd seen it and tested the differences, it wasn't a foregone conclusion that it would replace an A lens (it might for many people though). I think I'm pretty sceptical nowadays of any claims and I like to see for myself. I think I said that many times.
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Originally Posted by R Harkness /forum/post/21716451
It does no such thing! The differences may be real, someone may have a "clue," or not, or be very experienced with AV equipment. It doesn't matter - the placebo effect doesn't distinguish, we all have to be on guard for it. That's why the most experienced scientists appeal to blind/double-blind protocol.
To suggest that everyone is unaware and falling for the placebo effect isn't an accurate assumption either, and it does reduce with awareness. Especially if we question a lot of what is going on with the technology and the claims that are being made about it.
Placebo only really works if you're told or expect a difference and
believe that's what you're going to get. If you're not told that or don't believe it and need proof, then placebo doesn't have any real effect.
Don't forget that Placebo was originally a medical ploy to tell patients their treatment would make them better (usually an inert pill used as a control with other patients given a genuine pill that would give medical treatment). If you told a patient that they were given an inert pill, they would expect no difference and have no psychological or even physiological improvements.
Gary