[Jonathan S]

I'd like to replace my Panasonic PT-AE100 projector, partly because the lamp has just blown but also I was never really happy with its lack of colour uniformity. I watch a great many black & white movies and various colour hues were apparent in different areas of the screen when viewing these.

I've been looking at the BenQ 5120 but the general agreement seems to be that rainbows are very obvious when viewing in black & white - also on subtitles. Many of my favourite films are black & white AND subtitled!

Can anyone confirm that switching the colour to zero (on any DLP) does not help get rid of the rainbows?

I'm wary of getting another LCD projector as I've read they are susceptible to colour uniformity problems.

Does anyone reading this watch b&w movies on either a LCD or DLP projector they can recommend, i.e. without patches of discolouration (LCD) or bad rainbows (DLP)?

Is the answer to buy a more expensive DLP projector than the BenQ 5120?

Jonathan

[MikeK]

Can anyone confirm that switching the colour to zero (on any DLP) does not help get rid of the rainbows?

No it doesn't I'm afraid.
Turning the colour down simply affects the video signal content, not how such content is recreated on the screen, which with DLP is always sequential RGB images(unless it's a 3chipper).
If there's no colour in the signal, it simply means that the sequential RGB images will each contain the same amount of red green or blue - however they will still be made up from sequential RGB images - and that's where the rainbow effect comes from.


That said, some people don't see rainbows at all, or very rarely, so it may be worth checking first with a demo - remember though that it seems that not all DLP PJs are the same when it comes to RBE, even ones with seemingly similar specs.


Is the answer to buy a more expensive DLP projector than the BenQ 5120?

Probably - unless you aren't susceptible to RBE (as I said above, not everyone is)
Faster colour wheel models with more segments in the colour wheel seem to reduce or eliminate RBE for many - although it must be said that there are some people who still see the effect no matter what colour wheel is used.

[KraGorn]

The 5120 has a 5-segment, 2x speed colour wheel which means it'll be more likely to cause viewers to see rainbows than models with 4x and 5x systems, though these will be more expensive.

[Jonathan S]

Thanks to both for the info. RBE is beginning to sound like a disease or allergy! Something more to do with the viewer than the PJ. Yes, I probably need to get a DLP demo but I bet it's difficult: last time I bought a PJ the best "demos" I could get in Bath were in half-lit stockrooms (or even the main shop) with a PJ wobbling on a stack of boxes three feet from the screen!

I'd still love to hear from anyone who watches b&w movies on any PJ without any discolouration or rainbow problems.

I don't suppose anyone manufactures a black & white ONLY projector?

Jonathan

[NicolasB]

I would say that the inability to see DLP rainbows is an undesirable limitation of vision - they're always there, but people who can't see them have eyes and brains that work too slowly to detect them.

[cyberheater]

Originally Posted by NicolasB

I would say that the inability to see DLP rainbows is an undesirable limitation of vision - they're always there, but people who can't see them have eyes and brains that work too slowly to detect them.

You mean folks who don't see em have a better visual processing system

Jonathan S: If you can. Try to demo a faster wheel dlp machine. It might be worth your while.

[DEANO-B]

The very simple fact is that you need to demo some PJs. It may be a ball ache but it needs to be done. Can you post your budget please so we can suggest a shortlist of PJs. BTW LCD PJs have moved on a long way since the AE100 and are far far better now!

[Jonathan S]

Budget could be up to £1000 or even a bit higher to get what I primarily want, i.e. a solid sharp black & white (where appropriate) picture with no discolouration patches or frequent rainbows. This is more important to me than SDE concerns - that never bothered me at all on the PTAE-100.

Ideally I'd like true anamorphic widescreen (for the relatively few films I have in that format) as I've been used to that with the PT-AE100, whatever its other faults. I considered the BenQ 5120 because the next widescreen BenQ I could see listed was £1300 - quite a jump from £500! I lean towards BenQ as a brand because two (distant) friends who watch similar stuff to me both said the BenQ 7230 (?) is stunning - but that's a 4:3 machine.

I will consider LCD but would have to be convinced I'm not going to run into the colour uniformity problem again. I've researched the Toshiba ET-1 today but found several short user reviews where the lamps had blown after a few hundred hours - coincidence maybe?

Thanks for everyone's input - further suggestions welcome, especially from black & white movie buffs. Am I the only one on this forum!?

Jonathan

[MikeK]

I don't suppose anyone manufactures a black & white ONLY projector?


Not that I know of, but theoretically it shouldn't be that hard to modify a single chip DLP PJ to be B&W only.

Would probably entail replacing the colour segments in the wheel with suitable ND material, or else removing them completely and using an ND filter on the lens.
Depending on how the PJ is designed, it may be possible to remove the colour wheel completely - probably depends on how the PJ detects wheel speed (whether it's a sensor mounted near the edge of the wheel itself or whether the sensor is inside the wheel motor).

Would be interesting, but TBH you'd have to be a bit brave to take a screwdriver to a brand new PJ - even a modestly priced one such as the 5120.

[DEANO-B]

Originally Posted by MikeK

[I]Not that I know of, but theoretically it shouldn't be that hard to modify a single chip DLP PJ to be B&W only.

Would probably entail replacing the colour segments in the wheel with suitable ND material, or else removing them completely and using an ND filter on the lens.
Depending on how the PJ is designed, it may be possible to remove the colour wheel completely - probably depends on how the PJ detects wheel speed (whether it's a sensor mounted near the edge of the wheel itself or whether the sensor is inside the wheel motor).

Would be interesting, but TBH you'd have to be a bit brave to take a screwdriver to a brand new PJ - even a modestly priced one such as the 5120.

Don't be silly

[DEANO-B]

Originally Posted by Jonathan S

Ideally I'd like true anamorphic widescreen (for the relatively few films I have in that format) as I've been used to that with the PT-AE100, whatever its other faults. I considered the BenQ 5120 because the next widescreen BenQ I could see listed was £1300 - quite a jump from £500! I lean towards BenQ as a brand because two (distant) friends who watch similar stuff to me both said the BenQ 7230 (?) is stunning - but that's a 4:3 machine.

I will consider LCD but would have to be convinced I'm not going to run into the colour uniformity problem again. I've researched the Toshiba ET-1 today but found several short user reviews where the lamps had blown after a few hundred hours - coincidence maybe?

Thanks for everyone's input - further suggestions welcome, especially from black & white movie buffs. Am I the only one on this forum!?

Jonathan

Yes the Tosh ET1 is supposed to have lamp problems on some PJs. Mine has 407 hours on so far and has been great so far. For just over £1000 you can buy a Z4 LCD PJ which has no colour uniformaty problems and has lens shift so is easy to place in a room. For £1300ish you can buy the BenQ 7700 DLP PJ but may see RBE. The Tosh is not going to be as good as the other 2 PJs but is far cheaper. My advise would be to demo the Z4 and 7700 if your happy with spending the extra cash!

[Jonathan S]

Well, today I managed to get a demo of a DLP PJ - an InFocus Screenplay which I think must have been the 5700 as it was £2,000 at Moss of Bath.

I took in a black & white DVD of course - Orson Welles' CITIZEN KANE, chosen partly because it begins with dark mesh pattern (a fence) against bright light. I thought that would trigger the rainbows but it didn't, however much I blinked and moved my head. The overall picture quality was stunning - almost like watching it on 35mm.

AND THEN! We moved to a later scene (the opening is rather static), just a normal office sequence, nothing with really fast action, and I could see rainbows EVERY FEW SECONDS! Almost every time anyone moved. For me it seems triggered by high black/white contrast combined with movement.

Despite the overall superb quality of the image, I simply could not live with this - if I'd bought it without a demo the PJ would have been back to the shop (or on eBay) within 24 hours. Maybe I wouldn't have noticed the RBE on colour - I didn't have time to test a colour movie - but b&w films (most of my collection) would be impossible.

Unless someone can convince me the £2K Screenplay is especially bad for rainbows, I think it means back to LCD for me.

Jonathan

[Kalos Geros]

Agreed!! There were too many IFs with budget DLP like Benq 5120 for me so I decided on a budget Hitachi 550GBP WVGA LCD being more prepared to struggle with potential screendoor problem than with RBE...

[spickee]

Watched Sin City last night on the Z3 and to be honest it looked fantastic. Once your eyes have adjusted to the not quite black black, the image was superb. Thoroughly enjoyed the film, I would imagine other B&W films would look suitably nice on it as well.