16:9 Screen Vs. 2.37:1 CIH Screen

[Prof.]

Mark Techer wrote:

Prof,

Maybe I have got the math wrong...and it looks like your right...

My screen is 949mm high x 2.37 = 2250mm.

1st row 2000mm.

2nd 3000mm (a bit tight).

Projector, just behind that at about 3200mm.

Therefore TR should be 3200mm / (949 x 1.78) = 1.89:1

It looks like your screen size and TR are almost identical to mine...except I don't sit quite as close as you do..don't have the same resolution as the W5000..

So anyway, the pincusion was less than the 1.3:1, but not totally reduced. My screen is adjustable, so I can compensate here.

I'm guessing that with your current set up now, you probably have about the same amount of pincushion that I'm getting..
It would seem that the W5000 would fit nicely in my room..

The TR won't change as TRs for VCs are taken off the Scope Image width, not the 16:9 image width, but the projection distance will increase 3200mm to over 4250mm allowing better spaced seating.

WOW!!.I had no idea that VC would increase the projection distance by that much!!..which would put my projector outside in the yardl!!

Also with a VC, you don't get pincushion at all and I can actually go back to a flat screen. What you get is "barrelling" but the barrelling is much less than the pincushion.

That would be nice to have but unfortunately I don't have the length in the room..

CA that normally runs vertcially with a HE will now run horizontally, but I am not expecting to see any CA with my new lens (a shamless plug ) that is under development right now and will use achromatic doublets.

I'm very interested to see the pics of that lens when it's finished..

Lastly is the focus issue where typically a DIY prism lens tends to loose a bit of shapness towards the edges, the VC maintains sharpness all the way and this is why Panamorph used the VC design for so many years.

That would be nice to have..

If there is to be any loss in sharpness with the VC, it will be seen at the top and bottom of the image not the sides.

I would find that annoying, because I'm more aware of the sharpness, top and bottom of an image when watching a movie, rather than the sides..and it's only when I specifically look at th sides that I notice it in some scenes..

My lens is also cylindrical, not prismatic, so I have designed anstigmatism correction into the design as well...

Cool!!

The only problem with using a VC is that the lens must remain in the light path all the time or the 16:9 image become much taller. This is not really a problem (with 1080 anyway) as the light levels, pixel density and colour all remain the same when leaving the lens in place - which I have been doing anyway with my HE lens.

Likewise for me...I'm even leaving the lens in place for all AR's of the movies I buy or rent, so everything is viewed in cinemascope...even if the occassional head gets chopped off!!

[Mark Techer]

Prof. wrote:

It looks like your screen size and TR are almost identical to mine...except I don't sit quite as close as you do..don't have the same resolution as the W5000..

1080 rez allows you to sit close as you simply do not see the pixel structure. 2x the image height is actually quite good, but until I saw this for myself, I didn't believe it...

I'm guessing that with your current set up now, you probably have about the same amount of pincushion that I'm getting..
It would seem that the W5000 would fit nicely in my room..

Probably would...I like the BenQ despite the neg reviews it got from around the world....

WOW!!.I had no idea that VC would increase the projection distance by that much!!..which would put my projector outside in the yardl!!

I want the projector behind the seating and not above it, so this is the only way to do that...

That would be nice to have but unfortunately I don't have the length in the room..

Can't have everything

I'm very interested to see the pics of that lens when it's finished..

There will be plenty of pictures, don't worry about that

I would find that annoying, because I'm more aware of the sharpness, top and bottom of an image when watching a movie, rather than the sides..and it's only when I specifically look at th sides that I notice it in some scenes..

And the reason I am going cylindrical this time too - you can adjust the focus of the lens to be razor sharp corner to corner - prisms will never allow that..

Likewise for me...I'm even leaving the lens in place for all AR's of the movies I buy or rent, so everything is viewed in cinemascope...even if the occassional head gets chopped off!!

I won't chop heads. I use eithe the 4x3 mode or the letter boxed mode to ensure that I have true CIH for those ARs...

Mark

[Prof.]

Mark Techer wrote:

Probably would...I like the BenQ despite the neg reviews it got from around the world....

I've only ever seen good reviews..What are the negative aspects?

And the reason I am going cylindrical this time too - you can adjust the focus of the lens to be razor sharp corner to corner - prisms will never allow that..

So, still no possibilities for marketing the new lens.?

I won't chop heads. I use eithe the 4x3 mode or the letter boxed mode to ensure that I have true CIH for those ARs..

.
I'm afraid I've been utterly spoilt with cinemascope images..to the point where I'm very reluctant to watch any movies in 1.78...It just seems so boxy!!..almost like the old 4:3 box TV..

[Mark Techer]

Prof. wrote:

I've only ever seen good reviews..What are the negative aspects?

Where to begin? I don't want to come across as negaitve, but there are many issues with these projectors. BenQ have done the right thing and arranged repair or exchange when faults are reported so well done to them for that. The 8720 was a beast of a projector, and I had just hoped that quality would have been carried into the new models. It seems that was not the case and that legacy ended at W10000.

Some of the issues are simply manufacturing - the have done the right thing by keeping prices low, but QA did drop a touch - it had too. Take the lenses for example. Many (not all, as mine seems to be one of the good ones) have silicon contamination. I am told that this means that the sand used to make the glass was not pure silcon sand, and I have even seen artifacts such as "blue blobs" (like dust blobs on LCDs) projected on screen from several W5000s and a W20000.

Light leakage is a concern and it too can be seen on screen in some instances because of the way the vents are aligned.

FW updates - BenQ have been really good here updating FW for free and even arranging pick up and drop off of the units for people - talk about great customer service here!!!

But for the money, this product is still one of the best projectors out there and allowing true HD for that price is something BenQ have done well...

So, still no possibilities for marketing the new lens.?

No, I have the ZEMAX designs now Just looking for manufactures that can make that diameter lenses. As soon as I get glass, I will be posting images - lots of them

I'm afraid I've been utterly spoilt with cinemascope images..to the point where I'm very reluctant to watch any movies in 1.78...It just seems so boxy!!..almost like the old 4:3 box TV..

Scope is great, but not everythig was filmed that way, so in the name of "preserving the art" I will watch the smaller ARs when such films are presented as such.

For me, AR change is easy. I just switch from Letterbox to the 4 x 3 mode. For you, you would also have to toggle the EZ View mode taking the player back to WIDE first, then switching the projector to 4 x 3...

Mark

[Prof.]

Mark Techer wrote:

Where to begin? I don't want to come across as negaitve, but there are many issues with these projectors. BenQ have done the right thing and arranged repair or exchange when faults are reported so well done to them for that. The 8720 was a beast of a projector, and I had just hoped that quality would have been carried into the new models. It seems that was not the case and that legacy ended at W10000.

Some of the issues are simply manufacturing - the have done the right thing by keeping prices low, but QA did drop a touch - it had too. Take the lenses for example. Many (not all, as mine seems to be one of the good ones) have silicon contamination. I am told that this means that the sand used to make the glass was not pure silcon sand, and I have even seen artifacts such as "blue blobs" (like dust blobs on LCDs) projected on screen from several W5000s and a W20000.

Light leakage is a concern and it too can be seen on screen in some instances because of the way the vents are aligned.

FW updates - BenQ have been really good here updating FW for free and even arranging pick up and drop off of the units for people - talk about great customer service here!!!

But for the money, this product is still one of the best projectors out there and allowing true HD for that price is something BenQ have done well...

That is surprising!..I had no idea they were having so many problems..and no FW update is going to fix light leakage problems, or contaminated lens elements..and I can't see BenQ looking for a replacement lens, that doesn't have any contamination!!..

I would have to seriously re-think about getting one, when I upgrade to 1080p..
Pity really, as they looked to be a good choice for Anamorphic projection..
It's good to hear at least, that BenQ are doing the right thing by their customers..

Have you had this problem of light leaking onto the screen..or does the lens help to block this off.?

No, I have the ZEMAX designs now Just looking for manufactures that can make that diameter lenses. As soon as I get glass, I will be posting images - lots of them

Probably your best bet would be China..I had the name of a lens manufacturer in China who would make up any type of lens..and in relatively small quantities..I'll see if I can dig it up..

For me, AR change is easy. I just switch from Letterbox to the 4 x 3 mode. For you, you would also have to toggle the EZ View mode taking the player back to WIDE first, then switching the projector to 4 x 3...

Actually it's the same for me...The player stays on WIDE all the time and I just have to press 4 x 3 on the projector remote to go to 16:9..

[Mark Techer]

Prof. wrote:

Have you had this problem of light leaking onto the screen..or does the lens help to block this off.?

In the my case, the light leak is up higher than the screen, close to the ceiling. It is light coming out the exhaust vent.

Don't let the problems I have high lighted put you off. The projector is still very very good, but I have identified and reported the problems and thought I would share them here...

Probably your best bet would be China..I had the name of a lens manufacturer in China who would make up any type of lens..and in relatively small quantities..I'll see if I can dig it up..

That would be very good if you could Prof, thanks...

Actually it's the same for me...The player stays on WIDE all the time and I just have to press 4 x 3 on the projector remote to go to 16:9..

Yes, that is it

Mark

[Prof.]

Mark..This is the Chinese lens maker I was referring to..

http://en.highlight-opt.com/GeneralC...33c720fd0.html
You might even find something suitable off the shelf..

[Mark Techer]

Thanks Prof

Mark

[mnfish]

Mark, Any news of the new lens yet?

[mnfish]

BTW..I have a BenQ W5000 and am looking a getting or making a lens. I've heard good things about these projectors and was suaded over the Sony's, which I could get cheaper, for this one. I have a Screen Innovations Reference 92" 16:9 screen new in the box but am going to sell it and make a 110" 2:35:1 screen. I think in white? 1.0 gain? I'm not sure what my throw will be but I will probably hang the screen then move the projector back until I get the height correct on the v stretch mode and put it there on the ceiling. Will I need the anamorphic lens in place first before I do that? Might be hard to do? I might have to have two people hep me to do that?