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anamorphic lens question

post #1 of 48
Thread Starter 
do all anamorphic lens setups require a curved screen? do they all make the picture have a bowtie effect?
post #2 of 48
No they do not. The benefit of having a curved screen with an anamorphic lens is to alleviate what's known as the pincushion effect.



There are negatives to using a curved screen that you should be aware of. Curved screen setups are prone to hotspotting in the center of the screen.
post #3 of 48
Quote:
Originally Posted by Seegs108 View Post


Good image If your moving the lens out of the light path and watch about 50% 16:9, then you probably don't need or want a curved screen. In cases like mine where the lens in left in 100% of the time, the curved screen works to correct the distortion shown on the right. All my image have straight horizontal lines because of the curved screen.

Quote:
There are negatives to using a curved screen that you should be aware of. Curved screen setups are prone to hotspotting in the center of the screen.

A high gain flat screen can cause hot spots as well, so not just the cone effect caused by the curve.
post #4 of 48
Thread Starter 
how bad does the pincusion get? like say you line up the middle of the image with the top and bottom of the screen, how far over at the corners is the image? i know this is going to all be dependent on screen size, and lens type but just some examples of how controlled it can be?
post #5 of 48
Thread Starter 
also would i even be able to use an anamorphic lens with my projector? i have the epson 3010 3d, and the picture comes out flat out of the bottom of the projector( you have to have the bottom of the projector lined up with the bottom of the screen or mounted upside down and lined up with the top of the screen) would i be able to use a lens still?
post #6 of 48
Thread Starter 
im lookin at doing a 45"x106" screen
post #7 of 48
You have a choice. If you stay with a flat screen you will have pin cushion distortion with an A-lens for all 2.35 images.
If you go to a curved screen you will have little or no distortion using the A-lens for 2.35 , but you will have barrel distortion of all 16:9 images with the lens removed (as it should be).
post #8 of 48
Quote:
Originally Posted by counterbond View Post

how bad does the pincusion get? like say you line up the middle of the image with the top and bottom of the screen, how far over at the corners is the image? i know this is going to all be dependent on screen size, and lens type but just some examples of how controlled it can be?

Well it's dependent on your throw ratio, but if you're say a ways out, like in the 2x throw or more, then you're looking at probably on the order of a quarter to half inch.

Quote:
Originally Posted by counterbond View Post

also would i even be able to use an anamorphic lens with my projector? i have the epson 3010 3d, and the picture comes out flat out of the bottom of the projector( you have to have the bottom of the projector lined up with the bottom of the screen or mounted upside down and lined up with the top of the screen) would i be able to use a lens still?

Lens shift/offset doesn't factor into it.
post #9 of 48
Thread Starter 
so the farther back you set your projector, and the smaller you make the image coming out of the projector, the less pincusion there will be?...hmmm.. wonder if i could get away with ceiling mounting with a retro reflective
post #10 of 48
Bouncing off a front surface mirror, retro prism, or whatever to lengthen the throw and narrow the projection angle is only going to give you more picture degradation to the point that the use of an A-lens (using that approach) is self defeating. If you cannot tolerate the pin cushion and/or barrel distortion that you will inevitably get to some degree with a lens then I recommend you stay with zooming which has none of these issues. Sometimes the simplest approach is the best.
post #11 of 48
Quote:
Originally Posted by counterbond View Post

how bad does the pincusion get? like say you line up the middle of the image with the top and bottom of the screen, how far over at the corners is the image? i know this is going to all be dependent on screen size, and lens type but just some examples of how controlled it can be?

It all depends on the throw. The shorter the throw, the worse it gets.

Quote:
Originally Posted by counterbond View Post

also would i even be able to use an anamorphic lens with my projector? i have the epson 3010 3d, and the picture comes out flat out of the bottom of the projector( you have to have the bottom of the projector lined up with the bottom of the screen or mounted upside down and lined up with the top of the screen) would i be able to use a lens still?

I would, but then again, I have a decent throw (2.1:1) and I have a curved screen, so pincushion is a non issue for me. Having tested a 3D projector with an A-Lens in my own room (HC9000), I want 3D and hope to have it this year sometime.

Quote:
Originally Posted by counterbond View Post

so the farther back you set your projector, and the smaller you make the image coming out of the projector, the less pincusion there will be?...hmmm.. wonder if i could get away with ceiling mounting with a retro reflective

Adding more complications that are not required. As taffman said, sometimes the simple things are the best. I'm not saying not to use a lens because I do use one, but the mirror will cause you grief.
post #12 of 48
The Isco lenses do not produce side bowing like your example.

By retro-reflective I'm sure he meant screen, not mirror
post #13 of 48
Quote:
Originally Posted by counterbond View Post

how bad does the pincusion get? like say you line up the middle of the image with the top and bottom of the screen, how far over at the corners is the image? i know this is going to all be dependent on screen size, and lens type but just some examples of how controlled it can be?

Tell me your screen size, and throw distance, I'll tell you how much pincushion there woudl be on a flat screen, with an Isco lens.
post #14 of 48
Counterbond,

AKAIK, only the 5010/6010's have a mode that will accommodate an anamorphic lens (ie. vertical stretch mode). You should check into that before you move on. If you can afford it and can return it, I'd suggest getting the 5010 which I'm pretty sure has anamorphic stretch and definitely has lens shift.

I have an Optoma HD3300 which has anamorphic stretch mode and it works in 3D as well (pretty amazing). That said, I think the image I have is too large for 3D. It's fine for 2D but in 3D some of the high speed scenes get pretty damned nauseating. Best overall 3D experience I've ever had, though, bar none. Christmas Carol 3D with Jim Carrey one of the most amazing things I've seen in my home theater.
post #15 of 48
Quote:
Originally Posted by blastermaster View Post

I have an Optoma HD3300 which has anamorphic stretch mode and it works in 3D as well (pretty amazing).

Good news. Does it have Horizontal Squeeze as well? This is looking as a good entry level candidate to replace the W6000.
post #16 of 48
It has three modes: Letterbox (used for vertical stretch), 16:9 and 4:3 (used for me when I'm lazy and want to keep my lens in place for 16:9 content). So I'm not sure about the horizontal squeeze.

For 2.35 3D blu ray movies, it is an absolute stunner. This projector is so much better than my Benq W5000 - the picture is so crisp and there is absolutely no unwanted grain that isn't part of the movie itself (Benq was bad for that).

Unfortunately, I just found out today that the Optoma has no support for anamorphic stretch of half SBS 3D content. Oh well, it's still great for its price point.

I've said this in other threads, but the Optoma ZD201 glasses are so incredible. I would suggest to not go cheap on the glasses - it makes a major difference. My cheapie 3D glasses have some ghosting, but the Optomas show none and also have much better contrast.
post #17 of 48
[quote=blastermaster;21844897]It has three modes: Letterbox (used for vertical stretch), 16:9 and 4:3 (used for me when I'm lazy and want to keep my lens in place for 16:9 content). So I'm not sure about the horizontal squeeze. [quote]

With 2D projectors, 4x3 is the horizontal squeeze mode assuming the scaling works for HD over HDMI.

Quote:
For 2.35 3D blu ray movies, it is an absolute stunner. This projector is so much better than my Benq W5000 - the picture is so crisp and there is absolutely no unwanted grain that isn't part of the movie itself (Benq was bad for that).

You didn't run "brilliant colour" did you?

Quote:
Unfortunately, I just found out today that the Optoma has no support for anamorphic stretch of half SBS 3D content. Oh well, it's still great for its price point.

So frame packed only? Strange. That would TTB would not work as well.
post #18 of 48
Quote:
You didn't run "brilliant colour" did you?

I'm ashamed to admit that I did strictly because it seemed to add more brightness to the picture and I was really hurting for lumens. I know it made it worse than not using it, but even with it off, the Optoma in 2D bests it by a fair margin. I bought the Optoma only because my Benq died and I didn't bank on enjoying 3D. But seriously, when its done right (Hugo, Tintin, Legend of the Guardians), it is absolutely spectacular.

As far as anamorphic support, the only other pj I know of that supports it in 3D is the Mits. 9000d which runs around $6k. This is amazing bang for your buck, and with the rate at which 3D is getting better, it's not worth putting a whole lot of money into one projector when it's going to be obsolete the following year. I'm still happy with my purchase despite the fact that anamorphic stretch only works for framepacked blu rays.

And from what I've seen/read, nothing does 3D like DLP, so even the 9000d is a no go for me. I love the pop!
post #19 of 48
Quote:
Originally Posted by blastermaster View Post

I'm ashamed to admit that I did strictly because it seemed to add more brightness to the picture and I was really hurting for lumens. I know it made it worse than not using it, but even with it off, the Optoma in 2D bests it by a fair margin. I bought the Optoma only because my Benq died and I didn't bank on enjoying 3D. But seriously, when its done right (Hugo, Tintin, Legend of the Guardians), it is absolutely spectacular.

I am curious to see this for myself. I recently did another full calibration of the W6000 and the gamma end up at 2.8, not 2.2. But it looks spectacular and so much better than the W5000 did at 2.2.

I've started re-watching those dreaded Star Wars BDs again and since the latest calibration, really don't have much to complain about this time round. In fact SW2 which was shot digitally looked almost too animated but the false grain that annoyed me the first time I screened these films, did not bother me anywhere as much. The only part that still looks dodgy is the "Tuskin Raider slaughter" where the sky is very pixelated.

Quote:
As far as anamorphic support, the only other pj I know of that supports it in 3D is the Mits. 9000d which runs around $6k. This is amazing bang for your buck, and with the rate at which 3D is getting better, it's not worth putting a whole lot of money into one projector when it's going to be obsolete the following year. I'm still happy with my purchase despite the fact that anamorphic stretch only works for framepacked blu rays.

All the new JVCs and SONY does too now. I've also heard INFOCUS does as well.

Quote:
And from what I've seen/read, nothing does 3D like DLP, so even the 9000d is a no go for me. I love the pop!

And that is saying something given that the HC9000 was almost 10K when I got to play with one in my own room. That unit produced amazing 3D pop out and depth. So if the Optoma is better, for almost 1/8th the price, then yeah, I'm excited. I am also keen on the BenQW7000 as it too is DLP link 3D with full scaling.
post #20 of 48
Quote:
And that is saying something given that the HC9000 was almost 10K when I got to play with one in my own room. That unit produced amazing 3D pop out and depth. So if the Optoma is better, for almost 1/8th the price, then yeah, I'm excited. I am also keen on the BenQW7000 as it too is DLP link 3D with full scaling.

I'm a big fan of DLP and would be hard pressed to convert to any other technology. I like the fact that the Benq has lens shift and all, but damn I had a bugger of a time with my W5000 and an even worse time with tech support such that I don't think I'd buy another pj from them. I've heard good things about InFocus in terms of customer support and was almost ready to shell out my beans for the SP8602. However, I had a good experience with my old Optoma H31, so I figured I'd give them another go.

Whatever way you go, 3D and DLP is a perfect match. There is no ghosting like I've seen on every other non-dlp set. The Benq will definitely give you better placement flexibility, but as I said, I had problems with them and as the saying goes, once bitten...
post #21 of 48
Quote:
Originally Posted by blastermaster View Post


Whatever way you go, 3D and DLP is a perfect match. There is no ghosting like I've seen on every other non-dlp set. The Benq will definitely give you better placement flexibility, but as I said, I had problems with them and as the saying goes, once bitten...

I am fan of DLP as well and don't particularly like the convergence issues associated with 3 chip systems. RBE was an issue when I first got into DLP, but what I found with both the W5000 and W6000 is that you do get used to it pretty fast and more so when the projector is calibrated. I don't even see it now on the W6000.

The W7000 uses the same chassis, so will bolt straight onto the mounting system I have made and because it has the lens shift, makes it very easy to install and align with my A-lens.
post #22 of 48
Quote:


how bad does the pincusion get

As I'm sure others will tell you on this forum, pincushion will depend on your throw ratio. That is, how far your projector is from your screen divided by the width of your screen. If you are at least 2.0 in this regard, you should notice very minimal pincushioning. Much less and you will be noticing pincushioning in a very noticeable way. Masking will help with this, though.
post #23 of 48
Cavx,

Sounds like you've had the W5000 and the W6000 and are about to take the plunge to the W7000. If you have had good luck with the BenQs thus far, I say go for it. Going from the W5000 to the Optoma has been a bit of a pain due to the lack of lens shift (although my Benq sh!t the bed and lens shift stopped working), but I've made due. I'd be interested to know if the Benq has the ability to stretch half SBS content. This is definitely something I'm going to look into.
post #24 of 48
My pincushion is one percent or 1/2 inch at the top and bottom of a 54" tall screen flat screen. I very particular about my image so I overscan a little. The 1/2 Inch is of no consequence to me.
post #25 of 48
Quote:
Originally Posted by GetGray View Post

The Isco lenses do not produce side bowing like your example.

By retro-reflective I'm sure he meant screen, not mirror

I wondered as my sides are perfect.
post #26 of 48
Quote:
Originally Posted by Fannie136 View Post

how bad does the pincusion get?

As said, the longer the throw, the less you see. I am at 2.1:1 and I still use a curved screen because I leave the A-Lens in place all the time. I decided that I wanted straight lines so curved my screen. I can run a PC desk top and not have any geometry issues that would otherwise plague a system with a flat screen.

Quote:
Originally Posted by blastermaster View Post

Cavx,

Sounds like you've had the W5000 and the W6000 and are about to take the plunge to the W7000. If you have had good luck with the BenQs thus far, I say go for it. Going from the W5000 to the Optoma has been a bit of a pain due to the lack of lens shift (although my Benq sh!t the bed and lens shift stopped working), but I've made due. I'd be interested to know if the Benq has the ability to stretch half SBS content. This is definitely something I'm going to look into.

Yeah I got the W5000 in 2008 and last year (just over 1500 hours) it got a case of the dreaded "vertical stripes". BenQ said they would fix it, but because it was out of warranty it would cost me just under $800 and they'd only give 28 days warranty on the new parts. I then got the chance to buy the W6000 at about half the original RRP with full warranty, so jumped on that. I would like to upgrade to the W7000 for 3D now as I am impressed with the W6000, and 3D would be just creme on the cake.

Quote:
Originally Posted by Edna236 View Post

There are negatives to using a curved screen that you should be aware of.

Well of course there are because the curved screen serves the purpose of correcting an issue caused by adding the A-Lens - that is pincushion.

When you remove the A-Lens, you have removed the very reason you curved the screen in the first place and the image now barrels. Some don't mind this as it is probably not as offensive as the pincushion the curve corrects.

In the end of the day, I don't want either pincushion or barrel and one reason why I leave the lens in place all the time. The other reasons are equal pixel density regardless of AR and only one calibration setting required is required. It also makes the system extremely easy to operate with a change in AR a simple push of a button.
post #27 of 48
Quote:
Originally Posted by GetGray View Post

The Isco lenses do not produce side bowing like your example.

I wonder if that is because of the cylindrical design? I am sure it was present on the older prism based lenses. I too have straight vertical edges, but I do wonder of the image was large enough (mine is under 4' tall), would any curve actually be visible? I've not really had the chance to project say 8' tall.
post #28 of 48
Quote:
Originally Posted by CAVX View Post

I wonder if that is because of the cylindrical design? I am sure it was present on the older prism based lenses. I too have straight vertical edges, but I do wonder of the image was large enough (mine is under 4' tall), would any curve actually be visible? I've not really had the chance to project say 8' tall.

Probably. My personal screen is 56" tall, I've seen the same Isco on much larger screens and still no side curvature.
post #29 of 48
you guys are just referring to the curve on the sides correct? the ISCO will still have the same curve on the top and bottom like prisms (just with straight sides)?
post #30 of 48
Quote:
Originally Posted by ojuicy View Post

you guys are just referring to the curve on the sides correct? the ISCO will still have the same curve on the top and bottom like prisms (just with straight sides)?

Similar but they are not exactly the same.
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