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Lens installed and my picture is all wonky ?

4190 Views 18 Replies 14 Participants Last post by dropzone7, Oct 31, 2011

jamieuk147

Discussion Starter · Aug 17, 2011

Hi I own a H-FE850R Lens and a HC3800

I have a 120" 2.35.1 screen and my projector is 11.5ft to my screen

No matter what I seem to do I cant get the projected image to look straight at all corners on my screen.

Here is what it looks like from the side

You will notice it starts to b

owe

The only way I can make the sides look striaghter is by using keystone

Do I just have to live with this or is there some way to make it look better ?

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1 - 19 of 19 Posts

The Killer

· #2 · Aug 17, 2011

I am no expert, but i think your problem is the keystone, for an anamorphic lens set up you should never have keystone adjusment, you should try to make the image and screen as square as possible, to avoid geometry issues.

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Josh Z

· #3 · Aug 17, 2011

^What he said. Avoid keystone at all costs. I think what this is going to come down to is just that your projector and lens are not precisely squared with the screen. You'll need to adjust their physical positions as much as possible to get a direct 90-degree perpendicular angle. Unfortunately, this may be difficult if you've already ceiling-mounted them.

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HogPilot

· #4 · Aug 17, 2011

There is absolutely no need for digital keystone in your setup. As the other two have said, this is an alignment issue. Anamorphic lens setups (depending up on the lens) are relatively sensitive to how the lens is aligned to the light beam. This starts with making sure the projector is properly aligned with the screen, i.e. not angled in any axis. Once you do this, then you need to make sure that the light beam passes through the lens without angling left, right, up, or down. In your case it looks like the up/down angle needs to be adjusted, which is causing the uneven pincushion.

However the pincushion you're seeing can only be reduced by increasing the throw of the projector. Shorter throw = more pincushion, longer throw = less pincushion.

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dropzone7

· #5 · Aug 17, 2011

Yeah, I think your throw must be at about 1.6 which a little short from what I understand. It looks like you have the projector mounted about as far back as it will go based on your photos. Like everyone else said, make sure you are square to the screen first and set all keystone correction back to "0". Laser levels and strings are your friends. Also, I see that projector has an offset lens so were your measurements squaring the projector to the screen or the lens itself? I made that mistake once.

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Brad Horstkotte

· #6 · Aug 17, 2011

I would take the lens out of the light path first, and then ensure that the projector is aligned such that with no keystone, you have it all lined up (use vertical / horizontal shift if necessary, but no keystone) as precisely as possible. Then add back the lens, and do the same to align the lens. The lens will only amplify any issues you may have with projector alignment.

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CRGINC

· #7 · Aug 18, 2011

I have used an H-FE1500M which is similar to the lens you have. I agree with everything Brad said but I can add a couple of things. First the lens has an offset built in. Check in the manual. In my case it turned out to be the projector and the lens needed about a 1" offset from the center of the screen. Second it appears the lens is rotated slightly relative to the projector. This is what creates the geometric distortion you are seeing. In the Prismasonic lens of this type with the two screws holding the lens vertical if they cause the lens to get tilted this will produce the kind of distortion I see in your pictures. Everybody and I agree that the alignment process is very critical and a slight misalignment is really noticeable on the screen.

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rboster

· #8 · Aug 19, 2011

I wonder if the OP has had a chance to try the suggestions ppl have made in this thread. I would be interested in hearing the results/resolution. It's nice to get follow up feedback with threads like this, so if others have a similar issue, they are use the positive results as a guide for their own set up.

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Trogdor2010

· #9 · Aug 19, 2011

I also wanted to ask (Since I see you use steam, I'm a steam user too), did you know you can make custom resolution on your desktop? If you check on your desktop's video control panel (Catalyst Control Center, NVidia control panel, Powerstrip) you can set a custom resolution (say 1920x810 for example) and it will make your scope screen into a desktop. Set it to either 16:9 or V-stretch, depending on how the signal accepts the image. In fact, with some games, you can actually get more picture info out of the image. I play alot of Team Fortress 2 (Free game now) which works perfectly fine.

I have screenshots of my games I play. Add me if you like.

http://steamcommunity.com/profiles/76561197976772214

(Keep in mind one of the screenshots is a test image for farther FOV, everything else works fine)

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dropzone7

· #10 · Aug 20, 2011

Quote:
Originally Posted by rboster /forum/post/20841775

I wonder if the OP has had a chance to try the suggestions ppl have made in this thread. I would be interested in hearing the results/resolution. It's nice to get follow up feedback with threads like this, so if others have a similar issue, they are use the positive results as a guide for their own set up.

Agreed. I have a CIH setup in my future and I'm curious what to expect with integrating the lens and projector. I picked up a used Prismasonic H1200R lens for a great price locally but don't have a projector yet. I know it's an older lens but I figured it would fine to start with and the price was too good to pass up.

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coolrda

· #11 · Aug 20, 2011

Another thing you can do is check center alignment. It important to have the projector precisely aligned before adding a lens into the fold. You can measure to make the projectors 16x9 picture is evenly pillarbox on the screen. Now zoom out to it hits the edge of the screen. Are both sides equal. If not the projector isn't perpendicular and the lens will just make it worse. Fractions of a degree can affect focus uniformity and you'll take a performance hit. Lastly you should adjust your pincushion so it's equal on the top and bottom, by simply rotating the lens up and down.

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rboster

· #12 · Aug 20, 2011

Here's a previous thread of the OP's asking about pincushion and keystone correction, so he should be well aware of issues of using keystone correction.

http://www.avsforum.com/avs-vb/showthread.php?t=1292380

It would help those that are trying to help him, if he report back in this thread.

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codeoverride

· #13 · Sep 8, 2011

nice

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CRGINC

· #14 · Sep 17, 2011

Per my suggestion above some prism lenses including the 850 introduce a horizontal image shift per Prismasonic. "NOTE: H-850M introduces some horizontal offsetto the image. The offset is to the left for table mounted, and to the right for ceiling mounted lens. This must be compensated by horizontally shifting the screen in respect to the projector, or if available, using the horizontal lens shift of projector." Therefore when using this lenses the projector is not dead center to the screen.

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santafe2

· #15 · Oct 30, 2011

Thanks everyone. This is a great little thread. I'm beginning to think I can set up my own HT if I pay attention to detail, keep making notes from these threads and asking questions here until I feel like I've got the basics down.

I've a question for those more experienced. When I looked at the OPs pictures and descriptions, I was thinking his TR was 1:1.15, (120":11.5'), but re-read another thread and realized I was using scope dimensions and not 16:9 to come up with that calc. I'm also assuming the OP is talking about screen width when he says he has a 120" screen. Is it a mistake to make this assumption?

One of the posters gave a 'back of the napkin' TR calc of 1:1.6 and when I use 16:9 I get a TR of 1:1.52 which is close so that should cause the pincushion unless I've missed something. After measuring my space for the 50th time it looks like realistically I'll have a 15' throw from the front of projector which means I should limit my scope screen width to 120-124" to keep my TR over 1.8.

I don't think I'll tackle CIH until I've had my projector for a few months and know a lot more than I do today. Thanks again for all the good information. I'm off to the screen threads to begin to tackle that piece of the process.

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Glenn Baumann

· #16 · Oct 30, 2011

Quote:
Originally Posted by CRGINC /forum/post/20963765

Per my suggestion above some prism lenses including the 850 introduce a horizontal image shift per Prismasonic. "NOTE: H-850M introduces some horizontal offsetto the image. The offset is to the left for table mounted, and to the right for ceiling mounted lens. This must be compensated by horizontally shifting the screen in respect to the projector, or if available, using the horizontal lens shift of projector." Therefore when using this lenses the projector is not dead center to the screen.

Sorry, I hope I am not highjacking this thread but my concerns center around the ability to have ample room to move the screen itself around to compensate for any A-lens or projector mounting imperfections.

Does anyone know if the Panamorph UH480 lens introduces any Horizontal OR possibly any vertical shifting of the image?

The reason I ask is, I would like to make the opening in my false wall where the screen mounts as small as feasible so I can move the screen up and down to compensate for any image shifting anomalies I might possibly encounter!

I would think that I should have some fudge room as the screen border is maybe 3.5" wide all around and factoring this in with a minimally sized false wall screen opening should theoretically allow me to compensate for any image shifting caused by the A-lens or imperfect projector mounting. I would hopefully be able to move the screen around as much as is required and also not be able to see a gap allowing the inside of the false will to be seen

Am I on the right track with this thinking?

...Glenn

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Kelvin1965S

· #17 · Oct 30, 2011

Sorry Glen I can't help with the UH480 horizontal shift or not...FWIW my Isco II doesn't but that isn't much help I guess.

What does amaze me though is that Jamie's threads seem to last longer than his interest in them.

I've replied to previous threads started by him and then seen him start another thread asking basically the same question again. There is no 'thanks' button on AVS unlike AVForums so unless someone posts a brief reply you're never really sure if they saw your reply or not...kind of makes me less inclined to reply in future when that happens.

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Glenn Baumann

· #18 · Oct 31, 2011

Quote:
Originally Posted by Kelvin1965S /forum/post/21146239

Sorry Glen I can't help with the UH480 horizontal shift or not...FWIW my Isco II doesn't but that isn't much help I guess.

What does amaze me though is that Jamie's threads seem to last longer than his interest in them.

I've replied to previous threads started by him and then seen him start another thread asking basically the same question again. There is no 'thanks' button on AVS unlike AVForums so unless someone posts a brief reply you're never really sure if they saw your reply or not...kind of makes me less inclined to reply in future when that happens.

You know what they say about asking the same question over and over again and expecting a different answer!

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dropzone7

· #19 · Oct 31, 2011

Glenn, as a fellow forum member I can't sit back and allow you to take such a chance with that lens. In the remote chance that it might be less than perfect I suggest you just box the whole thing up and send it to me. It's the least I can do...

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