Rear Projection

[jmig]

Has anyone done rear projection? If so, what did you use for the screen and what kind of results did you have?

In reading DIY forums on rear projection it seems people are getting mixed results unless they go to an expensive rear projector screen.

As I mentioned in my thread on projectors, will have shorter throws and smaller viewing images help or hurt us with rear projection?

[Trevor Hale]

John,

for years, I used Rear Projection, and was happy with it. I used a good quality 150 Thread count Bed sheet curved, and had quite good results. However, that being said, I am now moving to front projection curved, as with the rear projection I lost a lot of the night textures and the lights were too spotty.

Hopefully I will get better results this way.

Trev

[Westozy]

Hi John,

My set up uses rear projection onto a 230 thread count sheet. (Higher the thread count the better). I have the sheet stretched across a 16:9 rectangular frame made from 2" PVC pipe and elbows. The screen is mounted to the sim frame about 600mm from the windshield frame and it all works fine. The other side of the screen is our home theatre for watching movies etc.

Gwyn

[David Withers]

when compared to front projection....higher thread count is better....ie 1000 count will block hot spot etc..AND CATCH MORE LIGHT....hence you will see more detail.
colours will be blander and dimmer.....pixels will be blended better though.

it will all seem a bit "fuzzier".......sometimes that is nice.


but...front projection with or without a mirrior is way better if you can.

[Hardlight]

I agree that if you can get the correct distances front projection is the best way forward.

You may find this link useful.

http://www.hometheatershack.com/forums/projector-screens-diy-screens/8755-black-widow-pfg-discussion.html

I talks about different coatings you can put on a screen to improve picture quality (for front projection).

I think a coating such as the ones mentioned would be particularly useful for people who construct their own sometimes curved screens.

Kind Regards,
Will

[jmig]

I have an idea I want to bounce off you guys to see if it might work or if it is hair-brained.

I don't fly one airplane. I fly anything from Alaskan bush planes to jet fighters. They all have different panels and panel looks.

My idea is this: I take off the top 1/2 of my instrument panel, leaving the bottom half for switches, rotaries, etc. I mount a screen close to where the instrument panel would be and extending above and to the sides.

Using rear projection and IR Track, the aircraft's panel would be displayed on the lower part of the screen, as it looks on a monitor, and scenery on the rest.

Would that work? anyone tried it?

[Crescent]

This is exactly what I've decided to do with my Lancaster. The main reason I went with this is because I will primarily be using the sim for Battleground Europe which doesn't allow the different views like FSX does. The reaason is because it's a war simulator your only view would be in the cockpit anyway. I use trackir with it as well.

I will fill in the panel below the screens with whatever you normally wouldn't see while looking ahead and this should be a good compromise.

[Polmer]

I too am restricted with space to display a front image with the projector I currently own ( Epson PowerLite). I know there are short throw projectors available,but right not, its not in the budget.

Yesterday, I purchased a $8 white opaque shower curtain.
It initially had some folding wrinkles in it, but after removing them and then tightly stretching the vinyl material the result was pretty good.

I got the idea from this blog;

http://cmpalmer.blogspot.com/2006/08/rear-projection-bedroom-tv-project.html


I do lose some brightness compared to the front image, and Im wondering if a projector with higher lumens wouldn't have this issue(mine only has 1500). I have not tried a high tread count sheet yet, but will give it a go and come back with the comparison results.


~Polmer

[Matt Olieman]

Speaking of "Rear Projection" .... For those in the USA and have watched some of the political conventions, and the rear projection, it's amazing. I even see curved screens, and the visibility is fantastic from all angles. I should like to know what screen material they are using.

Anyone know anything about this, please share :)

Matt Olieman

[Bob Reed]

Speaking of "Rear Projection" .... For those in the USA and have watched some of the political conventions, and the rear projection, it's amazing. I even see curved screens, and the visibility is fantastic from all angles. I should like to know what screen material they are using.

Anyone know anything about this, please share :)

Matt Olieman

I think one of the folks who would know is Matt Ford.. Try dropping him a line...

[aviaparts]

I recently builded a (jentle)curved rear projection screen, using a bright polycarbonate and grey rear projection foil.
In combination with short throw projectors. There was absolutely no loss of quality compared to front projection.The only thing to make sure is that the bulb of the projector is below or above the field of view, otherwise you will have a bright spot.

Also, if using rear projection, the distance sitting from the screen and image dimensions need to be balanced to avoid pixels being to big.

[Polmer]

I have been in search of a good rear projection screen that wont break the bank but yet has a good enough quality that I can live with. I have now experimented with two inexpensive options; white opaque shower curtain, bed sheet ( 500 thread count). Here are my comparisons for all its worth;

Brightness: The Bed Sheet was much brighter than the Shower Curtain, but almost too bright. Some of the lighter colors became washed out. The opaque shower curtain reduced the brightness a little more that I liked, so a slight advantage goes to the Bed sheet here.

Color: The bed sheet produced better colors ,but again, sometimes to bright.
Slight advantage to the bed sheet again.

Lens hot spot: The clear winner here was the Curtain, and no hot spot could be seen even with the projector at eye level. The Bed sheet had serious issues here, even when I lowered the projector so that the lens was blocked from direct viewing.

Overall smoothness: The vinyl curtain gave a more professional looking image than the bed sheet.


Summary: No Clear winner, as each surface had different strengths & weaknesses. If it wasn't for the dull image brightness, I would probably stick with the curtain.

Are there any other surfaces that should be considered?


I saw the previous post mentioned;
"a bright polycarbonate and grey rear projection foil."

I would love to have more detail on this as well.


~Polmer

[Michael Carter]

I have been in search of a good rear projection screen that wont break the bank but yet has a good enough quality that I can live with. I have now experimented with two inexpensive options; white opaque shower curtain, bed sheet ( 500 thread count). Here are my comparisons for all its worth;

Brightness: The Bed Sheet was much brighter than the Shower Curtain, but almost too bright. Some of the lighter colors became washed out. The opaque shower curtain reduced the brightness a little more that I liked, so a slight advantage goes to the Bed sheet here.

Color: The bed sheet produced better colors ,but again, sometimes to bright.
Slight advantage to the bed sheet again.

Lens hot spot: The clear winner here was the Curtain, and no hot spot could be seen even with the projector at eye level. The Bed sheet had serious issues here, even when I lowered the projector so that the lens was blocked from direct viewing.

Overall smoothness: The vinyl curtain gave a more professional looking image than the bed sheet.


Summary: No Clear winner, as each surface had different strengths & weaknesses. If it wasn't for the dull image brightness, I would probably stick with the curtain.

Are there any other surfaces that should be considered?


I saw the previous post mentioned;
"a bright polycarbonate and grey rear projection foil."

I would love to have more detail on this as well.


~Polmer


You might try the bed sheet idea again with a much lower thread count. 150-200 might help to eliminate the hot spot. It will also lower the surface brightness as the weave will be more coarse.

[aviaparts]

Polmer,

To go a little deeper into the polycarbonate and foil. The polycarbonate is in fact the same as plexiglass but the difference is that it is very easy to bend it or drill holes or whatever, it will not break. You can use plexiglass as well, the result will be the same.

The grey rear projection foil is the standard foil used to build rear projection screens, you can find them at the companies building the screens, I contacted a few of them and received a few samples. The standard foil is not that expensive at all if you compare it to the rest of the cockpit stuff, it costs off course a lot more then a bedsheet but the overall result is not comparable.

Also if you have rear projection, you are sitting much closer to your screen so you don't need as much as you would be sitting further away.

[Matt Olieman]

I've used what they call Party Table Clothes (white) made from kind of plastic. I got the best results, of all mentioned above, and would use it again if I had to. It was $1.60 USD for a single 10 by 6 sheet. I ended going to front projection and the results were even better. Super white material.

[Polmer]

I have been in search of a good rear projection screen.
I have tried a high thread count liner, as well as a white shower curtain.
I have posted my reviews of these (earlier in this thread), but I wanted to post that I have finally found what I was looking for!

I sent a email to "Dazian" who makes professional screens & rear projection material and asked for a sample. They sent me back a vinyl material that was opaque & light gray in color. This got me thinking about the shower curtain idea again, but now I knew what to look for.

So today, I go to the home Depot ( A USA hardware store) and found a shower curtain Liner made by Zenith. It is called Zenith Bath styles Shower Liner, color ; Clear, Model # H28K. It is not actually clear, but a kind of fogged vinyl.

Anyway, I got home a checked it out.............Wow.
It is actually brighter on the reverse side that it is on the projection side!
You cant see the projector halo, and the colors are fantastic.

If anybody is interested, a link to the product is supplied below.
If you are experimenting with rear projection ( due to cockpit room size restrictions like I am ) give this a shot. Its only $8 us dollars.

http://www.mclendons.com/item.asp?sku=10293330


The only thing I would like is a bigger sheet. The one a bought today was 70" x 72" ( 178cm x 183cm).



Regards,

~Polmer

[jmig]

I have been in search of a good rear projection screen.
I have tried a high thread count liner, as well as a white shower curtain.
I have posted my reviews of these (earlier in this thread), but I wanted to post that I have finally found what I was looking for!

I sent a email to "Dazian" who makes professional screens & rear projection material and asked for a sample. They sent me back a vinyl material that was opaque & light gray in color. This got me thinking about the shower curtain idea again, but now I knew what to look for.

So today, I go to the home Depot ( A USA hardware store) and found a shower curtain Liner made by Zenith. It is called Zenith Bath styles Shower Liner, color ; Clear, Model # H28K. It is not actually clear, but a kind of fogged vinyl.

Anyway, I got home a checked it out.............Wow.
It is actually brighter on the reverse side that it is on the projection side!
You cant see the projector halo, and the colors are fantastic.

If anybody is interested, a link to the product is supplied below.
If you are experimenting with rear projection ( due to cockpit room size restrictions like I am ) give this a shot. Its only $8 us dollars.

http://www.mclendons.com/item.asp?sku=10293330


The only thing I would like is a bigger sheet. The one a bought today was 70" x 72" ( 178cm x 183cm).



Regards,

~Polmer

Thanks! Projectors are on my list.