hey togehter,

i still got problems with the blobs in my ReadDi Setup
first i had 950nm LEDs which were a bit to high for my camera.
now bought new spots from ebay with 860nm but the result is even worse.
They are really bright and i can see the light great in the camera image.
I used varnish foil to reflect inside the box and have quite a good illumination.
But the only blobs i can still see are dark shadows of my hand.

Filter: cut off higher then 800nm
Camera: Sensitiv up to +-930nm
Spots: 860nm (4x 48LED 12V)

(i am using diginline contrast and a glass surface, but also checked acryl and rosco gray in all combinations)

Thank you,

Jewe

what program are you using? tbeta or touchlib?
and im guessing you are using a projector as rear di wont work if you are using an LCD and any chance of pics???

cheers

is it working without the projector?

hi,

i am using ccv (tbeta) and a Acer s1200 Projector which is not an LCD projector.

here are some pictures. (see filenames for information)

thank you

edit: @vincent: no, same result without projector!

jachwe - 01 July 2009 08:42 AM

Filter: cut off higher then 800nm
Camera: Sensitiv up to +-930nm
Spots: 860nm (4x 48LED 12V)

So what type of filter are you using?  By cut off, that makes me think of a pass filter that only lets light through that is below 800nm, which sounds close to the results you are getting since you see a lot of ambient light in the last pictures you posted.  If you have a TON of sunlight coming in, or have other IR emitting lights than your pictures should look like that, but what you really want is it to be completely black with just the white of the LEDs coming through.  You want a high pass (infrared passing) filter, like a piece of floppy disk or a selective band pass filter.

By the way, how is the digiline contrast?

Hey peau,

sorry i was meant to send you pictures of digiline already (you asked for in annother thread). i just had no proper camera here till now.
I will try to do it tomorrow.

I definately have a filter which cuts of visible light. (check out the datasheet: http://www.farnell.com/datasheets/49938.pdf )
The color picture from the camera is only b/w now.
I do have normal ambient light in the lab at uni and the picture doesn’t really change when i go to a room with no windows.
I tried a lot but all i can get are these damn dark blobs.

Thanks for any more hints.

Jewe

Ok so you have a high pass filter, that should work.  Dark blobs are only usually made when you have more ambient IR light than you have IR light hitting your fingers from the sides (LLP) or below.  This is known usually as Front DI.  Something isn’t working with your lights....?

And about the digiline contrast, I’ll take the pictures, but I’m more intersted in your review on the material itself: ease of application, what did you stick it to, picture quality with what lumen projector, etc.

PeauProductions - 01 July 2009 12:38 PM

Ok so you have a high pass filter, that should work.  Dark blobs are only usually made when you have more ambient IR light than you have IR light hitting your fingers from the sides (LLP) or below.  This is known usually as Front DI.  Something isn’t working with your lights....?

And about the digiline contrast, I’ll take the pictures, but I’m more intersted in your review on the material itself: ease of application, what did you stick it to, picture quality with what lumen projector, etc.

The application of the Digiline was really charming. I had the Rosco before and it was nearly impossible to mount it under the glas so that is was straight. Even if you really spanned it, it lost tension after a few hours. The Digiline Contrast is self-adhesive, so you dont have that problem. With some Soap and Water you can easily bring it to the surface without any bubbles and exactly in the place were you want it. I actually sticked it into an area that i cut out of an “sandblast"-look foil (which looks quite the same, but is much cheaper) that is outside my projection area. You can hardly see the gap between those two because you can easily push around the Digiline as long it is still wet to bring it in the place where you need it. I mounted it on a 80x60cm (32x24inch) glass plate. I also tried it on a small piece of acryl for couriosity. It worked exactly the same.

I like the fact that it is almost neutral in color other than the really dark rosco screen. With no projection it looks a bit like sandblasted glass. When the projector is on you have a really nice picture. I use a Acer s1200 which got 2500 Lumen but run it in “Eco-mode” which is still more than enough. Well, there is a slight hotspot but only if you look directly into the lens. But the picture is clear, got good contrast and looks pretty much the same from any angle.

As far as i could test it it transmit the IR quite good. I just put different IR Sources on top of the screen and checked the camera picture, so i can’t exactly tell, but it seemed to be okay. We had a transmission between two mobiles working through the screen, mounted on the glass.

A big plus for the screen is that (if you order it at IFOHA in Germany) you can have it in every size and shape. You you get exactly what you need and got no wastage. The screen is expensive enough. I paid 120€ (170$) for this 80x60cm (32x24inch) piece. But delivery was quick and without any problems.

So after all, even i had no big chance to compare many more materials, i would recommend the Digiline.
Pictures are still to follow

(I am still open (and looking) for ideas that might help me with my problem)…

Greetings from Germany

Jewe

it seems that your hand and fingers are seen as shadows… --> to much ambiant light or not enough IR light…

Thanks for the review man, I’ll include parts of it in the large review I’m putting together (15+ projection materials).  Only problem with IFOHA that I’ve found is that they don’t ship out of the European area :(

PeauProductions - 01 July 2009 05:14 PM

Thanks for the review man, I’ll include parts of it in the large review I’m putting together (15+ projection materials).  Only problem with IFOHA that I’ve found is that they don’t ship out of the European area :(

They do ship out of the EU area. I’ve checked IFOHA.nl (because I’m dutch ) and it says following:
Alle verzendtkosten hebben de aktuele geldige BTW. De verzending wordt gedaan met UPS. (!!! Bij leveringen buiten de EU landen zoals Zwitserland, zijn eventueel aanvallende gegevens, zoals douane niet bij inbegrepen!!!)

Translation:
All shippingcosts are tax included. Shipping is done by UPS. (!! Shipments outside the EU countries like Switzerland, are costs due customs not included!!!!)

Gtrz T.

Good to know man, you can check out my review on the digiline stuff and other projection materials here: http://peauproductions.com/diff.html

jachwe - 01 July 2009 12:31 PM

...I do have normal ambient light in the lab at uni and the picture doesn’t really change when i go to a room with no windows.
....

Jewe

but your picture should be different if you move to a room without windows, especially with fluorescent bulbs, since they don´t emitt much IR-light…
do you get white blob when you´re using no filter at all? try a floppy oder exposed film filter, maybe they sent you the wrong filter