antiglare removal

[pepe303]

Originally posted by bw
Hi,
I also tried the AG removal. (7inch Hitachi - Lilli ) In my opinion, the light increase is about 5%, (like a UV FIlter will steal). Sharpness looks great after that Mod - thanks for the unlocked information here. After that camera / picture discussion, can you show me a realistic camera setting to show realistic results? I´m a little bit confused about ISO 100-400????

REGARDS BW

It's not my innovation, renan described how to remove a/g with a wet towel.

As for realistic camera settings, it depends. I think, for a screen like mine (2.8m wide), when taking the photo from the distance where the projector is located (about 3m from the screen in my case), if you need settings above ISO100, f2.8, 1s (either higher ISO, or lower f-stop, or longer shutter time, or a combination of them) to get a decent picture, it indicates a dim screen. It is watchable, as our eyes can adapt to a wide range of light conditions, and you can tweak gamma correction and other settings to make the screen watchable, with the expense of contrast ratio. And colour perception is weak in low light conditions. Think, that you can't see colours in the night, even if there is a full moon, you can see the objects around you, but your vision is mostly monochromatic in night mode.

Camera settings may depend on the model, but the exposure parameters are meant to be somewhat standard, like for traditional film cameras, so it should be rather consistent across varius camera models. Remember, that with a commercial projector, you would get a nice picture with 10x lower settings (like shutter speed 0.1s).

Regards

[Scubasteve2365]

Originally posted by Me2!
This is what I got off post#55 since you asked:

post-3-1107112475.jpg

Tag Name Value
010e ImageDescription 284 256 008 352
010f Make Concord Camera Corp.
0110 Model Concord Eye-Q 3346z
0112 Orientation 1
011a XResolution 96.0
011b YResolution 96.0
0128 ResolutionUnit 2
0131 Software Adobe Photoshop CS Windows
0132 DateTime 2005:01:30 14:05:58
0213 YCbCrPositioning 2
8769 ExifOffset 268
829a ExposureTime 1/4
829d FNumber 2.8
8822 ExposureProgram 3
8827 ISOSpeedRatings 200
9000 ExifVersion 0220
9003 DateTimeOriginal 2004:01:24 08:58:58
9004 DateTimeDigitized 2004:01:24 08:58:58
9101 ComponentsConfiguration 0x1 0x2 0x3 0x0
9102 CompressedBitsPerPixel 2818640/786432
9201 ShutterSpeedValue 10/53392
9202 ApertureValue 0.0
9204 ExposureBiasValue 0.0
9205 MaxApertureValue 3.7
9207 MeteringMode 1
9208 LightSource 255
9209 Flash 16
a000 FlashPixVersion 0x30 0x31 0x30 0x30
a001 ColorSpace 1
a002 ExifImageWidth 600
a003 ExifImageLength 450
a004 RelatedSound
a005 InteroperabilityOffset 704
0001 InteroperabilityIndex R98
0002 InteroperabilityVersion 0x30 0x31 0x30 0x30
a215 ExposureIndex 10.0
a217 SensingMethod 2
a300 FileSource 0x3
a301 SceneType 0x1
0103 Compression 6
011a XResolution 72.0
011b YResolution 72.0
0128 ResolutionUnit 2
0201 JPEGInterchangeFormat 830
0202 JPEGInterchangeFormatLength 2510

There was a fair amount of noise on the original. This is gone. The projection portion is not different from the original. I guess this was your old camera.

Thank you, you busted this conversation wide open.

Looking at the pic in post 55, its doest look half as bright as the pictures in the begining.

Thanks for confirming it was done with my old camera, if thats the case. As the details indicated the exposure was at ISO200, and is says the F was 2.8 (Most camera's default to this in the night mode)

That particular camera did NOT have a shutter speed control, and it definatly was NOT open for 1sec. The value indicated above is 1/4, perhaps that stands for 0.25secs.

If that is the case, then pepe had a longer exposure in his posted image, than I had of that image in post 55.

0.25secs x ISO200 = 50 (my image on post 55)
1sec x ISO100 = 100 (Pepe's image)

So by using his, standard on measuring brightness, then my image must be more than TWICE as bright as his, after all the color saturation in my picture is alot better. And since my overall exposure is HALF of what his is.

In reality, YOU cant tell.

But compare the first images I took, and the last image I posted. Different Camera, Different Settings, ECT.

0.25secs x ISO200 = 50 (Image in post 55)
1secs x ISO400 = 400 (My first images)

There is a difference of 8 TIMES greater exposure on the second camera. Do my images posted in the beginning look 8 TIMES BRIGHTER, NO, they dont. This picture observation method proves NOTHING. Ive shown you, that I have quality results, because I have given you a good picture taken with lower exposure times

I think I made my point when I say, the ISO settings dont effect the brightness of the image much, you can also get a better picture of your PROJECTION RESULTS from a further distance, If I had taken that picture from post 55, on the same settings up close from the distance of the projector, then the corners would have been severely DIM. Afterall, thats why I was taking shots from that far back in the first place.

The ISO speed does effect the image, but on my camera, the ISO speed effected the picture results MUCH less, than the F-stop and Exposure speed settings. The ISO speed had other effects, that are NOT related to brightness. At a lower ISO speed, more noise was present, and the quality of the picture was reduced. I will try to dig up the first images I took with this camera, as everything was set to AUTO. If In the dark conditions of the room, and the camera sets to AUTO, when you go into Night mode, and it defaults to bigger aperatures, or faster film speeds then perhaps that is what we should use.

In any event, I have dispelled your theory on ISO settings being LINEAR versus Lumen Output of the projector. There is NO way in Hell the first images I posted are 8x BRIGHTER then the last image I posted.

[Rox]

why do not use the tools they where designed for; luxmeters.

they will meassure objetivelly with better or worse accuracy the contrast/brightness on the projectors. Isn´t this the best way?

I never agreed taking photos as "quality representation".

I was looking to a somewhere 2-4 lumens output image for a month (crt tv+fresnell) dim image but enough for that purposses.

[bw]

What i mean was that in an other forum ;-) the information is locked, the information in diyaudio.com is free to the public...like in our german forum.
This is one of my last result pictures after removing the AG Filter. The Exif information is in the picture it is not modified just downsized to 800x600.
ISO100
F 3.07
Time 0.5952823
What does it say to you, realistic?

Please excuse my bad english....

REGARDS BW

[pepe303]

Originally posted by Scubasteve2365

The ISO speed does effect the image, but on my camera, the ISO speed effected the picture results MUCH less, than the F-stop and Exposure speed settings.

Sorry, but you misunderstand that. ISO value has the same result on the final image as shutter speed and f-stop, in terms of amount of light gathered. If you don't agree with that, we can't continue this discussion, as you are negating a very basic fact. Just read somewhere, like here for example:

http://www.silverlight.co.uk/tutoria...exposure1.html

or any other tutorial on photography. And you also misunderstand my concept of comparing brightness, that I described on LL. There was an assumption that screen size is fixed, and the screen image fills almost whole frame in the photo. I don't really know how to interpret your photo from post #55, how much brighter or dimmer it is compared to your first picture.


BW: you seem to forgot to include the image?

Regards

[bw]

it was there, admin removed that? are there any rules exept the size? it was 5x kb???
Oh i forgot to describe my system : 250W HQI, normal Fresnel method, 7" TFT, 325mm tripplet...
OK another try now in 640x480.

REGARDS

[superdaveumo]

So wasn't this thread about A/G filter removal? I would suggest a moderator move all these LUX and ISO posts to another thread. They are really clogging this thread up (3 pages???). It's not bad info, just not the topic here.

[Netlist]

Originally posted by bw
it was there, admin removed that?

No, just a small latency due to you being still under moderation.
You are now registered.

/Hugo

[bw]

ahh!, thanks.
Have anyone tried to remove protection-a/g on both sides? Are there any improvements to the projection? BTW : I used destilled water to remove the filter, it is less dangerous, I think, If you forgot to care about some.

REGARDS

[Scubasteve2365]

Originally posted by pepe303


Sorry, but you misunderstand that. ISO value has the same result on the final image as shutter speed and f-stop, in terms of amount of light gathered. If you don't agree with that, we can't continue this discussion, as you are negating a very basic fact. Just read somewhere, like here for example:

http://www.silverlight.co.uk/tutoria...exposure1.html

or any other tutorial on photography. And you also misunderstand my concept of comparing brightness, that I described on LL. There was an assumption that screen size is fixed, and the screen image fills almost whole frame in the photo. I don't really know how to interpret your photo from post #55, how much brighter or dimmer it is compared to your first picture.


BW: you seem to forgot to include the image?

Regards

If ISO and Shutter Speed are the same thing, then why do they have both. Clearly the two must have different results, effects, or variations on the picture. Different ISO settings, didnt change the percieved brightness of my photo's very much. Thats all im saying.

Two, you cant do a histogram, on that image in post 55, unless you crop it down. Nonetheless, in your post, you say due to the camera settings that your PJ should be 4x brighter than mine, you then said that that cant possible be true, which your right, its not true.

Looking at my image is post 55, you can see that even at a very fast shutter speed, and a lower ISO (ISO200) I still get a good image, Thats been the whole point. I still get a very impressive image with a fast shutter speed.

You said that members of LL must edit their pictures in photoshop to get good results, I showed you unedited photos, you then critiqued my camera settings...

So, I showed you an image with good color saturated results and brightness with lower settings, all done with much lower camera settings.

Fact of the matter is, I get nice bright images at all settings, sure they look a little more dim, but not by much. I only adjusted those things up so high to fight the effect of dimmed corners. Again thats why that image in post 55 was taken so far back, That was a crappy *** camera to, with NO MANUAL options at all. All I could do was set it to night mode.