8mm Forum: Digital projection. A question

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Posted by Tom Photiou (Member # 130) on November 18, 2017, 02:47 PM:

Just a quick question from a newbie in digital projection.
First of all, i am fully aware that to get top quality in this field one needs to part with many pounds. I am enjoying this form of projecting but while i get a very good image what i notice on bright images is a type of see through lines that fans out if you understand what i mean. Its only there on very bright areas.
The other evening i put the shinning onto the big screen but unfortunatly on this one the lines were very prominent. I will put up a screenshot soon but this really doesnt show it much. I use an epson eb955w. I am aware that this isnt a home cinema model but after trying every form of adjustment listed i just cant clear these lines. If i zoom in and out they dissapear for the duration of zooming, as soon as i fix the image there back. The lines are only there during the playing of dvds or blue rays. No other time. Any ideas if i am doing something wrong or is it simply not suitable for movie projection. Aside these lines everything else is tops.

Posted by Stuart Reid (Member # 1460) on November 18, 2017, 03:51 PM:

If they're horizontal and vertical lines it's probably what's known as the chickenwire effect, what your seeing is the tiny tiny gaps between each LCD pixel. If it's only horizontal lines i would suggest that the projector is running in interlaced mode instead of progressive. What source are you using and how is it fed, hdmi, component etc.

Posted by Tom Photiou (Member # 130) on November 18, 2017, 05:32 PM:

Hi Stuart, i use a HDMI cable direct to a blu ray player,

Posted by Paul Adsett (Member # 25) on November 18, 2017, 08:45 PM:

Tom, the projector you are using is really intended for data. Even so, it should project a reasonable video image, but will probably not have nearly the contrast that a home theater projector will give you.
It sounds to me that your projector may have a fault. You should not be seeing any lines. These days, even an inexpensive home theater projector will give you a near flawless image.

Posted by Tom Photiou (Member # 130) on November 19, 2017, 02:37 AM:

thanks Paul, it is a very good image, the lines are very difficult to explain, there not solid lines they are like faint waterlines but only visible on very bright images and and they are not straight they curve out,
i do have an idea that you guys are correct and that it is probably the limits of the projector. [Wink]

will pop an image here shortly.

Posted by Mark Todd (Member # 96) on November 19, 2017, 03:27 AM:

Hi Tom I wonder what it is, I never saw them.

On the LCD structure its very good on that machine at around 3 million pixels but you can just very very slightly defocus the picture and they will vanish and it will still be sharp.

Obviously depends where you sit etc.

Have you tried another player or HDMI lead ?

Best Mark.

Posted by David Hardy (Member # 4628) on November 19, 2017, 04:49 AM:

I get a very slight chicken wire effect from my Panasonic PT-AE700E LCD video projector. As I state it is only very slight and you cant see it most of the time and has not even been an issue for me the past 10+ years.

I have to stick with LCD projection as i am blessed ( or cursed ) with having blue eyes and can see that dreaded rainbow effect trails on fast moving objects on domestic DLP projectors.
Which for me is a lot more annoying and spoils my viewing pleasure.

For me the compromise on LCD is worthwhile rather than having to view faded , soft focus and very badly tramline or cross scratched unsteady film prints.

I treat the slight chickenwire effect as a bit like film grain.

Posted by Dave Groves (Member # 4685) on November 19, 2017, 07:26 AM:

I use an Epson TW9200W and the picture is superb. I bought a Sony 3D camcorder and holiday pictures really come to life. Like you David, I too see the rainbow effect. When I bought my first cheap projector, also an Epson, the rainbow drove me mad. I wrote to the Managing Director of Epson to complain and was told 'the faster your brain processes information, the more you see the effect. It's not a fault with the projector, simply an operational anomaly'. I got rid of it pretty sharply. Now I've got the best of all worlds. Great old films on 16mm and great new one's on dvd.

Posted by Rob Young. (Member # 131) on November 19, 2017, 09:03 AM:

Don't forget LCOS technology as used by Sony and JVC.

I believe it is the best domestic video projection technology available, apart from 3 chip DLP, which is expensive.

I think if Tom can possibly get some screen shots up it might help to diagnose the problem.

Posted by Tom Photiou (Member # 130) on November 19, 2017, 11:18 AM:

Thanks again for the feedback.
Dont get me wrong here chaps, it's not making the films i view impossible, on the contrary, the majority i view are excellent.
Here is a screenshot from the shinning, its taken with a mobile phone but you need to zoom in to see what i am trying to explain, look at the light parts and you can probably make out what i would call waterlines, (possibly the chicken wire effect), on the actual viewing they are very prominent on this particular film as it is very bright and even the dark scenes are lit very brightly, especially visible on the snow scenes.

As you can see the image is actually very very good,
Hey Mark, definatly not grumbling here, i am just trying to see if i can get shot of these lines.
We also viewed the remake of the magnificent 7 the other night, it was brilliant to see it up on the big screen but that film showed very little in the way of the waterlines.

You may need to save the image and zoom in, unfortunately the image doesn't show it the way the eye does.

Posted by Rob Young. (Member # 131) on November 19, 2017, 02:02 PM:

Tom, this is possibly banding, where one grade of the image moves to a lighter or darker shade, but rather than being a smooth transition, a banding effect occurs.

Is it also visible on, say scenes with lots of blue sky, where the sky moves from darker to lighter areas?

If so, it is possibly the image processing within the projector.

I once owned a relatively expensive Optoma DLP machine, designed for home cinema, which was truly dreadful in this regard, far worse than you are seeing.

Try looking at scenes with large areas of similar colour, but which move from brighter to darker areas and see if it is also there?

If it is the image processor, DVD will suffer more than Blu-ray.

Teaching to suck eggs I know mate, but do check that the Blu-ray player output is set to 1080p / 24 Hz, assuming that is the capability of the projector.

EDIT: Just looked up the spec. It's classed as HD ready, not full HD as the panel is 1080 x 800.

Full HD is 1080 x 1960 and HD ready is usually classed on a video display as 1080 x 720.

So maybe also try re-setting your player to 1080 x 720 output resolution?

Posted by Tom Photiou (Member # 130) on November 19, 2017, 02:24 PM:

I shall take a look Rob. Thanks for the info again. As i understand it the Epson machine i use isn't compatible for full hd so that may also be a factor. DVD is definatly more noticeable than blu ray.

Posted by Rob Young. (Member # 131) on November 20, 2017, 08:53 AM:

Tom, is this the kind of thing you are seeing?

https://en.wikipedia.org/wiki/Colour_banding

Posted by Tom Photiou (Member # 130) on November 20, 2017, 04:30 PM:

Rob, that image showing the blue sky is exactly it. [Smile]

Posted by Rob Young. (Member # 131) on November 21, 2017, 04:28 AM:

In that case, I would say it is the video processing in the projector.

Still, a nice machine for the price though.

Tom, I'm probably like you in that it amazes me that some folk really do think that any form of "video" is plug in and play...whereas there are actually more potential complications than film projection!

Still, it's all the fun of a hobby. [Smile]

Posted by Tom Photiou (Member # 130) on November 21, 2017, 06:18 AM:

I agree Rob, the projector produces amazing quality pictures for the 300 quid i paid, my audiences are always pleased as am i. As you say, one thing about super 8/16mm is that the projectors that are 40 years and still working today need no upgrades and still show the standard formats of film with A1 image.
Digital is great but this years model will be out of date by next year and is a constant upgrade unless you spend absolutely thousands.
This one will do me for years, all i will do is be choosy with what i watch. [Wink]

Posted by David Hardy (Member # 4628) on November 21, 2017, 07:17 AM:

My 50inch TV sometimes has this banding effect.

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