Is this normal....? Please help! (1 Viewer)

[Stefan_Stoev]

Hi all, sorry to bother you with newb questions but I really need help.

I just got an AKAI 42" RPTV and when the whole screen is black I can see a circle of light at the midlle of the screen. It looks like there is a flash light inside pointing at the back of the screen. I know that the RPTV's have lenses but I'm not sure if they are supposed to do this. Its very annoying because its visable while watching movies with dark scenes. Is this normal?

I also have thin line across the screen, wich I notice when the screen is bright. It looks like the line my old SONY CRT has. Is this normal?

Thank you very much!!!!

 

[Jack Briggs]

You are looking at a phenomenon known as "hot spotting." Normal with CRT-based RPTVs. Some sets control it better than others.

 

[ChrisWiggles]

hotspotting on a black screen? Maybe it's exaggerating the effects of a raised black level....

I dunno, I'm getting tired of people buying akais and having problems with them..

 

[Massimo N]

What you're seeing is the internal reflections from the lens, mirrors and cabinet. You will notice this on all CRT RPTVs. Some TVs exhibit this more predominantly than other.

You should not notice this on a completely black screen. This will show up when there is something else being diplayed. For example, if you have a black screen, and then display the menu, time or any other image, the effect becomes very noticable.

If I understand correctly, the thin lines you see are most likely the screen. I forgot the terminology, but the screen of a RPTV is not smooth. It is ribbed. The lines that show up is a function of the manufacturing process of the screen. Again, some sets exhibit this more than others, and this will vary set to set within the same brand. If you were to exchange the set, I would imagine the lines you're seeing would still be there, but in a different spot.

The second issue (lines) there's not much that can be done, but you can do quite a bit to reduce the "halos" or internal reflections.

The first thing you should do is perform a basic calibration of the set if you haven't already. I would recommend AVIA, or Digital Video Essentials (DVE). If you don't have these discs, then use one of the THX optimizers found on many DVDs. You will need to set the contrast, brightness and sharpness at a minimum. Properly setting colour and tint require filters (they come with AVIA and DVE).

There is a direct correlation to the contrast and how prodomenant the Halos are. You will never get rid of them, but you will be able to reduce the effect significantly without comprimising the overall picture quality.

More advanced tweaks to help with the halos are lining the interior of the set with dark fabric, creating a hood for the crt lences ... all in the effort to reduce the internal reflections. This should not be done, unless you know what you're doing and should be left to an ISF calibrator. This technique require the removal of the screen.

If done correctly, the Halos will still be there, but they won't interfere with regular viewing or show up quite as often. The secondary benefit of reducing contrast is the "lines" you see will not jump you as much.

 

[Eric Samonte]

U say its happening when its off or u have a black screen and its on? I would assume it to be a reflection off the screen protector if its off. If on, it maybe another problem. If u notice it while watching darker scenes then a light source shows up producing that effect, then its normal as the inside of the RPTV reflects said light. Installing some Duvetyne and/or painting reflective parts flat black inside may diminish it.
I hope someone else chimes in like Mike the ISP guy.

On another note, I must say that not everyone can buy expensive sets. We all have to start somewhere and I guess u get what u pay for. But we are here to try and help out in anyway to make one's HT exprience as great as possilbe.

 

[Stefan_Stoev]

Thanks to all of you for the help!

Chris, no offence but....what Eric said.

Massimo, Thank you for the detailed explanation of the problem. I bought an AVIA CD from Ebay but it didnt come with any filters. I was wondering if I can get those from elsewhere because the disk is worthless without them...
I got it used and as is, I should've read more about it first.

Eric, the spot is there only when the set is on, it very visable when the whole screen is black. I'm thinking to have a CC technitian come over and if they can't fix it, I'll decide if I'd keep it or not.

Thanks again!

 

[Chuck_D]

I have the same Akai TV and it was set up in torch mode out of the box. After using DVE to set brightness, contrast, tint, and color I don't notice the hotspotting now. It was very obvious when using the standard setup. I have been very pleased with this low cost TV but you have to work with it initally to get it looking good, just like you do with most sets.

 

[Stefan_Stoev]

Chuck, do you mind posting your picture settings?

 

[Chuck_D]

I'll do it when I get home.