Monitor effect

[Robfry2]

Hi if someone could enlighten me if this is an issue or fixable via adjustments or just an effect that is inherent with monitors. On the far right and left at the edges of the monitor the pixels seem more separated and darker, you can see the difference if you look at the middle of the screen you see normal scan lines but the edges seem more pixelated. Any info would be great thanks.

 

[pooman2084]

Can you put up a test screen and take a picture as I’m struggling to see what you are describing?

 

[Robfry2]

You can see on the yellow side the pixels are very different from the ones in the centre screen

 

[Sbdesign]

still hard to see in the quality of the photo.

 

[big10p]

I see what he means. Scanlines are more severe at the side. Don't know how to fix this though, other than playing with the focus and contrast pots. Might just be a 'feature' of the specific monitor, maybe. What monitor is it?

 

[gunblade]

what chassis is it?

 

[Robfry2]

It is the one you serviced for me think it’s a ms9 nanao

 

[lix]

The focus of the beam will always be different between the centre and the edges of the tube, more so on flatter tubes. Astigmatism is also a factor, the beam is unlikely to be a perfect circle which is why the effect will be more pronounced on one axis compared to the other.

Tweaking the focus may have a slight affect but in my experience it’s usually best left as-is. It’s an artifact that will always occur with single focus arcade grade CRTs.

Another thing I’ve also noticed on some tubes is the phosphor pitch can be far higher in the center of the screen compared to the edges, I don’t think that’s the case with the picture shown here though.

 

[Retroman839]

i have had some success with the rgb gain

for back ground brightness

but check this link for a great wright up on shmups forum for picture adjustments
and a mod for better blacks

https://shmups.system11.org/viewtopic.php?f=6&t=67477