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Screen resolution with HDMI - character rendition

Fired up my Pi with HDMI connected to a 1080p wide screen TV.

Fired up Raspbian Wheezy.

The picture of the raspberry looks fine, but all the text is very poor - almost unreadable.

I was expecting a display with a similar resolution to a PC monitor. The PC I am posting from is in 1920 * 1080 native mode and the font below the icons looks good and the text within a terminal window is also very clear.

So is there some basic difference using HDMI as opposed to DVI/VGA?

Is the graphics chip on the Pi much less able than the average PC?

Or is there something which needs modifying to get a decent screen resolution?

Cheers

Dave R

Reply to
David.WE.Roberts
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Some TV sets have a (mis)feature called "overscan". This is a leftover from the old CRT days, where it was almost impossible to let the displayed field exactly fill the picture, and to avoid transient effects at the edges.

Today with flat screens and digital transmissions this is completely unnecessary, but still in the specs of HDTV there is a 16-pixel edge area that the set is not supposed to display.

There still are manufacturers who strictly adhere to the standard and take the 1920x1080 image presented at the HDMI input, crop off 16 pixels all around, and then scale the resulting 1888x1048 image back up to the 1920x1080 resolution of the panel.

This is not noticable for "TV" content, but it is horrible when displaying pixel-perfect images like characters.

So, check in your TV if there is some setting in a menu to toggle the "overscan" feature. It will make the picture much better and you also don't lose some stuff at the edges of the screen anymore.

Reply to
Rob

The HDMI output is generally excellent - that's what it was specifically designed for.

However sometimes it can't auto-detect the TV/Monitor it's connected to. Start here:

formatting link

Gordon

Reply to
Gordon Henderson

Thanks - and thanks to Rob as well.

I've relinquished the TV for the night (it's in the bedroom and has been requisitioned by a higher authority) but I'll give it a go tomorrow.

Cheers

Dave R

Reply to
David.WE.Roberts

I had to tweak about 5 settings on my TV to get a decent picture

nah, just the TV is rescaling the image for some reason.

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?? 100% natural
Reply to
Jasen Betts

+1

On ours it defaults to having some underscan which was corrected by editing the config.txt file as described in the above link.

Ours also used to sometimes output on composite instead but this was also corrected by editing the aforementioned file.

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(\__/)  M. 
(='.'=) If a man stands in a forest and no woman is around 
(")_(") is he still wrong?
Reply to
Mark

Not IME no... I have seen Pi output on "ordinary" HD TVs that looks nearly as good as on a DVI/HDMI monitor.

Might be a setting in the TV doing the damage... things like overscan, picture sharpeness controls and various other motion precessing effects can knacker nice crisp text.

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Cheers, 

John. 

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Reply to
John Rumm

In many it will be in the picture format selection along with 4:3, 16:9 there may another option call Screen Fit or similar.

Cheers

Reply to
druck

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