1080p Resolution but Text is Blurry!


15 posts
by HeWasOnly3 » Mon Dec 17, 2012 4:39 pm
Dear raspberry pi gurus, recently I have just purchased a spanking new raspberry pi. I am tried to set the resolution to full hd which is 1080p 60 Hz. The config.txt that I had enabled was:
hdmi_drive = 2
hdmi_group = 1
hdmi_mode = 16 (1080p 60Hz)
hdmi_boost = 4
disable_overscan = 1
The monitor that I am using is 23 inch Dell Ultrasharp U2312HM. The pi is connected via HDMI to VGA converter (PI-VIEW) sold by element14. I have a steady 5V 1 amp PSU and I don't believe that the PSU is problematic.

I did the /opt/vc/bin/tvservice -s and it shows that my current resolution is 1920x1080, progressive. The only issue that I had is that the texts are blurry. Its kinda hard to read them, and is there any idea on how to make them sharp? I mean when I connect my PC via VGA mode, it still looks sharp on 1920x1080p. Please advice thank you ;)
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by drgeoff » Mon Dec 17, 2012 10:11 pm
Usually when using an analogue input to an LCD monitor there is a 'clock phase' adjustment available on the monitor which can improve the horizontal sharpness. Generally, different sources will require a readjustment of that. Some monitors have an 'auto' button on the front panel.
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by HeWasOnly3 » Tue Dec 18, 2012 2:01 am
Alright thanks for the info will try that when I reach home :)
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by HeWasOnly3 » Tue Dec 18, 2012 6:34 am
I have tried pressing the auto adjustment button and setting the hdmi_boost = 7, the text is still blurry. :(
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by Narf03 » Tue Dec 18, 2012 11:49 am
can your "pi view" do 1080p 60hz ? if it cant maybe it will drop in quality ? why dont u start with something lower, then slowly jack it up and see where the problem starts ?
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by RaTTuS » Tue Dec 18, 2012 12:02 pm
why not use either the HDMI or DVI instead of a VGA ?
it can do 1920x1080 according to the specs
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by Narf03 » Tue Dec 18, 2012 12:03 pm
RaTTuS wrote:why not use either the HDMI or DVI instead of a VGA ?
it can do 1920x1080 according to the specs


the spec say it can do 1080p, but never mention about frame rate.
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by -rst- » Tue Dec 18, 2012 12:48 pm
New'ish Dell monitors don't have HDMI - they have a DisplayPort instead...

Not sure why there is a difference between your RPi and PC, but why would you want to use HDMI-VGA conversion when you could go for HDMI-DisplayPort (converter) or HDMI-DVI (simple cable)?

We have similar Dell monitors at work (used with Windows PCs/laptops). Initially we connected them using the VGA cables that came included, but on any higher resolution most of the displays looked blurry. Switching over to DisplayPort and HDMI-to-DVI cables (depending on the PC connectors) resulted in perfectly clear displays.
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by HeWasOnly3 » Tue Dec 18, 2012 2:15 pm
-rst- wrote:New'ish Dell monitors don't have HDMI - they have a DisplayPort instead...

Not sure why there is a difference between your RPi and PC, but why would you want to use HDMI-VGA conversion when you could go for HDMI-DisplayPort (converter) or HDMI-DVI (simple cable)?

We have similar Dell monitors at work (used with Windows PCs/laptops). Initially we connected them using the VGA cables that came included, but on any higher resolution most of the displays looked blurry. Switching over to DisplayPort and HDMI-to-DVI cables (depending on the PC connectors) resulted in perfectly clear displays.


Hi there thank you for all the advice, finally I am able to get raspberry pi to run crystal clear 1080p via HDMI-DVI cable. It appears that the HDMI-ANALOG cable causes the video quality to drop as well. I even tested the PIVIEW on my old 17inch Samsung LCD Monitor at 1280x1024 75Hz. Although the image is sharper compare to my current 23 inch Monitor, the text is still blur. Later on, I hooked up the HDMI to DVI cable and the result is amazing. Unfortunately for the display port , I have tried the Active Displayport to HDMI converter, my monitor doesn't show any video signal at all. I wonder why is that? Thank you for all of your help and fast feedback really love this forum :). I can safely conclude that by using HDMI to Analog converter will results in poor image quality when used in FULL HD ala 1080p. :)
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by HeWasOnly3 » Tue Dec 18, 2012 2:16 pm
RaTTuS wrote:why not use either the HDMI or DVI instead of a VGA ?
it can do 1920x1080 according to the specs

Because I am shortage of video port hence VGA is the only port that I can hook it up :)
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by HeWasOnly3 » Tue Dec 18, 2012 2:17 pm
Narf03 wrote:can your "pi view" do 1080p 60hz ? if it cant maybe it will drop in quality ? why dont u start with something lower, then slowly jack it up and see where the problem starts ?


I think the PIVIEW is capable of running 1080p 60Hz but I am not sure why it produces low image quality. Perhaps I should buy an externally powered HDMI to VGA converter box instead? :)
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by RaTTuS » Tue Dec 18, 2012 3:23 pm
HeWasOnly3 wrote:
RaTTuS wrote:why not use either the HDMI or DVI instead of a VGA ?
it can do 1920x1080 according to the specs

Because I am shortage of video port hence VGA is the only port that I can hook it up :)

what else - because the others may be a better bet for vga ;-p
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by Narf03 » Tue Dec 18, 2012 3:47 pm
VGA is analog, and hdmi is digital, so i don't think that is a cable, it should be a converter(should have some electronic components inside). Seems like its not doing a good job. I have a converter too, it labelled hdmi2vga, which its not good either, can only do 16bit color and slightly blue when displaying text.
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by bf109 » Sat May 04, 2013 3:03 am
simply try to add
hdmi_ignore_edid=0xa5000080
to the config.txt
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by pi3g » Tue Jul 16, 2013 11:00 pm
Thank you! The hdmi_ignore_edid=0xa5000080 did the trick for me on an ASUS Full-HD display.

The display is connected via HDMI. It also had trouble activating the sound, these lines will enable everything at FullHD res:

hdmi_ignore_edid=0xa5000080
disable_overscan=1
framebuffer_width=1920
framebuffer_height=1080
hdmi_drive=2

To be put into /boot/config.txt (edit as root, or on a different PC).
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