Why does 75 hz look better than 85hz on my crt?

luminous · 3 Feb 2007 at 20:55

Just wondering here i have a samtron 78e and its a budget 17" crt till i upgrade.
75 hz looks sharp but at 85hz its less sharp,like everything `smoothed` out but less detail and its hard to look at.
I`m guessing its just not really a good enough monitor to show the difference.

DasFruitMachine · 3 Feb 2007 at 21:10

It possibly can't hack it at 85hz. Find out what refresh rate your monitor can do at that resolution and don't exceed it.

edit -

1,280 x 1,024 @65Hz
1,152 x 864 @77Hz
1,024 x 768 @86Hz
800 x 600 @109Hz
640 x 480 @134Hz
1,024 x 768 @85Hz

So, if you're running at 1152 or above, you can't use > 75Hz.

luminous · 4 Feb 2007 at 20:54

Cheers,its 1,024 x 768 @85Hz but 75hz looks much better

harris1986 · 5 Feb 2007 at 08:30

my crt says it won't do over 75hz at 1024x768 but forcing it up to 100hz makes it look so much smoother!

Captain Fizz · 5 Feb 2007 at 14:44

2 things...
Monitor quality - Running it out of spec = Not as sharp.
The usual culprit:
Poor cabling - if it's fat cables, they will take much higer bandwidth. (frequency * resolution)
Thin cables will drop image quality the higher you go in either resolution and/or frequency.

If your monitor supports BNC connections - The £15 cable (D-Sub -> BNC) is well worth it - It will improve picture quality. A lot if it was a poor cable, will still give an improvement on most cables.

fish99 · 5 Feb 2007 at 19:37

There will usually be one refresh rate for each resolution that is a 'preset' which means the screen is setup so that it will look best in that particular mode. The non-preset modes will have messy geometry that you need to spend time in the menus correcting, and they can sometimes be blurry.

My last CRT did 60, 75, 85 and 100 Hz in 1280*960, but on that particular screen the preset mode was 85 Hz and it looked the best.

It could be down to a poor cable too, but you'd have to assume the cable that comes with the screen is good enough for every mode it does.

Just stick with 75 Hz.

snowdog · 5 Feb 2007 at 20:23

Depends on what you find more important, image quality or refresh rate, persoanlly i cant live with 75hz as it flickers too much for me in windows, 85hz is a minimum for me usually in main windows usage, in games tho i usually dont notice any flickering on 75 hz, you could just use different refresh rates for different apps...

Inazuma · 5 Feb 2007 at 21:45

Question: My LCD says it has an optimum resolution of 1280x1024 @ 60hz, yet it can run at 70hz. I personally can't tell much difference, but which in theory would be better?

snowdog · 5 Feb 2007 at 22:54

SebC said:
Question: My LCD says it has an optimum resolution of 1280x1024 @ 60hz, yet it can run at 70hz. I personally can't tell much difference, but which in theory would be better?

LCD's have a different way of displaying than crt's, i never noticed any diff between 60 and 75 hz, running on 75hz as my tft says thats its optimal resolution&refresh...

Also to prevent confustion (about tft's running on 85hz or whatever) about my older post, i'm using a dual mon setup one tft one crt...