[PyMOL] effect of number of pixels on ray image quality

[yvonne l. <le...@sa...>]

Hi everyone,

I would like some confirmation or explanation about the differences I 
see, and the way I understand it.

I was comparing the quality of images with different numbers of pixels 
along the length and width,

e.g. ray 1000,750

I used the above command initially, because the highest display option 
on my Mac G3 is apparently 1024 x 768

I also decided to try higher numbers like 1200,1000 and
1500,1200.  I also did the default option of just typing 'ray' without 
specifying pixels.

The default ray command gives the the poorest quality image by visual 
comparison.  The 1024 x 768 gave quite acceptable quality.  But I was 
surprised that I could create and save images with higher pixel values 
than the apparent display limits.  There was a small improvement in 
quality in these too, but the image size was much bigger.  Furthermore, 
in one case, the image was slightly magnified/'zoomed in' when compared 
to the default, and the right and left edges were 'cropped'.  But the 
quality was still better than the 1000x750 image.  I suppose I could 
have kept increasing the numbers of pixels, but the tradeoff would be 
unacceptably large images.

And the reason for all this is ...
... is a *.png image created with ray 1000,750 going to be good enough 
for publication standards?  Is there much benefit in going higher?  what 
causes the limits, if any?

Yvonne