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300 dpi

Posted: 23 Jun 2010, 20:58
by Paul Fierlinger
I have to deliver some ad illustrations using characters from a commercial I'm completing. How should I convert bitmaps into dots per inch? The drawings will be freshly drawn for the illustrations so it's not that I need to convert frames to dpi; I just don't know where to start when creating a project window so that I can be confident that the drawings will be the equivalent of 300 dpi? Please enlighten me someone.

Re: 300 dpi

Posted: 23 Jun 2010, 21:13
by malcooning
if 300 dpi is your aim, all you need to do is calculate:
use this calculator
it has 2 parts.
You feed your existing image dimensions in pixels in the lower part of the calculator, then choose 300 dpi, and the result it gives is in millimeters.
so if you have a drawing sized 1920x1080 pixels, at 300 dpi you get a 16.2x9.1 cm printed image.

If you want to go the other way around, meaning that you have the the desired dimensions of the printed project, you should feed it in the upper part of the calculator, and receive the needed file size in pixels.
so, if you need, say, a final print of 20x25 cm at 300 dpi, your project should be made at 2362x2953 pixels.

Re: 300 dpi

Posted: 23 Jun 2010, 21:30
by Paul Fierlinger
Great helper -- just what I was hoping for. I still can't get my head wrapped around this; if a 1080p frame is just 16x9 cm, how come it covers a 23 inch monitor when set to full size and can be blown up to a 30 foot screen with no visible pixilation of lines, yet for a film poster it's never big enough. You don't have to answer this -- it just baffles me.

Re: 300 dpi

Posted: 24 Jun 2010, 07:50
by slowtiger
Just one concept: resolution of the eye, and viewing distance, or better, viewing angle. A drawing which covers 25° of your view will always need the same amount of pixels to look sharp, no matter wether you watch it from 30 cm or from 30 m.

As for creating print artwork in TVP: you could draw a grid with lines every 300 px, so you have the inches on your screen. (The same applies to outher resoutions.)

Re: 300 dpi

Posted: 24 Jun 2010, 08:05
by malcooning
Make a distinction between 'no apparent pixelation' and sharpness. The technology allows screens to seem full enough of information. But if you take a native 1920x1080 image on screen, and next to it you put a smilarly physically-sized real photo (like 23" diagonal picture) at 300 dpi, you'll see ALOT more detail in the real photo. Screens are much softer and blurry compared to real images (funny term, "real image"). Therefore screen are much more forgiving, and print is much more demanding.
Screens don't use dpi. they use absolute measures, which are pixels. If you take the same image size as before, a 1920x1080 pixels image, and print it at a resolution more common with digital images (like, the way they are displayed in websites etc.), which is 72 dpi, you'll get a much larger print: 67x38cm.

Re: 300 dpi

Posted: 24 Jun 2010, 22:13
by Paul Fierlinger
slowtiger wrote: As for creating print artwork in TVP: you could draw a grid with lines every 300 px, so you have the inches on your screen. (The same applies to outher resoutions.)
Thanks Mark; this works perfectly for me. I wish I had asked a long time ago.

Re: 300 dpi

Posted: 25 Jun 2010, 07:58
by slowtiger
Hu, my spelling is abysmal ...

Re: 300 dpi

Posted: 09 Nov 2010, 03:15
by maorlavi
Here is another, (for me) simpler idea..
Open Photoshop, make a new document with all the parameters (Size, Resolution )
now, just [ Ctrl + Alt + i ] / Image -> image size and just look at the pixel dimensions -
then just copy and past into TVP..
Cheers.

Re: 300 dpi

Posted: 09 Nov 2010, 03:19
by Paul Fierlinger
So what's Photoshop?

Re: 300 dpi

Posted: 09 Nov 2010, 09:20
by mox
Of course, the solution is to buy an Adobe license just to work those DPI out! :mrgreen:
And thanks for the calculator Asaf!

Re: 300 dpi

Posted: 09 Nov 2010, 10:12
by Mads Juul
mox wrote:Of course, the solution is to buy an Adobe license just to work those DPI out! :mrgreen:
And thanks for the calculator Asaf!
But maybe It was a Feature Request.
To make the New Project. Have Pixels-Cm-Inches And DPI interface.
I have photoshop on My maschine And I use it for this calculations as well. and using aonther software(Photoshop or a calculater) Maybe shows that there is a need for this in TV-Paint.
-mads

Re: 300 dpi

Posted: 09 Nov 2010, 10:32
by Byron
Indeed - the ability manually to set the DPI in TVP would save a lot of head scratching for me. I know it's a straightforward calculation, but somehow it's one of those things that always gets me in a muddle.

Re: 300 dpi

Posted: 09 Nov 2010, 12:01
by mox
(Sarcasm shall not be taken too literally :] )
DPI is indeed a long time feature request, nothing new here... (the search query doesn't work very well though) but for the time being, a calculator such as the one provided by Asaf does a good job in a snap ;)