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Lunar Unit
09-14-2005, 10:52 AM
I'm attempting to render a high resolution image of my object so my client can use it for print. He wants the resolution large enough for use with on a billboard. I have exported large PSD files using the resolution multiplier of 400%. While it is huge in photoshop, the ppi is only 72! I need at least 600 ppi, but 1200 ppi would be best. I know you can convert the ppi in photoshop, but it makes the image size smaller. Is there a way to increase the ppi when you render from Lightwave?

mattclary
09-14-2005, 10:59 AM
Yes, you increase the resolution.

toby
09-14-2005, 11:24 AM
LW doesn't render in inches, just pixels, as many as you tell it to. If you want 300 dpi then open the camera properties and multiply the resolution by 4.16, then convert the dpi in Photoshop.

art
09-14-2005, 11:38 AM
Isnt ppi/dpi an "artificial" measure used by printers? You can always change dpi in photoshop without affecting the actual resolution, in pixels, of the image.

If you want, for example, a 300dpi image that is 8x10 inches, multiply inches by dpi, which gives you image that is 2400 pixels by 3000 pixels. Set camera to that resolution and render. LW by default will save it as 2400x3000 @ 72dpi which would print 33inches x 41.6inches, not what you want.
Open your image in photoshop and change the resolution from 72dpi to 300dpi, just make sure you uncheck the "resample image" checkbox. This will change the print resolution and leave the pixel sizes intact.

I used 300dpi and 8x10 size as an example, but the same applies to any dpi and size.

Lightwolf
09-14-2005, 12:37 PM
Credit where credit is due: Kudos to lunar unit for actually using the right term ppi and not dpi ;)

Cheers,
Mike
P.S. Sorry, I've got nothing more to say, everybody else on the thread explained it well. ;)

art
09-14-2005, 01:49 PM
yeah, I never paid much attention to it, but I just noticed that photoshop also refers to it as points/inch and not dots/inch.
Nice catch. I'll be careful from now on :)

Lunar Unit
09-15-2005, 10:07 AM
Ok, that makes sense. I had an idea that's how it might work. I was worried that by converting it in photoshop I might loose some quality or something. Basically, if I need a really big image, export a huge resolution from Lightwave and convert it in photoshop, right?

art
09-15-2005, 10:12 AM
right, just make sure you uncheck the "resample image", otherwise it will change the pixel resolution as well.

Lunar Unit
09-15-2005, 10:39 AM
Thanks Art, very helpful!

Surrealist.
09-15-2005, 11:59 AM
I Don't know what version of LW you use but this little handy utility included in LW will help in the future. It will calculate the resulution based on the final size of the image and the desired Dpi Then in photoshop simply put the Dpi number in the Ppi field. :)

Lunar Unit
09-15-2005, 04:10 PM
I'm running LW 8.3. Is this handy utility not included in LW 8.3 now? If not, when will it be? I must have it.... :D

Surrealist.
09-15-2005, 05:21 PM
Yeah. Right here:

Eidt: By "in the future" I meant, future projects in case that was confusiing. :)

Filmdesigner
09-15-2005, 06:31 PM
What crazy printer would want to print a billboard at 600ppi? The most I have ever used was 24ppi. When printing film backdrops, which require a high res. I have got the ppi down to 8ppi. I have recently seen a 30x10 " billboard at 4 ppi to preserve the saturation of colours. It looked excellent from the car.

Surrealist.
09-15-2005, 08:53 PM
Well 600 may be much but every printer I have ever delt with including bilboard size stuff asked for at least 300.

Lunar Unit
09-16-2005, 10:06 AM
I'm no expert at this print stuff, but I must agree that every printer I've dealt with has also asked for at least 300 ppi. I really don't know how it all works but I'm trying to please my client and at the same time educate him. He thinks that only vector images work for large print stuff. I'm trying to convince him otherwise. So I don't need to have a lot of ppi to make a billboard or poster, huh? Why is that?

spec24
09-16-2005, 10:52 AM
I'm no expert at this print stuff, but I must agree that every printer I've dealt with has also asked for at least 300 ppi. I really don't know how it all works but I'm trying to please my client and at the same time educate him. He thinks that only vector images work for large print stuff. I'm trying to convince him otherwise. So I don't need to have a lot of ppi to make a billboard or poster, huh? Why is that?

For the same reason you don't need a lot of pixels in a very small image. What I mean by that is that if you take an image the is 4" x 6" at 24 dpi and look at it close up you can see the dots. Now, make this image smaller and smaller, you no longer see the dots and the image appears to look crisper. When viewing a billboard you are viewing it usually from far away. Walk up close to the billboard and the dots making up the image are quite large. These dots will never be seen at the distance you are viewing it from.

Lunar Unit
09-16-2005, 11:10 AM
That makes sense. Thanks for the info!

spec24
09-16-2005, 11:25 AM
..also, very few printers deal with Billboards and may not be aware of actual requirements.

Lunar Unit
09-16-2005, 11:44 AM
Yeah. Right here:

Eidt: By "in the future" I meant, future projects in case that was confusiing. :)


By the way... I feel a bit of a boob right now :foreheads , I've never noticed that print assistant thing. Thanks for pointing that out.