20x30 dpi print question

Hi folks,
I'm going to send off 2 ganged 20x30 pictures to aandi.com for them to print on their lightjet as a 40x30.

I'm starting with a Canon 20D (8.2MP) image shot in raw, etc. I'm using Genuine Fractals to uprez the image and Noise Ninja to smooth it out. My question is what dpi should I go? I know I can just do 300 and be done, but I'm hearing I can get away with 150. I just want to be careful not to over-rez it. I'm thinking 200.....?
I'm hoping someone in here can share the result of a similar situation.

Thanks!
Jason

You should ask the place you are sending them what to do to your images. Some won't take a file that is too big or too high dpi. They'll also tell you what format and bit depth they'll allow.

Read the FAQ of elco: http://www.elcocolor.c​om …nternet_only_sp​ecials.htm . Even better ask the lab. Make sure you don't go to too high a resolution, that's probably worse than too low.

I had a few 20x30s done there, I didn't upsize at all. I just sent them at the native camera resolution, with some mild sharpening applied (not too much). Recently i've been doing plenty of 8x12s for customers, i've been sizing then sharpening, they've come out great. When I do that i've been using noise ninja even for low ISO shots, with a bit of sharpening, then unsharp mask. I've played with the TLR sharpening toolkit but I prefer usm/smart sharpen still.