OT: expert help needed getting pictures to 4x6 properly

[trompet3]

I am using photoshop (finally got a full version) and need to get my pictures which are shot in 4mp to a 4x6. A few questions...
1. Photoshop is telling me that my image size is 31.556 inches (2272 pixels) width x 23.667 in (1704 pixels) height with a resolution of 72 pixels/inch. If I use the crop tool and set the dimensions to 4x6, should leave the resolution at 72, or let it set to the best resolution (200 something)? I'm not sure if setting a higher resolution "artificially" creates more pixels. Can you actually give the picture a higher resolution that it originally had (72) without negatively affecting the picture? Not sure if I'm thinking about this wrong.
2. Is this even the best way to do it?
3. Let's assume I'm going to use somewhere like ofoto to print the pics. Is there a different way you should go about it?
4. Is ofoto the best choice to print pics?
I know this isn't directly about fish (even though some prints are of them!) but thanks for the help anyway. Don't have much experience with manipulating pics or using photoshop yet.
Thanks!

 

[sammystingray]

If you are going to print them for framing....use the higher resolution...I usually use 300 and they look fine. If you are going to post them here....use 72 pixels per inch.....it's pretty standard. A 4x6 on here with a high resolution may "appear" to be 18 inches across depending on each persons monitor settings, but when printed, a 4x6 at any resolution will be 4x6. If the photo is 30 inches at 72 PPI, you can't jack up the resolution really unless you say went 144 PPI at 15 inches....make sense?? You can't really make pixels appear that aren't there. If you cut the photo size in half, and left it at 72, then you would simply lose half the pixels, but since the pixels are there....you can shrink the photo to half size, and keep all the pixels by doubling the PPI......which you would have to do to keep them all because there would be more Pixels per inch if you kept them all and shrank the photo down....OK, I rambling, but 72 is prefered here, and is standard internet size really. Your 30 inch pic would be 60 inches on my screen if you double the PPI, but print it, it is still 30 inches......no quality gain though unless you are shrinking it.....which you are.

 

[trompet3]

I think I'm understanding. I am looking to print them.
Is the way I'm doing it (through the crop tool) the best way to get the 4x6?

 

[trompet3]

Oh yeah, also, do you want to make adjustments such as sharpening, color, etc before or after you make size changes?

 

[trompet3]

Ok, when I'm cropping it both ways (72 and 266 pix/in) and line them up side by side zooming at print size, the higher resolution actually looks worse. You can see pixelation (objects look rough with boxy edges) in the higher resolution. Does this sound right?