stan0301 Loc: Colorado

We print 20x30 from D800 all the time--I never have gone about it from the direction you are, but, as photographic paper will only catch about 250 lines an inch (no matter what you throw at it) we send 20x30 at 240 and they work fine--at less than $10 for a print why don't you try and see for yourself. With Sam's Club--if (a big if) you can get your color figured out you can't tell their prints from a high price lab--the equipment is good enough--but their color balance can be weird--my take is send them "too light and too yellow" and you will be ok--but that is just one Sam's--each Club's machine may well have its own brand of weirdness.
Stan
Stan

PhotoArtsLA Loc: Boynton Beach

Oof... dare I comment? Generally, you want your printing resolution to be a multiple of the printer resolution, or close to it. This enables the printer NOT to due a lot of potentially image wrecking interpolation. For big prints on big Epsons (24x36 and larger) I use 240dpi. Good enough for normal viewing distance, and it does not take hours to print.

When working with a lab, or a Walmart, find out the resolution of their device, and then make a file to make the device happy.

As to:

The Exif for the image I want to print is:
JPEG Large Fine 8 bit - 7360x4912 pixels, 12.8MB
300 DPI, SRGB; Capture NX2 says the print will be 24.53" x 16.37".

This image is already at 8:1 or so compression in JPEG, but will make a good image from little to very big, using the right tools. But I would start with the RAW in Photoshop, and skip the compression. That's just me. RAW is also a lot better, quality wise. In JPEG, by direct comparison, you can see that compression saps a LOT of image information. RAW is the "new negative." Embrace it.

BboH Loc: s of 2/21, Ellicott City, MD

I took what you said and went to Sam's -it took my JPEG upload just as I described it - Glad I listened to you

BboH Loc: s of 2/21, Ellicott City, MD

I used the in-camera HDR wich is not operable when RAW is used.

PhotoArtsLA Loc: Boynton Beach

There are post process HDR solutions which will work with RAW or with TIFF files made from RAW. The in-camera could be the best, but when dealing with high end programs like Photoshop, you can often vastly exceed the capabilities of HDR, given the dozens of tricks which can be used.

Saying that, 8:1 compressed JPEG files, as you mention, should be just fine. The trick is in my previous post.

Dr Tare Loc: Central California

Hi MT, what kind of printer and model do you use?

Thanks,

MT Shooter Loc: Montana

My poster size printer is the HP 130nr model