ecobin Loc: Paoli, PA

If you need more pixels for printing then try Upscayl which is a Free and Open Source AI Image Upscaler for Linux, MacOS and Windows. I use it infrequently and it works great. It isn't as good as Topaz Gigapixel but since I rarely need to upscale this free app is fine.

ELNikkor

When in RAW, my D750 stores a high-res (up to 30 mb) image on the RAW card, and around 6 or 7 mb on the jpeg card. With my Topaz programs, I can sharpen and add a lot of mb for large blow-ups. (I wouldn't think of making a 3x6ft photo without Topaz enhancements.)

CHG_CANON Loc: the Windy City

In digital photography, the issue is the pixel resolution of the image file, not the byte-count of the storage size. The D750 can store files from the 24 megapixel sensor as 24 megapixel files, not a pixel more.

To maximize the data 'describing' each and every one of those 24-million pixels (6000x4000=24,000,000), one should capture in RAW where the color data maintains the 14-bit depth. With these camera settings, how big (or small) the file sizes on disk is immaterial.

DWU2 Loc: Phoenix Arizona area

OK, I've read this whole sequence of posts, but I'm kind of scratching my head. Let's establish a few things. You indicate you shoot in raw format, and you are concerned about the small size of a JPG. How did you get to the JPG? Are you shooting RAW+JPG in camera, or did you create the JPG from the raw file via some editor? If so, what editor? In most, if not all editors, such as Photoshop or Lightroom Classic, when you create a JPG from a raw file, you can set the JPG quality, which impacts the file size.

therwol Loc: USA

Again, and I'm not the only one who has said this, the size in this case depends on the amount of detail in the picture. The picture in question is about 2/3 pure white or pure gray. No detail. Fewer megabytes. If the trees took up the whole picture, there would be more detail and more megabytes of data. This is easily tested. Using the same camera settings and lens, take a picture with a lot of detail to capture, such as all trees with the limbs and leaves, and the photo will have the number of megabytes that you expect. I will even say this. Some lenses that are sharp will capture more detail of the same scene than lenses that aren't so sharp. The resulting files will be larger. I noticed this with some of my sharper primes in comparison to some of my zooms. For example, when I was using a Nikon D810, jpegs taken with my 24-120 f/4 would yield photos that were about 20-21 megabytes in size. Photos taken with my 50mm prime would give photos that were at a minimum 25 megabytes and sometimes as high as 28. Better lens = more detail = larger files.

DWU2 Loc: Phoenix Arizona area

Sure - I understand. The size of a JPG depends on the content of the photo. That's how compression algorithms work. And, the photo he shared is mostly white. But, my point was, he said he shot raw and he ended up with a smaller-sized jpg than usual. It was likely due to the photo's content. But, to create a jpg from raw, you have to process and export it, and if the quality slider was changed, it would result in an even small jpg file.

shells Loc: Chicago

Thanks, I shoot in RAW and use LR. When i export the image I have it set at: Quality 100, Resolution 300
As you can tell, I know what i know, but I don't understand it. I do however think the MB's are low because of too much white. At least that is what i am understanding. I had another photo that i loved that also had the same problem. I deleted it unfortunately.

Wrexrus Loc: MD

When you go to the settings/shooting menu for the D750, ensure you select RAW+fine for biggest image size, etc. when you open the editing phase, it will actually bring in both the RAW files and jpeg images.

CHG_CANON Loc: the Windy City

I'd rather have 24MP at 14-bit depth than 24MP at 8-bit, with ZERO consideration of the file size in bytes.