Converting NEF to JPEG and e-mailing images - how do I get good results?

desmobob

Senior Member
I just received an e-mail from a friend who is not a photography enthusiast. The message had an attached JPEG from her phone camera and the file was 105 KB. The image is sharp and maintains its quality when viewed in full-screen mode on my 13" MacBook Pro.

I sent a response to the message and attached an image from my D200 that I quickly converted in Nikon View NX-i from an NEF file with no cropping; just some sharpening. It was a JPEG measuring 101 KB with dimensions of 1205 x 807 pixels. The "Quality" setting slider was just left of center at "Good Compression Ratio." It doesn't look nearly as sharp as her phone photo and when viewed in full screen, shows pixellation.

Even though each of our files are almost exactly the same size, her is far nicer than mine. I've always been frustrated trying to get nice images to maintain quality when converting or re-sizing to small file sizes for e-mailing. Can someone school me on the process or point me to a good on-line tutorial? I'd really appreciate it!

Thanks for any help or suggestions,
Bob
 

desmobob

Senior Member
I think I see the problem (or part of it). I just tried it again. In Nikon View NX-i when I converted the NEF to a JPEG, I set the "Quality" slider to make the estimated file size 105 KB to exactly match the size of her attached photo so I can compare them fairly. But after conversion, the actual file size was 211 KB. When I attach it to a message in "Mail", it attaches it as a "Medium" sized photo in the message, with a size of 108 KB.

I guess my Mail program is processing and reducing the image a second time, reducing the quality. I think the answer is for me to select "Actual Size" in the selection area of the upper right corner of the message being composed. Then, it attaches the actual image I converted, rather than re-converting my image to an even smaller size.

Basic stuff, I guess. I'm not much of a computer person... :shame:

Stay sharp,
Bob
 

480sparky

Senior Member
If you downsized the image to 1205 x 807 pixels, you're gonna see pixelation, especially if your monitor has more pixels than that (many are 1920 x 1080 these days). You'll need an image at least the same number of pixels of the monitor to prevent pixelation.
 

Blade Canyon

Senior Member
Comparing the size of the files in KBs is not accurate because the compression can be totally different in two different JPEGs. (For example, a picture that has a lot of blue sky in it might have a small file size because the file can say "use this blue color for the next 150 pixels" instead of 150 different instructions for each pixel.)

Comparing the dimensions in pixels would be more accurate. What were the dimensions for the phone pic that she sent to you?
 

desmobob

Senior Member
Comparing the dimensions in pixels would be more accurate. What were the dimensions for the phone pic that she sent to you?

Checking into this leads to another surprise! On the original message from my friend, using the "Quick Look" shows a 105 KB JPEG. The attachment appears as an image in the message body. When I click on the paper clip icon at the top of the message, I can download the image. When I downloaded it, it was a 4032x3024 pixel 2.84 MB image!

Well, no wonder it looks better than my 101 KB image!

So... sorry for the confusion. I learned a bit from my blundering.

Thanks to all who responded,
Bob
 

aroy

Senior Member
If you do not want image degradation, use 100% quality. That will use non degrading compression. The file size may be slightly more. This is similar to using ZIP/RAR to compress files.
 
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