Railfan Technology > Photo preparation question

I have recently joined TO and wonder how folks reduce their pictures for posting.  I shoot raw Nikon NEF files and export to JPEG with Adobe Lightroom.  Without disclosing any trade secrets, of course, what tradeoffs do people make about size, compression, quality, etc. to get the best results?

Thanks,
Tom

I use linux... ufraw for the nefs, which I just use to export as *.png's.
Then gimp-2.9.1 (bleeding edge raw build from source) In gimp, I shrink to
1400 x 935 (for posting on abpr -- alt.binaries.pictures.rail -- usenet)
I'd post more here but I don't like the 1000 pixel limitation... too
restrictive with too much detail lost.

My nefs are from either a D200 or D600.

John.

Thanks, John.  I also found that the restrictions were "too restrictive with too much detail lost" as well, although it appears that some folks can make their photos look pretty decent.  My linux box is 10 years old now and not sure how long I want to wait for a make install of gimp, but it's not doing much right now so I might give it a whirl.  

Tom

Images are limited to 1000px on the long end, and IIRC, 500KB in size so scale the image accordingly then set compression to save a JPEG that fits the file size limit. If you try to upload a file that is larger than allowed, the TO server will resize it and that is when you start seeing problems. If you maintain control of the image and file size locally before uploading, you can retain decent detail with limited compression artifacts.

I use Photoshop Elements.

Victor A. Baird
http://www.erstwhilepublications.com

Another vote for avoiding the compression routine. If you have PS Elements you can use the 'Save for Web' selection, reduce the pixel dimension to 1000 on the longest side. At these resolutions, the file size is not a direct indication of resolution.
Works great.

Thanks for the useful tips - I will try rescaling and then reducing the file size and see how that works.

Tom

I exported with 1000x500 pixels with a file size limit of 500k and this is what I got (attached shot of CSX Intermodal train running through Eugene, OR)

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I use CS6 and after enhancing the Canon CR2 file (sharpening, rotation <if necessary>, etc) I then resize the image by setting the resolution to 72 pixels/inch, then set the horizontal width to 1000 pixels (letting the vertical resolution fall where it may (I crop most photos to 16x9), and then "save for web" at about 70%.

Photo attached is from my recent trip to Portland, OR for the National Train Show. Train is a westbound near Hood, OR at Tunnel 6.

Seems to work ok for me.....


Ted in AZ



Edited 1 time(s). Last edit at 10/16/15 22:31 by ACR_Ted.

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Ted,

I changed the export to only set width of 1000 pixels and 500 kb size and got a 450 kb file that looks decent as long as I don't enlarge it much.  Thanks for the tip!

Tom



Edited 1 time(s). Last edit at 10/16/15 23:42 by CBRL.

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The last image looks pretty good. Do all your editing before you scale it, including sharpening, and your images should stay relatively clean.

Ted, that BNSF photo looks really nice.  However, best of my knowlege setting PPI has no effect. 1000 pixel is 1000 pixels and your display determines resolution.
"Resolution", not sure if correct term in this use,  comes into play with prints where you want between 240 and 360  dpi with 300 somewhat the standard.

Bob

The pixel thing is what appears to trigger the TO compression software. The compression s/w appears to bring noise into the image, then leaves the pixel numbers at 1000. So it's not the ppi, it's the compression s/w that we're tricking out.

A number of folks have been going under the 1000 pixel number and have had noticeably better results. There's a number of posts from a couple of years ago that describe the concept. It would be an interesting test to see if the compression s/w is still being used.

It doesn't matter what the ppi is as long as the images is equal to or less than 1000 pixels on the long side.

"Resolution" is the term Adobe used in the dialog box in CS6......

I really don't know the differences in all of the different terms.



Ted