Since Lightroom is so good, what do you use Photoshop for?

Started Apr 25, 2014 | Discussions thread
Shop cameras & lenses ▾
ttbek Senior Member • Posts: 4,720
Re: Since Lightroom is so good, what do you use Photoshop for?

soloryb wrote:

Glen Barrington wrote:

That is not correct, there is nothing in a raw image than can be printed as an image. Certainly not one that has your edits applied, and in the pixel density you are expecting.

A raw developer that is capable of printing HAS to render the raw image into something printable before it can be printed, and that is a bit mapped image that is at least in the proprietary internal format that the Raw developer uses. It doesn't have to be a jpg or a tif, but it DOES need to convert to whatever internal rendering mechanism it uses first.

-- hide signature --

Thanks for confirming my understanding.


That did not confirm what you said at all, rather the opposite. In other words, LR does create an intermediate file for printing, and you should hope that it's not jpeg (depending on your printer jpeg may not support the bit depth of your printer). This file is probably created in your computers temp folder and deleted on a reboot or a need for more space in temp (this is a guess and may not be the case, but you could look for the file there if you want). Furthermore, the printer drivers may convert the file yet again before it is actually sent to the printer.

Also you have a weird idea of what "degradation" is. Just because pixels are changed does not mean an image is degraded, which would imply deterioration and loss of quality. Let me put it this way, if you alter and image and it looks better than before (including on 100% zoom or whatnot) then it is not degraded. My 2nd point, all edits, whether in lightroom or photoshop are applied before the image is exported. Suppose you brighten an image using both programs, in both cases every pixel in the image is altered. Printing works this way as well because the image will be exported for printing.

Actually, your idea of what is happening in these programs is completely misguided. All edits in all editing programs change pixels, the question is only, when are those changes applied and how does that affect your workflow. Both lightroom and photoshop apply these pixel changes to what you are viewing (changed in RAM) and to what is exported. The difference is mainly in how saved files are represented, essentially an image in lightroom is represented as an original file + a change list that is applied to the file in RAM when viewing or applied to the output file when exporting. In photoshop the representation is as layers, where the changes are applied directly to each layer, the layers are flattened in RAM for display and so flattening an image will not give you any lower quality that what you saw on screen. Supposing that I am doing the same image operations in lightroom and in photoshop, then the output files will be identical, including for print.

About interpolation for printing. This occurs only if your file is being resized for printing (which it likely is, since most of us don't have cameras shooting say, exactly 4x6 images at 300 dpi). I believe you can choose from several interpolation algorithms for this in photoshop, I don't recall the options offhand (I don't use photoshop very much), but they likely include nearest neighbour (maybe not this one since it isn't very good), bicubic, Lanczos 2 probably just this or bicubic, since they're practically identical, Lanczos 3, and possibly a spline based one?

Here is the wiki page on Lanczos, and they link to other interpolation methods in the See Also section:

This page is useful as well, though they go into more specialized methods later in the article for pixel art:

Here is a good thread comparing two particular methods and an expert (dmunsil) weighs in on the topic:

 ttbek's gear list:ttbek's gear list
Canon PowerShot SX10 IS Canon EOS 5D Samsung NX300 Canon EOS Rebel SL1 Samsung NX30 +37 more
Post (hide subjects) Posted by
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow