This is in the Exif standard for metadata, on page 26:
The unit for measuring
The same unit is used for both
If the image resolution in unknown, 2 (inches) is designated.
Tag = 296 (128.H)
Type = ...
An image doesn't have a DPI until you print it.
All it has are dimensions in pixels.
Anything else is simply an interpolation of one system to another in order to display on your screen... which is probably about 72dpi anyway.
If your image is 6000 x 4000 pixels, then that's its size, whatever dpi you think you may have saved it at.
This seems to be intended behavior in Darktable 2.6
Actually treating the group as a selection of two photos makes sense in most cases (Rating, Deletion, Move etc). However the good developers of DT knew that every change breaks someone's workflow so they added a new collection option named group leaders that allows the user to access the old behavior.
You have the Resize to Fit option checked in the Image Sizing section. This is going to resize the image, making it smaller. If your RAW file is 25MB, it must be about 20mp, or approximately 5790px in width, and you have the limit of 2400px set.
If you're exporting for stock photo, I'm guessing you want full size, so just uncheck the Resize to Fit option.
Why image's are very small like 300-400kb after export from Lightroom?
Judging by your screenshot, it's because you're resizing them and exporting them as a JPEG file. Those 25MB files you have are probably RAW files straight from the camera.
That looks more like color banding due to lower bit-depth and jpeg compression than noise. Such banding often looks very similar to chrominance noise.
Increase the JPEG quality when you export so that it isn't as heavily compressed and the issue should be minimized.
From MSDN Knowledge Database
Indicates the resolution units. Used for images with a non-square aspect ratio, but without meaningful absolute dimensions. 1 = No absolute unit of measurement. 2 = Inches. 3 = Centimeters. The default value is 2 (Inches).
It seems extremely unlikely that Lightroom would include a setting (whether obvious or secret) to deal with this obscure situation.
I think you're in a situation where the old joke applies:
Doctor! It hurts when I do this!
Well, don't do that.
You have a workaround. I'd focus on making that as painless as possible.
Unless you have the originals you will only be able to extract the preview images, which will be of lower quality. Adobe has a script which can do the extraction here. Adobe notes that
The extracted previews don't contain any metadata from the original image. (And)
The extracted previews don't contain an ICC profile. So, if you import the extracted ...
I had the same problem and I think I just figured it out.
When you do many edits on an image, including different times using the healing tools, at the end even though the image looks good, some parts get messed up when you export. And what I found out was to delete all the edits I made with the healing tool, and to fix all in only one edit at the end before ...
It sounds like the plugin Tree Export could work for you. https://www.photographers-toolbox.com/products/lrtreeexporter.php
"LR/TreeExporter is an export plugin for Lightroom 2 or higher that allows you to export images while preserving your folder tree (also known as the folder hierarchy).
I've used it many times in the past and it worked as described. It ...
Preview and exported images look different because the demosaicking and interpolation algorithms used are different. Even when viewing the exported image at reduced magnification, the down-sampling algorithms are likely different (nearest neighbor vs bicubic vs cubic vs lanczos). Bicubic and cubic will tend to look softer.
Consider adding a final sharpening ...
Per this thread, this effect could be because of the way the Profiled Denoise module:
The “profiled denoise” module and the way how the image preview is generated. To make it fast the preview only takes “part” of the image. IRC in the full image view, the image is not even demosaic? Once you zoom in a bit you will notice, that it gets unsharp like the ...
After some exploration, it is actually quite straight-forward. The process can be adapted for your own conversion requirements, but I wanted 8-bit TIFF - the reason why is irrelevant.
Open up 'Storage Options' in 'lighttable' section of Darktable, set the required settings. For me, TIFF, 8-bit, uncompressed. Set the desired path for file export to disk, and ...
You need to export to one of whatever various color profiles your print shop can use and embed the profile you actually designated in your export settings. The vast majority of print shops can handle sRGB, Adobe sRGB, and various CMYK based profiles. If they can handle Prophoto RGB (ROMM - Reference Output Medium Metric) then you can use that, too.
But in ...
It's probably not the application so much as it is the size of the data you are including. You've got two basic choices:
Add more RAM to your machine. You need enough to load all of the images at the same time. I'm not a MAC guy, but you may also be able to increase the amount of disk space allocated as "virtual memory" (Swap).
Divide the show into several ...
The short answer is not in any guaranteed way, it is even a bit worse in that it offers no way to even provide a unique image ID on export that you can trace back to the image much less an iteration of edits of an image.
You can get close to a unique image ID by renaming on import, and using the Image Number feature, which is mostly unique (i.e. it is an ...
Problem solved, per Goncalo Peres (Jun 22 '17 at 17:35):
Nevermind, problem was solved with the new updates. By accessing the collections through the shared link (either on FB Messenger or other platform) a button "Download" is going to appear and let you download all the collection through a .zip file.
While two questions, I think they have a common thread that unites them: the need to let Lightroom do everything, not trying to "help" by manual changes and moves.
As to removing the photo, the best plan with Lightroom is to do so in Lightroom. So if you wish to remove a photo entirely, do it without Lightroom and when prompted use the "Delete from disk". ...