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A7R4 File size is difficult to maintain in Lightroom/Photoshop


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Hi all,

I bought the A7R4 to be able to get large prints and the RAW files start at around 117Mb.

I made the mistake of saving the files as JPegs once I'd finished editing them in Lightroom and Photoshop, as they were coming out as 1Mb files!

I did some research and as a result I've started using TIFF files to bounce the image between Lightroom and Photoshop, and saving the final edit to 'TIFF' as well.

This has brought the file size up to between 30 - 50Mb (TIFF) which is an obvious improvement, but it still dosen't represent enough data for a large print, say 36" x 48" at 250 PPI.

I realise that the resolution is subjective to viewing distance, but a lower resolution seems to be a compromise from a camera with a 61Mb sensor.

I also know that the file size can be increased by various methods but thats not the point.

My question is: am I doing something during the editing process that could be eating the data? 

I would appreciate your help and suggestions


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Hi LiveShots,

Thank you for responding.

I've not used .DNG before but I have done some research on it and it seems to be very well favoured.

I have been trying to use it for the past hour or so, based on your suggestion.

It seems to match TIFF as far as being lossless, that is to say, when using basic edits; I still need to do a test when using Layers etc.

I will do what I can to switch to DNG after what I've read about it, but Adobe ain't making it easy!

Lightroom allows you to export in DNG but not directly to Photoshop.

Photoshop will allow you to import DNG's but not to export them, so it does mean saving it as a TIFF at that point, or a JPEG (won't be doing that!)

I don't think my problem has been down to using TIFFs at this time (after doing the comparison with DNG)

I agree that it should be 300DPI but at the time I was compromising at bit.

I'll have to do a more comprehensive test with Photoshops procedures to see if any of those degrade the image.

Thanks Liveshots I appreciate your help, and making me aware of DNG's.


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Tomservo, Basics.... a7R IV RAW files (ARW) are 117.76 MB when imported into Adobe Lightroom Classic. That's 9504 x 6336 pixels.

I cropped a little and exported to Photoshop (.psd) and have a file 9504 x 5344 pixels.

In Photoshop > Image Size pulldown > changing width & height to inches with ppi at 300, you'll see that will produce a 31.68 x 17.813 inches.

If you change ppi to 240 (decent printing can be done at 240), you'll see you'll get a print 39.601 x 22.267 inches. This is getting close to the size you want (48 x 39 inches). Personally, I'd tend to go to 300 ppi if the viewer is going to be close and up-rez the file until you get to your 48 and/or 39 inch dimensions. That amount of up-rez shouldn't be any problem. You can do it in Photoshop or any number of sizing software apps.

You mentioned "viewing" so you're savvy there. At one extreme, billboards are printed at 8 ppi. Then, the closer the viewer, the increase in ppi until we're 300 give or take.

Also, when thinking about resolution and file sizes, it's best to rely on pixel or inch dimensions rather than file sizes in MB since going from one format to another may compress the file.

Also, going from one RAW format to another isn't productive... i.e. going from ARW to DNG unless that's part of your digital workflow and maybe you trust the longevity/viability of DNG versus ARW. I typically trust DNG from drone ops, ARW from Sony, CR2 from Canon, FFF from Hasselblad, etc.. But, that's just me. Lightroom and Photoshop handles all of them quite nicely. From any of the RAW formats, I choose to save processed/retouched files as .psd, but I suppose .tiff would be okay, too and I save as 16-bit versus 8-bit to have the best a file can be. Again, this is only for the Select files, not every image from a shoot.


Sorry for the length here, just sharing what I've come to learn over the years and building a 354,000 image database.


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I appreciate your time Chris, thank you.

I take your point about dimensions over file size, and it's good to note you support 'up-rezzing', (I was always wondering if that was just a gimmick which was 'iffy')

Tiff was my recent choice only because the prefered printing company I use, only deal with Jpeg or Tiff.

It was only fairly recently I changed my setup from a Nikon D500 to the Sony A7R4 in an effort to ensure the capability of larger prints, and it was only then I looked into the difference between the two formats. (Jpegs/Tiffs)

With a database as large as yours, I'm guessing you would be able to answer my nagging question:

Is there anything that you know of in Lightroom or Photoshop, such as Layer blending or background changing, that should be avoided in the interest of maintaining the size of the image and it's integrity? ( apart from cropping!)


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Tomservo, best to leave your Selects at their maximum size.... basically forever; in my case an unflattened layered 16-bit .psd in Adobe RGB 1998 - in your case, an unflattened layered .tif. Then, create a new version for a given purpose as needed. You can downsize, up-size, make sRGB if going to the Internet, compress with .JPEG, shrink by going from 16-bit to 8-bit, etc.. I SAVE these purposed files if they may be used again or DELETE if a one-time use.

Layers are NAMED. Each one doing something specific, so you can go back and re-do a layer if you or a client change their mind about something.

A good example is if you're doing a knockout and changing the background. In Photoshop v23.x.x, you can use the Object Selection Tool to do the heavy lifting of the knockout, then manually fine-tune the selection as needed and insert a new background. Again, do any "work" on the file at its maximum size and resolution. It is your master. Then, make a client's or your size, shape, color, whatever as needed.

For Internet use (i.e. Social Media, Website, eMail, Texting, Messaging) I have a folder (CAC Blog) of files suited for that use. I make them 2048 pixels longest side, sharpened for screen at high, sRGB and put them in subfolders by category (i.e. People, Aerial, Underwater-Pool, Underwater-Location, Architecture, etc.) so they're sitting there waiting for a multiple uses. Check here if you want to see one use.... archive.chriscrumley.com. They are also synced continuously to my phone and iPad so I have them with me all the time.

I like to "talk" with photos. 🙂

Edited by Chris Crumley
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  • 2 months later...
On 12/17/2021 at 4:49 PM, Chris Crumley said:

From any of the RAW formats, I choose to save processed/retouched files as .psd, but I suppose .tiff would be okay, too and I save as 16-bit versus 8-bit to have the best a file can be. Again, this is only for the Select files, not every image from a shoot.

Why not TIFF 8-bit per component instead of 16-bit per component, since e.g. Sony ARW is max 14-bit depth for all 3 RGB components. 8-bit would then be max 3x8=24-bit depth so much more than Sony ARW with 14-bit depth can handle. Save some space without loosing information? When I look at file sizes it should be fine (Sony A7Rii):

Sony Raw image: 85,9 Mb

Tiff 8-bit per component export in Lightroom: 106,7 Mb

Tiff 16-bit per component export in Lightroom: 213,4 Mb!! 

So with Tiff 16-bit am I only storing useless information which wasn't there in the first place, since basic Raw was 85,9 Mb? 


Am asking since planning to convert my complete RAW library to TIFF 8-bit for Apple Photos and future use outside Lightroom (subscription) WITHOUT loosing any information, so lossless. I found I cannot edit a RAW for retouching and export as RAW which would have been the simplest approach..

Thanks in advance.


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