Lightroom editing of tif files?

[Eric Brody]

I was taught by Charlie Cramer that it is best to do as much editing as possible editing on the RAW file. I tryto do as much as I can in Lightroom Classic and import to Photoshop as a smart object so I can just click and return to Camera Raw to go back to the RAW file should I notice something that needs fixing. The good news is that I can do back to Camera Raw, the bad news is that I lose some Photoshop functionality as in content aware fill, etc.

I also do a lot of focus stacking. I use Zerene Stacker which returns a tif file. I save these in Lightroom.

My question is whether there is any image degradation if I were to modify this tif file in Lightroom. When I have looked, I do not see obvious differences.

I hope I'm making myself clear and look forward to any responses even if speculative.

Thanks,

Eric

[PeterAit]

You do not lose content aware fill with tiff files. It may depend on whether the tiff has layers and which layer you have selected. A text layer, for example, will not allow CAF.

Make sure your tiffs are 16 bits and you will not have any image degradation.

BTW, if you are using Lightroom why bother with Camera Raw?

[MDL_SD]

Yes, smart objects in Photoshop do prevent you from using some functions.

When you produce a focus stack, or otherwise combine images you have to work in some form of image file (TIF, JPG, etc.) as opposed to a data file (RAW).  My understanding is that using 16 bit TIFs with a large color space (adobe RGB or prophoto) is the best that you can do.  TIF files can be uncompressed so you should not generate image degradation when you edit those files.

[Eric Brody]

Hi Peter Ait,

I think you may have slightly misunderstood my question and info. As MDL_SD said, when importing from Lightroom Classic to Photoshop as a SMART OBJECT, you do lose the ability to use content aware fill and some other functions in Photoshop. I agree that you do not lose Photoshop functions just because it is a tif file but you do if the Photoshop file is a SMART OBJECT.

When a Lightroom Classic RAW file is imported into Photoshop as a SMART OBJECT, if you click on the base layer, it sends you to CAMERA RAW where you can use CAMERA RAW sliders not available in Photoshop such as clarity and dehaze as well as the incredible masks one can do in Lightroom and CAMERA RAW. One click sends the modified file back to Photoshop, another pearl I learned from Charlie Cramer.

[Redcrown]

When you edit a Tif in Lightroom, the edits are what's called "parametric." They exist only in the LR catalog. So, there is no chance for image damage or degradation until you export the image to a new, separate Tif (or jpeg) file. You can revisit the edits over time with no problem. All you are doing is changing the values in the LR catalog. Nothing really happens until you export.

Making repeated visits to Camera Raw, either via Smart Object or simply "Edit in Camera Raw" of a Photoshop layer does cause a little damage, but it's not very significant. That's because Camera Raw uses a unique colorspace and must convert the image to that colorspace and back again. Pixels don't all survive colorspace round trips.

If your image in Photoshop is in 16 bit Prophoto colorspace, the damage is minimal because that is very close to the Camera Raw internal colorspace. But if your image in Photoshop is in 8 bit sRGB, the damage is greater.

In Photoshop, you can measure the "damage" using 2 pixel layers and "difference" mode. Save a base image. Then pass that image through Camera Raw a few times. Then re-load the original base image and place it as a layer on top of the layer that has passed through Camera Raw. Put that top layer in Difference mode (and see a black screen). Then display the Histogram Pallet and look at the StdDev value.

Any StdDev value greater than zero says there is a difference. The bigger the StdDev value, the greater the difference. StdDev values less than 1.0 are insignificant and won't be visible anywhere. The more times you pass an image through Camera Raw, the greater the difference.

[mcbroomf]

Hi Peter Ait,

I think you may have slightly misunderstood my question and info. As MDL_SD said, when importing from Lightroom Classic to Photoshop as a SMART OBJECT, you do lose the ability to use content aware fill and some other functions in Photoshop. I agree that you do not lose Photoshop functions just because it is a tif file but you do if the Photoshop file is a SMART OBJECT.

When a Lightroom Classic RAW file is imported into Photoshop as a SMART OBJECT, if you click on the base layer, it sends you to CAMERA RAW where you can use CAMERA RAW sliders not available in Photoshop such as clarity and dehaze as well as the incredible masks one can do in Lightroom and CAMERA RAW. One click sends the modified file back to Photoshop, another pearl I learned from Charlie Cramer.

To get around the problem with Content Aware fill on a Smart Object.  Make your selection.  Create a new blank layer above the Smart Object layer.  Make sure the new layer is selected.  Do the Content Aware Fill.  The fill will sample from the layer below and create a new layer above the blank layer.  You can then merge as necessary.

Do the same if you want to spot or do small removes with the Remove Tool.  ie paint on a new blank layer above the SO layer.  Make sure there is no selection 1st, and make sure Sample All Layers is selected. 

However for both of these edits make sure it's the last thing you do as any changes to the SO will not be carried over to the blank layer which you painted on or did Content Aware Fill.  For example if you removed some power lines in the sky then decided to darken the image by editing the SO in ACR you will end up with a light shadow where you painted.  So do this last.

Also, you might feel you are seeing a shadow on some edits (sky for example) when viewed at a fraction of 100%.  This is normal and not be there at 100% and also will go away when you merge the layers for a final jpg or tiff.

[PeterAit]

I do not understand why photographers use smart objects at all. In 2 decades of serious digital photography I have never used them. Maybe there is something I am missing.