Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: D White on September 08, 2017, 11:20:55 pm
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Hi,
If one wants to print a file larger than it's native resolution, is there any advantage to upsample images at the time of RAW conversion to a tiff, versus upsampling the tiff later in photoshop as needed.
I have come up dry with web searches on this topic.
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Probably the less times you need to resample the better, so perhaps best to know the final resolution you want for printing before you export. The conversion will be happening once at the end of the raw processing stage. I thinks perhaps more important is the quality of the resampling tool you are using. I do 99% of all my image editing from raw in Lightroom, and print from Lightroom with the least amount of resampling necessary for conversion on the fly from raw data to the correct specification of printer-manageable data. Done this way I find Lightroom's handling of resolution to be very good.By the way, there is a lot of information on this website that covers these techniques; see in particular the tutorials by Jeff Schewe and Michael Reichmann.
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Mark,
Your suggestion to minimize the number of times a file is interpolated is well noted.
My workflow with luminosity masks etc requires an export as a tiff to PS and must "bake in" a master output size at this point. What I am trying to ascertain if there is an advantage to upsample to a larger than native size at the point of creating the tiff that I export to PS for final processing and saving. Or if no advantage it obviously keeps the file size smaller to stay at the native tiff output and only resize copies of the master file for print output, or print directly from my tiff image library catalog in LR.
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I think it best to try a few options yourself with typical photos you make and see what differences you notice. That's the surest way of getting what you want without disappointment. It will only cost you a bit of time, ink and paper.
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How much larger are you typically wanting to make your files, and what output resolution are you intending to create most of the time (are you printing to Epson (360/720ppi), new Epson (300/600ppi), Canon or HP (300/600ppi)?
Ideally, you would be guided by the desire to get as close to one of those ppi levels as is appropriate with the minimum of resizing.
Knowing the percentage of files that you will likely want to upres, will help determine whether this should be a standard function of your workflow or an exception (and if an exception, to then consider where to do it - at RAW or at TIFF to reflect your process).
Ideally, in order of preference:
1. Print at the higher native resolution of the printer without having to upres
2. Print at the higher native resolution of the printer with minimal upressing (personally, I would scale to 720 from anything lower to 540 or to 600 from anything lower than 450 - YMMV)
3. Print at the lower native resolution of the printer without having to upres
4. Print at the lower native resolution of the printer with minimal upressing
5. Print at the lower native resolution of the printer having upressed using a method which you have determined to be most effective for quality having regard to the nature of your images.
That bring us to your question. If you're not upressing much (in terms of change of resolution) and not doing it often, it probably makes sense to do it ad hoc at the TIFF stage (but do it in an application rather than relying on the printer driver).
If you need to upres a lot - it may make sense from a workflow perspective to do it in raw. Then it's done for everything. However, you will need to compare the quality of the image once printed to that of a TIFF-based upres using whichever application you have to do so. In short, different raw files are processed in different ways by different applications and so I don't think anyone can make a blanket statement that it's better or worse one way or the other - you need a specific result for what you're doing with the tools you have.
I hope this is helpful on some level, to illustrate what I believe is the best approach to determine what you really need and the impact of workflow versus quality.
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If one wants to print a file larger than it's native resolution, is there any advantage to upsample images at the time of RAW conversion to a tiff, versus upsampling the tiff later in photoshop as needed.
In my experience using Lightroom/ACR engine, yes, do so at the raw conversion stage with proper capture sharpening.
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I thank every one for the time taken to post advice on my topic. It has been helpful.