Busy reading an article Jeff Schewe wrote in 2005 - 'The Art of The Up Res' . Now it's 2013 - I have CS6 & ACR 7.3 so things may have evolved since then.
I also searched for an answer to my question online (& another forum) and am still looking.
I am asking what the best way is to upsample my images. Of course there are many variables that will influence quality but in general is it better to use ACR or bicubic smoother or look for a plug-in like Blowup or Genuine Fractals, or Photozoom etc or perhaps a combination of of the above?
I am no software engineer and some of the intricacies discussed on threads were beyond my comprehension.
This question arose for me because I have a file that originated on the 5D (the original version - I now have the Mk2) which was only 12MP. The dimensions are 4368 px x 2912 px (or 9.7 x 14.5 inches at 300dpi).
I have been asked for a very large 30 x 40 inch print which is 12000px x 8000px. That's almost 3x !
Of course the quality of the original file, print viewing distance, & subjective opinions about what constitutes 'high quality' means that 'good' is different to different people, and I can't quantify it with numbers except to say it has to satisfy critical pros.
Someone at a lab looked at my layered file (with D&B, healing/spotting/cloning, levels etc.) and asked for the original RAW file which he then graciously upscaled and sent back to me. I am retouching it now and have not yet seen a print but it seems promising.
I don't know how, or with what product, the upscaling was done ? It appears to be a "trade secret" because I asked and he won't divulge the method used.
Personally I don't know of a way other than ACR (up to 25mp), PS (bicubic smoother), or a plug-in.
I tried to replicate what he did but cant quite get the same 'smoothness' combined with 'sharpness' by first using ACR to the max (25MB) and then in PS bicubic smoother the rest of the way up.
Of course there may be variables such as the amount of sharpening applied in ACR (or none?) & other settings.
It's been like shooting in the dark...trial & error etc
Any light you can throw on the best way to up-sample (just a short version :-) is appreciated .