I purchased PTGui 1 week ago and now have has some experience with this suite and I have some observations to make.
Firstly may I say that PTGui is clearly the best suite developed so far. It outperforms Arcsoft and all others I have tried and so it is now my default stitcher. I need not detail its benefits here. I purchased the pro version mainly due to its ability to stitch bracketed images and apply in suite HDR and tone mapping. Thats important if you have a very high dymanic range in your required end image.
Wanting to gain the highest possible resolution I attempted an eight stitch image with 3 exposures per frame - a total of 24 vertically oriented (portrait mode) images and then applied the HDR at the end. I shoot full frame at 24 megapix per shot. To produce a good wide angle view (equivalent to a FL of about 20mm in my final stitch) I chose a 70mm FL for each frame. I have a very fast computer using Windows 7 64 bit and 12 gig of ram and a fast processor.
It took PTGui a total of about 90 minutes to complete the tasks required including creating and manipulating the HDR. I shot in JPEG and saved as a tiff - If I had shot in RAW that 90 minutes might translate to 90 hours (!!). I never tried.
The end result was fair - heaps of detail but I found the tones and colours in the final image rather bland and lacking that WOW factor. My end file was 400 megabytes and almost all my other applications could either not handle this (as they are written in 32 bits and so can only access 2 gig of ram) or took their time and in the end it became too much of a pain to enhance the images to the point I was pleased with them. I was NOT pleased with the colours or the tonal range.
I then did some maths and I recon that in terms of definition I had ended up with near 10" x 8 " film type detail.
Now the crux of the matter is this. Will this detail be visible in the end print???
That clearly depends on the size of print being created !!
I print up to 19 inch by 13 inch on an A3+ Canon printer. According to R. N Clark (whose opinion I trust) you need 600 DPI to satisfy the discerning eye in the final print. That is NOT the 300 DPI that is commonly touted (http://www.clarkvision.com/articles/printer-ppi/
Now with the 8 stitch image printing to 19 x 13 inches I would be using a 120 megapixel image - that is then 2.5 times more than the human eye can resolve assuming my printer would detail up (and I doubt that it could, but I have not done the maths).
Now shooting 3 vertical images in a horizontal row with a 55mm FL length lens I can use the in camera dynamic range optimisation that works well here (you cannot use this with an 8 stitch and a longer FL as each piece of the mosaic is too small and the end result is images with such and exposure difference you will end up with an awful result).
Stiching 3 in a row is quick and with this software yields perfect result. With a 20 % overlap the final aspect ration is 3:2 suiting standard paper formats.
I end up with a 65 megapixel file that most of my other photoeditors handle well for the fine tuning. The in camera DRO produces far superior HDR than the software HDR in PTGui.
The image looks natural. VERY natural. WOW !!
Now is this sharp enough?? To get 600 dpi on a 19 inch by 13 inch paper you need 48 megapixels.
I have 65 megapixels from this 3 in a row stitch. There is STILL detail there that the eye will not see.
PROVIDED YOU HAVE A FULL FRAME CAMERA WITH DYNAMIC RANGE OPTIMISATION - it seems to me that this is the way to go.
Unless of course you are lucky enough to own an A2 printer. I have not done the maths on that one.
The limiter is your printer - that is my message.
And thanks for introducing PTGui to me.