Photoshop memory and registry

[KRSESQ]

Of course, Adobe were always MAC-oriented, right from the get-go.

I use the same analogy to describe two antivirus programs on one system.

[Rakido]

have you tried the optimisation tricks that are available for Photoshop? There's quite a good article here ( http://www.quepublishing.com/article...aspx?p=2115887 especially #2 and #13) where you can limit the memory size Photoshop uses at all.

[Brian Ellis]

Out of curiosity, I tried the same NEF photo as below in Paintshop Pro. To do this, I imported the NEF file, did some brightness/contrast/colour editing in their RAW file (poor) as well as I was able to try and match the ViewNX 2 but it had only a fraction of the possibilities. Ithen transferred it to the native lossless editor and cropped it roughly to a similar field, resized it to 800 pixels wide and converted it to 8-bit jpg at the "highest quality" (pretty much the same as I did with the Nikon software.
Result:



As you can see, the detail on the carapace and the hairy left foreleg is definitely not as good and I could see this already on the NEF>RAW conversion, which I suspect may be 8-bit and not 12-bit as with the Nikon software. Unfortunately, the original NEF file was saved on the cam as this image (bad!), so I couldn't do any more experiments starting with it. However, I had a different NEF view of the same gr****opper and I converted it to lossless TIF and imported that into PSP. There was no loss of quality, nor at the end of much editing, until converted into 800 pixel-wide jpg, which is always over-compressed.

Perhaps PSP is not as good as I hoped and I may be able to keep my vow, but I'll keep on trying it out, in case I've misunderstood something.

Edit: cannot name an innocuous insect without the censors removing a-s-s-h from the middle of the word: this is going too far!

[Brian Ellis]

have you tried the optimisation tricks that are available for Photoshop? There's quite a good article here ( http://www.quepublishing.com/article...aspx?p=2115887 especially #2 and #13) where you can limit the memory size Photoshop uses at all.

Thanks, that's interesting! I think the following page says everything for me. http://www.quepublishing.com/article...15887&seqNum=2 A RAW file with several added layers may be, say, 500 MB long. That means I need several GB each of both scratch disk and RAM. If doing a composite with 3 such files, I would need at least a TB of each. Worse, closing PS would liberate the RAM taken by the software but not that (by default) taken by the working files. PS? No thanks!

[Brian Ellis]

Not being over-sure of what I wrote yesterday, I wanted to confirm it. I started with a NEF file that I knew was virgin in the camera and converted it to RAW using the Nikon ViewNX 2 software and displayed it on the screen at 200%, without any editing whatsoever. Rather than risk having any differences due to JPEG algorithms/settings, I took a screen dump of a small patch and converted it to highest quality JPEG. This is the result:



I then did exactly the same with the Paintshop Pro Camera RAW Lab, except that the screen dump was bigger, but the scale was the same. This is therefore an apples to apples comparison. This is the result:



I promise you that there is absolutely no reason for the quality of the images to be different, unless the NEF>RAW conversion in the softwares is not identical. This appears to be the case; look at the fine hairs on the insect's leg, as well as the general appearance. Now look closely at the places where there is a strong contrast on a diagonal; pixellation is more apparent in the second image. I speculate that the main difference is due to the Nikon software results in a 12-bit image (known) while Corel does it in 8-bit (guessed).

It would seem that not all camera>RAW converters are created equal, but some may be less equal than others (sorry, Mr Orwell!).

My daughter has a Canon camera and she will be visiting us in 3 weeks with it and the software disk. It will be interesting to see whether its RAW performance is similar.

[Brian Ellis]

I've done some further research into Corel PaintShop Pro (PSP) and the following quotation is copied from a post I made on the PSP forum run by Corel. As a result of this, I decided that PSP was unsuited to my needs, even if the latter are perhaps OTT. This inspired me to Google '16 bit image editor' and this came up with many results. Some of these were obviously unsuitable or too expensive but one caught my attention, Sagelight, and I downloaded its trial version (the licensed version is not expensive for a 'lifetime licence'). A first look at it showed that it converted NEF into RAW without losses and thence to 16 bit TIF, still without losses. In reality, it has two image editors, the first being for RAW files with all the features for preliminary editing (which PSP was less complete). The RAW file is then taken into the second editor, still at a 16-bit level, which is similar to a usual image editor. It has fewer bells and whistles than PSP or PhotoShop in this but the features include more than I'm ever likely to need. I'm still in the first part of the learning curve for the finer points and I have not decided to go ahead with it, yet. Oh! and it does not hog the computer resources, using the scratch disk seamlessly for these ultra-large files.

OK, I've done some more research and what I've found is not pleasing. Unfortunately, the RAW files and their derivatives involved are too big to post on a forum so, unless you duplicate what I did, you will have to take my word for my findings. Unless mentioned otherwise, n-bit in the following refers to per channel, e.g. an 8-bit RGB totals 24-bit or a 16-bit aRGB totals 64-bit

Phase 1
1a. I downloaded a virgin 12-bit NEF file into ViewNX 2 using default settings and converted it into a 16-bit uncompressed RGB TIF file
1b. I downloaded the same 12-bit NEF file into ViewNX 2 using default settings and converted it into an 8-bit uncompressed RGB TIF file
1c. I downloaded the same 12-bit NEF file into Paintshop Pro (PSP) Camera RAW Lab using default settings and converted it into an uncompressed RGB TIF file (no choice of bit size)
1d. Comment: I carefully examined the same part of the three images in their RAW state (before conversion) at 400% (the max allowed by ViewNX 2). 1a and 1b were identical, of course, and high quality. 1c was distinctly and visibly poorer in quality with larger pixels.

Phase 2
2a. I Opened the TIF 1a file into the PSP Editor
2b. I Opened the TIF 1b file into the PSP Editor
2c. I Opened the TIF 1c file into the PSP Editor
2d. Comment: I carefully examined the same part of the three images, as in Phase 1, in the Editor at 500% and, using the Tabs, was able to switch between them to get direct comparisons. To my total surprise, 2a and 2b were rigourously identical! In other words, the 16-bit file was converted in the editor to an 8-bit image, similar to 1b, which was poorer in quality than I expected, similar to 1a. Clicking on Image Properties, this confirmed that 2a was 8-bit. Disappointingly, high-resolution pixel corrections were therefore impossible. 2c was similar to 1c, poorer than both 2a and 2b.

Phase 3
3a. I did a few identical edits (Straighten, Crop, Duplicate layer, Resize and Brightness) to each of 2b and 2c, with a Save between each edit (it was deemed useless on 2a, being identical to 2b).
3b. Comment: At 1:1 frame size, the images were still good. Zoomed at 500%, the images had considerable pixel-shifts from the originals and 'pixel-clusters round a small or large artefact appeared totally different in size and gradation. One edge line of an object increased from an average three pixels between solid dark to solid light to five pixels on 2b. On 2c, it was more difficult to judge as it varied up to about 5 or 6 on 'before' and was worse on 'after', but almost impossible to put a figure on, as it was more random from the start. I then put the two images 3b and 3c on a full screen viewer. 3b showed a satisfactory image, looking acceptably sharp but 3c was visibly less distinct on careful examination. I guess that printed to A4 quality photo-paper at best, you would probably be hard-put to tell the difference but you probably could on A3 scale.
3c. Comment: In the editing in 3a at every save, I got the following message. The "24 bit depth" refers to 8-bit RGB. It would seem that PSP is paranoid about 16-bit TIF files or obsessive about 8-bit ones.



Conclusion: I'm not sure that PSP is the best choice at handling RAW and derivative uncompressed files. One can ask what the purpose is to shoot in RAW (or, in my case, NEF) format, if it can't be edited with as few losses and artefacts as possible? Note that what I have said applies only to the combination of NEF and TIF formats; other formats may be better or worse or just the same - this must be tested before being categorical.