Working with Large images in Photoshop? Using a "proxy Image"?

[l2oBiN]

I am wondering how people work with large images in photoshop. Is it possible to have a smaller version of an image on which to carry out all the actions/tools/edits on and then transfer that to the large image?

[Ben Syverson]

That's not really necessary with newer versions of Photoshop... Applying Adjustment Layers basically takes zero time, no matter how large the image, because it's not actually changing the underlying image data.

I routinely work with 20,000 x 24,000 pixel images in Photoshop on a laptop, and it's relatively smooth.

[RPNugent]

http://www.largeformatphotography.info/forum/showthread.php?t=60100

Check this thread for similar discussions. Yes it can be done and is well described in John Paul Caponigro's Photoshop book.

[timparkin]

I am wondering how people work with large images in photoshop. Is it possible to have a smaller version of an image on which to carry out all the actions/tools/edits on and then transfer that to the large image?

Yes I do this quite often especially when making masks as each mask will be quite a significant size.

My process is to scan my image (sometimes at 4000 dpi but usually downsizes to 3000dpi afterward) and then apply some basic capture sharpening (using Photokit sharpener) with the opacity turned down to 50%. I then flatten this image and spot it (the sharpening helps reveal many spots you may miss). This image then gets archives..

I then reduce the image down to 25% of it's linear dimensions and start work with adjustment layers etc.

Then, this image gets saved as the 'adjustment master'.

When I want to make a really big print, I upscale this image by 400% and paste in the original archive image at the bottom layer.

This can take a while because the whole image could now be multiple gigabytes.

Remove the 25% base layer and you have a full size image with adjustment layers.

The final comment is that I like to use 'shadow highlight' occasionally but it has a maximum radius of 2500px and my 3000dpi scans can be 15000px. However, with the downsized image, those dimensions are down in the 4000px range and so the radius is manageable.

[Preston]

There is a concept and procedure for using what is called "Guide File Workflow". There is a podcast that was developed by West Coast Imaging that you may find helpful. Link below.

Guide File Workflow-Pixel Podcast (http://www.westcoastimaging.com/wci/page/info/photoshoptip/podcast_guidefile.html)

I haven't used it, but I plan to give it a try.

--P

[Frank Petronio]

In the day, we used Live Picture for that ;-)

If you have a slower machine it can help to work out your ideas with a low-res version, jot a few notes down, and you can quickly experiment. Especially if you like using filters (yikes! they can take a long time to render though) or collages, it lets you work fast and make roughs. If you like a mask or curve or other setting you can usually save it in the dialog box.

But in general, the modern computers with sufficient RAM are fast enough to just work on most reasonable-sized images. It helps not to be stupid about it and scan everything to be 2gb in size. Generally, a 50-100 mb 16-bit Greyscale image is plenty of resolution for my needs, triple that for RGB.

I have no idea why so many people work on such large files when they can't afford to ever print them and they're just learning anyway -- save that stuff for Jeff Wall or Gursky, people who make huge prints for huge dollars. And then they work on them with maxed-out, top-of-the-line machines.....

Do you really want to spend hundreds of dollars and waste tens of hours to print 30x40s of your first mediocre large format attempts?