Image Size

[CatherineA]

I have run into problems with two images that I've been editing because I didn't pay attention to the file size. They are composites and have become so huge that PS and LR crash when I work on them. I need to reduce the size of them but before I throw away pixels I wondered what image size photographers look at when making that choice. I could aim to make it the size of, say, a 13" x 19" paper but do people often choose to keep more as a safety cushion? If so, how much more?

In one image the background layer was over 3 gb. When the composite was completed the image was over 4gb. I thought that I could go back and reduce the size of the background layer and maybe would be fine however now all the individual layers are that dimension. I don't understand that - I thought that the file size would be cumulative.

Thank you for any feedback.

[Manfred M]

Catherine - I suspect the issue is your workflow and methodology. I've made some huge and complex photo-composites and have never run into the problem that you describe. My files rarely get larger than 2GB (that would be the psd file format).

I use a rather long-in-the-tooth computer (around 8 years old) and I always work at full resolution and do not downsize my images until they are ready to output as a final image.

The main way one gets huge image files is if one keeps adding image layers. Work with layer masks and the files generally stay m manageable. Too many masks can slow the processing so I will sometimes collapse my files (compress all the layers) as a new working file, but will save the originals so that if I have to go back, I can do so without starting over again.

[CatherineA]

Manfred- thanks for replying. Going forward I will do things differently but in the meantime I am really hoping to be able to salvage these two composites because of the amount of effort and hope that went into them. I have kept the original images but I still don’t think that I replicate what I have done on these composites.

[Manfred M]

Try to flatten the image and save it with a new file name. That will shrink the file size down a lot and leaves you with the original file to go back to is there is a problem.

[CatherineA]

Thanks Manfred. I think a big problem with one of them is that the background layer os a path I created using PS brushes. I set the brush at a huge size to get the effect I was after. That background layer is over 3G . So even if I flatten that image the image is too big.

[pnodrog]

What are your current pixel dimensions? If you flatten or at least amalgamate most of your layers you should reduce file size considerably provided don't you have huge pixel dimensions.

Unless you are printing on a wall about 6000x4000 should be adequate for most things including a 19"x13" print.

[CatherineA]

Thank you Paul.

I made a copy of all the layers and then flattened the image. The dimensions are still unmanageably high: 23232x31680. I think that it might be because of how I started off the image with those PS brushes.

I guess that I will either reduce it in PS using Image Size or look up more about changing file size via Scripts in PS.

[Manfred M]

Catherine that is a huge image. A printer with a native resolution of 300 dpi (anything that Canon or HP make) would give you a print that is 77" wide x 106" high!

Change the image size by dividing both dimensions by a factor of 5 and you will still get a large size image. 4646 x 6336 is still going to be large enough for pretty well any purposes.

[CatherineA]

Thanks Manfred. Sure appreciate the patience of people on this site. So, when I look at the image before I increased the canvas size, the dimensions are 10560x14400 - still too big but not so crazy. (I don't know why an empty canvas adds so much to the size but I guess that is another matter.)

If I divide the dimensions by 5, that is no problem for the background layer that I should never left as large as that in the first place. But wouldn't also reduce the quality of the photos that are in some of the layers? I would have liked to maintain their resolution.

[Manfred M]

Take a look at the resolution your camera produces to give you some guidance as to what is reasonable.

The 151MP Phase One cameras (which is the highest resolution cameras on the market today) and sell in the range of $US 60K is 14204 x 10652 pixels. Your image is much larger than that. My long-in-the-tooth 36MP Nikon D810 is 7360 × 4912 pixels and I regularly print images that are several feet wide and long.

23232x31680 is massive overkill for most purposes.

[CatherineA]

The image that I want to edit further is 10560x14400. I will reduce that image to the size that you suggest. The increased size canvas is because I want to use the transform edit on it and it doesn’t seem right to reduce it the image based on a proposed size - although I do get confused with this.

I still don’t see why this might not negatively impact the resolution in some of the component layers that I didn’t want to lose resolution in, but it seems the best choice.

Thanks

[Manfred M]

I'm not sure I understand what the underlying issue is.

The largest element in the image stack will define the dimensions of the largest element in the image. If this is the background that you have created and all of the other elements that you have photo-composited in are much smaller, then we could be creating a problem.

I would hate to give you advice that will destroy your work.

Do you still have my email address and do you know how to use WeTransfer? If so, would you mind sending me a copy of the file so that I can look at it? Trying to do this using words is proving to be difficult.

[ajohnw]

This area also relates to image size in terms of pixels. Google bought this up near the top so obviously looked at by a number of people. There will be other. It relates to the size of image you finally want to produce. Specifically prints in this instance.

https://martinbaileyphotography.com/...n-podcast-532/

Something of a woolly area so there will be differing views. Some one for instance might choose to use figures based on 10x8 prints on much larger image. Only of any use if some one views it from 10" even though they can not appreciate the whole image.