# Can I change the resolution of many photos at one using CS5



## photographyfanatic

I have about 100 photos that were brought into photoshop at the resolution of 240. I edited and saved them all, but then realized I forgot to change their resolution. Is there a way in CS5 that I can change the res. on all of them at once so they can all be at 300?????? I sure hope so!!!! Thanks!


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## Derrel

Yes, that is changeable, in the preferences for the software.


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## Robin Usagani

Research on Actions.  Record your own action.  Not that hard to learn.


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## Peano

Just curious, are you changing the resolution in order to print the images? And if so, do you really need to increase the resolution (and resample the images)?


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## photographyfanatic

They come in at 240. Do they need to be upped to 300 for printing purposes?


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## molested_cow

Different resolution may cause physical dimension confusion.

Printers usually ask for 300dpi because they know the resolution is high enough for quality print. An image of AxB pix with 240dpi will print bigger than the same image of same pix at 300dpi.
So it depends on what is more important to you, resolution or the physical image size.


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## KmH

Printers usually don't ask for any specific PPI (not dpi, which is a printer resolution specification).

The printers rely on the RIP software of their print making machine(s) to handle the PPI needed. Often they just won't print a photo that would have a PPi that falls below their minimums.
A case on point is Mpix. They will not make a print at less than 100 PPI, not even if it is 99 PPI.

Back in the early days of digital photos, it took 300 PPI to get a print that looked about the same as a print made from a film negative. Of course back then, a top of the line pro camera had all of 5 MP.
Consequently, today the 300 PPI number has become more an urban legend than a true standard.

I'll mention Mpix again at this point. The print making machines they use output at 250 PPI.



> We do not require a maximum resolution for the images you upload. The higher the resolution, the better the picture will be. It's that simple. *The Mpix printers output at 250 ppi.* However, we are frequently asked what the optimal resolution is for the prints we offer.


 Mpix.com - Help

So, the bottom line is that PPI does not need to be set until a photo will be printed, and the PPI it needs to printed at really needs to be determined on an image-by-image basis based on  image quality.


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## SimpleFoto

Here's a tutorial covering exactly your question - using an action to change the DPI


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## Bynx

KmH said:


> Printers usually don't ask for any specific PPI (not dpi, which is a printer resolution specification).
> 
> The printers rely on the RIP software of their print making machine(s) to handle the PPI needed. Often they just won't print a photo that would have a PPi that falls below their minimums.
> A case on point is Mpix. They will not make a print at less than 100 PPI, not even if it is 99 PPI.
> 
> Back in the early days of digital photos, it took 300 PPI to get a print that looked about the same as a print made from a film negative. Of course back then, a top of the line pro camera had all of 5 MP.
> Consequently, today the 300 PPI number has become more an urban legend than a true standard.
> 
> I'll mention Mpix again at this point. The print making machines they use output at 250 PPI.
> 
> 
> 
> 
> We do not require a maximum resolution for the images you upload. The higher the resolution, the better the picture will be. It's that simple. *The Mpix printers output at 250 ppi.* However, we are frequently asked what the optimal resolution is for the prints we offer.
> 
> 
> 
> Mpix.com - Help
> 
> So, the bottom line is that PPI does not need to be set until a photo will be printed, and the PPI it needs to printed at really needs to be determined on an image-by-image basis based on  image quality.
Click to expand...


Days of old, or today, a pixel is a pixel which hasnt changed. Optimum quality will be a print at 300 dpi whether the printer will print that or not. Anything less than that is not optimum quality. At smaller size prints less than 300 ppi are ok, but larger size like 8x10 or 11x14 and up require 300 dpi to keep pixelization to a minimum. A program like Genuine Fractals is the best way to up sample the files to 300 ppi from 240 ppi. One thing to keep in mind is, 240 ppi is not a fixed number for all sizes of prints. While it is a fixed size for a particular size print, if that print is smaller then the ppi goes up. For example if your 240 ppi is for a print size of 6 x 8, if you reduce the print size to 6.4 x 4.8 then the resolution increases to 300 ppi.


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## KmH

Wall prints are viewed from further away, negating an absolute need for 300 PPI. The PPI would actually be more critical for desk sized prints, because they are more easily looked at close up.

Again, the PPI to print at really needs to be determined on an image-by-image basis based on  image quality


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