Photoshop Help: Resolution issues

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Hi all,

Hope you can help. I am currently importing images into Quark Express (publishing program). The original size of the images are the default 'straight from camera' dimensions of 3008x2000.

I have made the images considerably smaller (200x400) and for some reason Quark is showing them as very pixilated when you zoom in (when I say zoom in I don't mean ridiculously - I mean like 100%). What's going on?! Obviously if I were to make the images bigger it will lose quality - but making them smaller?!

FYI: When I changed the image to a smaller size the resolution was saying 72 - not to sound too dumb, but is this the cause? However if it is and you increase this, it increases the size of the image!

Please help guys, much appreciated
 
72dpi is fine for web use, if you want good images for printing, you need to use 300dpi when resizing, I've not used Quark but, is it possible the images are being changed to 72dpi when importing?
 
Basically, as I said before - the images are saved as 72 dpi as the images are so small, I cannot increase it to 300 dpi in Photoshop as that changes the image size. The image (200x400; 72dpi) is imported into Quark and then you 'print' the Quark file into a PDF. When you do this you have a choice to increase the resolution within Adobe, which I did to 1000dpi. However, looking at the PDF it still comes out pixilated.
 
How are you resizing the image in photoshop, if you click on the image tab, then image size, you would firstly resize the image to the required size in mm, cm or, inches, then set the dpi to 300.
 
Make sure you're using the right re-sizing algorithm. Its usually something like Billinear for downsizing and Bicubic for upsizing, although the terms vary from one package to another. If you use the wrong one it will produce just the effect you're getting.
 
What exactly are you trying to do with this?

Quark only uses previews. They will be replaced with the hi-res files when printing to pdf or printer.

You can adjust the quality of the previews under preferences > display.

Graham
 
Just remember that if you try and print a 400x200 pixel image at 300ppi, the resulting print will only measure 1 1/3"" x 2/3" - not very big.
 
PMK said:
, I cannot increase it to 300 dpi in Photoshop as that changes the image size. T.
Click to expand...

You can if you uncheck all 3 check boxes in the dialogue box, then change the 72 to 300.

Rgds
 
Always a difficult one this, but just remember that until you actually physically print something, ONLY the pixel dimensions matter.

So, an image of 300 pixels by 300 pixels is just that. Nothing more, nothing less.
If your screen is just 300 pixels by 300 pixels it will fill it.

Only when you print something does the DPI figure come into play. 300dpi is considered the norm for printing, so your 300x300 image will print at 1" x 1" when set to that resolution.

Set it to 150dpi and it will be 2"x2". There will be no extra information in the image of course, and the printed quality will be lower.

Hell, you could set it to 1dpi and get a 300" x 300" image.

Your 3000x2000 image will therefore print well at 10" x 6.6".
 
OK,

Take your original image and change the image size to 300dpi (pixels/inch). IMPORTANT - uncheck resample image.

Then import it into your quark layout. Scale to suit. Note the percentage size ie if you reduce it to 50%, make note of 50%.

Back to your original file. Image size > drop down box to percent (pixel dimensions) at the top. IMPORTANT - check resample image (we want to change the actual file size now).

This is the time to do any sharpening. Remember to make it CMYK. Your blues will be noticeably drabber!

Re-import your image at 100%. Job done.

Hope that helps.
Graham
 
I agree with the above, you were basically reducing the file size. Try to think of it like the relationship between shutter speed and aperture:

If you shoot something at 500th at F11 it's the same as 250th/F16, 125th/F22 etc

If you have an image at 72dpi and it's 2,500x3,500 pixels it will have a file size of about 25MB and the dimensions of the document would be 34x48 inches

I would normally change this in photoshop and have Constrain proportions and Resample image (Bicubic) checked.

So if you change the resolution to 300 the dimensions will change to 10,400x14,500 pixels (rounded up), and the file size will jump to 435MB. Now change the pixels back to 2500x3500 then the document size would be 8x11 inches and the file size will be back to 25MB.

What you did was decrease the size of the image and also keep it at 72dpi, basically reducing the size of the file (in MB's and area) and have 'less' pixels to cover the same area.

So what you did by reducing the size of the image to 400x200 at 72dpi was end up with a file size of 0.234MB! (234K), (sort of the equivalent of shooting a 10 second exposure on F32... ;))

In Quark you can import a 72dpi large size image and then scale it down, then this will give the same quality as smaller 300 dpi image at 100%.

Quark can handle scaling the image for you, however it's better (and faster) if you are importing images that are around 300dpi and 80% magnification. This means you can always scale something up if you want to move/crop the image. Don't enlarge the picture much past 120%, it's better to go back and increase the size of the image in Photoshop and resample rather than over enlarge it in Quark.

Hope this helps...
 
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