Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-21-2013, 03:08 AM   #1
Senior Member




Join Date: Oct 2009
Location: Florida
Photos: Albums
Posts: 235
Resolution

Quick question about file resolution on Pentax cameras. I searched the forums but didn't quite get the answer.

If you look at File Info or Image/Image Size in PS CS5 my k7 initially shows 300 dpi, my k-x shows 240 and K5iis shows 240. I read that this is print related only, but why do they show different initial settings, and does it matter? Is this related to the exif data in CS5 or is it pre-selected in camera. I don't think there is any way to change it in camera, right? I don't like altering a photo significantly as I've read this affects quality.

And on that topic, when resizing after cropping, since I usually reduce the size of the image down to around 8x10 or 5x7, what setting do you use for Resample Image? I see the explanations to the side of the selection (e.g. 'Best for Reduction') but don't know what to select if I up the DPI from 240 to 300 while reducing the overall size.

Sorry if this is the wrong section Adam...

Thanks,

Bill

12-21-2013, 03:38 AM   #2
Veteran Member




Join Date: Mar 2007
Location: U.K.
Posts: 685
The quick answer is that dpi means nothing when you're talking about an image file. All that has any meaning re resolution with a file is how many pixels WxH, or MP if you multiply them out.

Resampling in CS? Lots of schools of thought on that one. I use Bicubic Sharper for reductions in CS6.

For printing I use Qimage as it saves so much hassle, granted the interface is strange but when you get to learn it, it makes so much sense and you never have to worry about dpi or the correct amount of sharpening. Qimage also always automatically prints at your printer's native resolution so that the printer firmware doesn't mess with files at all (most do a poor job of resizing to native dpi).
12-21-2013, 04:36 AM   #3
Senior Member
Alcazar's Avatar

Join Date: Jan 2008
Location: Stuttgart, Germany
Posts: 212
there is no difference between these two:
- have a camera give you 300 dpi images
- or have a camera that gives you 240 dpi images, and then you set the value to 300 dpi in software

you can set it to 1 million if you like, there is no change in the image data.
all it is is you telling a printer: if you print this, i want it to be printed this big.

however, what's confusing to a lot of people is that contrary to what i just wrote, there *is* a change in image data in this case: when you go to the photoshop menu item "image>image size" and change the dpi while the "resize" checkbox is activated - then photoshop resizes your image and calculates the new pixel size by the relations of the old and the new dpi setting you gave it.

sorry for my english, i hope everything is clear?
greetings,
micha
12-21-2013, 06:13 AM   #4
Pentaxian
Miguel's Avatar

Join Date: Sep 2007
Location: Near Seattle
Photos: Gallery
Posts: 2,708
QuoteOriginally posted by Snydly Quote
I don't like altering a photo significantly as I've read this affects quality.
To be consistent with your intention, you should attempt to crop proportionally within the same 3:2 aspect ratio as the original image. That means print output at 4x6 in, 6x9, 9x12, 12x18 etc. That way resampling is unnecessary. Resampling tends to lower image quality, especially when the aspect ratio is changed.

M

12-21-2013, 10:26 AM   #5
Senior Member




Join Date: Oct 2009
Location: Florida
Photos: Albums
Posts: 235
Original Poster
QuoteOriginally posted by Alcazar Quote
there is no difference between these two:
- have a camera give you 300 dpi images
- or have a camera that gives you 240 dpi images, and then you set the value to 300 dpi in software

you can set it to 1 million if you like, there is no change in the image data.
all it is is you telling a printer: if you print this, i want it to be printed this big.

however, what's confusing to a lot of people is that contrary to what i just wrote, there *is* a change in image data in this case: when you go to the photoshop menu item "image>image size" and change the dpi while the "resize" checkbox is activated - then photoshop resizes your image and calculates the new pixel size by the relations of the old and the new dpi setting you gave it.

sorry for my english, i hope everything is clear?
greetings,
micha
That's where my confusion was. I knew I was altering the image but didn't know why. I always have the three boxes checked which includes the resize. The images were fine because I only ever print up to 8x10, but I can't stand not knowing how something works. Thank you all for the lesson.

Bill
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, cs5, dpi, dslr, image, photography, resolution, size
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Extreme resolution ivanvernon Photographic Industry and Professionals 4 09-07-2013 09:12 AM
Stacking resolution gabro822 Photographic Technique 2 09-17-2012 12:27 PM
Upping Resolution KnifeMaker Visitors' Center 4 07-28-2012 08:16 PM
Scan Resolution? Rockinghorse Winner Troubleshooting and Beginner Help 7 05-18-2012 09:16 AM
My New Years resolution. What's yours Ed in GA General Talk 24 01-24-2008 04:18 AM



All times are GMT -7. The time now is 12:46 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top