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07-27-2011, 12:47 PM   #16
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QuoteOriginally posted by sany Quote
I've only seen 300 dpi images supplied as high res images from photographers mostly coming out of canon and the likes
shoot raw, and export the jpegs at 600 dpi and you are going to be better then canon/nikon

07-27-2011, 02:00 PM   #17
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QuoteOriginally posted by stanic Quote
shoot raw, and export the jpegs at 600 dpi and you are going to be better then canon/nikon
Agreed. Shoot raw (why jpg?) and convert to 300dpi, which is the likely a good starting point for printing purpose. For web posting, 72dpi is good enough.
07-27-2011, 02:40 PM   #18
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dpi is only relevant when printing.
1000 pixels at 1dpi is equivelant to 1000 pixels at 1000dpi. Its still 1000 pixels.
Anything you do in the computer is irrelevant as the pixel count remains the same.

Printers can interpolate/extrapolate the image given to them based on DPI. This is the only place it matters.

The most irritating thing I hear almost every week, is to protect your images when posting them on the web by setting their DPI to 72. This is not only wrong, its naive and darned near irresponsible.
Changing the DPI itself does nothing about the number pixels or quality of the digital image.
07-27-2011, 04:16 PM   #19
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I do not know what the issue might be here but my K-r produces 300dpi photos even at 2MP + one star setting.
Software upgrade? Just a guess.

07-27-2011, 04:27 PM   #20
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QuoteOriginally posted by amoringello Quote
dpi is only relevant when printing.
1000 pixels at 1dpi is equivelant to 1000 pixels at 1000dpi. Its still 1000 pixels.
Anything you do in the computer is irrelevant as the pixel count remains the same.

Printers can interpolate/extrapolate the image given to them based on DPI. This is the only place it matters.

The most irritating thing I hear almost every week, is to protect your images when posting them on the web by setting their DPI to 72. This is not only wrong, its naive and darned near irresponsible.
Changing the DPI itself does nothing about the number pixels or quality of the digital image.
Unless you also change the overall size.

https://www.pentaxforums.com/forums/members/jeffjs-albums-single-january-picture17837.jpg

does not equal

http://farm6.static.flickr.com/5138/5403330719_b0b01c4afa_o.jpg

even though they are the same photo.

07-27-2011, 04:36 PM   #21
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QuoteQuote:
Unless you also change the overall size.
And if you do that, you didn't read or you didn't understand what I wrote. :-)
07-27-2011, 05:27 PM   #22
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QuoteOriginally posted by amoringello Quote
And if you do that, you didn't read or you didn't understand what I wrote. :-)
I read and understood it perfectly thank you very much. Which is why I said "UNLESS".

07-27-2011, 05:31 PM   #23
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QuoteOriginally posted by JeffJS Quote
I read and understood it perfectly thank you very much. Which is why I said "UNLESS".

Fair 'nough.
Thought you were disagreeing in some way.

(I just love the way forums lose conversational context. Sometimes smilies just don't do their job.)

07-27-2011, 08:07 PM   #24
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QuoteOriginally posted by sany Quote
many amateur publishing designers desperately try to boost a 72 ppi image
These are most likely 72ppi image file that were reduced in size and content (compressed) for internet use perhaps. This means the compression program has discarded, thrown away image data (colour depth and so forth) to make the file smaller. Once gone it can never be brought back. To make the file go back to anything bigger then it currently is a print or image manipulation program can do this only to a certain degree by inventing pixels it thinks may fill the gaps. It's called interpolation. The result is always very poor.

In my first post example, if the resulting image size of 10.88 x 8.16 @ 300dpi or the 45.33 x 34 inch of the 72 dpi is too big for you and you then downsample to a size of, say, half of this you then throw away half the pixels. If you save this image and than you want to go back to its original size it won't be possible and if you do you finish up with an out of control blocky image. I think this is what you are referring to.

Greetings
07-27-2011, 08:16 PM   #25
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QuoteOriginally posted by amoringello Quote
Fair 'nough.
Thought you were disagreeing in some way.

(I just love the way forums lose conversational context. Sometimes smilies just don't do their job.)
Yeah, I think my response may have been a little snarky. Apologies from me for that.

07-27-2011, 11:03 PM   #26
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QuoteOriginally posted by aleonx3 Quote
...
For web posting, 72dpi is good enough.
For web posting the dpi is complete irrelevent. If you don't believe me try it for yourself. Take an image, say 640 pixels wide. Alter the dpi to 72 without altering the number of pixels, save it. Alter the pixels to 300, again without altering the number of pixels and save in a different name. Create a tiny web page in the same directory (simplifies the HTML), view it and the two images will be the same size.

I say again, dpi has no meaning in a web context. It can matter when printing, and Word seems to take account of it when deciding how big a photo in a document should be.

But again, dpi has no meaning in a web context.
07-28-2011, 12:13 AM   #27
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QuoteOriginally posted by cats_five Quote
But again, dpi has no meaning in a web context.
Or any other on-the-screen use for that matter.

But that still does not answer the oryginal question.
@sany are you using any specific application to import your pics from the camers? If so dpi may be set by that application. Check dpi before importing files to see if it is any different.
And dpi can be easily changed in most aplications by 1-click so there is nothing to worry about. It has no effect what so ever on the quality of photos taken.
07-28-2011, 01:12 AM   #28
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Your print size straight out of the camera on the K-r/K-x should be roughly 60x40 inches @ 72dpi and around 5MB in size give or take. If you were to print it at this size and at this resolution, it would probably look like crap up close. That said a 60x40 print is probably not going to be made by the average person. You will probably be printing it at 8x10 (or smaller) in which case your printer will resample and condense the image automatically for you so you'll never notice the difference. That same image when converted to 300dpi works out to about 15X9 (ish) - which is more than what the average print would be.

What people are talking about when they say to reduce to 72dpi is 72dpi AND a reduction in physical size as well. A 15x9(ish) image at 72 dpi works out to around 500-600kb (more or less) - a good deal smaller and less detailed than the 5MB size you're seeing coming straight off the camera.

If your images coming off camera are wildly less than 4-6 megabytes, then you'll have an issue printing because you're losing data somewhere. If not, don't worry about it - you're looking at 72dpi, but its set for a wildly huge print size which you probably are never going to come close to touching anyhow.

EDIT: I worked a digital printers back in the day, so I actually know about this stuff. Granted back then digital cameras were only just starting to come into play, but the basic guts of the whole process is the same. Also, if printing large format for signs or display on a wall, etc, you're probably able to get away with lower resolution anyhow since people will be viewing your print from a distance to take it all in rather than from up close, so the 72dpi print resolution won't really matter then, either.
07-28-2011, 02:25 AM   #29
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QuoteOriginally posted by Sagitta Quote
...
What people are talking about when they say to reduce to 72dpi is 72dpi AND a reduction in physical size as well.
...
But for computer use they would do better (IMHO) to ignore the dpi and simply reduce to the the correct number of pixels.
07-28-2011, 08:09 AM   #30
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although it might have been better to have the default JPEG at 300 dpi, it really only impacts the linear measurement of the photo.

When you print, you can direct the printer to print at the default dpi or you can force the printer to print at any dpi you wish,

you can also in any good photo editor, set the dpi to 300 if you have a real requirement to have the dpi show up as 300.

I can;t give you the menu instructions for all programs, but in PSP X3 the rescale of the print DPI is done under Image -> resize

just make sure that you do not interpolate the image
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