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72 resolution
Posted:
Fri Aug 17, 2007 4:52 pm
by sunnylass
I had the lovely Bindii round to visit this afternoon, and she discovered (thank gawd) that my images once downloaded from my camera to my pc, are being stored at 72 resolution instead of 300. My pc goes through the process of initially importing the images etc through Adobe Photoshop Album Starter Edition 3.0 which I think came with my Canon camera software, and then I open them in Photoshop to sort etc.
Is there some setting I need to change, or can change to ensure that the images are saved at 300 please????????
If my waffling doesnt make sense, ask Bindii, she knows what I mean
Posted:
Fri Aug 17, 2007 5:22 pm
by ATJ
I understand what you mean. However, I don't think you need to worry unless you plan to print the images. For displaying images on the screen, it is the actual pixels that are displayed and the resolution is ignored. Even when you print the images, you can tell the printing software to ignore the resolution.
Posted:
Fri Aug 17, 2007 5:28 pm
by sunnylass
So its ok for the images to automatically be saved on my pc at 72? I just have to bump up the resolution to 300, and save the image before printing it then correct?
Posted:
Fri Aug 17, 2007 5:35 pm
by ATJ
Yeah, that's pretty much it for displayed images.
Are you taking photos in RAW or JPEG? Are you doing any conversion before you load them into photoshop? It is possible a default setting along the way is changing the default to 72 dpi.
I checked all my Nikon images and JPEG images are 300x300 dpi straight from the camera. I'm not sure if RAW images actually have a resolution.
Posted:
Fri Aug 17, 2007 5:42 pm
by jdear
I think canon (at least 20d, 30d) JPEG's are saved at 72dpi.
Posted:
Fri Aug 17, 2007 5:45 pm
by sunnylass
I'm presently using JPEG, but I dont do anything to the images before taking them off the camera. Its going to be frustrating if I have to remember to resize every image I want to print, before going ahead and printing them.
And it probably also explained why my images were printing out looking a little soft on focus.
Bindii tried her images on my pc, and they were saved at 300 dpi so I'm a little puzzled as to what is going wrong.
Posted:
Fri Aug 17, 2007 5:57 pm
by ATJ
I think Mr Dear may have the answer about the reason you get 72 dpi.
Printing at 72 dpi instead of 300 dpi just means the image will be larger, rather than softer.
e.g. a 1200 x 900 pixel image would result in a 16.67 x 12.5 inch print @ 72 dpi, but a 4 x 3 inch print @ 300 dpi. In the 72 dpi print, the pixels woudl be noticeable.
Posted:
Fri Aug 17, 2007 6:13 pm
by sunnylass
My canon is a 400D. And I'm still not sure I understand. So if my images are being printed out at 72 dpi that's ok? I was printing 8 x 10. The images looked nice and sharp on the monitor, but once printed werent sharp at all.
I find this all very confusing.
Posted:
Fri Aug 17, 2007 7:38 pm
by ATJ
I think you find it confusing because it is.
In terms of the image file, the resolution is somewhat meaningless. It is basically an instruction that can (bun not necessarily) be used by a printer to determine how large to make the image. I know when I print an image from my software, I can tell the software to completely ignore the resolution information. I hope I haven't confused you more.
Most image manipulation software will allow you to change the resolution without affecting the image in any other way - which reinforces the idea that it isn't all that important.
You don't want to print the images at 72 dpi - as this would make them very large and of poor quality - but as I said, you should be able to change them to 300 dpi in Photoshop before you print them.
Posted:
Sat Aug 18, 2007 8:51 am
by sunnylass
ATJ thank you for that. I hope you dont mind me asking more questions but I need to have it clear in my head so I know exactly what it all means.
So, if I import images off my camera onto my pc and they are automatically saved at 72 dpi, will it affect the image if before printing it, I save it at 300 dpi?
Posted:
Sat Aug 18, 2007 9:42 am
by colin_12
Hi Sunnylass,
You could always try transfering files directly from your camera/card to a folder as oposed to using any importing software.
I do it this way as it tends to be quicker and I can decide more readily where to store the images. There will also be alteration to the files this way.
Regards Colin
Posted:
Sat Aug 18, 2007 9:46 am
by sunnylass
Thank you Colin, I have to admit I've deleted the software that seemed to automatically start the whole process off.
What I'm wondering though is, if I have taken an image at the highest resolution I can on my camera, still a JPEG though, and then once its been moved from my camera to my pc, and its been stored by my pc at 72 dpi, has that image automatically lost resolution?
Posted:
Sat Aug 18, 2007 9:58 am
by olrac
Resolution and DPI are different things yet they are related
Resolution is how many pixels/dots an image is made up of eg 1000 x 640
DPI is how that information is represented in size e.g 72 Dots/pixels Per Inch.
How many Dots/Pixels Per Inch your monitor supports will be different to how many Dots/pixels Per Inch your printer will support.
Posted:
Sat Aug 18, 2007 10:13 am
by sunnylass
Ok, please be patient with me here, but this is still not helping answer my questions. I have my camera set on the highest quality size (JPEG), which is producing beautiful images. Now, when I take them off my camera and put them onto my pc, do the images lose any quality, resolution etc? As for printing them, I am going to be taking them to labs etc, so do I need to do anything to prep them before I get them printed out? I'm assuming that if I'm taking one of my images that shows the dpi being 72% isnt necessarily going to be a good result.
Posted:
Sat Aug 18, 2007 10:19 am
by digitor
sunnylass wrote:Ok, please be patient with me here, but this is still not helping answer my questions. I have my camera set on the highest quality size (JPEG), which is producing beautiful images. Now, when I take them off my camera and put them onto my pc, do the images lose any quality, resolution etc? As for printing them, I am going to be taking them to labs etc, so do I need to do anything to prep them before I get them printed out? I'm assuming that if I'm taking one of my images that shows the dpi being 72% isnt necessarily going to be a good result.
No, you have not lost any resolution. DPI is meaningless in this context.
All you need to do when you get them printed, is to tell them how big you want the prints. The DPI will be pixels divided by print size.
Hope this helps!
Cheers
Posted:
Sat Aug 18, 2007 10:49 am
by jamesw
Is it not the case that:
- DPI is mainly relevant when discussing dimensions in cm rather than pixels? if i want a image to be 20x20cm at 300dpi, it will contain a lot more pixels than 20x20cm image at 72dpi.
- DPI is largely irrelevant unless you are printing, as screens have their own DPI settings...
- The most important thing is to preserve your pixels
Posted:
Sat Aug 18, 2007 10:54 am
by sunnylass
Ok, now that makes sense. I had an 8x10 image printed, and considering it was printed out at 72 dpi, it should have been 300 dpi yes?
Posted:
Sat Aug 18, 2007 11:08 am
by ATJ
sunnylass wrote:Ok, now that makes sense. I had an 8x10 image printed, and considering it was printed out at 72 dpi, it should have been 300 dpi yes?
With the risk of confusing you even further, it would have been printed out at the resolution of the printer. e.g. my Epson is 240 dpi. The image resolution MAY be used by the printing software to convert the pixels to something the printer can handle, but I'm sure I have printed images where the image resolution made no difference at all.
Posted:
Sat Aug 18, 2007 11:16 am
by sunnylass
Aarrrrrrrrrrrrrrrrrggggggggggggggggh
LOL. I took them to a lab. So basically I could also assume my photography sux and its just a bad photo
Posted:
Sat Aug 18, 2007 11:30 am
by ATJ
I don't think you can say your photography sucks... maybe just your understanding of a very confusing aspect of digital photography sucks.
Posted:
Sat Aug 18, 2007 11:57 am
by sunnylass
Wow ATJ I just had a look at your marine set ups! I have two tanks, but one has bettas and the other has a combination of goldfish, platties and my gorgeous little bristlenose catfish Bobby!
I do find this whole printing thing confusing, I have to confess. Why can't it just be easier.
Posted:
Sat Aug 18, 2007 12:09 pm
by ATJ
sunnylass wrote:Why can't it just be easier.
Then nerds wouldn't have jobs.
Posted:
Sat Aug 18, 2007 12:17 pm
by sunnylass
LOL I was never a nerd. A bad girl maybe, but never a nerd. ~sighs~ maybe if I'd grown up being a good girl, I would have understood all this printing crap huh.
Posted:
Sat Aug 18, 2007 12:24 pm
by Mr Darcy
Pixels basically equals dots. There is technically a difference, but I think we can safely ignore that for now
The blobs of colour that make up an image tend to be called pixels when they are on a screen and dots when they are on a piece of paper.
If you have an image that is 720 pixels wide by 360 pixels high then when you print it out at 72 dots per inch (dpi) it will print out 10 inches wide and 5 inches high on the paper.
Alternatively, you can tell the software that you want the paper image to be 5" by 2.5" in which case it will print out at 144 DPI. or if you want it to be 20" X 10" it will print out at 36 DPI. If your printer can only cope with 72DPI, it will do a horrible job of both, as it will be simply unable to print the first (it will probably print every second dot), and it will print two dots for every one sent for the second, making a blocky print. This is just an example. Most new printers can print at higher resolution, and are fairly smart at handling other resolutions. The printer resolution is determined by the size of the ink droplet it can produce.
One possible cause of softness on the printed image may be your paper. If your ink is bleeding on the paper, it will cause a level of blurring. Try changinging your paper
HTH
Posted:
Sat Aug 18, 2007 12:28 pm
by sunnylass
Mr Darcy wrote:Alternatively, you can tell the software that you want the paper image to be 5" by 2.5" in which case it will print out at 144 DPI. or if you want it to be 20" X 10" it will print out at 36 DPI. If your printer can only cope with 72DPI, it will do a horrible job of both, as it will be simply unable to print the first (it will probably print every second dot), and it will print two dots for every one sent for the second, making a blocky print. This is just an example. Most new printers can print at higher resolution, and are fairly smart at handling other resolutions. The printer resolution is determined by the size of the ink droplet it can produce.
One possible cause of softness on the printed image may be your paper. If your ink is bleeding on the paper, it will cause a level of blurring. Try changinging your paper
HTH
I actually put the two images on my flash card and took them to a lab. I hadnt checked the dpi etc on the images before I took them to the lab, so I'm assuming the information was set at 72 dpi, arrrrrghhhhh I'm going to go and bang my head against a wall for a few minutes and see if that helps me get this information sorted out in my head.
Posted:
Sat Aug 18, 2007 12:41 pm
by Louie
This has been a very interesting thread to read!
This is something I struggle with too (among many other things) and the explanations have been very helpful.
I like Mr Darcy's blob explanation, that is the kind of terminology I can relate to
Elena
Posted:
Sat Aug 18, 2007 1:08 pm
by jamesw
sunnylass wrote:I actually put the two images on my flash card and took them to a lab. I hadnt checked the dpi etc on the images before I took them to the lab, so I'm assuming the information was set at 72 dpi, arrrrrghhhhh I'm going to go and bang my head against a wall for a few minutes and see if that helps me get this information sorted out in my head.
give the lab a call and see what res they printed it at. that will solve all your problems.
if i was a betting man, i'd put money on that they printed at their printers native DPI setting, disregarding any DPI instructions that were on the file.
Posted:
Sat Aug 18, 2007 1:36 pm
by sunnylass
Thanks James I will do that. I didnt however save the image at any settings before taking the flash card to the lab, so in fairness to the lab, its probably more my own fault than theirs anyway.
I just need to get a firm understanding on how to make sure I don't make the same mistakes in the future is all.
Posted:
Sat Aug 18, 2007 1:59 pm
by Matt. K
Sunnylass
72 ppi is not the native resolution of your camera...but your monitor. The pictures you sent to the lab are probably high resolution unless you changed the resolution to 72ppi in a program like Photoshop. Most confusion comes from the fact that monitors can only display 72/110 ppi but they don't change the captured resolution set in the camera.
Posted:
Sat Aug 18, 2007 4:42 pm
by sunnylass
Photoshop is changing the resolution to 72, I did nothing, I repeat nothing!
Posted:
Sat Aug 18, 2007 4:49 pm
by big pix
open photoshop go preferences>Units & Rulers>Print Resolution.....
set to your desired amount and restart photoshop......
Posted:
Sat Aug 18, 2007 4:57 pm
by Matt. K
sunnylass
What is your work flow? Do you simply download and then open in Photoshop or are you using other programs before you open in Photoshop? Photohop will not downrez an image unless you tell it to...or have some kind of preset enabled. Some programs, like Noiseware, will downrez without prompting...but not Photoshop...unless I'm missing something here.
Posted:
Sat Aug 18, 2007 5:45 pm
by sunnylass
They were initially being opened in Adobe Photoshop album starter or something, that I hadnt asked it to do. I think that came with my camera software. Anyhoo, I've deleted that. I've yet to try and see what happens now, but I'll have to do a test run cause I have work on tomorrow!
Posted:
Tue Aug 21, 2007 1:26 pm
by ATJ
I just did some testing printing an image and the "resolution" made no difference at all.
I am using Paint Shop Pro 9 and printed to an Epson Stylus Photo 830.
I started with an image that was 3028 x 1893 pixels. It had a default resolution of 300x300 dots per inch (78 pixels/centimetre). I printed it to photo quality paper to produce an image that was 200 x 125 mm in size.
I then converted the image to 72 x 72 dpi and printed it again to the same size.
There is absolutely no difference in the quality of the printed images.
Posted:
Wed Aug 22, 2007 2:36 pm
by Bindii
Yeah this drove me nuts... I can't see why images downloaded straight from Sunnylasses camera are arriving in photoshop at 72 dpi... I thought perhaps that the program that was opening the files (photoshop album starter) was doing it.. but when it opened an image of mine that I had saved for printing on a usb stick it opened at 300 dpi..
I have a 20D.. and for the most part shoot raw... when I open my images in photoshop the dpi is always high (around 500 something I think.. which I then sometimes set to 300 before printing depending on what the lab prefers)... I was always under the impression that 72dpi was for screen viewing only... but it seems that maybe that isnt the case????... so now you have two confused ....but not helpless.... females...
its gonna be a pain in the ass if she has to reset all her images before she goes to print them I would think... surely there is a way to stop this from happening..
Posted:
Wed Aug 22, 2007 2:55 pm
by stubbsy
If you are using Adobe Camera Raw to open your image there is a box where you specify the ppi to open it at. This defaults to 240 I think, but you can, for example make this 72 ppi. If you then save this as your default, all future images will have 72 there and unless you change it that's how they'll open in Photoshop. See the screen shot below. The first circled bit shows the image will open at 240ppi. If you click that it opens the second dialog shown here where you could change the 240 to 72 (again circled) and all future images would also open 72 ppi
Posted:
Wed Aug 22, 2007 7:29 pm
by xorl
The "DPI" setting within the file is advisory. Digital images are just pixels, they have no inherent physical size. An image editor might use the "DPI" setting to calculate rulers in inches or cm. This doesn't affect the image itself.
If you take an image to the lab they will print it at the size you choose - the advisory "DPI" setting within the file is irrelevant.
Posted:
Thu Aug 23, 2007 9:15 am
by sunnylass
I've read through all the responses and I'm still feeling like a bimbo. I have to get some more prints done today, or tomorrow, and I'm still freaking a little, worrying whether or not if I have to increase the dpi on the image before I save it to my flashcard and take it to the lab.
Posted:
Thu Aug 23, 2007 9:58 am
by Bindii
sunnylass wrote:I've read through all the responses and I'm still feeling like a bimbo. I have to get some more prints done today, or tomorrow, and I'm still freaking a little, worrying whether or not if I have to increase the dpi on the image before I save it to my flashcard and take it to the lab.
Ring the lab Teela... see what they want and go with that for now..
Posted:
Thu Aug 23, 2007 11:31 am
by xorl
sunnylass wrote:I have to get some more prints done today, or tomorrow, and I'm still freaking a little, worrying whether or not if I have to increase the dpi on the image before I save it to my flashcard and take it to the lab.
As above, the "DPI" setting is irrelevant when printing.
Posted:
Thu Aug 23, 2007 11:41 am
by digitor
digitor wrote:sunnylass wrote:Ok, please be patient with me here, but this is still not helping answer my questions. I have my camera set on the highest quality size (JPEG), which is producing beautiful images. Now, when I take them off my camera and put them onto my pc, do the images lose any quality, resolution etc? As for printing them, I am going to be taking them to labs etc, so do I need to do anything to prep them before I get them printed out? I'm assuming that if I'm taking one of my images that shows the dpi being 72% isnt necessarily going to be a good result.
No, you have not lost any resolution. DPI is meaningless in this context.
All you need to do when you get them printed, is to tell them how big you want the prints. The DPI will be pixels divided by print size.
Hope this helps!
Cheers
As above, DPI is meaningless in this context.
If you don't trust all this advice - try it for yourself - make two copies of an image, set one to 10 DPI, and one to 1000 DPI (that should be enough to see a difference if there is one) and get the lab to print them both at the same size.
Check the prints carefully to see if there is a difference. Please report your results!
Cheers
Posted:
Thu Aug 23, 2007 11:45 am
by sunnylass
Ok, please dont think I dont trust and appreciate the advice given here. I DO! I just need to get my head around it and understand it.
Posted:
Thu Aug 23, 2007 12:34 pm
by sirhc55