Canonites help

GREAPER

I dont know if this is the right forum, but I know someone can help me.

I have a friend thats uses a Canon 20D. He called me today with questions about changing the resolution of his files. It seems that the camera saves them all as 72 dpi files.

I told him how to do it, but I told him I thought he ought to be able to have the camera save them as 300 DPI files in the first place.

As many of you know, I have a nikon. It's files are all 300 dpi out of camera.

Is there a way for him to change it?

Where would he find it.

Thanks in advance.

Brian

Bodley

GREAPER wrote:

I dont know if this is the right forum, but I know someone can help me.

I have a friend thats uses a Canon 20D. He called me today with questions about changing the resolution of his files. It seems that the camera saves them all as 72 dpi files.

I told him how to do it, but I told him I thought he ought to be able to have the camera save them as 300 DPI files in the first place.

As many of you know, I have a nikon. It's files are all 300 dpi out of camera.

Is there a way for him to change it?

Where would he find it.

Thanks in advance.

Brian

Where does this cause a problem? Is my ignorance showing?

GREAPER

According to the manual of his printer, the best results can be obtained by printing at 300 dpi.

He currently changes the resolution of the image to 300 dpi, the adjusts the image size for printing. It is his thought (and mine) that starting out at 72 dpi is just adding a step to his workflow.

I know there are many different theories on printing, but that is currently what he is doing.

Frog Lady

I get the same thing, but I'm not sure if its the camera or photoshop (I use Elements 2.0 - I think).

It didn't happen w/ my old dRebel, but when I open a picture in PS, it shows up as a 32 x 48" picture at 72 dpi (2336 x 3504 pixels). But if I crop (and have the crop set for, say, a 4x6" picture, no resolution specified, and then do a minimal crop (or even select the whole image), the resolution jumps up to where I think it should be (ie, about 580 dpi).

any one know whats going on?

tx

C.

Bob Bell

72 DPI is the standard monitor resolution so most programs do that. I use ACR in photoshop and have its default to 300 DPI. Im sure you can do that for other programs. Most of the commercial printers I work with require 300 DPI files so it saves me a step.

HeldDown

It's not the camera determining the dotpitch, it's software. Make sure you set 300dpi as your default like Bob said.

Bodley

GREAPER wrote:

According to the manual of his printer, the best results can be obtained by printing at 300 dpi.

He currently changes the resolution of the image to 300 dpi, the adjusts the image size for printing. It is his thought (and mine) that starting out at 72 dpi is just adding a step to his workflow.

I know there are many different theories on printing, but that is currently what he is doing.

My understanding is (and I'm probably wrong) photos are in so many pixels by so many pixels and the software assigns the inch dimensions.

I bring the full photo into PSCS select a crop ratio such as 4x6. Crop and print. I don't worry about having more than 300 dpi.

GREAPER

He has the same preferences set in PS 7 as I do.

His opens a file at 72 DPI, cannon, mine 300 DPI nikon

Frog Lady

I went to "edit", "preferences" and selected "units and rulers" and found a screen that indicated I could set the print and screen resolutions. The print res was/is set to 300 and the screen to 72 dpi. So I changed the screen res to 300 and imported a new picture. No difference. So I shut down PS and reopened it. Checked to see that the pref had been saved (it had), but it still indicates dpi = 72 for newly imported pics. Other suggestions?

C.

StevenV

Perhaps you should just have them read this. The reported resolution doesn't matter in most cases.

GREAPER

Bodley wrote:

I bring the full photo into PSCS select a crop ratio such as 4x6. Crop and print. I don't worry about having more than 300 dpi.

Odds are (as I understand it) your printer is designed to print best at 300 DPI, if you are printing at a higer DPI than that, you are just wasting ink, and possibly getting lower quality prints than you would.

I could be wrong.

TristanP

Dpi is just an arbitrary number assigned by software for that particular camera. It means nothing until you get a printer involved. Pixels are what matter.

Some links of interest:

http://forums.dpreview.com/forums/read.asp?forum=1009&message=16337944
http://www.steves-digicams.com/techcorner/January_2005.html

Andy

StevenV wrote:

Perhaps you should just have them read this. The reported resolution doesn't matter in most cases.

DPI is meaningless. Total pixels matter.

GREAPER

I think I follow what was said in that thread, but I dont know if I agree with it completely.

Rather than debate it, I will revert to the original question.

He and I both use PS 7. I have a Nikon, He has a Canon 300d and a 20D. He has also opened files from a Nikon coolpix 8400 is his PS version.

In all of these cases, the resulution is set to 300 DPI for the Nikons and 72 DPI for the Canons out of camera.

The preference settings for bith versions of PS 7 have been compared and are the same.

Is there some setting in camera that will change the reported DPI of the image or is he stuck with the option of changing it himself for each image or changing his workflow.

GREAPER

I see what you are all saying about the arbitrary nature of the resulution, but even the articles you folks link to say it is meaningless except at print time.

I guess for my tastes, I print at 300 DPI and resample the image to get various sized prints. If I am printing at 300 DPI I would rather have the file at that resolution for the entire process than have to change it at print time.

I guess what I am hearng is that NO, there is no way to change it and that he must accept it or adjust his workflow accordingly.

ziggy53

Greaper,

If your friend shoots in RAW, so that the images are processed a bit first, many RAW software has the ability to automate the output files, JPG etc., to report 300 dpi. I do not believe the camera has settings to change the DPI, so that JPGs out of the Canon 20D camera are always 72 dpi.

ziggy53

TristanP

GREAPER wrote:

Is there some setting in camera that will change the reported DPI of the imag...

No, it's simply a meaningless EXIF tag put there by the camera's software.

Your file is never at 300 (or any other) ppi until it gets sent to the printer which understands that it has to print a 3000 x 2000 pixel image in a 10" x 6.67" area (which we calculate as a photo quality 300 ppi). The only thing PS or other editors understand or care about (until they print) are absolute pixel dimensions.

I guess what we're trying to say is: go take pictures, edit them, and print them like you always have.

gluwater

I realize this is an extra step from what your friend would like to take but why not just create an action to resize to 4x6 and 300dpi, or whatever size he/she prefers?

BigAl

gluwater wrote:

I realize this is an extra step from what your friend would like to take but why not just create an action to resize to 4x6 and 300dpi, or whatever size he/she prefers?

Nick is right, but you must resize without decreasing the total number of pixels. I haven't used PS for ages, so I don't know the exact steps in the resize dialog, but the first chapter in Scott Kelby's book on PS for digital photographers goes into this in some detail. I don't have the book here, so can't help there. In PSP, in the resize dialog, just switch off the "resample using" check box and set the size/resolution to whatever you want it.

[Edit]I've just checked in PSE 2 and in Image>Resize>Image size, switch off "resample image". The pixel dimesions then remain the same and you can set whatever size/resolution you want.[/edit]

Bodley

GREAPER wrote:

Odds are (as I understand it) your printer is designed to print best at 300 DPI, if you are printing at a higer DPI than that, you are just wasting ink, and possibly getting lower quality prints than you would.

I could be wrong.

I print on the Epson R800 and believe the sweet spot is some number like 720 (it's been a long time since i looked at the information so this could be way off).

Anyway, I crop my shots at full resolution to retain as much information as possible. I never know if I'll want a 4x6 or 8x10. When print time comes I crop at full res. by the desired ratio ( I don't set a resulting res). The cropped res. is generally higher than necessary (above 300). Yes this waste ink but in order to decrease the resolution I'm asking a program to throw away data (detail) and blend. Just strikes me wrong. Do I think it will be visually detectable - probably not. Am I an idiot, considering the price of ink, probably so.

Somebody straighten me out!!!!

Yorkie Dad

Monitor Resolution
I do not recall the source of this information but hope that it helps clarify the issue of monitor resolution:

Grab a ruler (a real ruler) and open any image in PS. Make sure rulers are turned on in PS (view - rulers), choose view - print size and then view - show rulers
Now hold your real ruler up to the screen and the ruler on the screen and the one in your hand don't match.
The 2 rulers don't match because PS makes an assumption that all screens are 72ppi which is not true today.
Start by choosing file - new. Set the width to 1 inch and the resolution to 72 ppi (the height and other settings don't matter in this case) and click OK. Next choose view - actual pixels and make sure your PS rulers are visible (view rulers).
To determine the actual resolution of your display hold the physical ruler up to your screen and adjsut the percentage setting shown in the lower left of the document window until the on screen ruler matches the real one. To adjust the percentage, just click on it, type in a new value and then press shift/enter. Shift/enter keeps the percentage highlighted so that you can quickly change the setting multiple times. Once the two rulers match, grab a calculator and multiply the new number by 72 (in my case it is 116% so that would be 72 x 1.16 = 83.52). The number you get is the precise resolution of your specific screen in pixels/inch (every screen will have a different resolution, even if the model and brand are identical)
To check it out create a new document that’s 1" wide and has the same resolution as your screen. Next choose view-actual pixels and measure it onscreen with a physical ruler. If its not 1 inch then calculate your screen resolution again..
Now lets use PS to display all our documents correctly in print size view. Choose - edit - preferences – units & rulers, set the screen resolution setting to what was calculated above and click OK. Now open any image and choose view-print size to see if it is accurate. Compare the onscreen ruler to your physical ruler and ....wait a minute, it hasn't improved. But with the same document open, click on the zoom tool in the toolbox and click on the print size button that appears in the options bar. That should cause your image to display correctly.
There are actually 2 print size commands in PS. They should work the same but they don't. The one in the view menu always assumes that your screen resolution is 72 ppi while the zoom tool's option bar uses the screen resolution setting in preferences to determine the true resolution of your screen - therefore displaying images accurately.
So once everything is set up correctly, just ignore the view-print size command and instead use the zoom print size button.

Frog Lady wrote:

I went to "edit", "preferences" and selected "units and rulers" and found a screen that indicated I could set the print and screen resolutions. The print res was/is set to 300 and the screen to 72 dpi. So I changed the screen res to 300 and imported a new picture. No difference. So I shut down PS and reopened it. Checked to see that the pref had been saved (it had), but it still indicates dpi = 72 for newly imported pics. Other suggestions?

C.

StevenV

BigAl wrote:

[Edit]I've just checked in PSE 2 and in Image>Resize>Image size, switch off "resample image". The pixel dimesions then remain the same and you can set whatever size/resolution you want.[/edit]

Right, that just changes the "useless" tags, the pixels stay exactly the same... which is what's being asked for here.

If you want to a 4x6 print on a 300dpi printer, you need 1200x1800. End of story. It doesn't matter if some "useless" tags call it 4x6x300 or 8x12x150 or 16.6x25x72 (or whatever).

Then the app that's printing should figure things out from there