DPI/PPI question 300D vs 20D

[tommykjensen]

Prompted by my question abot different font sizes I looked at the dpi/ppi of my photos shot with both 300D and the 20D.

When examining the 300D original files I see that the JPG's have 180 ppi the raw files have a ppi of 240 ?

On 20D the JPS have 72 ppi ??? I can't see what the ppi are for the raws but Digital Photo Proffesional default DPI output is 350.


Up til now I have not given dpi/ppi any thought and I may inadvertently have changed dpi in PS CS in the raw converter but don't think so and can't remember that I have played with that setting.

So what should the dpi/ppi be when pulling the photos directly from the camera?

[blinking8s]

on your computer anything over 72/90 dpi will not matter at all seeing as how thats all your monitor will display. It all has to do with printing the pictures.

I would hope the 20d is not 72dpi...i would expoect 180 or 300 from any high end camera...even my nikon point and shoot from 3 years ago takes great pics for printing when in HQ mode at 300dpi

[PacAce]

With PSCS, EVU and probably other raw converters, you can set a default DPI if you want. The DPI really doesn't matter for a lot of thing but there are instances when it does matter, such as when you were trying to copy your sig from one image window to another when the dpis were different.

Since most printers work very well with 300 dpi, I just set my raw converter to use 300 dpi, too. That way it's set and I can just forget about it.

Also, remember that you can change the dpi to anything you want at anytime and as long as you do not resample the image while doing that, it won't affect your image one bit. What changing the dpi will do in this case, for those who aren't aware of it, is to change the size, in inches, of the image although the actual number of pixels will not change.

[tommykjensen]

I know that dpi is mostly for printing but I find it weird this big difference.

The original JPG's from 20D show as 72 dpi in PS CS.

[PacAce]

I know that dpi is mostly for printing but I find it weird this big difference.

The original JPG's from 20D show as 72 dpi in PS CS.

THis is because you have it set that way in PSCS or whatever program it was that you used to convert your 20D raw files. Next time you're doing a raw conversion, set the DPI up to 280 or 300 or whatever you want.

[tommykjensen]

No I mean the REAL original files straight from the camera. I shot RAW + JPEG and it is the JPEG files that show as 72 dpi in both PS CS and in Thumbs Plus. They have not been edited at all.

[PacAce]

No I mean the REAL original files straight from the camera. I shot RAW + JPEG and it is the JPEG files that show as 72 dpi in both PS CS and in Thumbs Plus. They have not been edited at all.

oh! Sorry I misunderstood you. :oops:

Is it like that for all JPEG sizes or just the SMALL?

[tommykjensen]

It is like that for Large fine.

[Jesper]

Why bother? The DPI setting saved with the images doesn't really mean anything anyway. It's just a number that suggests how large the image is in real world dimensions (for example, when printed out). When you print a photo, it's most likely that you want to resize it anyway.

[PacAce]

Why bother? The DPI setting saved with the images doesn't really mean anything anyway. It's just a number that suggests how large the image is in real world dimensions (for example, when printed out). When you print a photo, it's most likely that you want to resize it anyway.

Yes, most of the time it doesn't really matter but there are times when it does. And during those times when it does, it helps when your images are consistent. For example, as I pointed out earlier, when you are working with fonts, the dpi of the image affects the actual size of the font created. Wouldn't it be a little frustrating if, everytime you selected, say, the 18 pt, hte size of the text was always different. Or if you tried to copy the same text from one image to another and it gets messed up because the dpis are different? Of course, you can change the dpi when needed but if it can be set to one value as a default, then why not?

[tommykjensen]

I just think it is strange that the dpi on 300D and 20D are so different straight out of the camera.

[tommykjensen]

Yes, most of the time it doesn't really matter but there are times when it does. And during those times when it does, it helps when your images are consistent. For example, as I pointed out earlier, when you are working with fonts, the dpi of the image affects the actual size of the font created. Wouldn't it be a little frustrating if, everytime you selected, say, the 18 pt, hte size of the text was always different. Or if you tried to copy the same text from one image to another and it gets messed up because the dpis are different? Of course, you can change the dpi when needed but if it can be set to one value as a default, then why not?

Yes and thats why I am asking, in the weekend I posted a question regarding the font size of text I was adding and how I after resize to 800 on longest edge had to use different font sizes, sometimes it ws 8 pkt sometimes 6 and with the 20D I suddenly had to go up to 18 pkt.

[PacAce]

I just think it is strange that the dpi on 300D and 20D are so different straight out of the camera.

You know, Tommy, this sound so "deja vu". I kind of remember the same thing being said a while back and I think it was for the 300D but I'm not sure. And again, I'm not sure, but I think it was a firmware change that caused that. The details are foggy at this point but I do remember this same topic coming up once before.

[Jon]

OK - Canon expects you to use the JPG on the 20D only for quick viewing on the computer screen if you're shooting RAW + JPG. Thus 72 PPI. The 300D assumes printer output for the JPG at roughly the size (but not resolution) of the RAW.

But like others have said, the DPI/PPI isn't really relevant until you go to put it on paper.

What do you see if you shoot only JPG?

[tommykjensen]

OK - Canon expects you to use the JPG on the 20D only for quick viewing on the computer screen if you're shooting RAW + JPG. Thus 72 PPI. The 300D assumes printer output for the JPG at roughly the size (but not resolution) of the RAW.


Why do You think they expect that? The jpeg is full resolution large fine. And direct printing only works when shooting jpeg.

I have not yet checked the files if only shooting jpeg.

[Jon]

Well, you're shooting raw, so they obviously expect you're going to massage the hell out of the image before final prints. The JPG is provided as a convenience, as they say on the Canon web site: "The JPEG recording format is ideal for purposes such as Internet image transfers that require reduced file sizes". PictBridge, which bypasses the computer, doesn't need to pay attention to the PPI setting in the file.

[PacAce]

OK - Canon expects you to use the JPG on the 20D only for quick viewing on the computer screen if you're shooting RAW + JPG. Thus 72 PPI. The 300D assumes printer output for the JPG at roughly the size (but not resolution) of the RAW.

But like others have said, the DPI/PPI isn't really relevant until you go to put it on paper.

What do you see if you shoot only JPG?

I guess you haven't read my posts completely. DPI IS relevant when it comes to fonts and font sizes when you are editing the images.

[tommykjensen]

Just a little followup.

I found out why the DPI had an impact on the font size.

It was because I had PS setup to use pkt for fontsize instead of pixels. When choosing the font size in pixels the resulting text is the same size regardless of the DPI setting.