Photos Not Good Enough Quality to Print From Canon 40D

[Kirsty_koch]

Hi Guys,

When taking the pics off my Canon 40D they come off at 72dpi and then I usually batch them in Photoshop to 300dpi. (If anyone can tell me how to get jpgs off my Canon at higher res that would be great).

When I took them to get printed today they (the photo machine) says they are not good enough quality to print and they look terrible on the screen. However, I have checked them again and they are definitely 300dpi. What is going wrong?

 

[Ptyler22]

I am not sure what's going wrong, but I have printed them at that resolution, at 16'X 24' and the prints were flawless quality, so I wouldn't worry about the quality of them.

 

[Chris of Arabia]

What is the overall image size in pixels that you are trying to get printed?

 

[chrisburke]

sounds like your shooting at a lower resolution...

also, i'm no photoshop genius, but i'm pretty sure if you have an image that is originally 72dpi, and then you up it to 300, your going to ruin it...its going to get very pixly..

 

[Katier]

sounds like your shooting at a lower resolution...

also, i'm no photoshop genius, but i'm pretty sure if you have an image that is originally 72dpi, and then you up it to 300, your going to ruin it...its going to get very pixly..

Depends how it's done.

With PS you can either.

Just change the dpi, this doesn't do anything to the image size but is very handy where software uses the dpi. An example is quark xpress, I often have to fiddle the dpi to get images to import properly. The physical image size is the same, just the dpi changes.

i.e. a 2000x2000 image @ 100 dpi would be 20x20 but just changing it to 200dpi makes it a 10x10.

Obviously however if you have it so the dpi scales the image ( i.e. the 200dpi image becomes 4000x4000) you will get a loss in quality.

 

[Tighearnach]

Hi Guys,

When taking the pics off my Canon 40D they come off at 72dpi and then I usually batch them in Photoshop to 300dpi. (If anyone can tell me how to get jpgs off my Canon at higher res that would be great).

When I took them to get printed today they (the photo machine) says they are not good enough quality to print and they look terrible on the screen. However, I have checked them again and they are definitely 300dpi. What is going wrong?

72dpi is the default setting on my 400D too. When i first got a photo blown up they said 72dpi was no good but when i went to another printer they blew it up to A3 size and the quality was good.

As far as i know the dpi setting on the jpg is not the deciding factor. The actual size of the image is. I.e you can select different levels of quality of jpg to shoot in with 2592x3888 being the highest quality my 400d can shoot (and your 40d too i think)

If you have it set to 72dpi but also 2592x3888 then printing should be of very high quality.

The problem is either your conversion to 300dpi in photoshop or else the guy in printing shop doesnt know what hes on about (as was the case with the 1st guy i went to)

 

[Big Mike]

This has been covered many times, the following is from a thread just yesterday.

Firstly, it's actually PPI (pixels per inch) not DPI (dots per inch).

Secondly, that (72) is just a default value. It's the typical screen resolution for a monitor...so that's why it's a default.

Lastly, it's mostly a meaningless number when talking about the quality or resolution of the actual image. You could change it to 50 or 5000 and if that is all you change...it won't change the image at all. It just tells the computer how big to display it on the screen.

The important number is the size of the image in pixels. As long as you have enough pixels...you will be OK for printing.

To make things easier for yourself...you can change the PPI number to 300 (without resampling) and then everything should fall into place.

If you shoot in RAW, you will be able to set the PPI in the RAW conversion software.

 

[swatspyder]

This has been covered many times, the following is from a thread just yesterday.



If you shoot in RAW, you will be able to set the PPI in the RAW conversion software.

I was about to post this... Shoot RAW and learn how to work the image in post processing. You will see a huge benefit and enjoy learning how to make alterations and slight adjustments.

 

[jeljohns]

This post made me curious too, because when I download my pictures off my camera and open them in Photoshop they say 72DPI, this is without doing anything to them and my camera is set at a high resolution (highest before RAW). So...should I be manually changing the DPI to 300 every time I open a picture? I remember back in college my graphics professor said when you do that the computer invents pixels and the image quality goes to crap.

 

[mrodgers]

Jeljohns, the key is in BigMike's quoted post above....

To make things easier for yourself...you can change the PPI number to 300 (without resampling) and then everything should fall into place.

Without resampling, the image size stays the same thus the quality stays the same. If you were to resample, it would change the overall image size and the quality would suffer.

 

[Big Mike]

The PPI is just a number to tell the computer how big to display the image on the screen.

For example, if I have an image in Photoshop; the size is 3504 x 2336...and it's set to 72 PPI (which gives it a size of 48.667" x 32.444". I have it zoomed to fit all of it on my screen and the zoom level is 33%. This is just the size on the screen.

Now, if I open the Image Size control and uncheck the 'resample' box...I can change the PPI to anything I want. The image will still be 3504 x 2336 and the image quality in not changed or affected in any way.

Of course, if you leave the resample box checked...it will change the image by adding or removing pixels...which does change the quality.

For printing, the standard is 300 PPI (but it doesn't have to be exactly that number). So if you are going to print the image, you may want to change the PPI to 300 (without resampling) to see what the document size will be.
For my example image, it becomes 11.687" x 7.79"...so that's the size of high quality print I could make with 3504 x 2336 pixels.

Further to that, you can add pixels to get enough resolution for large prints. For example, if I wanted to make a print 16" wide...I would leave the resample box checked, make sure that the PPI was 300 and change the width to 16". The height becomes 10.665" and the size of the image is changed to 4800 x 3200 pixels.
Now, because I'm adding pixels, the image quality will go down...but you also need to consider that a 16" wide print isn't meant to be viewed close up. Hanging on a wall from 6 feet away, the print would probably look just fine. I could even change the PPI to something like 240, so that I don't have to add as many pixels.

To sum up...the important thing to be aware of is the actual size of the image...in pixels.

 

[Kirsty_koch]

Thanks for all your help so far, am still a little confused though. So the picture straight off my camera is this 3888px wide and 2592px high. It is 72dpi. What I did was (in PS) untick resample image and typed 300dpi into the resolution and tick resample image again. The pixels remain the same. Is this unnecessary? Do I just leave it at 72dpi?

 

[Katier]

Thanks for all your help so far, am still a little confused though. So the picture straight off my camera is this 3888px wide and 2592px high. It is 72dpi. What I did was (in PS) untick resample image and typed 300dpi into the resolution and tick resample image again. The pixels remain the same. Is this unnecessary? Do I just leave it at 72dpi?

ok your image is 3888x2592 that's the raw size of the image and the bit that controls quality.

Screens are nominally 72dpi - i.e. 72 dots ( or pixels ) on every inch of the screen.

i.e. to zoom in 100% would need a 54" by 36" screen.

When you look at your picture on the screen at the top of the window it gives you a percentage right? (probably 16.7 or 33% ) and you can see the whole image?

That's because the size of the image is too large to display at full size on the screen. ( in fact if you think abotu it this makes sense as you are trying to display an image that is 3888 pixels high on a screen that's probably 1050 or 1200 or so pixels high ).

Print however is higher resolution. To get a good print image you generally work at 300dpi ( although a good printer may just about work at 150 you shouldn't really go below 180dpi).

Now having said all that, for printing out on a printer you generally don't need to worry about the dpi setting.

Take 180dpi as the minimum, you can manually work out that your image will be 21.6inches by 17.3 inches.

So if you print at that size or smaller.. and just tell the printer to 'resize to page' you WILL get a quality image. In your case you can print on anything just under A2 paper size or below and retain quality.