Can the 10D produce 300 DPI pics?

[nat869]

I just got done shooting pics for a fitness model, which I will post here for people to see, but I was hoping to get 300 DPI pics that could be sent in to a magazine. When I opened them in photoshop, it reads at 180 DPI. I did not shoot in RAW just the best jpeg mode I could. Can I just change the DPI for the image? Will I lose some quality? If I shoot Raw, can I extract 300 DPI pics? Thanks for any help, I will show off some of the pics this weekend.

[SeanDempsey]

just change the dpi in photoshop. The print size will be smaller, but the resolution higher. The image is the same pixel width no matter what, you can print it at any dpi you choose.

[Jesper]

The number of dots per inch (DPI) is not a property of a digital image. It is saved along with the image in the JPEG or TIFF file, but the number itself doesn't do anything to the image data. A digital image consists of a matrix of pixels, nothing more and nothing less. The DPI number in itself doesn't mean anything. It only means something in relation to the size you print an image at.

An image from the 10D, straight from the camera in the highest setting, is 3072 by 2048 pixels. If you print this at 300 DPI (actually, PPI - pixels per inch - would be more accurate), the image will become 3072 / 300 = 10.24 by 2048 / 300 = 6.83 inches.

You can change the DPI number in Photoshop by choosing Image / Image Size. Make sure the Resample Image checkbox is unchecked and change the number in the Resolution editbox to the number you want. The image will stay exactly the same, just the DPI number changes.

Look here for more info: Display, Printing, DPI and PPI (http://www.photo.net/learn/resize/)

[Calvillo]

you can also re-size the image when you open it in Camera Raw. At the bottom of the screen is a is a box that says size and has a choice of smaller, normal and larger pixel dimensions. Below the size box is a Resolution box that allows you to change the ppi.

You should experiment with these settings because when increasing file size you're asking the software to interpolate (educated guess) what the image should look like at an increased size. With small to moderate up-sizing there won't be noticable loss of resolution, but you can go too far.

In effect you're using Pshop to do what Genuine Fractals or Smart Scale software does better, but also for $150 - $200 extra depending on which plug-in you get.

The best way to determine how much you can upsize in Camera Raw/Pshop is to print the same image at different settings to determine where you feel quality/resolution starts to fall off.

[gcogger]

I think you're straying into an unrelated issue here - we don't want to confuse the OP :-)

Changing the dpi (actually, ppi) of an image does not involve any resizing or interpolation of the image. All that changes is a single number in the file (e.g. a value of 180 is replaced with a value of 300). See Jesper's reply for how to do this.

I think that there would be far fewer confused people in this world if the image files did not contain a 'dpi' value.

[meesey]

i hope that you got your problem solved, this is a subject to which i don't think enough of us photographers are educated in. i have a 10D also and yes when you open it in PS they are 2048x3072. in my experience i have never needed to change the ppi(aka dpi). i have read here http://photography-on-the.net/forum/showthread.php?t=36389 that someone printed a larger prints without doing anything special, i think a lot of people get confused about this subject of ppi and interpolation, i would say if it is for a magazine to just leave it alone if it will be like 8x10 or interolate it if it will be turned into a poster, but dont mess with the dpi, they say that most poster and billboards have low dpi anyway so 180 sounds just fine for most applications, but i would say do more research for yourself and to weigh all of your replies and see what you find out for yourself

[robertwgross]

I print my 6Mp images up to 13x19 inches.

I can frankly state that I have never even looked at the dpi setting for any file I'm printing. It comes out of the camera at 180, but that doesn't mean anything at all.

I simply let the printer driver of the editing program handle scaling of the image up to the specified paper size.

---Bob Gross---

[evilenglishman]

I recently had one of my images printed in a magazine as the poster.

The magazine people managed to print it at 235mm x 495mm (approx 9.25 inches x 19.5inches) at 300 DPI. It looks okay but close study of it reveals the odd pixel here and there.

[BarbaraS]

I resize a lot but I just let photoshop cs change my images to 360dpi and they come out great. I have no problem upsizing and printing to 13x19. And I have seen images easily print in poster size.

I think the 10D is a heck of a lot of camera for the money and don't even plan to upgrade to the 20D. I want to wait for whatever replaces the 1Ds.

[Hellashot]

I've found that Roxio Photosuite, I have v5, does a much better job for dealing with my D300 pictures. I thought Adobe Photoshop Elements was good until I used Roxio.

Hellashot