What will print & what wont ?

gus

For the 1st time im going to print some shots off. Im looking to get them as large as possible A3 maybe. (:scratch ..mericans dont know what A3 is do they ?...lets call that 12" x 17" )

Now i did search but you search printing in here ..you will read til the cows come home.

What size photo will print to what size on paper ? I have single photos ranging from 900 KB through to 9 meg. I understand that a lot of that info is colour etc.

I really dont know how to post the question actually. I dont want to try & get a 900 KB shot printed at say 12" x17" & it turns out all doggo when that would look fine at 5" x 7".

Harveylevine

Humungus wrote:

For the 1st time im going to print some shots off...

What size photo will print to what size on paper ? I have single photos ranging from 900 KB through to 9 meg. I understand that a lot of that info is colour etc.

I really dont know how to post the question actually. I dont want to try & get a 900 KB shot printed at say 12" x17" & it turns out all doggo when that would look fine at 5" x 7".

Gus:
The key point to understand about printing image files is that it typically takes something like 300 pixels per inch to make a quality print. You might get away with as little as 200 ppi, depending on the subject and the printing equipment. For example, using 250 ppi for the resolution and printing from a 6 megapixel DSRL file of 3000 x 2000 pixels, you can calculate the maximum print size to be 12 in x 8 in. (3000 / 250 = 12 in) Using Photoshop or other image editing software, you can choose Image Size (don't select resample). Change the resolution to 250 ppi (or whatever you want) and the software will tell you the size of the print.

If you want bigger pictures, you can check "Resample" and besides choosing the resolution, you can also choose the size of the resulting print. The software will interpolate the additional pixels needed. In Photoshop you can choose the resampling algorithm too. The usual recommendation is to choose "Bicubic Smoother" for upsampling (increasing the number of pixels).
There are plugins, such as Genuine Fractals, that do a good job of upsampling without too much softening of detail if you want to make even bigger prints.

Usually you want to so some sharpening before printing since interpolating pixels generally softens the image.

You might also want to read Smugmug's help file on printing. Their view is that you can make quality prints with lower resolutions than the values above.

Perhaps you might want to create smaller prints first to see how the color and sharpness looks before springing for large size prints.

Good luck,

Harvey

Sam

Gus,

Harvy did a very good job job of explaining this, but what the heck I'll babble a little on this and see if it helps.

The 20D records 3504 X 2336 pixels (8.2 MP). Various methods of printing need a min / max of pixels per inch (can be converted to pixles per mm : )
There are many opinions as to the min required, but I think if you work between 180 ppi, and 300 ppi you will get good results.

Your 20D will will provide a file (3504 X 2336) that at 300 ppi will print out a 11.68" X 7.79" picture.

Let's take your desired dimentions of 12" X 17" and do some division to determin if we have enough pixels to print at this size without any interpolation.

3504 pixels divided by 17 " is 206.12 ppi. 2336 divided by 12" is 194.64.

Now here is where opinions may vary. Depending on the photo, method of printing, and viweing distance, this may be ok, or you may need to up the resolution a little.

This would probably print out fine on my inkjet as is.

I'm sorry ther isn't a straight forward black, and white answer to this questuion, but then you knew theer wouldn't be.

Oh, any cropping will will alter the pixels, and dimentions.

Use the resize window in photoshop. It will do all the math and let you see what you have.

Bottom line though is I have printed out 20" X 30" pictures from a 6 MP file with excelent resutls.

It's all in the details. :

Sam

gus

Thankyou for your replies gents. I forgot to mention i was talking about stuff that has been cropped also but your math is fine for me to get a start with.I will read & digest your answers. I have a colour biz printer worth maybe $60-70K avail to me but i does crappy prints...the inks band & it really isnt designed to do this job so i have to go & do it at a shop.


Thanks
Gus

Shay Stephens

Work your way up
In the end, it doesn't matter much. If you have a 20D and send full size images, don't worry about it. I print 30x40 images that look great with the 20D. And I don't do much hoop jumping to get them.

Do make sure the color and contrast look good. Sharpen it up like normal so it looks good at 100% on your monitor and you're good to go. Send off one or two as a test. As you gain experience and confidence in making prints that look good to you, send more. Just don't send off a boat load all at once ;-)

gus

Thanks shay..i will give it a go.

Dee

And yes, I know what A4 is!
Do I ever! One of our medical clients was producing collateral for Europe and we got introduced to A4 and it "messed up" a lot of our designs and took hours to "re design" things to fit in that format. It's narrower and taller than our letter size of 8.5 x 11 inches.

I used a Canon i9100 (?) inkjet printer with I believe 7 individual ink cartridges. I made 11 x 17 borderless prints that came out extremely well. One print was from a 6 megapixel aerial photo of the town I live in which I obtained online. And one or two were printed from my 8 megapixel Sony.

I was talking with my print broker and he has a 3 megapixel digital camera and he printed at home on his inkjet, but wasn't too thrilled with the results. So he went to one of these printing machines at a photo store and printed a few 4 x 6 prints and was "blown away." As he said, if he'd known his camera took such good pictures he'd gotten a lot more prints!

So it's definitely the printer you use as to the results you will get.

And, depending on the printer you use the "dpi" can vary a great deal. Also depending on the detail in the photo and the type of photo you can get away with less dpi on some prints, while you need the printer's minimum requirement on others.

If you ever get into one of these threads (elsewhere) on which printer makes the best prints you will learn more than you ever wanted to know! Or care about, for that matter :

Real concerned photographers get ICC profiles for the printer they will be using -- and yes some go so far as for the individual printer they are using. If your local place doesn't know what an ICC profile it, or if one is available for their particular machine, or the particular system, well that tells you a lot right there.

But will most people notice or care? Probably not. You will probably notice better "smoothness" and depth and richness of color on the machine prints.

Keep us posted on your results! Thanks.