Print Size

[DangerouslyMoody]

What is the smallest size file you can print large images in? I shoot with a 10MP camera and the file sizes are pretty large until I edit, then they drop way down....will this affect my prints if I wanted to print 16x20 or larger??

[fishcat]

?? Are you losing file size due to cropping? You can upsample to regain lost pixels, but if you are cropping that much, it's better quality-wise to get the composition right in the camera to avoid or minimize cropping. A program like genuine fractals does a better job restoring pixels than PS, IMHO. You generally need 240 to 300 pixels per inch to get reasonable quality with an ink jet printer. I routinely print up to 24 x 36 (through a lab) from a 12 MP image and 12 x 18 on my printer from a 6 MP (D100) file. It can be done, but the quality has to be there from the start.

[DangerouslyMoody]

Ok, I think this is where I am getting confused...big time LOL

My images are changing size when I do any kind of edit, but someone explained its because Im going from raw to jpeg...so if I have a file that is a jpeg and is 1.5-3MB, will that still print good larger? I shoot with a 10mp and I shoot at 10mp as well...

[rab3rd]

If you are working in RAW, dont save your changes as jpeg. Save them as TIFF or PSD until you are finished and ready to post on the web. Each time you save as a jpeg it compresses. Thats EACH and EVERY time you save your file gets compressed. If you are just printing and hard drive space is not an issue, there is no real reason to save to jpeg. Print from PSD, and save as PSD or some other lossless file type. Save a seperate file for the web reduced to the size you want and a ppi setting of around 100.

[DangerouslyMoody]

I use iphoto, it automatically saves to jpeg but I think its non-destructive or something, thats what Ive been told and have read

[rab3rd]

sorry, dont know anything about iPhoto.

[Dobick]

You should not worry so much about the megabytes that a file is taking up. There are a lot of factors that can go into determining how large of a footprint that an image will take up in file size.

a rough estimate for how large you can print will be to look at the number of pixels on the long side of the photo, and then divide that number by 240. That will give you a rough estimate of the inches that you can print. Any larger and you will start to degrade. So lets say for instance you have a photo that is 3000x2000 pixels, that should yield decent results up to 12.5 x 8.3 inches. Not an exact science on that, but that is a good guide to go by.

What you are seeing with the file size is the fact that a jpg compresses information. Lets say for instance, you have a row of pixels, well each one of those pixels has a host of information attached to it, such as RGB color info represented in a Hex code. So in that whole row, if all the pixels are the exact same color, then the compression takes over and says, don't worry about drawing out each pixel, the next 6000 pixels that you draw are the exact same color, so instead of having to write instructions for 6000 individual pixels, it writes the instructions for 1 pixel and tells the software to repeat it 6000 times. Same as at the grocery store if you buy 20 bottles of gatorade -- it is easier for the cashier to hit the number 20 and then scan 1 than it is for her to scan all 20.

I explain all that to say that different photos will have different ways of compressing the info. The best way to find out how big you can print is to print some up to a size that ends up too large.

[sjordan]

It really depends on many things.

A good well exposed 10MP shot should print fine at 16x20 as long as you don't view the print from 1-12 inches.

I use OnOnes Fractals to enlarge my images when printing larger than 16x20. I have printed as wide as 40 inches on a 12MP 5D shot and it looked fine.

My 5D mark II I have printed a few 40x60's with no issues. I scaled them in fractals and they looked great. Again, a print is meant to be viewed from a distance. Printing is all about proper contrast and sharpening