Question on print size?

52Caddy

What would the largest print I could have made with the following info:
2048 x 1536 pixels
24/16 million pixel depth/colors
Not sure what other factors would affect the print size. I took it as a Tiff image.
What I'm wondering is how large of a print I could have made and still have it look real good.
Thanks for any info!

cletus

It's really up to you and how good you want the print to look. My guess would be you could go at least 8x6" or so before you could notice any fall off in quality.

pathfinder

52Caddy wrote:

What would the largest print I could have made with the following info:
2048 x 1536 pixels
24/16 million pixel depth/colors
Not sure what other factors would affect the print size. I took it as a Tiff image.
What I'm wondering is how large of a print I could have made and still have it look real good.
Thanks for any info!

Like Cletus said, but .... at 150 dpi you could print some images 10 x 13 inches without resampling. With resampling I bet you could get close to 12x18 or even larger - depends on the quality of the original image, the paper, and the viewing distance.

PerezDesignGroup

Here's the math in case you were curious.

2048 pixels divided by 240dpi (photo-like inkjet resolution) = 8.5 inches

1536 pixels divided by 240dpi (photo-like inkjet resolution) = 6.5 inches

If you plan to print at lower or higher dpi's, just plug in a new number instead of 240. Common ones are 150, 240 and 300. Anything over 300 is barely noticeable to the human eye if my memory serves correct.

Aaron Wilson

dpi
If i read right... using 300 dpi as max? so printers that do 1400x1200 are not worth buying? or is the pics set for 300 dpi print? I know in my raw mode I can change the photo's dpi.

PerezDesignGroup

Aaron Wilson wrote:

If i read right... using 300 dpi as max? so printers that do 1400x1200 are not worth buying? or is the pics set for 300 dpi print? I know in my raw mode I can change the photo's dpi.

300dpi is a normal, commercial offset printing standard and typically used in magazines and brochures. A 1400 x 1200 printer is capable of printing at a much higher resolution than 300dpi thus making it an excellent purchase.

As for dpi in the camera, I was under the impression that number was fixed by the manufacturer but I could be wrong. My Canon 300d claims it captures at 160dpi.

cletus

Aaron Wilson wrote:

so printers that do 1400x1200 are not worth buying?

Actually the higher res printers can produce smaller ink droplet sizes making for smoother tone in prints... so the extra resolution capability isn't really being wasted.

mercphoto

dpi

PerezDesignGroup wrote:

As for dpi in the camera, I was under the impression that number was fixed by the manufacturer but I could be wrong. My Canon 300d claims it captures at 160dpi.

I've never actually understood dot-per-inch ratings when it comes to digital images. It seems the only thing that matters is the number of pixels. I mean, how can Canon know how large a print I intend to make? The camera spits out some number of dots, and I make a print of some number of inches.

Likewise I've never understood when someone wants a "72 dpi image" for a webpage. I can make my 8.2 megapixel image into a 72 dpi image, but by then its like four feet wide! Just how wide do you want that 72 dpi image to be?

Maybe there is just too much engineer in me...

tmlphoto

You can change the DPI in the RAW conversion because the software just adjusts the picture dimensions (Width x Height) in inches so that the number of pixels your camera has is displayed at the the requested DPI. If the DPI is high, the size is small. The default DPI for my 10D is about 180 dpi with an image size of about 11 x 14 inches or so. If you convert from RAW at 300 dpi the image size is about 8 inches or so. Of course you can always upsample or downsample and image to change the dpi without altering the document size. For the image in question at the top of the thread one could use a bicubic resampling to increase the image density and allow printing of a larger print up to a point.

That said, I think you could easily upsample to 8x10 inches and maybe 11x14 depending on the image and viewing distance as Path has said.

Andy

check this out re: print sizes
some awesome p00p from our own shay stephens

Aaron Wilson

is there a formula?
is there a formula for taking a size of a picture and convert the correct dpi to make that new size?

example... my 20d raw did a print at 2336x3504x24b

now in the converter it shows a dpi of 350
I want to have it printed poster size of about 30"by40" so do i change the dpi? I noticed that if in photo shop i make the canvas that size my pictures fit perfect or sometime i loss a little... I would like to make a spread sheet so I know if I should raise or lower the dpi for the diffrent sizes.

PerezDesignGroup

Aaron Wilson wrote:

is there a formula for taking a size of a picture and convert the correct dpi to make that new size?

example... my 20d raw did a print at 2336x3504x24b

now in the converter it shows a dpi of 350
I want to have it printed poster size of about 30"by40" so do i change the dpi? I noticed that if in photo shop i make the canvas that size my pictures fit perfect or sometime i loss a little... I would like to make a spread sheet so I know if I should raise or lower the dpi for the diffrent sizes.

Here is a calculator. I honestly wouldn't print any posters below 240dpi. But that's just me.
http://www.scantips.com/calc.html

That same site can also answer a lot of these questions. This article is pretty good...
http://www.scantips.com/basics02.html

pathfinder

PerezDesignGroup wrote:

Here is a calculator. I honestly wouldn't print any posters below 240dpi. But that's just me.
http://www.scantips.com/calc.html

That same site can also answer a lot of these questions. This article is pretty good...
http://www.scantips.com/basics02.html

www.scantips.com is a great resource for those new to scanning film or flat bed images. Much of the information is relevant to digital photography also, as digital cameras are really just optical scanners also....

Like Shay said - It is important to realize that the pixels per inch of your iimage is not the same as the dots per inch that a printer puts to paper - one image pixel may have many dots from the printer to create it and the ink dots may vary in size AND color for the single pixel printed...
Also - many of us are used to printing at high resolutions - 240 or 300 ppi, but many images look fine at 150 ppi, and some printers actually take the 300ppi and convert it to 200 or 240ppi before printing the image anyway....