Image size

[alaskanaturally]

My camera takes images of about 24x16 inches at 180 ppi. My publisher requires images of 300 dpi with a size of at least 10x6 inches. Would the ones I take meet his minimum?

 

[NS: Nikon Shooter]

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Full frame cameras record RAW files in a 2:3 ratio and given resolution.
Just invoke the export toolbox and configure the required parameters.

Mine looks like this:

 

[photo1x1.com]

My camera takes images of about 24x16 inches at 180 ppi. My publisher requires images of 300 dpi with a size of at least 10x6 inches. Would the ones I take meet his minimum?

Your camera would take 14.4x9.6 inches at 300dpi (ppi).

 

[Strodav]

PPI really don't mean much until you go to print. From your publisher's specs, they are looking for a 3000 x 1800 pixels image (10" x 300ppi = 3000 pixels , 6" x 300ppi = 1800 pixels) or 3000 x 1800 = 5.4 mp image at a 10"/ 6" = 5 / 3 ratio. Your camera makes 4320 x 2880 images or 12.44mp images at a 3 / 2 ratio (cell phone cameras are usually at 12mp at a 4 / 3 ratio). So, you have more than enough mp / resolution, but your ratio is different than requested, which means you need to crop your images to the required 5 / 3 ratio and then resize to meet the 3000 x 1800 pixel specs. Your publisher probably wants a specific image file types as well like jpg or tiff.

You camera probably came with software that allows you to crop, resize, and export to various file types. I'd start there. There are many 3rd party image processing packages out there that can do the same thing, many of them free. You can do an internet search for software that meets your needs and runs on your computer or cell phone. Personally I use Adobe's Lightroom for most of my work, which I run on both a PC and ipad.

You might find this video helpful: , which describes image ratios.

 

[wfooshee]

What they're specifying is the number of pixels per axis, not really any actual size requirements. Multiply 24 by 180, you get 4,320 pixels on the long dimension. Multiply 16 by 180 and you get 2,880 pixels on the short dimension. Your camera is 12 MP, basically.

Do the same math with their specification, you get 3,000 by 1,800 pixels. They are specifying a 5:3 aspect ration instead of the 3:2 that most cameras shoot (based on the original 35mm frame size,) but you can see that the pixel count in your images exceeds their specification.

300dpi is a publishing standard of sorts, and if you tried to print your image at 24 inches and 300 dpi, it would get a dithered, pixelated look in the printing process. It still well exceeds their pixel density at the size they specified.

Another way to look at it is that 180 dpi is 6-tenths of 300 dpi. Take 6-tenthes of your dimensions and if that's larger than their 10 x 6, then you're good. 6-tenths of 24 is 14.1, well over 10. 6-tenths of 16 is 9.6, again well over their 6.

Your images have the required pixel density, unless you crop them severely. As for cropping, you can figure out the limit for that easily enough. Don't go less that 3,000 x 1,800. That's all there is to it. 3,000 x 1,800 pixels, you're good.

 

[alaskanaturally]

My Mac has a photo processor. It allows me change the dimensions of the image and the ppi. If the camera puts out an image of 24 by 16 with 180 ppi and I reduce the size to 12x8 and change the ppi to 300, will that be within the specs specified?

Y'all have been most helpful. Thank you.

 

[wfooshee]

You really don't need to do anything. The math they're using is just a way of specifying pixel count. You already exceed their pixel count. The dpi and size specs don't mean anything from your side. When they size the image to print, they need a certain pixel density. When your images are reduced to their size, the pixel density is there.

 

[NS: Nikon Shooter]

… will that be within the specs specified?

Yup!