Printers require 300 dpi - A different question/issue about 72 dpi

Question

Hello,
I've read through many of the threads on 300 ppi/dpi. I understand the solutions offered such as batch processing and how the printer will print the image size that equals the 300 dpi. However, I have a different issue. I purchased just this week a Rebel T5 with the assumption that I would be able to take 300 dpi images not 72. I create books for print and my printers require 300 dpi. They will not do the conversion. My options in the past have been film camera to CD (old, I know) or the iPhone. I was spending a lot of time in Photoshop getting the images to printer requirements. So imagine my dismay uploading the first batch of photos into Photoshop and seeing 72 dpi. Yes I was able to change them 300 - but this is exactly the production work I had hoped to not have by purchasing the new Rebel. 
There has got to be a better way?
Or is it a different digital camera I need to purchase?
Thank you for your help.

Answer 1

writerinpjs wrote:
Hello,
I've read through many of the threads on 300 ppi/dpi. I understand the solutions offered such as batch processing and how the printer will print the image size that equals the 300 dpi. However, I have a different issue. I purchased just this week a Rebel T5 with the assumption that I would be able to take 300 dpi images not 72. I create books for print and my printers require 300 dpi. They will not do the conversion. My options in the past have been film camera to CD (old, I know) or the iPhone. I was spending a lot of time in Photoshop getting the images to printer requirements. So imagine my dismay uploading the first batch of photos into Photoshop and seeing 72 dpi. Yes I was able to change them 300 - but this is exactly the production work I had hoped to not have by purchasing the new Rebel. 
There has got to be a better way?
Or is it a different digital camera I need to purchase?
It's that you (abetted by Photoshop) are reading too much into the term "dpi". The size of a digital photograph is measured in pixels, not inches. For a given pixel count, the picture will print smaller at 300 dpi than at 72 dpi, but will have, by definition, a correspondingly higher resolution. You start with a RAW image and crop it to the desired aspect ratio. Then you compute how many pixels you need in, say, the longer dimension, given the native resolution (e.g., 300 dpi) of the printer and the desired picture size (e.g., a length of 10 inches). Finally, you convert the image to JPEG, setting the number of pixels in the long dimension of the converted image to that computed number (e.g., 3000). Then when you print the image, things will come out right. What you describe above is Photoshop trying to do the calculation for you. But IMO, that usually just adds confusion. Work in pixels and you won't go wrong.
The calculation is different, though just as straightforward, if the printer differentiates "dots" from pixels. But I think most modern printers either don't make that distinction or do it behind the scenes, so that you can specify everything in pixels.
Bob
Boston, Massachusetts USA