10-07-2018 01:34 PM
10-07-2018 01:52 PM - edited 10-07-2018 01:53 PM
I just did a job for the school where they were making posters on canvas. They posters are 24x36 inches which is not to far off from what you are doing. The important thing here is to have the ratio of your image file the same as the final product. In my case I sent 8x12 inch jpg's at 300 dpi to the printers'. All the printer had to do was scale my file up by a factor of 3.
If you don't observe this, cropping will happen or the printer will have to do some more editing. They don't like that!
You can do the initial editing and image resizing in Photoshop. Get the ratio right! Don't worry about dpi. There is no dpi until the photo is printed.
10-12-2018 12:00 PM
Images don't have "ppi" ... only displays have that. I honestly wish this particular bit of meta-data was removed from image files entirely. You can edit the value of ppi all you want and absolutely nothing about the image will be changed in any way. It's a made-up value that is completely meaningless.
If your image sensor is 6000x4000 resolution and let's just suppose it's a "full frame" sensor camera... then that's 36mm x 24mm... then surely there are a lot more than 240 pixels in an inch. 240 "ppi" doesn't represent anything about the image as it was recorded by teh camera.
240 ppi *can* say something to software about how you'd like to have it displayed on a monitor. 6000 ÷ 240 = 25. This implies you'd like the image to be displayed 25" wide (in the long dimension) when shown on a monitor ... regardless of the physical size of the monitor.
But of course nobody really does that... they size things however they want when displaying the image. So "240 ppi" is basically a suggestion ... it doesn't materailly change the image.
Your print size has a ratio of 4:3 (80 x 60). But your original image has a ratio of 3:2 (6000 x 4000). This means you're going to need to crop things to fit because you are changing the aspect ratio.
Meanwhile 80 cm = 31.5". 6000 pixels divided by 31.5" = 190 dpi.
190 dpi is a low resolution if a view is standing close to the image. But if a viewer is farther away... it's fine. Billboards have very low DPI ... because they're meant to be viewed from hundreds of yards away.
10-12-2018 12:16 PM
10-12-2018 12:57 PM
Thanks for the replies I'm curious as to how this picture will turn out and if I can charge for it. I'm guessing this picture will be hung in a living room or other small space. So I hope it looks good despite the short viewing distance.
Another question. I don't think there are many cameras capable of higher resolutions. With this in mind, how do they blow up larger pictures without them getting too pixelated? Like large window photos in a clothes store for example?
Those exremely large yet ultra-sharp images are usually not "one" photograph.
Suppose instead of your one image with a 6000 x 4000 resolution... you build up a large image which is 60,000 x 40,000 pixel resolution... by shooting many adjacent images (overlapping) ... so now you have many columns and rows of images that combine to make an ultra high-res result.
Many landscape photographers use this technique. When you do this, the resolution of the camera doesn't matter anymore ... becuase you just keep shooting until you get enough data to build up the ultra-high-resolution result.