Resizing photos to inches from pixels (Page 2): :sm24: :sm24: :sm24: (But there really is an "intended" viewing distance for a certain size print, probably described in an old Kodak...

Longshadow Loc: Audubon, PA, United States

CamB wrote:

Viewing distance? I stand in the gallery and watch people looking at art on the walls. Some are three feet away, some are five feet away, some are eight feet away. There really is no “viewing distance.” If pixel figuring works for you, that’s cool, but I always found it confusing and don’t think it’s necessary with today’s programs. Im not trying to put you down. In the world of art, it’s all about what works for you.
...Cam

(But there really is an "intended" viewing distance for a certain size print, probably described in an old Kodak book.
But I don't think many people know about it anymore. Or care.)

EDIT: Found it-
"The optimal viewing distance for a print is between 1.5 and 2 times the diagonal length of the print."
So an 8x10 should be viewed from about 20 to 26 inches.
I view prints at a distance I like.......

yssirk123 Loc: New Jersey

Lots of good information here. One additional suggestion would be to look into Qimage which is a very robust and inexpensive printing application; it would allow you to print in inches, and has many other advantages.

Bill_de Loc: US

Skylum has some videos that start with the basics. Once you learn to do your 4x6 images it will be easier to get into other options.

https://www.google.com/search?q=sizing+print+in+luminar&rls=com.microsoft:en-US:IE-Address&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7ADFA_enUS433&gws_rd=ssl

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burkphoto Loc: High Point, NC

Longshadow wrote:

img src="https://static.uglyhedgehog.com/images/s... (show quote)

The vast majority of photo labs (and even computer companies who make "retina" displays) know that the standard viewing distance is the diagonal dimension of the image, up to 1.5 times that dimension. IN PRACTICE, better labs want AT LEAST 240 original, processed from raw or in-camera generated JPEG file pixels per inch in an 8x10. We want around 300 PPI in a 5x7, 200 in an 11x14, 180 in a 16x20, 100 in a 32x40.

Viewing distance really does affect visual perception. Take a 1920x1080 pixel image, and make an 8" by 4.5" photographic print from it. Then realize that your 60" HDTV displays the same exact size image! If you hold the 8x4.5" print 9.25" from your face, and stand so you can see the same image displayed on your 60" (diagonal) TV screen, 60" away from you, they will not only appear the same size, but they will seem to have identical amounts of detail.

There’s input resolution (pixels processed from a camera or scanner capture with NO interpolation), which is measured in absolute, X by Y pixels. Then there’s output resolution (printer dots, created from FILE pixels), measured in dpi (dots per inch). In between, there’s a potential to resize, either via interpolation, or by changing the actual number of input pixels per inch. This is where the appropriate measurement is PPI, or pixels per inch. PPI (sometimes called print resolution, which is NOT the same as printer resolution) always has an associated, intended output size. "Per inch" adds that.

Pixels are just digital numbers in a file. They are *derived from* square scanner cells, or multiple adjacent digital sensor sensels... Those had physical, analog size. But pixels have no physical properties! You can reproduce them at any needed size. They are just numbers representing color and brightness. Bits do not equal atoms. But they can represent them!

The resolution header of an image file is merely intentional in photography. It is listed in 'dpi' because of its roots in the graphic arts industry, where scanner operators most often created files "to their output size". If an editor wants an 8"x6" image at 300 PPI, the scanner operator sets the scanner to output an 8x6 at 300 DOTS per inch. But the file contains 2400x1800 PIXELS, not dots. The editor wants 300 PPI so she can resize the image UP by 50% or DOWN by any reasonable amount, and still maintain quality on the printed page (with a 150 line per inch CMYK color separation). PRINTER resolution is practically irrelevant to the editor. She's been told what to assume the press will do.

In photography, all that really counts is how many absolute pixels you have in an image. If you have enough pixels FROM THE CAMERA OR SCANNER to spread 240 of them horizontally and vertically across an 8x10 print, and you view that print at about 13 inches, your eyes will resolve maximum detail (assuming fully corrected vision). MORE pixels at that size will not result in a perception of more detail. FEWER pixels at that size will resolve fewer visible details, and the pixels themselves will become visible at some point as you reduce print resolution (not printER resolution in dpi!). The limiting factor is our eyes. We're not eagles!

Some folks here have duly noted that most software does the resizing for printing for you. It does, but you have to be reasonable about it. Fortunately, in 2018, MOST digital cameras produce enough pixels to make prints of nearly any size, so long as they will be viewed at their diagonal distance or greater, and as long as you don't crop the original file TOO much.

You usually DO have to tell your software what INPUT resolution to the printer you want. For instance, my inkjet printer sprays 2880x1440 dots per inch. For small prints (4x6, 5x7) I send 360PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 4. That reduces processing time and required network bandwidth a little. For larger prints (8x10 and larger), I send 240PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 6. The input resolution is set in Lightroom's print module for each and every layout you create.

If you send work to a lab, ask them about file resolution. Labs vary in their requirements. Most have input systems that automatically kick out any files that they consider too small for the size print ordered. The better ones have remote order entry systems that refuse an image before you submit something that would make a mess.

You can STILL make a mess by interpolating a tiny image to a large size, before sending it to the lab... A 320x400 pixel image will NOT make a nice 8x10. If you interpolate it to 1920x2400, it still won't. It will just be a very fuzzy blow up of an image that should be no larger than 1" by 1.25" in a printed form.

The smart thing to do for maximum quality is to start with enough pixels, then resize images for the precise output sizes, substrates, and sharpening characteristics that you want for the printer you are using. Personally, I like to send files to labs that are sized for the largest print I'm ordering. But I do a calculation before resizing, to make sure that my absolute number of available pixels derived from the camera will be appropriate for the size I want to order.

Longshadow Loc: Audubon, PA, United States

burkphoto wrote:

The vast majority of photo labs (and even computer companies who make "retina" displays) know that the standard viewing distance is the diagonal dimension of the image, up to 1.5 times that dimension. IN PRACTICE, better labs want AT LEAST 240 original, processed from raw or in-camera generated JPEG file pixels per inch in an 8x10. We want around 300 PPI in a 5x7, 200 in an 11x14, 180 in a 16x20, 100 in a 32x40.

Viewing distance really does affect visual perception. Take a 1920x1080 pixel image, and make an 8" by 4.5" photographic print from it. Then realize that your 60" HDTV displays the same exact size image! If you hold the 8x4.5" print 9.25" from your face, and stand so you can see the same image displayed on your 60" (diagonal) TV screen, 60" away from you, they will not only appear the same size, but they will seem to have identical amounts of detail.

There’s input resolution (pixels processed from a camera or scanner capture with NO interpolation), which is measured in absolute, X by Y pixels. Then there’s output resolution (printer dots, created from FILE pixels), measured in dpi (dots per inch). In between, there’s a potential to resize, either via interpolation, or by changing the actual number of input pixels per inch. This is where the appropriate measurement is PPI, or pixels per inch. PPI (sometimes called print resolution, which is NOT the same as printer resolution) always has an associated, intended output size. "Per inch" adds that.

Pixels are just digital numbers in a file. They are *derived from* square scanner cells, or multiple adjacent digital sensor sensels... Those had physical, analog size. But pixels have no physical properties! You can reproduce them at any needed size. They are just numbers representing color and brightness. Bits do not equal atoms. But they can represent them!

The resolution header of an image file is merely intentional in photography. It is listed in 'dpi' because of its roots in the graphic arts industry, where scanner operators most often created files "to their output size". If an editor wants an 8"x6" image at 300 PPI, the scanner operator sets the scanner to output an 8x6 at 300 DOTS per inch. But the file contains 2400x1800 PIXELS, not dots. The editor wants 300 PPI so she can resize the image UP by 50% or DOWN by any reasonable amount, and still maintain quality on the printed page (with a 150 line per inch CMYK color separation). PRINTER resolution is practically irrelevant to the editor. She's been told what to assume the press will do.

In photography, all that really counts is how many absolute pixels you have in an image. If you have enough pixels FROM THE CAMERA OR SCANNER to spread 240 of them horizontally and vertically across an 8x10 print, and you view that print at about 13 inches, your eyes will resolve maximum detail (assuming fully corrected vision). MORE pixels at that size will not result in a perception of more detail. FEWER pixels at that size will resolve fewer visible details, and the pixels themselves will become visible at some point as you reduce print resolution (not printER resolution in dpi!). The limiting factor is our eyes. We're not eagles!

Some folks here have duly noted that most software does the resizing for printing for you. It does, but you have to be reasonable about it. Fortunately, in 2018, MOST digital cameras produce enough pixels to make prints of nearly any size, so long as they will be viewed at their diagonal distance or greater, and as long as you don't crop the original file TOO much.

You usually DO have to tell your software what INPUT resolution to the printer you want. For instance, my inkjet printer sprays 2880x1440 dots per inch. For small prints (4x6, 5x7) I send 360PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 4. That reduces processing time and required network bandwidth a little. For larger prints (8x10 and larger), I send 240PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 6. The input resolution is set in Lightroom's print module for each and every layout you create.

If you send work to a lab, ask them about file resolution. Labs vary in their requirements. Most have input systems that automatically kick out any files that they consider too small for the size print ordered. The better ones have remote order entry systems that refuse an image before you submit something that would make a mess.

You can STILL make a mess by interpolating a tiny image to a large size, before sending it to the lab... A 320x400 pixel image will NOT make a nice 8x10. If you interpolate it to 1920x2400, it still won't. It will just be a very fuzzy blow up of an image that should be no larger than 1" by 1.25" in a printed form.

The smart thing to do for maximum quality is to start with enough pixels, then resize images for the precise output sizes, substrates, and sharpening characteristics that you want for the printer you are using. Personally, I like to send files to labs that are sized for the largest print I'm ordering. But I do a calculation before resizing, to make sure that my absolute number of available pixels derived from the camera will be appropriate for the size I want to order.

The vast majority of photo labs (and even computer... (show quote)

My brain hurts. I'll just continue to print from the <large> original.

burkphoto Loc: High Point, NC

Longshadow wrote:

My brain hurts. I'll just continue to print from the <large> original.

Hey, that usually works!

rayofgray

I'm giving up on Luminar. Their support system recommends that I download an alternate printing app, which I don't want to do. There must be a photo editor that allows you to resize in inches! Anyway, thanks for all your help and advice.

CamB Loc: Juneau, Alaska

Lightroom, lightroom, lightroom

rayofgray wrote:

I'm giving up on Luminar. Their support system recommends that I download an alternate printing app, which I don't want to do. There must be a photo editor that allows you to resize in inches! Anyway, thanks for all your help and advice.

CamB Loc: Juneau, Alaska

I think I should print and post this next to the computer to remind me why I don't know all this. It's a good explanation, and it's good to read through this once in awhile, but for me, (and maybe this is my artsy side showing), I can never take it all in or remember what is what. The numbers just don't stick. This is a good post though, and I'm glad you put it up.
...Cam

burkphoto wrote:

The vast majority of photo labs (and even computer companies who make "retina" displays) know that the standard viewing distance is the diagonal dimension of the image, up to 1.5 times that dimension. IN PRACTICE, better labs want AT LEAST 240 original, processed from raw or in-camera generated JPEG file pixels per inch in an 8x10. We want around 300 PPI in a 5x7, 200 in an 11x14, 180 in a 16x20, 100 in a 32x40.

Viewing distance really does affect visual perception. Take a 1920x1080 pixel image, and make an 8" by 4.5" photographic print from it. Then realize that your 60" HDTV displays the same exact size image! If you hold the 8x4.5" print 9.25" from your face, and stand so you can see the same image displayed on your 60" (diagonal) TV screen, 60" away from you, they will not only appear the same size, but they will seem to have identical amounts of detail.

There’s input resolution (pixels processed from a camera or scanner capture with NO interpolation), which is measured in absolute, X by Y pixels. Then there’s output resolution (printer dots, created from FILE pixels), measured in dpi (dots per inch). In between, there’s a potential to resize, either via interpolation, or by changing the actual number of input pixels per inch. This is where the appropriate measurement is PPI, or pixels per inch. PPI (sometimes called print resolution, which is NOT the same as printer resolution) always has an associated, intended output size. "Per inch" adds that.

Pixels are just digital numbers in a file. They are *derived from* square scanner cells, or multiple adjacent digital sensor sensels... Those had physical, analog size. But pixels have no physical properties! You can reproduce them at any needed size. They are just numbers representing color and brightness. Bits do not equal atoms. But they can represent them!

The resolution header of an image file is merely intentional in photography. It is listed in 'dpi' because of its roots in the graphic arts industry, where scanner operators most often created files "to their output size". If an editor wants an 8"x6" image at 300 PPI, the scanner operator sets the scanner to output an 8x6 at 300 DOTS per inch. But the file contains 2400x1800 PIXELS, not dots. The editor wants 300 PPI so she can resize the image UP by 50% or DOWN by any reasonable amount, and still maintain quality on the printed page (with a 150 line per inch CMYK color separation). PRINTER resolution is practically irrelevant to the editor. She's been told what to assume the press will do.

In photography, all that really counts is how many absolute pixels you have in an image. If you have enough pixels FROM THE CAMERA OR SCANNER to spread 240 of them horizontally and vertically across an 8x10 print, and you view that print at about 13 inches, your eyes will resolve maximum detail (assuming fully corrected vision). MORE pixels at that size will not result in a perception of more detail. FEWER pixels at that size will resolve fewer visible details, and the pixels themselves will become visible at some point as you reduce print resolution (not printER resolution in dpi!). The limiting factor is our eyes. We're not eagles!

Some folks here have duly noted that most software does the resizing for printing for you. It does, but you have to be reasonable about it. Fortunately, in 2018, MOST digital cameras produce enough pixels to make prints of nearly any size, so long as they will be viewed at their diagonal distance or greater, and as long as you don't crop the original file TOO much.

You usually DO have to tell your software what INPUT resolution to the printer you want. For instance, my inkjet printer sprays 2880x1440 dots per inch. For small prints (4x6, 5x7) I send 360PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 4. That reduces processing time and required network bandwidth a little. For larger prints (8x10 and larger), I send 240PPI to the printer driver, because it's evenly divisible into the printer resolution by a factor of 6. The input resolution is set in Lightroom's print module for each and every layout you create.

If you send work to a lab, ask them about file resolution. Labs vary in their requirements. Most have input systems that automatically kick out any files that they consider too small for the size print ordered. The better ones have remote order entry systems that refuse an image before you submit something that would make a mess.

You can STILL make a mess by interpolating a tiny image to a large size, before sending it to the lab... A 320x400 pixel image will NOT make a nice 8x10. If you interpolate it to 1920x2400, it still won't. It will just be a very fuzzy blow up of an image that should be no larger than 1" by 1.25" in a printed form.

The smart thing to do for maximum quality is to start with enough pixels, then resize images for the precise output sizes, substrates, and sharpening characteristics that you want for the printer you are using. Personally, I like to send files to labs that are sized for the largest print I'm ordering. But I do a calculation before resizing, to make sure that my absolute number of available pixels derived from the camera will be appropriate for the size I want to order.

The vast majority of photo labs (and even computer... (show quote)

HarryBinNC Loc: Blue Ridge Mtns, No.Carolina, USA

rayofgray wrote:

I'm giving up on Luminar. Their support system recommends that I download an alternate printing app, which I don't want to do. There must be a photo editor that allows you to resize in inches! Anyway, thanks for all your help and advice.

Photoshop!