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Urgent ?: Screen size vs. picture size, photoshop ? to take to the lab

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Drew Loker

Drew Loker

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Sorry for the urgent title, but I had posted this deep inanother thread, and I have not gotten a response. And I have got to take some prints to the lab today.

Question:

When I open an image off the camera, and it opens at 41.778 in x 27.778 in. If I use the crop tool, and crop it to a 5x7 to take to the lab, what have I done? It seems like a bad thing to take a 47in picture and reduce it to a 5 in. All I want, is for the lab to be able to print a 5x7 or an 8x10. I realize that the lab will make a 5x7 out of the 41x27, I just want to make sure I give them the right proportions.

So what do I need to do to make sure that I have the correct proportions, that I have not cropped to much, or that I will ge the print I am expecting?

SPecifically, I am using Photoshop elements, but Photoshop is similar.

When I attempt to resise the image using "IMage Size" I have two main sections to contend with: Pixel Dimensions and Document Size. If I change the Document Size from 41 in to 5, the file size shrinks from 17.3m, down, so I know I am getting rid of stuff I don't want to get rid of (resolution and detail that is).

Should I be using some other tool? When I use the crop tool, it get similar results as resizing the document.

Thanks for any afeedback!
Drew
 
The first thing you want to do is get the PPI (pixels per inch; AKA DPI: dots per inch) to the resolution appropriate for your printing needs.

Given the physical dimensions of your image, I'm assuming the picture comes out of your camera at 72 DPI. Find out what DPI your lab needs, then adjust the image to that DPI. A 41-inch wide image at 72 DPI becomes a 9.84-inch wide image at 300 DPI (note: the total number of pixels in the image are the same, you are not upsizing or downsizing the image, you are simply adjusting the printed resolution).

Once your DPI is correct, you may then downsample (reduce the physical dimension) or crop to get the image to the correct final printing size.

Hope this helps!

-Steve
Drew Loker said:
Sorry for the urgent title, but I had posted this deep inanother
thread, and I have not gotten a response. And I have got to take
some prints to the lab today.

Question:

When I open an image off the camera, and it opens at 41.778 in x
27.778 in. If I use the crop tool, and crop it to a 5x7 to take to
the lab, what have I done? It seems like a bad thing to take a 47in
picture and reduce it to a 5 in. All I want, is for the lab to be
able to print a 5x7 or an 8x10. I realize that the lab will make a
5x7 out of the 41x27, I just want to make sure I give them the
right proportions.

So what do I need to do to make sure that I have the correct
proportions, that I have not cropped to much, or that I will ge the
print I am expecting?

SPecifically, I am using Photoshop elements, but Photoshop is similar.

When I attempt to resise the image using "IMage Size" I have two
main sections to contend with: Pixel Dimensions and Document Size.
If I change the Document Size from 41 in to 5, the file size
shrinks from 17.3m, down, so I know I am getting rid of stuff I
don't want to get rid of (resolution and detail that is).

Should I be using some other tool? When I use the crop tool, it get
similar results as resizing the document.

Thanks for any afeedback!
Drew
Click to expand...
 
A digital file has no real inherent dpi/ppi size. Rather it is jus a pixel array of a certain number of horizontal and vertical pixels (say for example 1600 * 1200 pixels).

When you print that file at a given size (say a 10 inch wide print), you can say it then has a dpi value (for a 1600*1200 image this will be 160dpi).

If you print it 20 inches wide you can say it has a dpi of 1600/20 = 80dpi.

if you print it 40 inces wide you can say it has a dpi of 1600/40 = 40dpi.

But soon as the print is finished you still have a 1600*1200 file just like when you started that has no inherent dpi... the dpi figure is meaningless until you actually define an output size.

When you look at an image in an editing package it often displays it at a default size - usually very large - that equates to typically 72dpi. This doesn't actually mean anything, it's just a convention.

To print a picture of anysize, just supply the file and ask for the required printsize - you don't need to do anything to the file.
Drew Loker said:
Sorry for the urgent title, but I had posted this deep inanother
thread, and I have not gotten a response. And I have got to take
some prints to the lab today.

Question:

When I open an image off the camera, and it opens at 41.778 in x
27.778 in. If I use the crop tool, and crop it to a 5x7 to take to
the lab, what have I done? It seems like a bad thing to take a 47in
picture and reduce it to a 5 in. All I want, is for the lab to be
able to print a 5x7 or an 8x10. I realize that the lab will make a
5x7 out of the 41x27, I just want to make sure I give them the
right proportions.

So what do I need to do to make sure that I have the correct
proportions, that I have not cropped to much, or that I will ge the
print I am expecting?

SPecifically, I am using Photoshop elements, but Photoshop is similar.

When I attempt to resise the image using "IMage Size" I have two
main sections to contend with: Pixel Dimensions and Document Size.
If I change the Document Size from 41 in to 5, the file size
shrinks from 17.3m, down, so I know I am getting rid of stuff I
don't want to get rid of (resolution and detail that is).

Should I be using some other tool? When I use the crop tool, it get
similar results as resizing the document.

Thanks for any afeedback!
Drew
Click to expand...
 
DavidMillier said:
To print a picture of anysize, just supply the file and ask for the required
printsize - you don't need to do anything to the file.
Click to expand...
Thanks for the feedback so far. I am still trying to understand why the file size opens as a 72dpi straight off the camera?!?!

When I scanned photos, I would scan at 150 dpi and the image was an 8x10, or whatever.

But, let me explain again what I am trying to do.

Let's say I have a horizontal, and I want to have a 5x7 printed, maybe even a vertical 5x7 out of the horiz image.

When I open the image, it is 41 inches, at 72dpi. And I want to crop it to the same proportions that I am wanting the lab to print. When I crop, it turns from a 41in 72 dpi, to a 7 in 72 dpi. ???? THat can't be right.

Now, if I change the "image size", then the dpi stays proportional, but if I change the image to 5x7, I still need to crop. If I resize it enough to still be able to crop it, then I don't have the size right. ?!?!?

AM I just making this difficult?

THanks!
Drew
 
The image file header contains a field for dpi values. Commonly this is set by the camera to 72dpi as this is a common standard for displaying pictures on monitors.

The value is however meaningless, it's just there as a helpful guide to Photoshop etc.

When photoshop opens the file it has to decide on a default size to display the image - does it show you a 1 inch square image or a 3 foot wide one?

The file header gives it a clue - display the file at a size that is equal to 72dpi.

Beyond this that measure is meaningless.

The important thing is the actual height * width pixel dimensions.

eg If you crop a 100 * 100 pixel section out of the image and print it 10 inches wide the resolution of your print will be 100/10 = 10dpi (not very good print!)

I'm afraid I couldn't quite follow what you meant in the second half of your post....
Drew Loker said:
Drew Loker said:
To print a picture of anysize, just supply the file and ask for the required
printsize - you don't need to do anything to the file.
Click to expand...
Thanks for the feedback so far. I am still trying to understand why
the file size opens as a 72dpi straight off the camera?!?!

When I scanned photos, I would scan at 150 dpi and the image was an
8x10, or whatever.

But, let me explain again what I am trying to do.

Let's say I have a horizontal, and I want to have a 5x7 printed,
maybe even a vertical 5x7 out of the horiz image.

When I open the image, it is 41 inches, at 72dpi. And I want to
crop it to the same proportions that I am wanting the lab to print.
When I crop, it turns from a 41in 72 dpi, to a 7 in 72 dpi. ????
THat can't be right.

Now, if I change the "image size", then the dpi stays proportional,
but if I change the image to 5x7, I still need to crop. If I resize
it enough to still be able to crop it, then I don't have the size
right. ?!?!?

AM I just making this difficult?

THanks!
Drew
Click to expand...
 
Drew Loker said:
When I open the image, it is 41 inches, at 72dpi. And I want to
crop it to the same proportions that I am wanting the lab to print.
When I crop, it turns from a 41in 72 dpi, to a 7 in 72 dpi. ????
THat can't be right.
Click to expand...
When you resize the image to 7", uncheck the box that says 'Resample Image'. The print size of the image will be reduced to 7", but the resolution will jump up to 300 or more pixels per inch. No data will be thrown away. Do a Save As to keep your original unchanged. ~ tom
 
DavidMillier said:
I'm afraid I couldn't quite follow what you meant in the second
half of your post....
Click to expand...
Thanks for your reply. I am really trying to understand. Thanks for taking the time to explain.
DavidMillier said:
DavidMillier said:
Now, if I change the "image size", then the dpi stays proportional,
but if I change the image to 5x7, I still need to crop. If I resize
it enough to still be able to crop it, then I don't have the size
right. ?!?!?
Click to expand...
Click to expand...
Ok, let me try again. The goal is to walk into a lab with my image ready to print. What do I need to do to get the image to be the right proportions at the highest possible resolution?

In photoshop, the option to change the image size allows me to change from a 41" to a 7", but when I do, the file size goes from 17.3 mb to 495k. Something definately is not right. I can change the Resolution up from 72 up to 400, but I have to guess, to get it up to the previous pixel dimensions. Like when I punch in 450, it goes up to 18.9 mb.

I just don't understand how to take an image off the camera, and crop it like what I want, make sure I get the 5x7 (or 8x10, etc.) proportions. I just pull out a crop mark, I mess the whole thing up.

So what do I need to do when I have an image I want to take to get a print of?

Thanks!
Drew
 
Drew

I'm not a photoshop user so I have to guess a bit here but there is a difference between merely defining an image size without changing the original file and resampling (which processes the file).

When you resample, photoshop will interpolate the file and generate new invented pixels (upsampling) or delete some pixels (downsampling). This will change the file size - You probably don't want it to do this!

You need to find out how to change the image dimensions without triggering the resampling feature.

It's probably an option you can select somewhere. Fotunately,most people here probably are PS users someone will know the exact trick...
Drew Loker said:
Drew Loker said:
I'm afraid I couldn't quite follow what you meant in the second
half of your post....
Click to expand...
Thanks for your reply. I am really trying to understand. Thanks for
taking the time to explain.
Drew Loker said:
Drew Loker said:
Now, if I change the "image size", then the dpi stays proportional,
but if I change the image to 5x7, I still need to crop. If I resize
it enough to still be able to crop it, then I don't have the size
right. ?!?!?
Click to expand...
Click to expand...
Ok, let me try again. The goal is to walk into a lab with my image
ready to print. What do I need to do to get the image to be the
right proportions at the highest possible resolution?

In photoshop, the option to change the image size allows me to
change from a 41" to a 7", but when I do, the file size goes from
17.3 mb to 495k. Something definately is not right. I can change
the Resolution up from 72 up to 400, but I have to guess, to get it
up to the previous pixel dimensions. Like when I punch in 450, it
goes up to 18.9 mb.

I just don't understand how to take an image off the camera, and
crop it like what I want, make sure I get the 5x7 (or 8x10, etc.)
proportions. I just pull out a crop mark, I mess the whole thing up.

So what do I need to do when I have an image I want to take to get
a print of?

Thanks!
Drew
Click to expand...
 
SpinThis! said:
SpinThis! said:
uncheck the box that says 'Resample Image'.
Click to expand...
Give that man a prize! I was waiting to see who was going to catch
that "resample checkbox" thing. Notice when you turn off that
checkbox, the pixel dimensions on the top don't change which is
what you want. Doing this, you can print a 5 x 7 at about 400 dpi.
Click to expand...
Wow!! Thanks! I can't believe it was that simnple. And I am sorry for not trying that. I had played around with the "constrain proportions" checkbox. I didn't even think to try tht e"Resample". It is pretty obvious it does the trick. Duh!

Then to answer the reset of my question,, at least with Adobe Photoshop Elements, there is a place to set the crop dimension when using the crop tool.

So, now here is hopefully the last question here:

What size do I want to crop it down to for an ideal size to keep on file, or do I need to size it down at all, other than for composition? In other words, if I only want to print a 5x7 now, but later may want to print a 16x20, etc. I mean, I don't really care what the image size is, because whatever size I walk into the lab with, the lab is going to print. If I have a 41", then they can print it at 7.

If I walk in with a 5x7 at 400 dpi and ask for an 11x14, will I get the same quality as if I took them a 41x36 at 72 dpi? I am going to assume the answer here is yes, because the pixel and file size has not changed?!?!

So, there is no reason to shrink it down to 5x7, if all I am wanting to do is to get the final image to have the final composition that I want.

SO, back to the last question: I just want to make sure that what I walk into the store with, is a workable proportion, realizing that 8x10 and 5x7 are not the same proportion, what ideal size should I keep it at?

Thanks so much!!!
Drew
 
Hi Drew,

You can leave the image the original size. There is a combo box on the PS Elements toolbar where you can select "Constrained Aspect Ratio". You can set the width and height to 5x7, 8x10, or whatever you want and then crop. Notice that these numbers indicate the aspect ratio, not the size. If you crop t a 5x7 aspect ratio and may later want to do 8x10, save the 5x7 as a new file. This way, you can have a number of the cropped aspect ratios of the same picture.
Hope this helps.
--
  • Arnie
Drew Loker said:
Drew Loker said:
Drew Loker said:
uncheck the box that says 'Resample Image'.
Click to expand...
Give that man a prize! I was waiting to see who was going to catch
that "resample checkbox" thing. Notice when you turn off that
checkbox, the pixel dimensions on the top don't change which is
what you want. Doing this, you can print a 5 x 7 at about 400 dpi.
Click to expand...
Wow!! Thanks! I can't believe it was that simnple. And I am sorry
for not trying that. I had played around with the "constrain
proportions" checkbox. I didn't even think to try tht e"Resample".
It is pretty obvious it does the trick. Duh!

Then to answer the reset of my question,, at least with Adobe
Photoshop Elements, there is a place to set the crop dimension when
using the crop tool.

So, now here is hopefully the last question here:

What size do I want to crop it down to for an ideal size to keep on
file, or do I need to size it down at all, other than for
composition? In other words, if I only want to print a 5x7 now, but
later may want to print a 16x20, etc. I mean, I don't really care
what the image size is, because whatever size I walk into the lab
with, the lab is going to print. If I have a 41", then they can
print it at 7.

If I walk in with a 5x7 at 400 dpi and ask for an 11x14, will I get
the same quality as if I took them a 41x36 at 72 dpi? I am going to
assume the answer here is yes, because the pixel and file size has
not changed?!?!

So, there is no reason to shrink it down to 5x7, if all I am
wanting to do is to get the final image to have the final
composition that I want.

SO, back to the last question: I just want to make sure that what I
walk into the store with, is a workable proportion, realizing that
8x10 and 5x7 are not the same proportion, what ideal size should I
keep it at?

Thanks so much!!!
Drew
Click to expand...
 
Each camera has its aspect ratio. Commonly for consumer digitals this is 4:3 (800x600,1600x1200,etc). Your 10x8 is 5:4 so there is a difference here. The shop will just take the middle bit unless you ask them to do something else. If you want to be sure to get a print of the whole image you give them you will need to have the same aspect ratio as the paper. Don't worry about the dpi, keep the file as pixel big as you can, then you'll get the best dpi your camera can manage.

If you original image is 1600 x 1200 and you want to do a 5:4 aspect ratio the biggest image you can manage is a 1500 x 1200, so crop 100 pixels from the width. I never really bother with this and just take a bit of cropping at the printing stage.

This has alway happened with 35mm film which has an aspect ratio of 3:2, not the same as 5x7 or 8x10. There is no one size that fits all. The D100 uses a ratio very close to 3:2.

So, my answer to your last quetion - what is the ideal size? - is to use the original image but be aware of what cropping will take place. You can often adjust for it in the picture taking if you commonly print to one size.
Drew Loker said:
Drew Loker said:
Drew Loker said:
uncheck the box that says 'Resample Image'.
Click to expand...
Give that man a prize! I was waiting to see who was going to catch
that "resample checkbox" thing. Notice when you turn off that
checkbox, the pixel dimensions on the top don't change which is
what you want. Doing this, you can print a 5 x 7 at about 400 dpi.
Click to expand...
Wow!! Thanks! I can't believe it was that simnple. And I am sorry
for not trying that. I had played around with the "constrain
proportions" checkbox. I didn't even think to try tht e"Resample".
It is pretty obvious it does the trick. Duh!

Then to answer the reset of my question,, at least with Adobe
Photoshop Elements, there is a place to set the crop dimension when
using the crop tool.

So, now here is hopefully the last question here:

What size do I want to crop it down to for an ideal size to keep on
file, or do I need to size it down at all, other than for
composition? In other words, if I only want to print a 5x7 now, but
later may want to print a 16x20, etc. I mean, I don't really care
what the image size is, because whatever size I walk into the lab
with, the lab is going to print. If I have a 41", then they can
print it at 7.

If I walk in with a 5x7 at 400 dpi and ask for an 11x14, will I get
the same quality as if I took them a 41x36 at 72 dpi? I am going to
assume the answer here is yes, because the pixel and file size has
not changed?!?!

So, there is no reason to shrink it down to 5x7, if all I am
wanting to do is to get the final image to have the final
composition that I want.

SO, back to the last question: I just want to make sure that what I
walk into the store with, is a workable proportion, realizing that
8x10 and 5x7 are not the same proportion, what ideal size should I
keep it at?

Thanks so much!!!
Drew
Click to expand...
 
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