300 dpi for printing

[wisann]

Hi guys,

This is my first time sending my images for printing. I am setting up a flush mount album for myself. Now, the guy from the shop tells me that they would need the images resolution to be in 300 dpi. Last time I checked, image from my D700 shows it is 240 dpi. Do I need to sample my image from 240 dpi to 300 dpi? Or can I just send my 240 dpi image to print? Does it make any difference?

Sorry if this sounds so newbie. First time printing

 

[David Kwok]

How big is your print ?

Read this http://www.clubsnap.com/forums/threads/976109-D300-Raw-Print-Size

Also Read this http://www.clubsnap.com/forums/threads/976008-Does-Dpi-even-matter

Hi guys,

This is my first time sending my images for printing. I am setting up a flush mount album for myself. Now, the guy from the shop tells me that they would need the images resolution to be in 300 dpi. Last time I checked, image from my D700 shows it is 240 dpi. Do I need to sample my image from 240 dpi to 300 dpi? Or can I just send my 240 dpi image to print? Does it make any difference?

Sorry if this sounds so newbie. First time printing

 

[wisann]

12" x 12", with 300 dpi, meaning the resolution becomes 3600 x 3600, true?

So, in my current image, when I check the image size via photoshop, it mentions the dpi is 240. Can I simply change the 240 to 300 and save the image for printing?

 

[wisann]

How big is your print ?

Read this http://www.clubsnap.com/forums/threads/976109-D300-Raw-Print-Size

Also Read this http://www.clubsnap.com/forums/threads/976008-Does-Dpi-even-matter

I replied to you before I read the link. Let me check them out first. Thank you

 

[David Kwok]

With resampling, that is correct. But that will not make your photos sharper than it already is. It is just stuffing more pixels in between to beef up the resolution. But doing so, you do get the opportunity to ensure better interpolation, using 16bits as your resampling should your image is stored in 16bits having the original input to be 12bits/14bits from the RAW. This will give you better interpolation, though most likely your eyes can't tell easily unless it's blown up real big over very gradual tone areas. You also get the opportunity to sharpen at the enlarged images for sharper output.

If you just set the DPI to 300 without resampling, it will just retain the image size and adjust a variable. That's all. No work done. 0 joules.

12" x 12", with 300 dpi, meaning the resolution becomes 3600 x 3600, true?

So, in my current image, when I check the image size via photoshop, it mentions the dpi is 240. Can I simply change the 240 to 300 and save the image for printing?

 

[ortega]

an image that is 3000px by 2000px at 300dpi
is the same as
an image with 3000px by 2000px at 240dpi
is the same as
an image with 3000px by 2000px at 72dpi

they are all still 3000px by 2000px

if you are using photoshop just select image -> image size and change the resolution with the resample image unchecked

 

[wisann]

With resampling, that is correct. But that will not make your photos sharper than it already is. It is just stuffing more pixels in between to beef up the resolution. But doing so, you do get the opportunity to ensure better interpolation, using 16bits as your resampling should your image is stored in 16bits having the original input to be 12bits/14bits from the RAW. This will give you better interpolation, though most likely your eyes can't tell easily unless it's blown up real big over very gradual tone areas. You also get the opportunity to sharpen at the enlarged images for sharper output.

If you just set the DPI to 300 without resampling, it will just retain the image size and adjust a variable. That's all. No work done. 0 joules.

I think I am starting to get this haha..

So, am I correct to say, before I am doing the layout for the album, it's better to resize and resample all my images to 300 dpi?

And to sharpen the image using unsharp tool after the resizing and resampling, is there any formula I can follow?

 

[David Kwok]

Before we dwell further, tell me what is your objective print out size and what is the pixel count of the image after your post-processing. Then I will tell you what to do.

I think I am starting to get this haha..

So, am I correct to say, before I am doing the layout for the album, it's better to resize and resample all my images to 300 dpi?

And to sharpen the image using unsharp tool after the resizing and resampling, is there any formula I can follow?

 

[wisann]

Print out size: 12" x 12"

Most of the images are uncropped, that would give me 4256 x 2832 (I am using D700).

Even if I cropped, I am guessing I would still have at least 80% of 4256 x 2832 (need to confirm this back at home haha)

 

[David Kwok]

Since it's just at most 30% enlarge from the short end (2832), just do a simple bicubic smoothing resampling in photoshop. Set your DPI to 300, set the height to 3600 and let the S/W do the job. On practical side, I think 300 is on the high end side, I feel at 250dpi, your eyes can't discern the differences at all. Most likely the printer will down sample before printing and back to square one.

What are you printing with ? Inkjet ?

Print out size: 12" x 12"

Most of the images are uncropped, that would give me 4256 x 2832 (I am using D700).

Even if I cropped, I am guessing I would still have at least 80% of 4256 x 2832 (need to confirm this back at home haha)

 

[wisann]

Since it's just at most 30% enlarge from the short end (2832), just do a simple bicubic smoothing resampling in photoshop. Set your DPI to 300, set the height to 3600 and let the S/W do the job. On practical side, I think 300 is on the high end side, I feel at 250dpi, your eyes can't discern the differences at all. Most likely the printer will down sample before printing and back to square one.

What are you printing with ? Inkjet ?

For the flush mount album type that I am gonna print, I don't think the shop will use inkjet. They have other types of albums that will use inkjet.

They only tell me that the image must be 300 dpi. Even when I asked whether the image must be in specific color space or not, they said it doesn't matter.

 

[David Kwok]

Probably it's photographic development from digital files then, just a guess. Then just give them 300dpi since they asked for. Since your image enlargement is not significant, it shouldn't matter much.

Deliver your image in TIFF. That should do.

For the flush mount album type that I am gonna print, I don't think the shop will use inkjet. They have other types of albums that will use inkjet.

They only tell me that the image must be 300 dpi. Even when I asked whether the image must be in specific color space or not, they said it doesn't matter.

 

[ellery]

wisann - the reason for this is......you are using Lightroom. On export options just set the dpi to 300. In a large fine jpg file or a Camera Raw file there is no dpi setting - there is only the pixel size of the file. In preparing the files for the album layout - if you are cropping in Lightroom - set the dpi 300. It of course better that the file used be already exported to a size that allows for direct layout - ie its a 12inchx12inch album and you go out put files of size 8inch x8inch and expect to use transform to fit the file to the required size - that way is plain silly.

More important question is if they (original files) were jpgs - did you use large fine for max file size. Resizing say for a small basic is a bad bad idea. You can check what is the pixel dimension of the file - divide this by 300 and you will know what size of print the file will produce before any interpolation. Which is always a bad idea generally.

240 vs 300 - not sure it may depend on the printer used. some are sensitive to the input dpi. I guess that if printed large enough the difference of 60 dpi will become visible - question is at what size.


99% of the time any party printing will be doing so in RGB color space. The only printing (normally) that is done in CMYK is off set printing film, very few photo paper printers can print in AdobeRGB, send a file to them and if they do not convert for you to RGB, the returned print will be undersaturated and very flat.

 

[wisann]

@ellery:
My images are always in RAW (.NEF) format, max file size.

Um, if I get this right, meaning before I start the post-processing, I should have set the image to 300 dpi, is that true? I want to be sure this time, so that I can get it right from the beginning for my batch of editing.

And, for my current images which have been edited and stored as JPEG, I would do batch resize and resample to 300 dpi (using bicubic smooter algorithm), then apply sharpening on the images. Like this, my workflow is correct, isn't it?

 

[David Kwok]

The only printing (normally) that is done in CMYK is off set printing film

I agree with a wrong colourspace used that will affect the accuracy and vibrance of the output colour. I don't quite get that although you stressed NORMALLY, how is offset printing being CMYK and yet normal general printing technologies such as inkjet, laser are not mentioned as also within CMYK ? Even higher end printing technologies such as dye sublimation and thermal transfer are essentially CMYK and very well within the CMYK gamut.

I presume that offset printing are what commonly know as spot-colours ? Perhaps you know any printing technologies that are RGB ? I do know one though.

Care to share ?

Thanks

 

[David Kwok]

@ellery:
My images are always in RAW (.NEF) format, max file size.

Um, if I get this right, meaning before I start the post-processing, I should have set the image to 300 dpi, is that true? I want to be sure this time, so that I can get it right from the beginning for my batch of editing.

It doesn't matter what DPI you are in when you are editing. All raster operations deal with the pixels and take no reference from DPI, not unless if you are mixing vectors and raster operations together.

And, for my current images which have been edited and stored as JPEG, I would do batch resize and resample to 300 dpi (using bicubic smooter algorithm), then apply sharpening on the images. Like this, my workflow is correct, isn't it?

If your source is RAW, you should store in TIFF 16bits if possible. Only upon printing that you convert the colourspace to sRGB if required, or CMYK if you want to fit the printer profile, but so far, I find it hard to get the print house ICC profile. I talk with one like 10 years back and they don't even know what is ICC profile. They just knows if you want to ensure consistency of colour, use spot colours or pantone as the standard. I'm like duh.... It's a photograph.

In any case, store without compression or with lossless compression during editing. JPEG are for final output and normally web or output devices that have memory constraint.

 

[wisann]

It doesn't matter what DPI you are in when you are editing. All raster operations deal with the pixels and take no reference from DPI, not unless if you are mixing vectors and raster operations together.



If your source is RAW, you should store in TIFF 16bits if possible. Only upon printing that you convert the colourspace to sRGB if required, or CMYK if you want to fit the printer profile, but so far, I find it hard to get the print house ICC profile. I talk with one like 10 years back and they don't even know what is ICC profile. They just knows if you want to ensure consistency of colour, use spot colours or pantone as the standard. I'm like duh.... It's a photograph.

In any case, store without compression or with lossless compression during editing. JPEG are for final output and normally web or output devices that have memory constraint.

My usual workflow is:
1. Open .NEF in adobe camera raw, do some adjustments
2. Next, continue it on photoshop
3. After I finished editing, I will store the image with its layers as .PSD file
4. Flatten the image, and store as JPEG (so basically I have two copies, one .PSD and another one is JPEG file)
5. JPEG is the one I deliver to clients

Now I know that I need to print at 300 dpi, I need to resize/resample at step 4 right? That means, I will have 3 files:
- one .PSD
- one JPEG (to deliver to clients)
- one resized/resampled JPEG (to print)

Does my workflow above make sense?

 

[catchlights]

My usual workflow is:
1. Open .NEF in adobe camera raw, do some adjustments
2. Next, continue it on photoshop
3. After I finished editing, I will store the image with its layers as .PSD file
4. Flatten the image, and store as JPEG (so basically I have two copies, one .PSD and another one is JPEG file)
5. JPEG is the one I deliver to clients

Now I know that I need to print at 300 dpi, I need to resize/resample at step 4 right? That means, I will have 3 files:
- one .PSD
- one JPEG (to deliver to clients)
- one resized/resampled JPEG (to print)

Does my workflow above make sense?

what still confuse about 300ppi thingy?
please refer the Mod Ortega post, you need not set to 300ppi to your file, it is meaningless, all you need to know is your file shouldn't have less then the pixel size needed for the paper size you want to print.

if you want a 4R print, just give your printer a image file in 1800x1200 will do, whether is set to 72ppi or 1200ppi is all meaningless, the file is still 1800pixel x 1200pixel, good for a 4R print.

you need not downsize the file for printing, you have a larger pixel size file for printing but not smaller, a bigger file will not have any benefit on the print quality, but might save you a little extra work downsizing them.

 

[ziploc]

DPI has no meaning unless the dots (or pixels) are presented onto a media. Let's look at an example: I have a picture that is 300x300 pixels. If I print this onto a piece of paper that is 1"x1", I get 300 DPI. Now if I print it 10"x10", it now becomes 30 DPI. The picture is still 300x300 regardless. Usually the way is to work backwards, so using the above example, if I am printing 10"x10" and want 300 DPI, I need a picture size of at least 3000x3000 pixels.

Since the raw size of your D700 is 4256 x 2832, for 12"x12" print the worse case DPI you get is 2832/12 = 236 DPI. This is in fact quite adequate and you really don't need to resize your pic. Btw since your original pic is not matching the size of the 12"x12", are you fitting in or cropping?

 

[wisann]

DPI has no meaning unless the dots (or pixels) are presented onto a media. Let's look at an example: I have a picture that is 300x300 pixels. If I print this onto a piece of paper that is 1"x1", I get 300 DPI. Now if I print it 10"x10", it now becomes 30 DPI. The picture is still 300x300 regardless. Usually the way is to work backwards, so using the above example, if I am printing 10"x10" and want 300 DPI, I need a picture size of at least 3000x3000 pixels.

Since the raw size of your D700 is 4256 x 2832, for 12"x12" print the worse case DPI you get is 2832/12 = 236 DPI. This is in fact quite adequate and you really don't need to resize your pic. Btw since your original pic is not matching the size of the 12"x12", are you fitting in or cropping?

Oh, not necessarily cropping, because I am printing a wedding album. So, the layout is 12" x 12", and in a page, it might contain several images or one image only. And for certain image, I might print it in 2 pages (that means it is a 24" x 12" layout).

I hope I get my questions right ^^;

Sorry if I keep asking stupid questions, totally newbie in this area. Also, I understand the dpi thingy now. But as ziploc mentioned, the image from my D700, in worst case I get 236 dpi only. Now, since the printing house is asking 300 dpi. What do I do? What I have in mind is:
1. Create a layout of 12" x 12" in 300 dpi, meaning I get 3600 x 3600
2. Now assuming I print one image in a page (my raw size is 4256 x 2832), that means I will need to resize my image so that at least the 2832 becomes 3600, and this means I will have to crop the width of the image. Do I get this right?

Another option:
1. Create layout of 12" x 12" in 240 dpi, that means I get layout of 2880 x 2880
2. Assuming I print one image in a page, with my raw size is 4256 x 2832. For this, I will still need to resize the height 2832 to 2880, and crop the width.
And if I send this 240 dpi layout to the printing house, will this be okay? From calculation, if they are doing printing in 300 dpi, the 12" x 12" that I sent will become 9.6" x 9.6" only.