I need to create a 20"x24 320dpi print from 12mp Sony A700...

[SebastianStudios]

I need to create a 20"x24 320dpi print from 12mp Sony A700 I am using Lightroom 2 to process the RAW file, I need to know what is the workflow needed to end up with a 20" x 24" 320dpi Photoshop file, that I will then be sending out to a lab to get printed.

As always thanks in advance for you reply,

Sebastian

 

[spamjim]

The output size you describe is 6400 pixels by 7680 pixels.

The input size you describe for the A700, a 12 megapixel camera, is around 4000 pixels by 3000 pixels.

You cannot deliver the intended output with the limited resolution of that camera and at that aspect ratio.

A 12 megapixel image at a resolution of 320 ppi will print around 9.5" x 12.5".

 

[SebastianStudios]

spamjim,

With this being said, what is the workflow that will enable me to achieve my goal? I know it is possible I am just not sure how to go about the steps necessary to achieve my goal. Help is greatly appreciated.

As always thanks in advance for you reply,

Sebastian

 

[cebebe]

Hi, your camera has an image of 4272 x 2848, that is a 1.5 ratio and you want one of 1.2 ratio. The only way for you is to cut off (crop) part of it. No other possibility except to distort it!
The second problem regards the size of the image. Here you will have to use the interpolation capability of Photoshop : >Image >Image size > enter the height in pixels (6400), check "Constrain proportions" and Resample : bicubic. Nothing else.
And you will have the size and resolution you need. BUT, as you more than double (2.25x) the native image, no miracle, even with Photoshop, you will not have the result of a mid-size camera back.

 

[spamjim]

what is the workflow that will enable me to achieve my goal?

The 'workflow' would be to hire a photographer with a camera that could support that resolution. Otherwise, you simply take your low resolution image into Photoshop and screw up the image size to fit your requirements.

Photoshop's Image Menu->Image Size

 

[Hawthorne]

Hi

A 12 mega pixel file is adequate to make a 20 by 24 print if you are using all of the image and the original image is sharp.

I assume you don't intend for people to be looking at it from 2 feet away.

Just open the image in Photoshop and change the resolution to 320 PPI and Change the 9.5 dimension to 20" the Width will then be a little over 26".

Crop the width down to 24" and save the file as something non destructive like a native Photoshop file or a .tif file.

That's all there is to it.

.

 

[Gruuuu]

The "right" solution is not always the "best" solution.
This is where ingenuity comes in.

cebebe's suggestion is the first step.

Afterwards, you WILL have a blurry, ugly image. He is correct in that you cannot gain the detail that would be obtained with a camera capable of shooting that image.

BUT you can make it look a little better.
The first, and clunkiest option is the Sharpen filter. It finds changes in hue and value and accentuates them. This sortof battles the blurry effect of interpolation. It's also hideous, don't use it.
But it also has a cousin, the Unsharp Mask. It basically works the same, but you can control some of the option, such as how much of the effect you want, and how much of a change in hue or value is necessary before applying the effect.
The problem is, this is still the same effect, and is still hideous, if less so.

But still useful.

You will want to use this effect to accentuate or suggest detail in the image, no actually change it.
So what you will do is create copies of the image into new layers (Layer->Copy Layer or something like that).
How many copies depends on how much time you want to spend. Let's start with 2.

Make sure these layers are on top of your original image layer, and adjust the transparency to something like 30% for both.
Apply the unsharp mask to both layers.

At this point, it's all up to you. You will need to play with three variables: Blend modes of the layer copies, degree of Unsharp Mask effect, and transparency level of the layer copy.

If you really want to get into the minute detail and nitty gritty, you can use more layers(6 or 9 if your image mode is RGB, 8 or 12 if your image mode is CMYK. also if your image is grayscale, 2 will suffice. If it is monotone (sepia?) you may want 4 or 6).
Basically you would have a Highlights and a Shadows (and maybe a midtones) layer for each channel.

Again I will reiterate, you will not get the detail to match the resolution, but you can fake it just a little. Sometimes, the effort is worth it, especially if it's an image you really need but cannot reproduce.

 

[apepp]

...also to chip in a bit here...

...depending on the final printed output device you go to, together with the "effective" resolution of your image at a given size, there are times it is of no advantage to be performing any resampling in photoshop, but to rather print at a lower resolution (200dpi effective resolution image in photoshop as opposed to 300dpi to a high resolution inkjet printer for example)...

...for very large poster work you can achieve fine prints at 100dpi or lower from photoshop. Largely depending on the source image there are times you have to resample it to a higher pixel count for large poster work, in these situations the on1 plugin genuine fractals is far superior to that of photoshops own resampling algorithm:

http://www.ononesoftware.com/

andrew

============

http://www.apepp.info

============

 

[Pixelchik]

What about the Photoshop plug-in Genuine Fractals? Would that help boost the resolution needed?

 

[Hawthorne]

Hi again

I might ad that I have had better results when going to an outside provider for large printouts of posters when supplying them with a PDF file rather then a standard graphics file as far as color accuracy goes.

Things like this that I have done usually have type as will as an image and a PDF file will preserve the clarity of the type.

It seems that everyone can print from Acrobat and get similar results, rather then printing from some other programs where inconsistency's in in settings come into play.

.

 

[spamjim]

PDF is not a magic format for ensuring accurate color & quality. You will notice that when you save to PDF from Photoshop, you have many options, including the type/level of JPG compression - - - so it is possible that saving a certain type of PDF may not be any better than saving a lousy JPG. Review those settings carefully if sending as PDF.

 

[Hawthorne]

I just select "High Quality".

I do a lot of large posters this way for restaurant weekly specials and stuff like that. The food colors usually come out very close to what I see on my computer.

Of course I'm working with the same shop to print the images all the time. I suppose it depends a lot on who you are going to.

 

[Hawthorne]

PS. I'm using a Nikon D200 10 mega-pixel camera and while I process the images in Photoshop I ad the type and create the PDFs in InDesign.