Getting the best BIG print?

Stustaff · August 28, 2006

Ok the background to this is that I ordered a 20x30 print from smugmug and whilst the actual print quality is fantastic, Im not 100% happy with the image.
I just want to re-iterate that the issues I have with it are due to what I did to the image, there is no issue with the print quality.

The aim of this thread is to all share tips, best practice, etc to create a precise step by step guide to creating a great BIG print from a digital camera.

What is the best way to crop, what DPI to use, when to increase the image size before uploading an image etc etc

So anyone got anything to start me off

Brett Mickelson · August 28, 2006

http://www.smugmug.com/help/print-quality

For a 20x30 print, you'll want 254 dpi.

Stustaff · August 28, 2006

interesting link brett cheers, follow up question on it though

for a 20x30 am I better of creating a specific 20x30 inch file with a dpi of 254?

or just setting them all to 302 and letting the printers up or downsample?

EDIT - sorry to clarify when I create my first JPEG from a raw in PS what DPI and image size should I choose?

mercphoto · August 28, 2006

We don't really have enough information here. While the printer itself is 254dpi (I'm assuming that info is correct), simply up-rezzing the iamge to 254dpi is likely to have little impact on the image quality. For reference I routinely print 20x30 poster prints with zero up-rezzing from an 8.2 million pixel camera. This is a paltry 117 dots per inch at that size, yet the prints are tack-sharp.

I highly doubt what you have is a problem with dots per inch.

What camera are you using and how many mega pixels does it have? What lens are you using? How are you post-processing the image, in particular sharpening? Lastly, what precisely about the image quality are you unhappy about?

mercphoto · August 28, 2006

Stustaff wrote:

EDIT - sorry to clarify when I create my first JPEG from a raw in PS what DPI and image size should I choose?

Its irrelevant, do not fret about DPI and image size. It makes zero difference when printing to a lab such as Smugmug. This is not the same as printing at home from Photoshop.

Set your RAW converter to give you a non-interpolated image. You want to have the same number of pixles that your camera created. Image size and DPI are not meaningful values and you do not need to worry about that. All you are concerned with is total number of pixels, which you want to keep at your camera's native resolution.

For example, my Canon is a 8.2 MP camera: 3504 by 2336. When I do a conversion from RAW I want it to stay that way. It does not matter if it is sized as 8x12 at 292 dpi or 4x6 at 584 dpi. All that matters is pixels.

Stustaff · August 28, 2006

Its not a particular image thing as I cant actually remember what I did with the image!

More of a what should I do in future.

I have a canon rebel XT/350D and shoot RAW and then post process in PS

One thing I have done in the past is crop to 4x6 with dpi set to 300. could that be causing a prob?

When I want to crop my images to print at say 4x6 or the equivalent ratio what should I be putting in the crop tool as my settings?

mercphoto · August 28, 2006

Stustaff wrote:

Its not a particular image thing as I cant actually remember what I did with the image! More of a what should I do in future. I have a canon rebel XT/350D and shoot RAW and then post process in PS. One thing I have done in the past is crop to 4x6 with dpi set to 300. could that be causing a prob?

When I want to crop my images to print at say 4x6 or the equivalent ratio what should I be putting in the crop tool as my settings?

Well, let's do some simple math. 4x6 at 300dpi becomes a 2.16 million pixle image (4 x 6 x 300 x 300). Not many pixels to be printing a 20x30 at. In fact its only 60 dpi. So if you are cropping to 4x6 at 300 dpi, then trying to print that file at 20x30, then yes that woud be a problem.

The best way to crop in Photoshop is to set the width and height BUT LEAVE THE DPI FIELD BLANK. What this instructs Photoshop to do is crop pixels out but not do to any interpolation.

What lens are you using? The quality of the glass will have a very large impact on the quality of your prints.

Stustaff · August 28, 2006

a few mostly the canon 18 - 75 that comes with and a sigma 18 - 200 DC.

I think my main prob is the cropping though!

Rene` · September 1, 2006

What is interpolation???
Are you saying that it leaves the resolution as if it cam straight from the camera? What is the resolution --straight from a 6megapixel camera?

mercphoto wrote:

Well, let's do some simple math. 4x6 at 300dpi becomes a 2.16 million pixle image (4 x 6 x 300 x 300). Not many pixels to be printing a 20x30 at. In fact its only 60 dpi. So if you are cropping to 4x6 at 300 dpi, then trying to print that file at 20x30, then yes that woud be a problem.

The best way to crop in Photoshop is to set the width and height BUT LEAVE THE DPI FIELD BLANK. What this instructs Photoshop to do is crop pixels out but not do to any interpolation.

What lens are you using? The quality of the glass will have a very large impact on the quality of your prints.

claudermilk · September 2, 2006

Rene` wrote:

Are you saying that it leaves the resolution as if it cam straight from the camera? What is the resolution --straight from a 6megapixel camera?

What size are you printing? Resolution is a meaningless parameter until you put a physical size to that collection of pixels. If it's 300ppi for a 4x6, then the same file is about 150ppi for an 8x10. Reread merc's post.

JBurt · September 3, 2006

Stustaff wrote:

Its not a particular image thing as I cant actually remember what I did with the image!

More of a what should I do in future.

I have a canon rebel XT/350D and shoot RAW and then post process in PS

One thing I have done in the past is crop to 4x6 with dpi set to 300. could that be causing a prob?

When I want to crop my images to print at say 4x6 or the equivalent ratio what should I be putting in the crop tool as my settings?

It sounds like what you are doing is resizing, Not cropping.
The Rebel XT has a 2:3 aspect ratio. You don't need to crop for a 4x6 or a 20x30.

Do your initial adjustments of your RAW image then do a Save-As to .psd ?? (I use PSP so not sure what the PhotoShop extension is)

That will give you an image the same size as your original with no loss.

Do Not Resize!

You can then do what ever manipulation you want,

Do Not Resize!

Save-As a .jpg and upload it to SmugMug.
The lab will take that image and do what ever extrapolation necessary to get a good 20x30 print.
******************************************

If you are cropping your original image to get a better composition, you still don't want to resize it. Just make sure you crop to the correct 2:3 ratio and let the lab do the extrapolation.

Umm... you are archiving your original RAW images and only working with duplicates. Correct?

Getting the best BIG print?

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