Help with image upsizing

[grego]

Until now, the maximum size print I offered portrait clients was a 16x24 inch.


After attending a few seminars from leading pros here in Aus I decided to rework my packages to include larger prints up to 36x24 inches (90x60cm).


Realising that my camera's max output is a 24MB file in RAW (Fuji S5) which equates to about a 12x18inch at 300dpi and given that your average camera is between 12 and 21 Megapixels (I think) these days, I am wondering is there a preferred method for upsizing files?


I have experimented using "Genuine Fractals" vs Photoshop and can see only little gain in using Fractals. However at an image size of 24 x36inches I don't feel the image quality is up to where it should be.


So I was wondering what others do to get these large images, how far will they go (ie:upsizing) using what process ? starting with what file size and format and are they always happy with the result?


I need help please as I am not sure whether I am just starting with inferior images or I am expecting too much?


Feed back would be appreciated
Thanks

 

[Big Mike]

Welcome to the forum.

From what I can tell, Genuine Fractals used to be the gold standard for up sizing digital images...but Photoshop does a much better job that it used to and the difference now is minimal. I believed the preferred method in Photoshop is to use bi-cubic smoother, then sharpen the image after the resize.

I haven't done enough experimenting to know for sure, but many people will tell you that you don't need 300 PPI...especially on larger prints. 240 PPI is a common number to use, and some go even lower.

Remember that you need to take 'viewing distance' into consideration. A 24x36 image is meant to be viewed from at least several feet away...not with your nose pressed up against the print. So if you are going to judge the quality, stand back a bit. Chances are that you are a harsher critic that your clients, and they won't be disappointed.

And of course, enlarging prints will show an image's weaknesses. So if it's not completely sharp, that will become more evident as you get bigger. So if you anticipate large prints of an image you taking, do all you can to maximize sharpness. Tripod, remote release, mirror lock up, good quality lens and optimum aperture.

 

[rufus5150]

Try upsizing with the bicubic sharpener (the one that's intended for reducing image sizes). In most cases, it works way better than the smoother + sharpen method.

 

[grego]

Thanks Mike & Rufus
I used the bicubic smoother when comparing to Gen Fractals, I'll give the sharpener a go.
Maybe its time to invest in a new lens as well

 

[droyz2000]

Gen Fractals is pretty much the industry standard. I have toyed with it and think it is better than Photoshop.

 

[Dwig]

I recommend that you give this post, and the two additional posts, a good read:

The Online Photographer: It's Bigger, But Is It Better?

No one method or application is universally the best at upsampling images. Images vary too much and any upsampling involves compromises. The bottom line is that the sharpening methods used are probably more critical.

 

[Marc Kurth]

I'm sure that some people will argue strongly against me, but I can only offer my opinion based on my experience.

Assuming you are having the image printed by a lab, let their RIP handle the rescaling. It is specialized software, already fine tuned to that specific printer and will invariably do a better job than you can do.

Spend your time making sure that the file is clean, free of artifacts and properly sharpened for the intended print size, AND VIEWING DISTANCE. As Dwig already said, sharpening will make all the difference in the world.

Before presenting final prints to your client, run a few cheap experiments with files with slight variations - you may be surprised. For very low cost test runs, use these guys: http://www.elcocolor.com/poster_special.htm

Marc