Lightroom - How to boost image size to +25MP?

[F0kke]

I've been using Lightroom for a little while now and was wondering how I can boost the RAW files from my D200 to +25MP before opening them in PS. Before Adobe Camera Raw opened up automatically when I opened a raw image with Photoshop CS3, which allowed me to choose my preffered image size. From the native 10MP to the boosted 25MP size. I can't find this setting in Lightroom, and when I open a photo in PS from Lightroom, Adobe Camera Raw is not started. Am I overlooking something?

 

[Garbz]

I am not sure you can do it in lightroom, and even if you can selecting it via the CameraRAW interface is less than ideal. 10mpx to 25mpx should be doable in Photoshop with the bicubic re-sizer. More extreme resizes should use an external program that can handle lanczos filters or other more purpose designed algorithms.

The other question that comes to mind is why? Resizing requires interpolation which is not true to the original data. For instance you take your 10mpx image size it to 25mpx and back down to 10 you end up with different data than you started with. If the purpose is to make larger prints it may be better to keep the original picture at 10mpx for add editing purposes, save it, and just before printing re-size, print, and then close without saving.

 

[Sw1tchFX]

In my experiences, there's no real advantage with doing that in ACR, and in fact, is detrimental to the speed of your workflow, because it's a bigger image that you have to deal with, with no increase in quality.

 

[F0kke]

...
If the purpose is to make larger prints it may be better to keep the original picture at 10mpx for add editing purposes, save it, and just before printing re-size, print, and then close without saving.

Thanks! I'm quite new to printing, so your help is much appreciated. Until now I have always "boosted" my 6MP raw images (Nikon D70s) to 25MP in the Adobe Raw Converter, then resized the image to 70x50cm in photoshop (240dpi) before printing them on 70x50cm.

With my D70s the prints on 70x50cm were acceptable but not good enough to expose in galleries. I bought the D200 with the idea to get better quality prints on that same 70x50cm format.

The grey area for me is what comes after the final adjustments of the image. So basically what you two are saying is that is it better to just leave the raw image in its original 10MP size, make all necessary adjustments in Lightroom and afterwards resize the final image to 70x50cm in Photoshop and save it as a tiff?

When it comes to resizing the image in Photoshop, should I use 'Bicubic Smoother'?

'Bicubic (Best for smooth gradients)', 'Bicubic Smoother(Best for enlargement)' or 'Bicubic Sharper (Best for reduction)'

 

[gravy]

So basically what you two are saying is that is it better to just leave the raw image in its original 10MP size, make all necessary adjustments in Lightroom and afterwards resize the final image to 70x50cm in Photoshop and save it as a tiff?

When it comes to resizing the image in Photoshop, should I use 'Bicubic Smoother'?

that's what I do... do the editing first, and then resize.

I've used bicubic smoother with great results.

 

[Garbz]

Well yes Bicubic smoother is one to use, but as far as algorithms for enlargement go it's not all that good. Have a look around for programs which incorporate other methods. I believe the latest GIMP beta just included a (much better IMO) Lanczos resizer. It does the same thing but gives different quality results. Ultimately though the resize method depends on the image. Certain images will suit certain resizers.

 

[F0kke]

I will send off a couple after doing the bicubic smoother and will also try out GIMP and compare the results. Thanks a lot for your help guys, much appreciated!