I'm wondering is anyone has actually used an enlargement technique from Scott Kelby's book on CS3, CS3 for Digital Photographers.

The thing I hate about Kelby's books, other than his schlocky writing style is that sometimes he doesn't explain why, which isn't a big problem if you can figure it out yourself--which usually I can be comparing his techniques to other authors and methods.

In his newest book on page 168 he gives a "rule breaking" technique to enlarge to poster sized prints.

Using a 6MP camera to get a 25x36" print involves changing the resolution manually to what seems like an arbitrary number, which he gives as (360). And then using an algorithm that is not intended for upsizing, which is bicubic sharper for reductions. He says that this technique--not his own but a friends in the profession of photography--makes a very sharp and clean image.

The problem is that he doesn't explain the formula making the method possible with different pixel densities from various cameras and different poster sizes.

Is it possible that "360" is some magic resolution?

So, can anyone shed any light on this subject?

360 is claimed by some to be the native printer resolution for epsom printers, maybe thats got something to do with it??
Incidently Scott also claims converting to lab mode is lossless. Wayne

I don't know. I just wish I knew the formula so I can try this method. I find many of his tips too generic for my tastes, but he has other things that are nice to have on the shelf. As far as his photography goes, I pay him no attention at all. He's a photoshop expert, in my mind, not a photographer of any concern to me.

You might try posting the question on his blog, you may be lucky and get an answer from him. Wayne


scots blog

I was informed by an Epson rep that there is no such thing as native resolution for the current generation of Epson professional printers, and that with the current dithering and screening techniques they are using, there is a range of PPI one can send to the printer and obtain equally good quality results.

As for converting to Lab being lossless, this is a very old controversy. If Scott is saying this, he is only the second author of the lot I know about who thinks this. There are others who purport to have demonstrated that it is factually incorrect.

I have seen the idea elsewhere (forget where exactly) that Bi-cubic Sharper does a better job of resizing even when image size is being increased. Rather than trying to unscramble the omelet or depend on what others say, try and see. Duplicate an image with fine detail in it, increase the size and resize it using Sharper on one image and Smoother on the other. Print each result large enough to see differences (I would recommend at least A3 or Super A3) and observe whether it matters which one uses. For the range I've tested, just once a while back, I couldn't tell the difference. Since the resizing I sometimes do is small, I just go by what Photoshop recommends and the results are fine.