Enlargement for printing

[archonforest]

I want to print one of my render on A3/300 dpi. The render right now is 72 dpi and the resolution is 2000x1200. My idea is to pop the picture into PS and enlarge it to 300dpi. Now is this a good solution for a good quality render or I have to re-render the picture with a way higher res?

[Kadri]

* Make a blank new document in Photoshop.Look at the options.

* "Preset" then choose "International Paper"

* Find A3  in the "Size" option

* Look at the other settings and be sure to have 300 in "Resolution" (DPI)

* Change "Width" and "Height" to "Pixels"


Now you will see how big your render should be.

The way you wrote is not what you should do in general (but you should read the link below).

There are some threads here about this "DPI" problem! popping up from time to time.

Edit: http://www.planetside.co.uk/forums/index.php/topic,10040.msg104641.html#msg104641
        I mostly link to this thread. Especially PorcupineFloyd's link there.

[archonforest]

Thx Kadri. i found some of this threads but not the one u mentioned.

[Kadri]

[Dune]

You may get away with 200dpi if rendering is taking too long for you. That would mean 42cm/2.5x200=3360 pixels wide. For 300dpi it's 5040 pixels, but that may take 3 times as long, if not longer. Especially with soft shadows on, lots of cloud and water, that can take a long time, depending on your machine.

[archonforest]

Thx Dune
I will try the 300DPI option. I calculated that the image needs to be 4961x3508 for A3 size and that is just within the limit of the Creative version of TG
So next overnight render is just up

[jaf]

I don't have the latest PS (mine is getting ancient -- CS3) but I've had good luck with onOne Perfect Resize.  http://www.ononesoftware.com/products/resize9/  Not free though.

[archonforest]

Thx Jaf. CS3 still rocks

But folks I have another question. So I re-rendered the pix with the needed resolution (4961x3508) but the dpi is still only 96. Better than 72 but still not 300. So what we do now? Seems to me TG will not give me this 300 therefore I have to crank it up in PS...   any input

[Dune]

DPI doesn't 'say' anything really about quality. You just change the dpi in Photoshop to 300, but without resizing! And save. Px will remain the same, but printsize will go down.

[archonforest]

but printsize will go down.

What do u mean with this?

[Dune]

Well, if you print at 72 dpi all pixels will be spread over a larger area then if you print with 300dpi (which has the pixels denser for print).

[archonforest]

I see...thx for the answer. I will do a test print and I will see how the stuff is coming out.

[archonforest]

So finally I printed one of my TG image on A3. It turned out very well. Looks sharp no pixels, great colors...etc.
If anyone is interested here are the specs of the doc: 300DPI, 4961x3508 pixels res.

[PabloMack]

I want to print one of my render on A3/300 dpi. The render right now is 72 dpi and the resolution is 2000x1200. My idea is to pop the picture into PS and enlarge it to 300dpi. Now is this a good solution for a good quality render or I have to re-render the picture with a way higher res?

That is just a printer option function. You can easily compute the resolution that any printer density will produce. Let's assume that your print is going to be 11 inches wide. At 72 dpi this will print all detail in an image up to 11*72=792 pixels wide. With an image of 2000 pixels wide, you will need a minimum of 2000/11=189 dpi to show all detail in your image. If you want to show all detail that 300 dpi has to offer when printing an image 11 inches wide then you should re-render at 11*300=3300 pixels wide (or better). For any other physical print width just go through all these calculations again by substituting the 11's with the desired width in inches. You can go through all of these calculations using height instead of width if you want to.

[archonforest]

Thx for the data. I saved it for future reference.