Very Large Maps, is it a problem?

[jwbjerk]

...the only real working difference is that when you zoom to 100%, the larger the ppi the smaller it will appear on the screen.

I don't know about GIMP, but in photoshop zooming to 100% means that every pixel on your screen represent a pixel in your document. I.E. there's a one-to-one correspondence. DPI or PPI is irrelevant to how "100%" looks on screen.


Some other Tricks:

* I like to use "Solid Color" Adjustment layers when they make sense in my maps. They create only 1 channel worth of information instead of 4.
The "foundation" layer that contains the shape of my coastline is a "solid color" layer, and i clip mask everything i want to conform to the coastline to it. To create a solid, semitransparent layer of color, like to delineate a temperature zone, political boundary, or a biome, i'll generally use a solid color layer. I can just paint on the mask to change the size-- i don't have to worry about selecting that precise color again, or accidentally painting on it.


* Gradient maps are a great way to make topographic effect that adjust themselves as you edit the map. They are also gentle on the file-size. See step #11 of my mini tutorial.


* In photoshop (and i think GIMP) you can set the bit depth of each channel. Going from 8 bits/channel to 16 or 32 greatly increases the file size and processing time. For map-making you will not regret leaving it at 8 bits/channel.


* You can never have too much RAM or scratch disc space for Photoshop. In Photoshop's preferences you can allow additional HardDrives to serve as a scratch disc. (the precise way you do this varies with the version). Adding fast drives, especially with lots of GBs free to the scratch disk list can greatly boost photoshop's performance on those time-consuming commands.

[su_liam]

* In photoshop (and i think GIMP) you can set the bit depth of each channel. Going from 8 bits/channel to 16 or 32 greatly increases the file size and processing time. For map-making you will not regret leaving it at 8 bits/channel.

Can you really? Do tell. If I could work out how to do this, it would be enormously helpful. I'd give a lot to be able to edit the elevation data in 16- or, better, 32-bit grayscale and apply gradient maps and lighting effects(I wish that was a layer effect) in 8-bit RGB.

EDIT: That, by the way, wasn't intended to be as smarmy, smug and generally asinine as it came out. I just really, really want to know how.

[jwbjerk]

Can you really? Do tell. If I could work out how to do this, it would be enormously helpful. I'd give a lot to be able to edit the elevation data in 16- or, better, 32-bit grayscale and apply gradient maps and lighting effects(I wish that was a layer effect) in 8-bit RGB.

OK.



To be clear you set the bit depth for the document as a whole. 32-bits was added recently CS3 or CS4, but the 16 bit option has been around at least for several versions before that.

[su_liam]

Okay. I gotcha. I usually do my HF editing and color texturing in separate documents anyway, when I don't just use Wilbur. Interestingly 32-bit was really crashy in the windows machines at school, but seems more reliable on my mac. Adobe and Apple get along so well inside the computer its a little odd how hammer-and-tongs they've gotten out here in the world.

[a2area]

I don't know about GIMP, but in photoshop zooming to 100% means that every pixel on your screen represent a pixel in your document. I.E. there's a one-to-one correspondence. DPI or PPI is irrelevant to how "100%" looks on screen.

Actually, you are right.. which means that PPI is totally irrelevant in relation to document fidelity unless your image is resampled as well. Still.. the original point remains.. if a document is 100 pixels by 100 pixels... then it remains so whether it's set at 1ppi, 10ppi or 100ppi etc..

[Hai-Etlik]

Actually, you are right.. which means that PPI is totally irrelevant in relation to document fidelity unless your image is resampled as well. Still.. the original point remains.. if a document is 100 pixels by 100 pixels... then it remains so whether it's set at 1ppi, 10ppi or 100ppi etc..

It's an option to choose which behaviour you want: View -> Dot for Dot