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30m DEM .... Worth it at this scale?

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#1
snowgage

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Good morning..

I am working on a map of the Northern Rocky Mountains and some of the Great Plains. The area will inlcude, Montana, Wyoming, Colorado, Nebraska, South Dakota, North Dakota and a little bit of Canada.

This map will show important topographic features, political boundaries, hydrology and some boundaries specific to my client's needs. It will be plotted at 42 inches and also be produced at a smaller size for other purposes.

I am a bit of a high-resolution snob and love the appearance of 30m hillshades (as compared to 90 or 1km).

When it comes to this project, I am covering a very small map-scale (i.e. 1:8,000,000). Does it seem reasonable to use such fine-scale DEM and hillshade data for this map? Not to worry about computer peripherals, I am well prepared and have the storage and processing capability to use such data. I am just worried that the resolution is so fine and the scale so small that once I get the data together, the detail of the hillshading will be lost and I may have better used the 90 or 1km data.

Any suggestions or insight from anyone? Thanks in advance...

cheers,

Josh

#2
Charles Syrett

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If I were doing this, I'd go with the 1 km, or even more coarse (ETOPO2). You can always play with it in Photoshop to improve the image quality, but at the coarse resolutions the DEMs give you much better portrayal of the large relief features. Forget 30m -- nothing would show up at 8 million.

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Good morning..

I am working on a map of the Northern Rocky Mountains and some of the Great Plains. The area will inlcude, Montana, Wyoming, Colorado, Nebraska, South Dakota, North Dakota and a little bit of Canada.

This map will show important topographic features, political boundaries, hydrology and some boundaries specific to my client's needs. It will be plotted at 42 inches and also be produced at a smaller size for other purposes.

I am a bit of a high-resolution snob and love the appearance of 30m hillshades (as compared to 90 or 1km).

When it comes to this project, I am covering a very small map-scale (i.e. 1:8,000,000). Does it seem reasonable to use such fine-scale DEM and hillshade data for this map. Not to worry about computer peripherals, I am well prepared and have the storage and processing capability to use such data. I am just worried that the resolution is so fine and the scale so small that once I get the data together, the detail of the hillshading will be lost and I may have better used the 90 or 1km data.

Any suggestions or insight from anyone? Thanks in advance...

cheers,

Josh



#3
snowgage

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Charles,

Thanks for the speedy reply.. I do all of my design work in Illustrator but do use Photoshop for photography. Any suggestions on photoshop or illustrator tools that can be used to improve the IQ of my topography layers?

cheers,

Josh

#4
Hans van der Maarel

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Thanks for the speedy reply.. I do all of my design work in Illustrator but do use Photoshop for photography. Any suggestions on photoshop or illustrator tools that can be used to improve the IQ of my topography layers?


What exactly do you mean by that? If you want to maintain georeference when working in Illy/Photoshop (and moving georeferenced content from Photoshop to Illustrator) I would recommend the Avenza product line (MAPublisher/Geographic Imager)
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#5
Charles Syrett

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The best resources are: http://www.shadedrelief.com/ and http://www.reliefshading.com/
Briefly, though -- the trick here is to use Photoshop to counteract any pixellation you may have from the original relief image. Try the blur and Noise>Median tools. For final edits, use the airbrush. Oh -- and don't forget to let us see the end result of your labours. B)

Charles Syrett
Map Graphics
http://www.mapgraphics.com

Charles,

Thanks for the speedy reply.. I do all of my design work in Illustrator but do use Photoshop for photography. Any suggestions on photoshop or illustrator tools that can be used to improve the IQ of my topography layers?

cheers,

Josh



#6
snowgage

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Thanks for the speedy reply.. I do all of my design work in Illustrator but do use Photoshop for photography. Any suggestions on photoshop or illustrator tools that can be used to improve the IQ of my topography layers?


What exactly do you mean by that?


Hans,

I was asking which Illy tools were best for assisting with the image quality (IQ) of coarser elevation data..

cheers,

Josh

#7
snowgage

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Charles,

Thanks for the tips on photoshop. I've used it for a long time and never realized that I could easily bring in my rasterized layers from Illy, reduce noise and paste them back in. Brilliant! Thanks again.

-Josh

#8
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I have recommended this tutorial before - by Alex Tait, on how to prepare shaded relief in Photoshop: http://www.internati...ef_Tutorial.pdf
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#9
Fran├žois Goulet

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I have recommended this tutorial before - by Alex Tait, on how to prepare shaded relief in Photoshop: http://www.internati...ef_Tutorial.pdf


That's a nice, clean and clear tutorial... Thanks!! :)




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