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Why Custom Maps?

Started by miked, August 01, 2012, 08:54:15 AM

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miked

I'm new so don't stone me.  I am thinking about getting an eTrex 30 or an Oregon 450.  What's the reasoning behind getting custom maps?  To save the $50 from buying from Garmin?  And don't custom maps slow down the gps unit and have other limitations?
Are custom maps superior to Garmins?
Thanks for the input.

maps4gps

QuoteWhat's the reasoning behind getting custom maps?  To save the $50 from buying from Garmin?
From what I have observed of users willing to make helpful comments about mapsets and as two users have posted - 'to cheep to purchase' is likely the main reason.

QuoteAnd don't custom maps slow down the gps unit and have other limitations?
Since what we know of how to make mapsets for Garmin GPSrs has been reverse engineered and found by trial-and-error; it is possible third party mapsets are not as well engineered for performance as Garmin's mapsets are.  Since Garmin does not reveal their data sources, I do not see how a valid test could be conducted to check.

QuoteAre custom maps superior to Garmins?
Should be obvious that it depends on who is using what criteria to define what superior means.  Garmin mapsets can include features which have not been reverse engineered or commonly included in third party mapsets and proprietary data not available to third party map authors.  Third party mapsets can and do include feature types Garmin's current mapsets do not and may be more current where Garmin is using the same source data available to the public.




Seldom

To add one thing to what maps4gps has said, there are two kinds of custom maps.  Most of the "Custom Maps" listed on this site are vector maps (lines are defined by connecting endpoints).  Some of the maps here are "Garmin CustomMaps" (note spelling).  CustomMaps are raster maps (entire map is a bitmap like a JPG) that have been georeferenced.

dbperry

Quote from: Seldom on August 01, 2012, 10:36:50 AM
To add one thing to what maps4gps has said, there are two kinds of custom maps.  Most of the "Custom Maps" listed on this site are vector maps (lines are defined by connecting endpoints).  Some of the maps here are "Garmin CustomMaps" (note spelling).  CustomMaps are raster maps (entire map is a bitmap like a JPG) that have been georeferenced.

I think this clarification is important. I'm not familliar with calling the "Garmin Custom Maps" "CustomMaps" with no space - I wish Garmin had named their "Custom Maps" something like "Gazooble Maps" then we wouldn't get confused. But, as someone suggested to me, when I'm talking about "Garmin Custom Maps," I try to refer to them as "Custom KMZ Maps."

Anyway, for the benefit of the OP, here is what we're talking about when we're talking about "CustomMaps" or "Custom KMZ Maps" or the "georeferenced raster maps":
http://www.garmin.com/us/products/onthetrail/custommaps

And to add to the discussion, I think the two different kinds of custom maps solve two different problems:
1) "Vector custom maps" (installed as .img files) offer the 'cheap' and/or (depending on your opinion) better (or not better) information as an alternative to purchased Garmin maps.
2) "Custom KMZ Maps" offer the ability to add information to the GPSr that (a) might not be readily available in any other format, and/or (b) is easy for the very casual user to create and install.

Dave
My custom KMZ map collection:
http://www.gpsfiledepot.com/maps/byuser/13384/

Boyd

Quote from: miked on August 01, 2012, 08:54:15 AMWhat's the reasoning behind getting custom maps?

I think you need to answer this for yourself, since it can be very subjective. Find the available maps for your area here: http://www.gpsfiledepot.com/maps/

Install Basecamp (which is free) then download any maps that look like they might be interesting or useful. Now spend awhile with them on your computer. If you like what you see, you're good to go. If you feel they are lacking, you can view Garmin's 24k maps online here: https://buy.garmin.com/shop/shop.do?cID=255&fKeys=FILTER_SERIES_TOPOUS24K,FILTER_REGION_NORTHAMERICA

Click on the link for the DVD version that covers your area. For example, this is the Topo West DVD: https://buy.garmin.com/shop/shop.do?cID=255&pID=35407

Now click on the tab that says "Coverage Details". You should now see a link that says "Click to view a detailed interactive map". This will start the map viewer and you can zoom in on a familiar area to  see what you think. For example:

http://www8.garmin.com/cgi-bin/mapgen/webmap.cgi?p=21626881&u=1&v=0&cp=4B21D85AFEFD585A&z=2&w=600&h=450&d=2&rz=0&k=1&sc=1

Seldom

\Garmin\CustomMaps\ (no space) is the folder KMZ maps have to go into.  It seemed a reasonable way to distinguish between them.  FWIW, the vector maps I make for the part of the world I'm interested in have more types of data on them than a printed USGS topo.  But sometimes that data is hard to find in vector form.

SmugWimp

#6
In my area (the Marianas Islands in the Pacific), Garmin produced maps are just not available. And most sources are somewhat inaccurate.

If it weren't for sites such as this, and folks like these (Indrid, Oz, Seldom, Boyd, and all of the fine folks who volunteer their time) then I wouldn't have the skills to produce them nearly as well.

That's 'my' story, and I'm sticking to it.

-- Smug

In a nutshell, I get claustrophobic.