Great Britain Discoverer National Parks 1:25k Lake District-Brecon Beacons-Peak District

**catymag** · 1st February 2011, 10:00 PM

Originally Posted by campbela

The Lake District img appears to be corrupt. I have tried downloading it again, but I get the same error.

I've checked the Lake district img in GmapTool, you'r right, the map is damaged-Some parts are ok and these are probably the parts I could see in my 62st (the posted screens ).Gps reads what it can.

GmapTool log

Code:

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The other 2 maps are ok and i could unlock them both with Fast Img Unlocker

**Brilliant Trees** · 2nd February 2011, 01:18 AM

Hi All

First Post so excuse me if I'm being dense and go easy on me

The Lake District Map appears to work on my Edge 800. In my test I've disabled Base Map in the device and loaded an SD card with just the Lakes as a GMAPSUPP.IMG.

It shows up OK in Map list.

Thing is, this looks like a 1:50K OS map to me rather than the 1:25K that it suggests it is on page 1 of the post. I'm comparing with my paper Explorer Maps (Old Skool) and also with both a Memory Map 1:50K & 1:25K electronic version of the Lake District National Park and this sure looks like 1:50K to me.

Am I doing something wrong or has anyone else noticed this?

Also the map although of the Lakes seems to have Road Mapping for the whole of the UK (which looks like a nice bonus) Does this mean that there's no need to load City Navigator as well or is there less detail in the "Road Supplement" on the Discoverer maps?

Cheers

**Mordorf** · 2nd February 2011, 10:59 AM

I'll re upload the file for the Lake District and edit the link. I'll post when this is complete but for now the link will be unavailable.

**Mordorf** · 2nd February 2011, 12:20 PM

The re upload is now complete and I have edited the original post with the new download link.

**tbzr** · 2nd February 2011, 01:46 PM

Lake District now seems to work for me on oregon. (Thanks)

**Brilliant Trees** · 3rd February 2011, 01:51 AM

Hi Again

Have tried the new version and this still seems to be 1:50K scale on my edge 800.

Am I doing something wrong?

Also zooming below 500ft is very blurry. My Memory Map software on my PDA is able to render maps perfectly down to a much smaller range than this. Is this a problem with the Edge 800 or is the Discoverer map just not great when fully zoomed in?

**fluorescent** · 3rd February 2011, 08:37 AM

The map is blurry because it is a rastermap. To explain the difference between a vectormap and a rastermap:

If you want to draw a line in a vectormap the you "draw" a geometric point from which the line starts and a geometric point where the line ends. And if you enlarge the map the points and the line still remain geometric points and lines which have no width and are always clean points and lines. The size of the mapfile in bits is very small and it does not matter if the map covers 5 meter by 5 meter or 50 kilometer by 50 kilometer. A second line: mapfile is double in bits. A map with say 37 lines is 37 times as big as a map with one line.

If you draw a point in a rastermap you have a raster and you must fill one field of the raster with black colour and all the other fields with white colour. From some distance you see a black point in a white field. To draw a line you must fill many many fields of the raster which give - looked at from some distance - a line. If you get closer you see the "fields" and therefore a rastermap looks blurry if you enlarge it too much. The size of the mapfile in bits increases dramatically if the map covers a bigger area as you need more fields of the raster or if you use a more fine raster. A map with say 37 lines instead of one line is only a little big bigger than a map with one line for only the information "white" is exchanged against the information "black" for the fields of the raster where the lines are.

**Brilliant Trees** · 3rd February 2011, 10:39 PM

Thanks for this explanation fluorescent, I assume from this that Memory Map OS Maps are Vector Maps and the Discoverer is a Raster. I may be being picky but compared with my MM OS maps on the PDA the Edge is poor at rendering the map detail. That said its still better in detail terms than the old Garmin Topo Map.

Does anyone else have a comment on the 1:50K v.s. 1:25K issue I raised, while I'm grateful to the original poster for making this available is appears to be a 1:50K and in that regard no different from the full GB Discoverer.

**Brilliant Trees** · 5th February 2011, 02:51 AM

Cheers Mordorf

I tested this tonight and at 500ft zoom the map does indeed switch to 1:25K view, so obviously has both 1:50K & 1:25K on the same map. I guess this is just my ignorance of Garmin conventions. On Memory Map which I'm familiar with on both PC & PDA if you load a 1.25K then it stays at 1.25K regardless of zoom.

On the negative side it would be nice to have the Garmin zoomed out a little more and still be able to benefit from 1:25K. At 500ft zoom you can see so little of the surrounding area that plotting a course is more difficult.

**Finbarr** · 6th February 2011, 04:39 PM

Cheers Mordorf

Lake District map works fine on my Oregon 450t. Went for a low level walk today in the miserable rain and wind around Nether Wasdale and it's great. Far better than the 1:50k for this neck of the woods. As you state though it only cuts into the 25k map when you zoom to 500ft. Does anyone know any way round this? Not a major downer but otherwise fantastic.

Thread: Great Britain Discoverer National Parks 1:25k Lake District-Brecon Beacons-Peak District

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