Discussion: O-circle

Last weekend I was competing at two o-races and both maps have scale: 1:10.000 but diameter of O circle was different. You could see maps at http://www.alessiotenani.it/

Is this depends from Organizers and terrain?
I thought that this is standardized for different scale of maps?

it depends on the "settings' of the course setter. sometimes is easier/better to adjust those diameters and have a better reading of the map around the circles, but normally should be the same.
I looked at the maps.. the night O was mostly on open field and lots of controls and numbers to be printed , so probably that was the reason for smaller circles

The ISOM standard calls for the same size overprinting symbols on all maps (this is different from the actual map symbols, which are always sized proportional to map scale). The exception to this is when the same map is printed at two different scales (1:15 for elite, 1:10 for age groups). In that case a 150% enlargement of overprinting symbols is acceptable.

That said, the standard is very loosely applied. I've seen lots of deviation from the 6mm circle size and 4mm number height, even on maps from major competitions. I personally don't mind the control circle being larger than 6mm, but I don't like it when it's printed much smaller. It's too easy to miss a control when three controls are all in a line if the circle is really small (this hasn't happened to me, but it's not uncommon).

I am thinking more and more that the ISSOM stanard for course markings is not the best. This comment applies only to 1:5,000 maps, so bears limited relevance to the original post.

If you use a "regular" (ISOM) map, drafted with OCAD scale set to 1:15,000, and then print it at 1:5,000, most symbols will be twice as large as the ISSOM specification. If you then use regular-size course markings (6 mm circles in both ISOM and ISSOM, 0.35 mm purple line width, text scaled appropriately), the visual impact of the purple lines is diminished in comparison with the too-thick brown contours. This effect is more noticeable on a forest map with a lot of contours, and less so on an urban map. I think enlargement of the purple markings in this case is all but required. As our experience shows, competitors will most likely preceive this problem as the purple color being too light. We got these complaints at FLO 2006 and Umstead 007. The purple color itself was just fine, matched to the PrintTech offset sheet; and the same color elicited no complaints at 1:10,000.

However, even if your map and markings are fully ISSOM, I think the same effect applies on forested maps with a lot of brown lines. I don't know exactly what it is that misleads the brain in this case, since the relative sizes of the symbols on an ISSOM 1:5,000 are the same as those on an ISOM 1:10,000. Our Umstead symbols were actually in-between blown-up ISOM and ISSOM, closer to the latter. So, I guess that one may need to enlarge the purple symbol sizes given by ISSOM by about 30% to achieve good legibility on a map of forested terrain drafted with ISSOM symbols.

I'm no expert here, but I've got a few thoughts anyway.

I use 6mm circles and 4mm numbers as much as possible. I used big circles (9 or 10mm) on a sprint series event, and stopped when the ISSOM dictated 6mm. I figure if IOF is going to use a particular size, we should try to match it to help the elite competitors prepare.

The first thing I'd recommend to Tundra/Desert is to try 100% magenta instead of trying to match purple with CMYK inks. On page 6 of the ISOM2000 there is a table that shows 100% magenta is recommended (over all other colors) for CMYK processes, while Pantone PMS "Purple" is recommended for spot color. In my experience, using 100% magenta *really really* helps.

I have wondered about larger circle sizes (not 10mm, but 7 or 8mm) for sprints, particularly for older competitors and to help with reading the map while running. Unless there is an outcry that 6mm is just too difficult for certain people to see, my recommendation would be to stick with 6mm for three reasons:

1. Elite Preparation (IOF uses it for big events).

2. It seems to limit the use of column C ("Which of any single feature") in control descriptions, making them simpler and quicker to read while running.

3. It allows more flexibility regarding minimum spacing of controls and, more importantly, connection lines between circles, so courses can have more crossing-over and more changes of direction. If the circles are too big, they dominate the map and make it very difficult to read the course and map.

In my experience, using 100% magenta *really really* helps.

... unless you happen to be colorblind. My understanding is that pure magenta is not as bad as red, but still much worse than purple; you need cyan/blue in the ink to make it distinct to those who are colorblind.

In my experience, using 100% magenta *really really* helps.

Speaking as a colorblind guy, I'll opine that adding a bit of black (like, 10%) to magenta is actually more helpful. But I'll also note that there's more than one kind of colorblindness, and mine (protanopia) is not even the most common one. Other people who I've showed courses to did generally seem to agree that magenta with a little black was good.

Just doing some internet searching for protanopia, I found this colorblind demonstrator, and what surprised me was that purple and magenta both look identical when I click the "no red" button---interestingly, they both look sort of light blue.

(And if you go there, be sure to click "normal", then find an orange color, then click "no red". How would you like to compete with flags of that color?)

I assumed magenta was not pure red. Webster's says it's "a deep purplish red", which surprises me---it looks pinkish red to me. This shows that magenta is red and blue (or perhaps the "opposite of green"), so apparently what we were taught in grade school is...incomplete.

I'm all for trying the 10% black. I do know that for me, magenta looks a lot better than purple from CMYK printers. Purple is too dark, and obscures the detail. (Spot color printing excepted, of course).

My dad is colour blind (red-green) and I've never heard him complain about the control circle colours. He gets far angrier when correct printing techniques aren't used and he can't tell the difference between yellow and green of similar intensities (you can imagine how much it stuff's up your route choice when you're expecting to run through a big clearing...
As for control flags - there's no chance he's jusy going to spot one out of the corner of his eye when he's not quite in the right place.

(And if you go there, be sure to click "normal", then find an orange color, then click "no red". How would you like to compete with flags of that color?)

Huh? Doesn't really change the color much, just kind of makes it lighter...

I'm quite fond of this colorblind demonstrator. The first three images aren't so good, but the rest, especially the rainbow and the final street cafe scene, are excellent. When I alternate between the Normal and Protan buttons, there's barely any change.

I have also been busted by the yellow/green issue on inkjet/laser maps. It's an advantage of offset printing, where the color actually consists of a pattern of small dots of the full-strength color (e.g. light green is tiny dots of dark green). That actually looks different than a continuous area of lighter ink, or a pattern of yellow and cyan dots. I have definitely had some cases where there was light green adjacent to light yellow and I couldn't see the difference at all (and the "light green" turned out to be pretty nasty thorny stuff). Also note that traditionally, Swedish maps used a bluer form of green, and Norwegian maps a yellower form. I've been told that this was because there was a time when the mapping chairman in each of those countries was colorblind, and each insisted on a green color that worked for him.

It would be neat to have a demonstrator set up with several O-map images, including perhaps these Swedish/Norwegian greens and a PrintTech sheet. Maybe even a comparison series of bags/flags/prisms/kites in traditional orange/white and the newer style in orange/white/blue in some common O' settings.

Maybe it's not just seeing fewer than three colors that we have to think about: :-)

http://www.4colorvision.com/files/tetrachromat.htm
http://www.post-gazette.com/pg/06256/721190-114.st...

(These were fun articles.)

Orange/white/blue controls aren't new; they existed when I was young. They seem useful, having orienteered in a forest when every leaf was bright orienteering-control-orange. (The red punches and blue water bottle caps were easier to see than the controls...and I'm not colorblind (though my father is, so I've heard his tales of having to "triangulate" where the control circle was, based on where the stuttering red line from the previous control entered the light green and where the line to the next control left the green).)