Author: admin

Andromeda galaxy (M31)

andromeda

A stack of four 10 minute exposures at iso400 through a 200 mm F5.6 lens. I really need to get a handle on processing these RAW frames for best results...

Autoguiding now seems to work quite well, here's a comparison between 10 min frames with guiding on/off:

guiding_works

More exposure is better, this one has about 40 min in total, previous attempts had only about 12 min and 8 min.

A second GPS test

drumso_run

A secodn GPS test, this time with the 405cx on my left wrist and the N95 in my right hand. I had hoped this would expose the N95 antenna and improve its performance. Not so. The red trace (405cx) still looks much better while the yellow one (N95) jumps wiggles and snakes around. The summaries are:

N95: 8.30km in 53 min 13 s, 727 kCal
405cx: 7.92 km in 53 min 31 s, 627 kCal

If you zoom in, the N95 has me walking on water. To be fair the 405cx also looks a bit lost at the beginning of the run (far right), but it does get the street-crossing spot on (middle-right in the pic).

walk_on_water

Then for a straight bit along 'Nokia avenue':

wiggly

That's not pretty. I guess you could argue that on the way out (top) the street has tall houses on both sides, so the N95 (yellow) has a hard time finding satellites, while on the way home (bottom) it's more open and both GPSs perform roughly the same.

Here's part of the route in more open terrain. That seems to confirm that the N95 needs wide open spaces to do well.

drumso

For the record, my N95 8GB runs V 15.0.015 firmware (which I've several times unsuccessfully tried to update with Nokia PC-Suite 🙁 ) and I'm using Nokia Sports Tracker v2.06 (S60 3.1). Today I had GPS-filtering turned off in sports tracker.

Somewhat surprising results! I would have thought GPS-positioning is a plain-vanilla technology by now and every company does it with equivalent hardware and software. Apparently not, or the N95 antenna is really inefficient, or I'm doing something wrong...

N95 vs. 405cx GPS test

GPS-running is so fun I decided it's time for a new toy: A Garmin 405 cx ! Out on a walk we go, comparing the N95 running sports-tracker with the 405cx.

whole_walk

Here's a test where I wore the 405cx (red trace) on my wrist and the N95 (yellow trace) with sports-tracker running in my pocket. I didn't turn them both on exactly at the same time, but there does seem to be a difference in the distance and kCal values. In addition to the time/distance data the 405cx also uses heart-rate data for computing calories.

N95: 6.58 km, 1h 4 min, 576 kCal
405cx: 6.32 km, 1h 7min, 324 kCal

The N95 GPS data is much more wiggly, as seen in this picture of a long straight bit of the walk:

straight_line

That probably also explains the extra distance on the N95, since the wiggles never go away:

n95_jumpy

Although the GPS-Filtering was set to "High" on the N95, it shows strange jumps along the shore-line where the satellite visibility to the South should be OK.

n95_low_and_right

Here it looks like the N95 position (yellow) fix is first a lot to the east, and then significantly south of the bridge I actually crossed. Then for some reason the 405cx (red) and the N95 agree again. I think the 405cx samples position at 4 s intervals, so some cutting of corners is understandable.

This test wasn't entirely fair since the 405cx was on my wrist while the N95 was in my pocket. I need to re-do this test with the N95 and its antenna held at a similar height/visibility compared to the 405cx.

Garmin is doing a lot of things right with the 405cx: No extra GPS-pod like with the Polar products, a set of nice youtube-videos practically replace the manual, charging through the USB-port(why doesn't the N95 have this?), to name a few.

Links - September 10, 2009

Fireworks

The annual fireworks competition in Helsinki was fired off Hernesaari this year. Two sudden rain showers interrupted the show, and security had placed the fence quite a long way away from the fire and explosions - otherwise the event was nice. Taking pictures of fireworks is fairly easy with the right equipment, these are shot with a 40mm lens stopped down to F10 and exposing by hand via cable-release in bulb-mode for whatever seemed to be a suitable time/display. Bring a tripod.

Links - September 3, 2009