Orion with astrotracer miscalibration fix

Started 7 months ago | Discussions
OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

chris gunn wrote:

Polacofede wrote:

This time i wanted to test the DA*60-250.

First I tried to compensate for -15º but results were not good, after some tests i decided to use just the magnetic declination value for the place -8º and it worked very well imho.

In desperation, resort to reading the manual.....

Page 8 of the manual: "Calibration is the operation to get the electronic compass to work accurately"

Page 11: "0 deg is based on True North, not Magnetic North"

Page 19: "Accuracy +- 5deg (precise calibration)"

So, it is supposed to sort out the declination somehow.

If it doesn't work well with iron adjustment for 0 deg error, probably a new calibration is required, which would be impossible using rod?

I do gps calibration without the rod. Precise calibration never worked in my camera. +-5 seems like too much when i could prefectly set a more accurate value to the location, they over complicated it by miles imho with all this magical precise calibration when they could have just given the possibility to enter it.

Still interesting results! Try for partial correction only! Testing thoroughly will be time consuming...

barely noticeable, Flame & Horse Head, da*@250mm iso1600 f4 100s ( max value allowed by astrotracer for 250mm and that orientation )

Bit of spherical aberration. And you managed max exposure! You pro!

I submit a single shot just to show the movement quality achieved when i compensate my K3II compass.

Something i noticed again is that, if i leave the rod in a fixed position ( sticking it to the camera top ) to apply the compensation at certain camera orientation and then i turn the camera then the effect caused by the rod is not the same. This has sense to me as after re orientating the camera the way the rod "interacts" with the magnetic field and hence the compass is not the same.

Yes, I would expect that.

So, applying a workaround like this requires a bit of work on each shot, i did that by leaving the camera screen in compass mode.

Irritating.

yep, kind of, depending if one could think in a practical way to move the rod easily

18 shots f4 250mm 100secs shots stacked (dss average)

As I had some shots I considered stacking them as it was for free. Nothing to be proud but I think astroacer can be a much more amazing tool.

So, 30min @f4. Not bad! You need a lot of light to get the Horsehead.

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

IMHO all this leads me to thing that, if Pentax would add the option to enter by some way the compensation value, that simple thing ( no technical excuses here ), would turn Astrotracer in a piece of cake and give it much much better accuracy, hands down.

True.

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

chris gunn wrote:

Polacofede wrote:

This time i wanted to test the DA*60-250.

First I tried to compensate for -15º but results were not good, after some tests i decided to use just the magnetic declination value for the place -8º and it worked very well imho.

In desperation, resort to reading the manual.....

Page 8 of the manual: "Calibration is the operation to get the electronic compass to work accurately"

Page 11: "0 deg is based on True North, not Magnetic North"

Page 19: "Accuracy +- 5deg (precise calibration)"

So, it is supposed to sort out the declination somehow.

If it doesn't work well with iron adjustment for 0 deg error, probably a new calibration is required, which would be impossible using rod?

I do gps calibration without the rod. Precise calibration never worked in my camera. +-5 seems like too much when i could prefectly set a more accurate value to the location, they over complicated it by miles imho with all this magical precise calibration when they could have just given the possibility to enter it.

Expecting people to work out the local mag field, and effects of the iron in the mount etc are a bit much, I can understand what they were thinking. I do want all control and info though!

I checked my mounts/tripods with a magnet. I can't say one is worse than the other.

Still interesting results! Try for partial correction only! Testing thoroughly will be time consuming...

I submit a single shot just to show the movement quality achieved when i compensate my K3II compass.

Something i noticed again is that, if i leave the rod in a fixed position ( sticking it to the camera top ) to apply the compensation at certain camera orientation and then i turn the camera then the effect caused by the rod is not the same. This has sense to me as after re orientating the camera the way the rod "interacts" with the magnetic field and hence the compass is not the same.

Yes, I would expect that.

So, applying a workaround like this requires a bit of work on each shot, i did that by leaving the camera screen in compass mode.

Irritating.

yep, kind of, depending if one could think in a practical way to move the rod easily

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

I've only tried this with a k135, and this is certainly better. Bg colour is off though.

60s! You have mastered the Rod!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

chris gunn wrote:

Polacofede wrote:

chris gunn wrote:

Polacofede wrote:

This time i wanted to test the DA*60-250.

First I tried to compensate for -15º but results were not good, after some tests i decided to use just the magnetic declination value for the place -8º and it worked very well imho.

In desperation, resort to reading the manual.....

Page 8 of the manual: "Calibration is the operation to get the electronic compass to work accurately"

Page 11: "0 deg is based on True North, not Magnetic North"

Page 19: "Accuracy +- 5deg (precise calibration)"

So, it is supposed to sort out the declination somehow.

If it doesn't work well with iron adjustment for 0 deg error, probably a new calibration is required, which would be impossible using rod?

I do gps calibration without the rod. Precise calibration never worked in my camera. +-5 seems like too much when i could prefectly set a more accurate value to the location, they over complicated it by miles imho with all this magical precise calibration when they could have just given the possibility to enter it.

Expecting people to work out the local mag field, and effects of the iron in the mount etc are a bit much, I can understand what they were thinking. I do want all control and info though!

yeah! both options shall be available.

I checked my mounts/tripods with a magnet. I can't say one is worse than the other.

Still interesting results! Try for partial correction only! Testing thoroughly will be time consuming...

I submit a single shot just to show the movement quality achieved when i compensate my K3II compass.

Something i noticed again is that, if i leave the rod in a fixed position ( sticking it to the camera top ) to apply the compensation at certain camera orientation and then i turn the camera then the effect caused by the rod is not the same. This has sense to me as after re orientating the camera the way the rod "interacts" with the magnetic field and hence the compass is not the same.

Yes, I would expect that.

So, applying a workaround like this requires a bit of work on each shot, i did that by leaving the camera screen in compass mode.

Irritating.

yep, kind of, depending if one could think in a practical way to move the rod easily

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

I've only tried this with a k135, and this is certainly better.

thaks! btw, what is a K135? the SMC Pentax 135mm F2.5 ?

Bg colour is off though.

it seems will take me a while to learn to post process. I think that when i be able to go to a less light polluted site it will be easier for me.

60s! You have mastered the Rod!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

I've only tried this with a k135, and this is certainly better.

thaks! btw, what is a K135? the SMC Pentax 135mm F2.5 ?

Yup.

I'm wrong though, it was the K200/2.5 with a step down ring => f/3.2 for 220s integration.

Red or purple halos everywhere. And it didn't focus to infinity (I had a lens tech max the focus).

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

I went out with some magnets and the 400/5,6 to see what I could do.

I tried the Flame for the first time, and without even calibrating, it could do 30s+, so I did 50+ frames (26min total, from 90% selection) to get this:

Could be sharper.

Then I tried in the direction of Carina (near the Southern Cross). Playing around with the magnet, I almost got a 400mm 40s, but no keepers. Then I tried the 138/1.8@2.8, and trying more things, I managed a keeper at 100s, which still isn't at all impressive.

I tried mimicking the inclination, which seemed to work better from above (such as you did). A separate holder, like you suggested would be a good idea.

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

Roland Karlsson Forum Pro • Posts: 27,491
Re: Some more tests

chris gunn wrote:

...

I tried mimicking the inclination, which seemed to work better from above (such as you did). A separate holder, like you suggested would be a good idea.

This seems so awkward. As far as I understand, all this messing with magnets is to force the camera to choose the correct direction for south.

Please Pentax - solve this. Make it possible to fix the south direction!

-- hide signature --

/Roland
Kalpanika X3F tools:
https://github.com/kalpanika/x3f

 Roland Karlsson's gear list:Roland Karlsson's gear list
Sigma DP3 Merrill Sigma dp2 Quattro Sony RX100 III Pentax K-3 Pentax K-1 +14 more
OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

chris gunn wrote:

Polacofede wrote:

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

I went out with some magnets and the 400/5,6 to see what I could do.

I tried the Flame for the first time, and without even calibrating, it could do 30s+, so I did 50+ frames (26min total, from 90% selection) to get this:

Could be sharper.

did you removed the photo? it seems as a broken file to me.

Then I tried in the direction of Carina (near the Southern Cross). Playing around with the magnet, I almost got a 400mm 40s, but no keepers. Then I tried the 138/1.8@2.8, and trying more things, I managed a keeper at 100s, which still isn't at all impressive.

but 100s is not that bad either

I tried mimicking the inclination, which seemed to work better from above (such as you did). A separate holder, like you suggested would be a good idea.

I went last week to a bit darker place, 40km from home with the 400mm f5.6 and the rod. I just tried with Orion, the problem was that by the time ir reached the place Orion was getting the zenith and the astrotracer seems to have some issues with it or maybe was the camera position. At the moment i thought that the shots were ok, but wen i zoomed in later they displayed a quite amount of trailing, so at that point the rod seemed useless as i got much better looking stars from my backyard when orion was lower. I will try again soon, taken this things into consideration.

The way i did the shots was using the remote shutter and the rod, so i approached the rod to the camera to apply the compensation that i estimated to be the best ( with the screen in compass mode ) while keeping it there i released the shutter with the remote control. I guess that at release time is the time the astrotracer measures it's position.

I think next time i will try to leave the rod somewhat "fixed" but with some way to be able to apply a correction time to time.

I know the results were not outstanding but, is fun anyway and i saw several shooting stars ( one really impressive ), satellites and some nigthjars. And by the way, just focusing this lens requires some work.

i fixed the stars with photoshop to make them appear a bit rounder. 24 x 50seconds frames iso 800.

without stars fixes 24 x 50s frames iso 800 + 4 x 60s frames iso 1600

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

chris gunn wrote:

Polacofede wrote:

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

Could be sharper.

did you removed the photo? it seems as a broken file to me.

I removed it, because I managed a far superior PP! I'm a bit proud of this result (not sure about my focus) 26min:

I made several uses of the "screen" layer in Gimp instead of using custom curves.

Then I tried in the direction of Carina (near the Southern Cross). Playing around with the magnet, I almost got a 400mm 40s, but no keepers. Then I tried the 138/1.8@2.8, and trying more things, I managed a keeper at 100s, which still isn't at all impressive.

but 100s is not that bad either

I went up the local volcanic hill with the intention of doing a 135mm pano, but failed to do as well as 25s around Carina (I didn't actually try for long, but I was impatient). It was happier with the LMC where I used 30s @ f2.8 (460s total):

I also discovered that I could use 6s untracked around Carina, so I did a timelapse @f/1.8 (a bit jumpy due to wind) and did a stack with ~130 frames:

I went last week to a bit darker place, 40km from home with the 400mm f5.6 and the rod. I just tried with Orion, the problem was that by the time ir reached the place Orion was getting the zenith and the astrotracer seems to have some issues with it

Yes, I've had trouble with straight up before. No trouble with the 24mm though.

The way i did the shots was using the remote shutter and the rod, so i approached the rod to the camera to apply the compensation that i estimated to be the best ( with the screen in compass mode ) while keeping it there i released the shutter with the remote control. I guess that at release time is the time the astrotracer measures it's position.

Are you approaching horizontally?

For a software upgrade, I was thinking that instead of just a compass adjustment, it might be a good idea to directly give the compass and inclination.

I think next time i will try to leave the rod somewhat "fixed" but with some way to be able to apply a correction time to time.

I know the results were not outstanding but, is fun anyway and i saw several shooting stars ( one really impressive ),

If it's unusually bright/big and long, it may have been a Fireball. It's very rare to see one! I saw two in a recent meteor shower, and was confused about what I saw.

satellites and some nigthjars.

"nigthjars"?

And by the way, just focusing this lens requires some work.

I bought a focus mask, but I didn't use it....

i fixed the stars with photoshop to make them appear a bit rounder. 24 x 50seconds frames iso 800.

Next time!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

chris gunn wrote:

Polacofede wrote:

chris gunn wrote:

Polacofede wrote:

last night, from my backyard

34 shots, iso 1250 (i think), 60s, FA*400 @5.6, i need more light and less pollution

Could be sharper.

did you removed the photo? it seems as a broken file to me.

I removed it, because I managed a far superior PP! I'm a bit proud of this result (not sure about my focus) 26min:

I made several uses of the "screen" layer in Gimp instead of using custom curves.

pretty nice!!! ( though i don't get how did you use those screens, i dont use gimp just ps and a newbie at it too )

Then I tried in the direction of Carina (near the Southern Cross). Playing around with the magnet, I almost got a 400mm 40s, but no keepers. Then I tried the 138/1.8@2.8, and trying more things, I managed a keeper at 100s, which still isn't at all impressive.

but 100s is not that bad either

I went up the local volcanic hill with the intention of doing a 135mm pano, but failed to do as well as 25s around Carina (I didn't actually try for long, but I was impatient). It was happier with the LMC where I used 30s @ f2.8 (460s total):

cool

I also discovered that I could use 6s untracked around Carina, so I did a timelapse @f/1.8 (a bit jumpy due to wind) and did a stack with ~130 frames:

I went last week to a bit darker place, 40km from home with the 400mm f5.6 and the rod. I just tried with Orion, the problem was that by the time ir reached the place Orion was getting the zenith and the astrotracer seems to have some issues with it

Yes, I've had trouble with straight up before. No trouble with the 24mm though.

The way i did the shots was using the remote shutter and the rod, so i approached the rod to the camera to apply the compensation that i estimated to be the best ( with the screen in compass mode ) while keeping it there i released the shutter with the remote control. I guess that at release time is the time the astrotracer measures it's position.

Are you approaching horizontally?

i approached the rod to the left of the astrotracer housing side.

For a software upgrade, I was thinking that instead of just a compass adjustment, it might be a good idea to directly give the compass and inclination.

could be, but wouldn't that require changes each time you move/yaw/pitch/roll the camera a tiny bit? maybe i'm not following...

I think next time i will try to leave the rod somewhat "fixed" but with some way to be able to apply a correction time to time.

I know the results were not outstanding but, is fun anyway and i saw several shooting stars ( one really impressive ),

If it's unusually bright/big and long, it may have been a Fireball. It's very rare to see one! I saw two in a recent meteor shower, and was confused about what I saw.

ohh, it seems you are right again, i didn't knew it was called fireball

it looked like this ( with a long trail with sparks and it was not a fireworks 100% sure )

https://ar.pinterest.com/pin/477451997987825562/

and well i was confused too, amazed

satellites and some nigthjars.

"nigthjars"?

This little buddies

https://www.flickr.com/photos/polacofede/39549626534/in/dateposted/

And by the way, just focusing this lens requires some work.

I bought a focus mask, but I didn't use it....

i fixed the stars with photoshop to make them appear a bit rounder. 24 x 50seconds frames iso 800.

Next time!

for sure!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

I made several uses of the "screen" layer in Gimp instead of using custom curves.

pretty nice!!! ( though i don't get how did you use those screens, i dont use gimp just ps and a newbie at it too )

PS also has a "Screen" option for Layers.

For a software upgrade, I was thinking that instead of just a compass adjustment, it might be a good idea to directly give the compass and inclination.

could be, but wouldn't that require changes each time you move/yaw/pitch/roll the camera a tiny bit? maybe i'm not following...

Yup, I was suggesting it could be good to input all info besides GPS coords.

ohh, it seems you are right again, i didn't knew it was called fireball

it looked like this ( with a long trail with sparks and it was not a fireworks 100% sure )

https://ar.pinterest.com/pin/477451997987825562/

and well i was confused too, amazed

If a normal meteor is like a pencil slash, this was like a marker pen, over a lot of the sky. Four seconds?

Airplane? Can't be. Missile? Can't be. Satellite? Can't be......

I reported them to an international Fireball database. http://fireball.imo.net/members/imo/report_intro

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

just another test from my backyard, don't know the nebula name but it seems it was in carina

26x40s iso100 FA* 400mm f5.6

it would be cool to get some light pollution filter maybe...

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

just another test from my backyard, don't know the nebula name but it seems it was in carina

26x40s iso100 FA* 400mm f5.6

it would be cool to get some light pollution filter maybe...

That's Carina. You should be able to get double the exposure you do at Orion (1/Cos 60deg = 2x), but you've got star trails!

I've also been struggling with Astrotracer for this subject (especially recently!). I've gotten much more light from 600mm at 24 deg (1/cos 24 = 1.09x)for the Lagoon Nebula.

600mm Carina:

400mm:

There's actually a lot of red around it. Here's 135mm f2.8, 40s:

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

GimbalLock Regular Member • Posts: 132
Re: Some more tests
2

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

well i was thinking on something similar, however i think i would need to set and remove it constantly to be able to see the actual compass setting for the orientation to estimate which correction should i apply. i will give that a try

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
GimbalLock Regular Member • Posts: 132
Re: Some more tests

Polacofede wrote:

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

well i was thinking on something similar, however i think i would need to set and remove it constantly to be able to see the actual compass setting for the orientation to estimate which correction should i apply. i will give that a try

-- hide signature --

I used an app on the phone to get the current heading to Orion (for instance) and then dialed it in with the knob. Problem is though that Orion kept on moving so one had to constantly adjust it.

OP Polacofede Contributing Member • Posts: 901
Re: Some more tests

GimbalLock wrote:

Polacofede wrote:

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

well i was thinking on something similar, however i think i would need to set and remove it constantly to be able to see the actual compass setting for the orientation to estimate which correction should i apply. i will give that a try

-- hide signature --

I used an app on the phone to get the current heading to Orion (for instance) and then dialed it in with the knob.

Problem is though that Orion kept on moving so one had to constantly adjust it.

yeah! i know how it feels! orion moves quite fast, yesteday i took some shots of Carina it was at zenith, but it seemed to me to move slower...

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

Polacofede wrote:

GimbalLock wrote:

Polacofede wrote:

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

well i was thinking on something similar, however i think i would need to set and remove it constantly to be able to see the actual compass setting for the orientation to estimate which correction should i apply. i will give that a try

-- hide signature --

I used an app on the phone to get the current heading to Orion (for instance) and then dialed it in with the knob.

Problem is though that Orion kept on moving so one had to constantly adjust it.

yeah! i know how it feels! orion moves quite fast, yesteday i took some shots of Carina it was at zenith, but it seemed to me to move slower...

Yes, Carina moves at half the speed.

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

chris gunn
chris gunn Veteran Member • Posts: 8,515
Re: Some more tests

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

That sounds awesome!

Pics please. Mechanism, and some results would be nice!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

OP Polacofede Contributing Member • Posts: 901
Filter?

I have a Hoya red intensifier from a previous lens is a 58mm filter.

I was thinking if it would be a way to cut it and  mount it inside the camera body where i have found no room at all or maybe in the lens back somehow. Any ideas?

-- hide signature --
 Polacofede's gear list:Polacofede's gear list
Panasonic Lumix DMC-FZ200 Olympus XZ-2 iHS Pentax K-50 Pentax K-3 II Pentax smc DA* 60-250mm F4.0 ED (IF) SDM +6 more
GimbalLock Regular Member • Posts: 132
Re: Some more tests
2

chris gunn wrote:

GimbalLock wrote:

A few years ago I did some tests of the accuracy of the magnetic compass in the OGPS-1 mounted on a K-5, and it COULD be pretty accurate, if you were lucky during the calibration. Sometimes you had to redo it a number of times before getting a good reading 360 degrees around.

Then I got the K1 and unfortunately the electronic compass (in at least my copy) is not as precise. I guess it’s due to the sensor being closer to the SR mechanism which is full of powerful magnets. Even the flip out screen interfere with the compass, move the screen around and the compass bearing changes (in certain directions). Not an ideal situation since the flip screen is very nice to use when aiming for the sky.

So I made a device that could be attached to the hot shoe, a knob with a couple of tiny magnets. By rotating this knob I could set whatever heading I wanted.

That sounds awesome!

Pics please. Mechanism, and some results would be nice!

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

Well first of all it isn't pretty. It's only a proof of concept contraption built of things I had laying around. At both ends of the metal rod there are tiny magnets. I didn't want to use something to strong and risk magnetizing the whole camera. They are just strong enough to work.

Keyboard shortcuts:
FForum MMy threads