×
INDI Library v1.8.1 Released (09 Sep 2019)

Monthly maintenance release INDI v1.8.1

Meridian flip

1 month 2 weeks ago
khobar
Senior Boarder
Senior Boarder
Posts: 49
More
Topic Author
Meridian flip #44832
Last night imaging M31, I (apparently) experienced meridian flip. However, while the camera kept taking pictures, M31 was in frame but no longer centered (see picture).

I didn't do anything special - I actually hadn't anticipated the flip. But based on this video:
and my picture, I think my mount performed the flip rather than Ekos. How else would I have both images of M31 in the same frame?

Anyway, here is the picture:
Attachments:

Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
starman345
Senior Boarder
Senior Boarder
Posts: 76
More
Meridian flip #44836
I think you have the cem25p? I also have that mount and had something similar happen. When I was done for the night I sent the mount to the home position and noticed it was just slightly off. Later when looking at the images, the target was moved just like yours after the flip. I'm guessing the ra stepper motor slipped during the flip. I was always careful balancing my mount but now I take extra time. So far it hasn't happened again. Might not be your problem.....
I have the mount set to flip a couple of minutes after Ekos . I think Ekos mount meridian flip tab is set to all zeroes and the CEM25P is set to a couple of minutes after meridian. It seems to work fine.

-Brian

Kstars-Ekos-INDIE
NanoPC-T4 - Armbian Ubuntu 18.04
iOptron CEM25P mount
Photoline 80mm triplet
ZWO ASI294MC Pro Imaging camera
ZWO ASI290MM mini Guide camera


Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
sterne-jaeger
Platinum Boarder
Platinum Boarder
Posts: 392
Karma: 5
More
Meridian flip #44846
It looks like the image you‘ve posted here is a live stack, right? When a meridian flip happens, you need to re-align the image. And you have to take into account in live stacking, that after a meridian flip the image is upside down.

- Wolfgang

TSA-120 + FSQ-85 + GSO 150/750 | Avalon Linear + M-zero | Moravian G2-8300 + ASI 1600mm pro + ASI 294mc pro | KStars/INDI on Raspberry Pi 4 with Raspbian 10

Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
El Corazon
Platinum Boarder
Platinum Boarder
Posts: 430
Karma: 3
More
Meridian flip #44902
I had a similar issue with the Meridian flip on an iOptron SmartEQPro+ mount the other night. The flip was initiated, but during the flip the next exposure was triggered, which caused the flip to be abandoned after the mount had moved by about 10 degrees. The mount then kept that new position and continued to shoot empty sky.

That was with the 10/19 nightly build.

I tried to upload the logs, but realized that I had selected all the logs, including verbose output, but kept the 'Default' setting instead of selecting 'File' . So no logs were saved.

I reverted back to 3.3.6 and will retest as soon as the weather improves. DId not have that problem before. Has anyone experienced that with a non-iOptron mount?

Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set

Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
khobar
Senior Boarder
Senior Boarder
Posts: 49
More
Topic Author
Meridian flip #44913
Hi Brian - I do have the CEM25p. I sure hope it's not motor slippage (or worse, the dreaded gear slip)! ;) However, you gave me the idea to check the settings and I've done something similar to you so thanks!

Hi Wolfgang -not a live stack. It's one of the images captured during the session. I'm sure this is the result of the mount rather than Ekos performing the flip. Last night I had changed the settings and got the flip though there's something I still need to change in the settings.

Hi El Corazan - very interesting. Now I'm anxious to give my DIY mount a try with this!

Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
TallFurryMan
Platinum Boarder
Platinum Boarder
Posts: 737
Karma: 13
More
Meridian flip #44920
Yes it really seems that the mount did the flip while the capture was in progress. You should be able to see faint rotating star traces when stretching. Nice puzzling capture indeed :)

-Eric

HEQ5-Pro - Atik 314E - Orion ED80T - DMK21 on Orion 50mm
DIY 3D-printed Moonlite and FWheel RGB/LPR
KStars and indiserver on two Atom 1.6GHz 1GB RAM Linux, VPN remote access

Please Log in or Create an account to join the conversation.

1 month 2 weeks ago
Ihoujin
Platinum Boarder
Platinum Boarder
Posts: 709
Karma: 3
More
Meridian flip #44932
Cone error could account for some of the misalignment if the flip was not followed up by an alignment routine.

INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.

Please Log in or Create an account to join the conversation.

Time to create page: 0.680 seconds