what am i missing

[dnl]

Hi

Ive just started using my nikon d80 through a skywatcher 120 to try some pics using an eq5 mount with ra motor .

Ive polar alligned using polar scope in the mount and adjusted the mount so thers no slop in the ra or dec .

when I focus it recovers very quickly if i notice at all.

Below are some pics i tried of Andromeda and from the colour i think youll work out which was the longer exposures .

I think my tracking is ok as id expect the trails to get longer as the exposure increases if it wasnt .

Am i just experiencing a bit of wobble from wind or is my motor drive sticking/juddering  a bit ?

Any suggestions welcome .

Ive also added one i did of orion the same night which was a single exposure.  Cheers Dave

[Galen Gilmore]

Exposure details?

The 2nd picture looks like wind or shake from the ground, although it's hard to tell when I don't know how long you were exposing for.

[happy-kat]

Yes the second looks either wind or say stiction. The last looks ok. The other two could be wind but look like tracking, check balance.

Edited January 24, 2020 by happy-kat

[CloudMagnet]

As above, the second picture looks like the wind. As someone that used to image with a single motor drive on the EQ5, you will get drift on your exposures as the motor just simply turns at a set speed and doesn't make any adjustments for drift. You could check to make sure that your clutch that connects your motor to the RA axis is tight as if this slips slightly it will cause issues. Also make sure that the motor is firmly attached to the mount, the gears are meshed together fully and the scope is well balanced.

Otherwise, it could just be the limit of your setup and looking at upgrading to guiding will (almost) remove this issue. Your last picture is basically the best I could get out of my EQ5+RA motor combination. I know this would be a big investment, but for me it is worth it in the long run to guide and have no drift.

[Marvin Jenkins]

I know we are all aiming for more but for first time with just RA motor I think you need to be less hard on your self. I think you have done well.

Just last week I did the same as you for the first time and finished with M42. Your first picture looks to be closer to the right exposure time, but your framing has excluded M101.

The next three are very bright but the framing has got all three in the picture. The plus of these exposures is that you have captured a dust lane in the spiral. Perhaps a middle ground with exposure and framing will give you the detail you need plus all three galaxies without the grey sky.

Your M42 is not that dissimilar to mine, I too use a Nikon. I set it to ISO 800 with an exposure time of 120 seconds which I have been informed is about 90 seconds too long! I not been able to test this yet due to the weather.

Keep up the good work and please post any improvements you have made and how.

Marvin

[ollypenrice]

Don't ask too much of an EQ5, unguided and driven on only one axis. That has a fighting chance of delivering decent low resolution images but you are imaging at very high resolution - about 1.26 arcseconds per pixel if I haven't slipped up. That means you really need a tracking precision of about half that - say 0.6 arcsecond. That's quite a big ask for an autoguided EQ6 let alone an unguided EQ5. I know that, when you start out, you think, 'Why do I need dual axis drives if I'm polar aligned?' and the answer is that, unfortunately, at the insane resolution we're asking for, there are so many small errors in our systems that we just do.

I agree with Marvin, above. You've done well.

Olly

[Marvin Jenkins]

Dave, I couldn’t agree more with Olly. I too am using an EQ5 but with dual motors and the SynScan V 5 kit. It seems to be a written rule (many times) that the minimum requirement for DSO Astro is an HEQ5, and let’s face it M31 and M42 are large and bright.

Keep doing what you’re doing and work on those camera settings whilst being accurate in your set up. I will be doing the same as a newbie. Inevitably you and I will find the limits of our kit, it’s about getting what we can out of it and enjoying the process.

Marv