First light ZWO2600MC -> M42

[Davey-T]

4 hours ago, Allinthehead said:

Nice first light Adam, how did you find the ha filter? I'm looking for a way to image with the moon about and as I only have a duo band filter I was considering an Antlia 3nm to pair with my 2600mc with one eye on possibly using it with a mono Imx571 in the future. My only concern is whether 3nm is too narrow at f/3.3.

Not to hijack Adams thread but had an Antlia 2" 3nm Ha filter delivered this morning, will try it in the 2600MC with Baader filter draw and the troublesome f/2.8 Sharpstar which I've just about beaten into submission.

ZWO ASI2600MM on order for it.

Dave

[Davey-T]

48 minutes ago, tooth_dr said:

Does anyone have any idea what is causing these unusual spikes?

Sorry forgot to actually answer the question, something in the light field obviously, maybe lens clips, can you see them looking up / down the tube ?

Dave

[Allinthehead]

2 hours ago, Davey-T said:

Not to hijack Adams thread but had an Antlia 2" 3nm Ha filter delivered this morning, will try it in the 2600MC with Baader filter draw and the troublesome f/2.8 Sharpstar which I've just about beaten into submission.

ZWO ASI2600MM on order for it.

Dave

👍 Nice, will you tag me when you get to test?

[Allinthehead]

3 hours ago, tooth_dr said:

the stars are much larger than I expected in my first light, so am just trying to get to the bottom of that.  I dont think it was focus because I rechecked it twice during the run.

They do look a little fuzzy, maybe you're over exposed at 300 seconds and gain 100. I find my fwhm drops significantly at gain 0.

I had similar fuzzy stars in this image, 240 seconds at f/5.5

Never got to the bottom of it as I bought the Epsilon soon after.

[The Admiral]

2 hours ago, tooth_dr said:

Does anyone have any idea what is causing these unusual spikes?

 

Hmm, they look like Bahtinov mask spikes 😉. They couldn't be, could they? I'm sure you'd recognize them if they were.

Ian

[Davey-T]

2 hours ago, Allinthehead said:

👍 Nice, will you tag me when you get to test?

Will do when / if it stops raining 

Dave 

[tooth_dr]

2 hours ago, Allinthehead said:

They do look a little fuzzy, maybe you're over exposed at 300 seconds and gain 100. I find my fwhm drops significantly at gain 0.

I had similar fuzzy stars in this image, 240 seconds at f/5.5

Never got to the bottom of it as I bought the Epsilon soon after.

I think then that 300s at F4.4 was part of the issue here.  I am going to try gain 0 next time I'm out (whenever that may be).  Thanks Richard

 

Adam.

[MartinB]

Microlens artefacts?

[tooth_dr]

1 hour ago, MartinB said:

Microlens artefacts?

Something is amiss.  I had a check there and its actually in all the subs from two different nights, 30s 120s and 300s subs.

I’d expect to see this in other people’s 2600MC images though if it was microlensing?  I haven’t come across that. 

Edited January 30, 2021 by tooth_dr

[gorann]

Never seen it with my ASI2600MC or seen any reports about microlensing. Must be something in the optics. Have you seen it with any other camera attached to this scope? Was it cold? Could it be pinched?

[Davey-T]

Guess you could make an aperture reducing ring out of cardboard to see if it has any effect.

Dave

[clarkpm4242]

19 hours ago, tooth_dr said:

Does anyone have any idea what is causing these unusual spikes?

 

I have exactly the same on my RASA 8, ASI2600MC combo.  Thought they reduced when I opted for a single curved cabling approach instead of two cables in a circle.

Is bearable if no bright stars in FOV.

Paul

[tooth_dr]

5 minutes ago, gorann said:

Never seen it with my ASI2600MC or seen any reports about microlensing. Must be something in the optics. Have you seen it with any other camera attached to this scope? Was it cold? Could it be pinched?

It was cold, but not cold cold, probably around 0 deg.  Plus I have a dew strap running always on the lens to remove dew.  I've only tried one other camera, D800E, and the artefact wasnt visible on the same stars.  However there were unexplained diffraction spikes on a couple of other bright stars and a strange pattern closely around the body of the star: see below.

Today I received the 2.5" field flattener, and intend to try this out as an alternative to the 0.8x FR, which I think might be the issue here.  This will help rule that out.

[tooth_dr]

1 minute ago, clarkpm4242 said:

I have exactly the same on my RASA 8, ASI2600MC combo.  Thought they reduced when I opted for a single curved cabling approach instead of two cables in a circle.

Is bearable if no bright stars in FOV.

Interesting, especially since I'm using a refractor!

[clarkpm4242]

1 minute ago, tooth_dr said:

Interesting, especially since I'm using a refractor!

Indeed!!   I did wonder about temperature.  AP, endless 'fun'...

[clarkpm4242]

Browsing ASI2600MC Pro images on Interweb, I can see many have similar star issues...

[Davey-T]

2 minutes ago, clarkpm4242 said:

Browsing ASI2600MC Pro images on Interweb, I can see many have similar star issues...

Do they have equipment and camera settings listed ?

Dave

[gorann]

I have so far only had my ASI2600MC on the RASA 8 and I now looked through my images to find the one with the brightest stars, and it is probebly the one of M45, and I cannot see any such artifacts on the stars. It could of course be QC issues at ASI but my bet is on the optics. Gain 100, offset 30, -15°C, no filter.

Edited January 30, 2021 by gorann

[clarkpm4242]

18 minutes ago, gorann said:

looked through my images to find the one with the brightest stars,

They do show similar effects though very tolerable!  Failure to get any of the other variables correct - alignment, focus, optimal exposure, cabling, temperature, tracking and processing could all add to it.  Especially in my case! 

Edited January 30, 2021 by clarkpm4242

[gorann]

37 minutes ago, clarkpm4242 said:

They do show similar effects though very tolerable!  Failure to get any of the other variables correct - alignment, focus, optimal exposure, cabling, temperature, tracking and processing could all add to it.  Especially in my case! 

In my expereince almost all bright stars show a rather symmetrical ray pattern like that with any telecope or camera - it could even be of atmospheric origin. Maybe someone knows.

[gorann]

21 hours ago, tooth_dr said:

Does anyone have any idea what is causing these unusual spikes?

 

Looking at your image again Adam, it struck me that the spikes look rather nice and at least not less attractive than the "inverse light house beam" stars produced by many Tak refractors, see for example this post and Olly's comment. If Tak owners accept such artifacts maybe you should not worry too much about it and see it as a signature of your telescope. However, I notice some chromatic aberration around your stars in the image. That is a bit surprising in a triplet APO with two ED glass elements so maybe it is caused by the focal reducer.