First attempt with PHD2

[Nicola Hannah Butterfield]

What a wash out this last 6 months has been, even the planets in the greenhouse thought it was autumn in August.

After the debacle of changing energy suppliers in the summer, and paying 2 D.D. till it was sorted, I finally got round to getting a cheap guide scope and camera, £190 ish, early Nov 2020, and I am gobsmacked, like I said the summer here as been well not good, (and other things) so I thought I had done as much as could with my resources (yea I know could also do more), I used to polar align best I could visually, but had no way to improve it, drift align mmm I work on a budget of £170 p/w and limited knowledge, anyway, I recently got the RVO package of a RVO 32mm F/4 Mini Guide Scope and ZWO 120MC-S. West Yorkshire Skies being what they are i had to wait ttwoo week till I could even attempt anything in the sky.

I can polar align visually to about 30' which usually left star trials after about 30-60's

Using Sharpcap polar alignment feature on Friday, I got this. the the 30' went to

30"

A quick exposure, gave me 60's round stars, they did start to trial after that.

PHD2 after another weekend of intermittent cloud, and other commitments, got everything set up, and tried PHD2, (basic level, which is why it and other numerous other issues is not perfect), but to me I went from 30-45's subs at best, to what almost seem rock solid 5 min exposures, plus the three at slightly shorter exposures the stars didn't move (in camera) during those exposures, myphds2 final screen capture, yea I know all over the place.

 

Finallay a 5 min sub of M33 at ISO 100

 

 

[Nicola Hannah Butterfield]

Forgot to mention the scope is 1000 mm 200P Skywatcher, guided by a 128 mm guide scope, Canon 6D prime focus.

[wimvb]

That's a good start, I think; you have a guiding rms of 0.5 pixels. Just two remarks: 1. the guide star snr is very low, and it almost looks like you're guiding on noise. Try to find a better star to guide on. If you move the slider next to the exposure time, you can darken the live capture image and maybe see better guide stars. 2. You are fighting an uphill battle, because your guide scope gives you 6"/pixel according to the stats in the screen dump, and you have the minimum movement (MinMo) set to 0.18 (pixels) which is more than 1". Imo, you should try to get a longer fl guide scope, so that the guide pixel scale comes closer to the image pixel scale.

Good luck

[Nicola Hannah Butterfield]

11 hours ago, wimvb said:

That's a good start, I think; you have a guiding rms of 0.5 pixels. Just two remarks: 1. the guide star snr is very low, and it almost looks like you're guiding on noise. Try to find a better star to guide on. If you move the slider next to the exposure time, you can darken the live capture image and maybe see better guide stars. 2. You are fighting an uphill battle, because your guide scope gives you 6"/pixel according to the stats in the screen dump, and you have the minimum movement (MinMo) set to 0.18 (pixels) which is more than 1". Imo, you should try to get a longer fl guide scope, so that the guide pixel scale comes closer to the image pixel scale.

Good luck

Thanks for your reply, It had a some cloud towards the end. what surprised me is how it managed to lock on to a star with so much cloud coming in, yet still hold to an exposure of 5 mins, like I said, my very first phd track, 5 mins round stars, compared with less than 40's  before, pretty cheffed nonetheless, no deep sky wonders from it mind.

Edited November 16, 2020 by Nicola Hannah Butterfield
spelling.

[ebdons]

Hi, not sure if you've binned the camx2 as that can help sometimes, also what mount have you got unless I missed it, I image with an f4 10" newt and find my best settings always need fine tuning from night to night, I have the focuser "hanging down" and increase the HYS to very high (60+) and have the exp set to 1 sec or 0.5 sec, but whatever works for you is ok, as it takes sometime to perfect the guiding at least it did for me. clear skies Ton

[Kryptic]

Waiting \ hoping for some clear skies to test the same bundle from RVO. 

[Nicola Hannah Butterfield]

12 hours ago, ebdons said:

Hi, not sure if you've binned the camx2 as that can help sometimes, also what mount have you got unless I missed it, I image with an f4 10" newt and find my best settings always need fine tuning from night to night, I have the focuser "hanging down" and increase the HYS to very high (60+) and have the exp set to 1 sec or 0.5 sec, but whatever works for you is ok, as it takes sometime to perfect the guiding at least it did for me. clear skies Ton

Mount is a Skywatcher HE6 Pro, as I said it was the first attempt, and a very brief one clouds came in but got the chance to get two five minute exposures that previously I had to shoot high iso and less than 45's usually on occasions I did manage to get close to 60's, but I guess my polar alignment was better on those days. I found the polar alignment feature in Sharpcap amazing as I could do 60's unguided with perfectly round stars, the best I had ever done to that point, well worth the price.

 

1 hour ago, Kryptic said:

Waiting \ hoping for some clear skies to test the same bundle from RVO. 

Guess it is worse in Lancashire than here in West/East/North/South Yorkshire (yes i live close to all four, I can easily cycle in all four with about 1/2 an hr.

The focusing isn't great, but close enough to plate solve and guide.

[Kryptic]

18 minutes ago, Nicola Hannah Butterfield said:

Guess it is worse in Lancashire than here in West/East/North/South Yorkshire (yes i live close to all four, I can easily cycle in all four with about 1/2 an hr.

Yeah, we dry the clouds out before sending on to you 

[Nicola Hannah Butterfield]

4 hours ago, Kryptic said:

Yeah, we dry the clouds out before sending on to you 

Shame you could hoover them up as well.

If you use plate solving as I am just learning how to use as well, you will be surprised how much easier it is to centre your objects, this is cropped to a Canon half sensor i.e. those not full frame, I get a lot of vignetting on my 6D on my set up, even with flats, but I digress, using Stellarium and the viewing the sensor/scope overlays it is bang dead centre.

This is the quick stack I did nothing special, but only about 13 mins two 5 min one's one 2 min and one 60's all 100iso, flats shot at 200iso, bias darks taken from another day, it isn't great, but just testing software to see what I have learnt.

This is a screen grab from Stellarium

This is the last time I did M33

Of which non of the exposures were longer than 45-60's would need to look that up.

So providing I can improve on the stacking integration. Hopefully I can produce better this winter  and next year.

Hope you get some clear views soon so you can try it all out.

 

Edited November 16, 2020 by Nicola Hannah Butterfield

[Nicola Hannah Butterfield]

17 hours ago, ebdons said:

Hi, not sure if you've binned the camx2 as that can help sometimes, also what mount have you got unless I missed it, I image with an f4 10" newt and find my best settings always need fine tuning from night to night, I have the focuser "hanging down" and increase the HYS to very high (60+) and have the exp set to 1 sec or 0.5 sec, but whatever works for you is ok, as it takes sometime to perfect the guiding at least it did for me. clear skies Ton

The "hanging down" perplexed me for a while, blonde moment (sorry to all the intelligent blondes no offence meant).

From the phd2 screen grab exposure was 2's as @wimvbpointed out the focal length of the guide scope is a possible issue when compared with the f.l. of the 200p, that said of the 4 exposures I managed to get before the clouds from Lancashire once again ruined the evening only one showed any sort of elongation, this wasn't star trialling more a flattening of the stars, a bit like when Galileo first draw Saturn, and then only just.

The main thing I think I really need to work on is excess light entering the tube. Flats can reduce a lot, but I am still getting a centre bright area, I think this due to neighbours light going straight down the draw tube, because over head it is much less, M33 so far to me has been low E NE when shot and whilst not many towns in that direction, it does look across neighbours house and low. Alt/Az yesterday was 87 02' and 30 47' pretty much where I took the one in the summer.

[Kryptic]

51 minutes ago, Nicola Hannah Butterfield said:

Shame you could hoover them up as well.

Aye, sorry

52 minutes ago, Nicola Hannah Butterfield said:

If you use plate solving as I am just learning how to use as well, you will be surprised how much easier it is to centre your objects,

I'm new to AP, but have set up with Astroberry and got plate solving working offline (need to travel up onto the moors for some darker skies), and managed a very brief guiding test.

55 minutes ago, Nicola Hannah Butterfield said:

Hope you get some clear views soon so you can try it all out.

Thanks - hope so too - for you, me and everyone else.

[wimvb]

11 minutes ago, Nicola Hannah Butterfield said:

this wasn't star trialling more a flattening of the stars, a bit like when Galileo first draw Saturn, and then only just.

I have found the bulls eye view in phd usefull as an estimate of what star shape to expect. The dots or crosses hopping around reflect the stars ”hopping around” on the sensor. Unfortunately, round stars are not an indicator for good guiding. If the RA and DEC steps are random, large steps will give you round but also fat stars.

With a 1000 mm fl reflector you should probably consider an oag or a ST80 as guidescope. Binning your guide camera if you already have 6”/pixel (again, according to your screen capture), is counterproductive.

[Nicola Hannah Butterfield]

20 minutes ago, wimvb said:

I have found the bulls eye view in phd usefull as an estimate of what star shape to expect. The dots or crosses hopping around reflect the stars ”hopping around” on the sensor. Unfortunately, round stars are not an indicator for good guiding. If the RA and DEC steps are random, large steps will give you round but also fat stars.

With a 1000 mm fl reflector you should probably consider an oag or a ST80 as guidescope. Binning your guide camera if you already have 6”/pixel (again, according to your screen capture), is counterproductive.

Not got to the bull's eye bit yet (is that the upper right named target in the phd2 screen grab), caring tends to get in the way, I wasn't referring to the shape in the guide camera but more that in the capture image, an ST80 is more out lay, I have limited income, on esa, caring for someone no one else will, so my primary concern is stable track, which this package from the only test I have done has delivered, I am now actually more concerned with the image capture issues that have plagued me.

I could just add a Barlow 2x to the current guide system, would give about the same fl as the ST80 and aperture, and it is something I have considered trying, but how many clear nights have we had in the last 3 weeks,

[wimvb]

42 minutes ago, Nicola Hannah Butterfield said:

Not got to the bull's eye bit yet (is that the upper right named target in the phd2 screen grab),

That's the one.

43 minutes ago, Nicola Hannah Butterfield said:

, I wasn't referring to the shape in the guide camera but more that in the capture image

That's what I meant too. The guidescope/camera and imaging scope/camera should move together, so the image in the target (bulls eye) view taken over 5 minutes, should be similar to the star shape of a 5 minute exposure, not taking into account focus, diffraction, etc. What's more important is that if you see an elongated pattern in the target view, you can expect elongated stars in your subs.

[Nicola Hannah Butterfield]

3 minutes ago, wimvb said:

That's the one.

That's what I meant too. The guidescope/camera and imaging scope/camera should move together, so the image in the target (bulls eye) view taken over 5 minutes, should be similar to the star shape of a 5 minute exposure, not taking into account focus, diffraction, etc. What's more important is that if you see an elongated pattern in the target view, you can expect elongated stars in your subs.

The only elongation was in one sub of 4 I took,

[Starflyer]

3 hours ago, Nicola Hannah Butterfield said:

The main thing I think I really need to work on is excess light entering the tube.

A dew shield made from a rolled up camping mat, closed with duct tape, will really help reduce stray light. Make it so around eight inches sticks out from the end of the scope, and tight enough so it doesn't slip off under its own weight.

[Nicola Hannah Butterfield]

1 minute ago, Starflyer said:

A dew shield made from a rolled up camping mat, closed with duct tape, will really help reduce stray light. Make it so around eight inches sticks out from the end of the scope, and tight enough so it doesn't slip off under its own weight.

I know this, but would be, much better if people were aware of wasted energy from the light they think they need and actually need.

[Starflyer]

23 minutes ago, Nicola Hannah Butterfield said:

I know this, but would be, much better if people were aware of wasted energy from the light they think they need and actually need.

And the fact that they add nothing to security.  Burglars love to be able to see where they're going, makes their lives much easier than either carrying a torch around or falling over stuff.

[Nicola Hannah Butterfield]

2 minutes ago, Starflyer said:

And the fact that they add nothing to security.  Burglars love to be able to see where they're going, makes their lives much easier than either carrying a torch around or falling over stuff.

Dark equates to ghost stories, once we got the electric light they disappeared very quickly.

[ebdons]

Hi, I also have need of a light shield, I like mine as light as possible so use an old black pizza base which has been used and is also very light and can be secured easily, if you need an aperture mask on the primary than the outside edge of the pizza base can be just right and cut out a thin circle and fit it under the mirror clamps without introducing stress/tension to the mirror.  Keep going and you will find your "perfect" PHD2 setup, I sometimes use PHD1 as well when using a scope for planetary imaging etc. don't forget balance of your setup is important as I found out years ago. clear skies Ton