Path of progression

[Anthonyexmouth]

Well I finally bought myself a goto mount, HEQ5. mounted my camera and mak 90 as in the photos, sometimes having the dslr on the mak. RDF is as good as useless and without a decent finder im finding target location very frustrating. Polar alignment is ok but goto is always off, even after 3-4 corrections with stellarium/eqmod. maybe im expecting too much with such a narrow field on the mak 90. As ive really over shot the budget in the last few weeks ive got to make my next purchase very sensible even though i really shouldnt buy anything else for a while i feel i need to so i can quell this frustration. 

 

do i 

1. buy an ed80 pro so i have a wider field and a finder and i presume i can add another dovetail on top and mount my mak 90 piggyback?

2. WO Z61, use the dslr on that and the asi290 on the mak, hoping the wider field on the 61 will make finding stuff easier. 

3. ed50 finder and asi120mm and guide the mak with that.

 

or can someone else think of a better option for me. 

what i am primarily interested in is DSO, enjoyed capuring jupiter with the mak but being so low its been a pain with the wibbly wobbly atmo. 

[Rob]

Quote

 

If its DSO Imaging you want to do, think ED frac 70/80mm - Yes

[Rob]

Looks a nice setup BTW!..

[vlaiv]

There is simple trick that will improve your Goto precision considerably.

First, don't dismiss RDF - it is a very good tool for this job - it is lightweight so you can leave it on attached permanently and use it in this step before each session.

Trick is when you setup your mount and polar align it and do balancing (if you remove your scope before setting up everything, or attach DSLR or whatever) - to tell stellarium / eqmod to slew to a bright star.

It will surely miss it by fair amount. Before doing any alignment points in EQMod - undo your clutches and manually point the scope to particular star - this is where RDF comes in handy, provided that you aligned it properly to said scope - you can use it to get your scope very close to selected star. When you aligned your scope like this - tighten your clutches (make sure scope / finder stays on star as tightening the clutches can move scope slightly) and park to home. Unpark - go to some star, center in FOV and add alignment point, rinse / repeat as needed (I usually add just a few alignment stars - in the area I plan to image).

[Anthonyexmouth]

3 minutes ago, vlaiv said:

There is simple trick that will improve your Goto precision considerably.

First, don't dismiss RDF - it is a very good tool for this job - it is lightweight so you can leave it on attached permanently and use it in this step before each session.

Trick is when you setup your mount and polar align it and do balancing (if you remove your scope before setting up everything, or attach DSLR or whatever) - to tell stellarium / eqmod to slew to a bright star.

It will surely miss it by fair amount. Before doing any alignment points in EQMod - undo your clutches and manually point the scope to particular star - this is where RDF comes in handy, provided that you aligned it properly to said scope - you can use it to get your scope very close to selected star. When you aligned your scope like this - tighten your clutches (make sure scope / finder stays on star as tightening the clutches can move scope slightly) and park to home. Unpark - go to some star, center in FOV and add alignment point, rinse / repeat as needed (I usually add just a few alignment stars - in the area I plan to image).

this is were i get confused, seems 50/50 on the opinion whether you should release the clutch and manually slew. as for the RDF, maybe a good one is ok but the crappy skywatcher one that came with my mak 90 is wobbly and never holds true. 

[vlaiv]

6 minutes ago, Anthonyexmouth said:

this is were i get confused, seems 50/50 on the opinion whether you should release the clutch and manually slew. as for the RDF, maybe a good one is ok but the crappy skywatcher one that came with my mak 90 is wobbly and never holds true. 

Well, it works very well for me, and there is no harm in trying. I'll describe my process so if you wish, try it out and see if it works for you.

Since I haul all my gear in back yard in pieces, this is my setup routine:

- get tripod stable and level (I used masonry bubble level for this with stock tripod, and now with Berlebach planet - I just use simple one build in with tripod).

- attach mount head (power and eqmod leads)

- do polar align via EQmod helper (this is enough for me for guided exposures, I don't do drift align, but make sure I get regular polar align as good as possible).

- I attach weights, scope, all bells and whistles and do balancing and cable management.

- Return scope to roughly home position and tighten clutches - here is important part - you probably won't return it to true home position before tightening the clutches, so EQMod thinks scope is at home, but in reality due to clutches it is pointing somewhere else - a few degrees in RA and DEC.

- Now tell EQMod to go to a star. If scope was at true home and properly oriented, it would go to particular star and only alignment error would be due to cone error / clamping not being 100% perfect and aligned. But in reality you will end up at least couple of degrees of star. Now you undo clutches - point scope to star, tighten clutches - this has the same effect as if you were to properly orient scope in home position. Return to home and it's like you kept your mount at home position but had some sort of markers to tell you how to rotate your mount to properly orient scope with your clutches undone (prior to tightening them). You can either put some markers on mount, or you can rely on a star to be your marker - as above.

Like I've said - it is easy to try and it might improve your experience with go to and finding your targets.

[tooth_dr]

6 minutes ago, vlaiv said:

Now you undo clutches - point scope to star, tighten clutches - this has the same effect as if you were to properly orient scope in home position. Return to home and it's like you kept your mount at home position but had some sort of markers to tell you how to rotate your mount to properly orient scope with your clutches undone (prior to tightening them). You can either put some markers on mount, or you can rely on a star to be your marker - as above.

Well explained, makes a lot of sense.

[Anthonyexmouth]

34 minutes ago, vlaiv said:

Well, it works very well for me, and there is no harm in trying. I'll describe my process so if you wish, try it out and see if it works for you.

Since I haul all my gear in back yard in pieces, this is my setup routine:

- get tripod stable and level (I used masonry bubble level for this with stock tripod, and now with Berlebach planet - I just use simple one build in with tripod).

- attach mount head (power and eqmod leads)

- do polar align via EQmod helper (this is enough for me for guided exposures, I don't do drift align, but make sure I get regular polar align as good as possible).

- I attach weights, scope, all bells and whistles and do balancing and cable management.

- Return scope to roughly home position and tighten clutches - here is important part - you probably won't return it to true home position before tightening the clutches, so EQMod thinks scope is at home, but in reality due to clutches it is pointing somewhere else - a few degrees in RA and DEC.

- Now tell EQMod to go to a star. If scope was at true home and properly oriented, it would go to particular star and only alignment error would be due to cone error / clamping not being 100% perfect and aligned. But in reality you will end up at least couple of degrees of star. Now you undo clutches - point scope to star, tighten clutches - this has the same effect as if you were to properly orient scope in home position. Return to home and it's like you kept your mount at home position but had some sort of markers to tell you how to rotate your mount to properly orient scope with your clutches undone (prior to tightening them). You can either put some markers on mount, or you can rely on a star to be your marker - as above.

Like I've said - it is easy to try and it might improve your experience with go to and finding your targets.

I'll give it a go tonight, i did mark my mount as described in the astronomyshed video. 

[michaelmorris]

If you are using EQMod to control the computer, an obvious progression would be to use APT software to control the camera.  Now it take a bit of setting up the first time you install it, but APT comes with an amazing plate solving add-in called Platesolve 2.  Once set up, this works amazingly well and should give you reliable, accurate GOTOs every time.

https://ideiki.com/astro/Default.aspx

[Anthonyexmouth]

1 minute ago, michaelmorris said:

If you are using EQMod to control the computer, an obvious progression would be to use APT software to control the camera.  Now it take a bit of setting up the first time you install it, but APT comes with an amazing plate solving add-in called Platesolve 2.  Once set up, this works amazingly well and should give you reliable, accurate GOTOs every time.

https://ideiki.com/astro/Default.aspx

i am using APT. will check out the platesolving, been using the online platesolving so far, time consuming but works. desperately need something with a wider field of view though. just don't know what route to take. 

[michaelmorris]

48 minutes ago, Anthonyexmouth said:

i am using APT. will check out the platesolving, been using the online platesolving so far, time consuming but works. desperately need something with a wider field of view though. just don't know what route to take. 

If you need something with a wider field view, then your options could include, as you mention, a small refractor (you could use your Mak as a guide scope) or you could simply use a camera lens.

[Anthonyexmouth]

Just installed platesolve2, im guessing it needs the mount connected and relevent position data to work. 

[Davey-T]

9 minutes ago, Anthonyexmouth said:

Just installed platesolve2, im guessing it needs the mount connected and relevent position data to work. 

You should be able to solve previously taken images, may need ra /dec if they're not in the fits header, and scope , image scale.

Dave

[Anthonyexmouth]

APT wasnt connected to the mount, wasnt aware you could until today so that info wont be in the file. 

[Stub Mandrel]

Just to be sure, when you do your three-star align make sure that (even if you manually slew the initial one) all the others are corrected using the handset.

I sometimes use a 150PL which is the same focal length as the C90 Mak (1200mm)

I leave my mount parked aimed at the pole star. After polar aligning with the polarscope I manually get polaris in more or less the same place in the finderscope as it is in the finderscope. My first slew then puts a star within the field of view of the finderscope. After correcting this any further stars are almost always close to the middle of the view of a DSLR attached to the 150PL