SW 72ED stellar mira flattener and rotator back focus

[TiffsAndAstro]

40 minutes ago, AstroNebulee said:

It can be but once you've cracked it you shouldn't have to do it Again. Unless you change something with the imaging train. 

Tomatobro gave good advice to try it during the day on a far away object. Even when it's partially cloudy at night give it a go too.

Good luck, you can do it 👍. 

Lee 

Well it's arrived but slight hiccup.

I'll deffo try in daylight, no reason I can use my mount and point it at a distant power line, focus on that. Then use fine focus with my bahtinov mask on a bright star to get it spot on. In a few weeks when there maybe a clear sky.

I can deffo get the guide scope and camera going in the meantime. I will probably be tempted to try imaging something with the guide scope and cam lol.

[TiffsAndAstro]

ok lol so maybe i'm over confident but that was easy enough. i push the flattener in almost all the way until the lip is past t he locking screws. i'd moved the focus tube (i think correct term) out a bit via the focus knobs. after that i can easily focus past and back a power line tower maybe 3/4 mile away. im hoping that's close enough.

next dumb question: if i leave the flattener attached to the scope, it won't fit in the nice case it comes with   so the case is really only for medium to long term and i should leave everything set up as much as i can?

also i don't see anywhere in nina to set the guide scope focal length. do i need to install PHD2 because it looks like its included within nina already?

i focused the guide scope and cam via the asi tool seems ok.

Edited April 5 by TiffsAndAstro

[AstroNebulee]

17 minutes ago, TiffsAndAstro said:

ok lol so maybe i'm over confident but that was easy enough. i push the flattener in almost all the way until the lip is past t he locking screws. i'd moved the focus tube (i think correct term) out a bit via the focus knobs. after that i can easily focus past and back a power line tower maybe 3/4 mile away. im hoping that's close enough.

next dumb question: if i leave the flattener attached to the scope, it won't fit in the nice case it comes with   so the case is really only for medium to long term and i should leave everything set up as much as i can?

Did you insert the flattener all the way in and tightened the thumbscrew up? Or did I misread that part. 

An all screwed imaging train is best when you can manage it. That way you can eliminate a few errors that may crop up with an imaging train that has thumbscrews that hold parts together. 

If you get any partly clear skies at night you can now refine the focus position with your setup either in stars or the moon when visible. 

I always left my imaging rig set up when not in use, covered in a couple of sheets to keep the dust off and carried it out to my imaging area in a couple of trips when in use. 

Lee 

Edited April 5 by AstroNebulee

[TiffsAndAstro]

28 minutes ago, AstroNebulee said:

Did you insert the flattener all the way in and tightened the thumbscrew up? Or did I misread that part. 

An all screwed imaging train is best when you can manage it. That way you can eliminate a few errors that may crop up with an imaging train that has thumbscrews that hold parts together. 

If you get any partly clear skies at night you can now refine the focus position with your setup either in stars or the moon when visible. 

I always left my imaging rig set up when not in use, covered in a couple of sheets to keep the dust off and carried it out to my imaging area in a couple of trips when in use. 

Lee 

yeah in a perfect world i might be able to do that but not right now. ill break it down into bits but leave guide scope/cam  and flattenter in place.

the flattener is pushed in so that the little rim in gripped by the screws on the scope itself. the focuser is out a little. im guessing i will have to adjust this a little when i can test it on stars. it was surprisingly easy to get into focus on a quick test, so im a little skeptical i've done it 100% correctly  

not sure about my guide cam though. nina picks it up in equipment/camera tab though. are you plugged into an asi air there? my wiring is not as near ;(

we have a surprisingly similar set up. will post a pic if  get it all mounted later.

Edited April 5 by TiffsAndAstro

[AstroNebulee]

3 minutes ago, TiffsAndAstro said:

yeah in a perfect world i might be able to do that but not right now. ill break it down into bits but leave guide scope/cam  and flattenter in place.

the flattener is pushed in so that the little rim in gripped by the screws on the scope itself. the focuser is out a little. im guessing i will have to adjust this a little when i can test it on stars. it was surprisingly easy to get into focus on a quick test, so im a little skeptical i've done it 100% correctly  

not sure about my guide cam though. nina picks it up in equipment/camera tab though. are you plugged into an asi air there? my wiring is not as near ;(

we have a surprisingly similar set up. will post a pic if  get it all mounted later.

I'm sure you got it all sorted as best you can without a real world test in the stars. 

I was plugged in to and asiair in the photo. Though I don't do the imaging side with my scope anymore. 

I just do visual with another scope and lunar and planetary. Mostly dslr Widefield Nightscapes now. 

I'll look forward to seeing your setup. 

Lee 

[TiffsAndAstro]

14 minutes ago, AstroNebulee said:

I'm sure you got it all sorted as best you can without a real world test in the stars. 

I was plugged in to and asiair in the photo. Though I don't do the imaging side with my scope anymore. 

I just do visual with another scope and lunar and planetary. Mostly dslr Widefield Nightscapes now. 

I'll look forward to seeing your setup. 

Lee 

When I manage get a pic of it in a couple of hours, I'd suggest wearing shades before viewing

[WolfieGlos]

15 minutes ago, TiffsAndAstro said:

yeah in a perfect world i might be able to do that but not right now. ill break it down into bits but leave guide scope/cam  and flattenter in place.

That's exactly what I did with my 72ED, and I still do now with my SF102 since it's too heavy to carry on the HEQ5 with the tripod and mount too. You can buy a wheeled tripod, which might be of use if mobility (injury or otherwise) is an issue, or you don't want to break it down.

Like Lee, I also keep my rig setup, and I take the scope off of the mount and carry the tripod outside with the mount in one, and then attach the scope complete with flattener, camera, guide scope, etc, and connect it up. The only downside with this route is achieving balance in RA and DEC, so I actually bought one of theses clamps and clamp it to the end of my dovetail bar after I've found balance. This way, I know when I attach the scope to the mount, I don't need to worry about balance 🙂

You can just see it circled here, although I now have it mounted on the top of the dovetail bar, so I can just slide it in and it acts like a block to stop it sliding out whilst you tighten it all up. You can also attach a finder shoe to it, and use it to hold an ASIAIR in a similar manner to what Lee has.

[TiffsAndAstro]

2 minutes ago, WolfieGlos said:

That's exactly what I did with my 72ED, and I still do now with my SF102 since it's too heavy to carry on the HEQ5 with the tripod and mount too. You can buy a wheeled tripod, which might be of use if mobility (injury or otherwise) is an issue, or you don't want to break it down.

Like Lee, I also keep my rig setup, and I take the scope off of the mount and carry the tripod outside with the mount in one, and then attach the scope complete with flattener, camera, guide scope, etc, and connect it up. The only downside with this route is achieving balance in RA and DEC, so I actually bought one of theses clamps and clamp it to the end of my dovetail bar after I've found balance. This way, I know when I attach the scope to the mount, I don't need to worry about balance 🙂

You can just see it circled here, although I now have it mounted on the top of the dovetail bar, so I can just slide it in and it acts like a block to stop it sliding out whilst you tighten it all up. You can also attach a finder shoe to it, and use it to hold an ASIAIR in a similar manner to what Lee has.

I think this is my plan, but I'll mark it once I've balanced it. Famous ladt words, but balancing my dslr was no problem, but it's not a lot of mass. I'm guessing it will be trickier with my new stuff

[TiffsAndAstro]

Can't balance it with the vixen dovetail I bought as an extra so no pics for a few days until I return the short dovetail for the longer one I originally ordered.

Or find a weight and somehow attach it to the front but not keen.

Pretty annoying though, especially as I can see some blue sky peeking through and could have tested

 

ok this might not be quite accurate as I might be able to slide the tube forward a little in it's tube rings.

 

Stay tuned for more exciting updates

Seems balanced now, just without the wiring

 

Edited April 5 by TiffsAndAstro

[Elp]

It's similar to how I have my Z61, I had to mount the tube rings at the front of the dovetail so when I add the imaging equipment the once front heavy balances with the back end. Longer dovetail will be the more elegant solution. Sometimes with longer scopes you have the benefit of moving the scope within the tube rings like I can with my Starfield 102, yours is at its moveable limit.

Also check if the dslr is in "portrait" mode that it doesn't interfere with the mount.

Just a word of pre warning, that tripod will need upgrading.

Edited April 5 by Elp

[TiffsAndAstro]

7 minutes ago, Elp said:

It's similar to how I have my Z61, I had to mount the tube rings at the front of the dovetail so when I add the imaging equipment the once front heavy balances with the back end. Longer dovetail will be the more elegant solution. Sometimes with longer scopes you have the benefit of moving the scope within the tube rings like I can with my Starfield 102, yours is at its moveable limit.

Also check if the dslr is in "portrait" mode that it doesn't interfere with the mount.

Just a word of pre warning, that tripod will need upgrading.

Will check portrait mode I think it will be ok.

The tripod is ok for what it is, sky watcher 1.75 inch steel replacement will be here tomorrow or Monday

 

[AstroNebulee]

2 hours ago, TiffsAndAstro said:

Can't balance it with the vixen dovetail I bought as an extra so no pics for a few days until I return the short dovetail for the longer one I originally ordered.

Or find a weight and somehow attach it to the front but not keen.

Pretty annoying though, especially as I can see some blue sky peeking through and could have tested

 

ok this might not be quite accurate as I might be able to slide the tube forward a little in it's tube rings.

 

Stay tuned for more exciting updates

Seems balanced now, just without the wiring

 

It's looking very nice indeed. 👌 Exciting times ahead. 

What I did to help balancing in RA better was to mount the guidescope on a small dovetail bar on top of the scope so all was central and no excess weight either side of the rig. That was my ocd kicking in the though. But yours shouldn't weigh to much to affect RA. 

Lee

Edited April 5 by AstroNebulee

[TiffsAndAstro]

8 minutes ago, AstroNebulee said:

It's looking very nice indeed. 👌 Exciting times ahead. 

What I did to help balancing in RA better was to mount the guidescope on a small dovetail bar on top of the scope so all was central and no excess weight either side of the rig. That was my ocd kicking in the though. But yours shouldn't weigh to much to affect RA. 

Lee

Ty

I was dreading back focus issues, but as far as I can tell it's ball park with what seems like room to move focus tube in and out when I use bahtinov mask.

will try get everything connected to Nina tonight/tomorrow and take a chance dodging clouds

[TiffsAndAstro]

Does the dew shield actually detach from this? is it non detachable on later models? cos all mine seems to do is unscrew with the front element.

i don't want to try and slide it with too much force....

[WolfieGlos]

Yes, you should be able to unscrew it separately from the front element.

[TiffsAndAstro]

1 hour ago, WolfieGlos said:

Yes, you should be able to unscrew it separately from the front element.

ah i thought it slid up/down  ty so much

[TiffsAndAstro]

taking photos of bode's galaxy right now. after focusing for 3ppa used the manual focus target and using bahtinov mask seem perfectly lined up crosses (which im a tad suspicious at). my 1st sub had trails, but my second looked spot on.

not tried to get guiding going yet as i want to run 20 x 60 sec subs on bodes and then maybe an hour on m51 if clear skies last that long.

is there any other quick test i should run so that people on here could spot any obvious problems? 3ppa was a bit of a pain but i ran a second one went well.

**********

ok trail i thought i saw might be a double star

***********

holy f&^£*&^g [removed word]. this dummy pressed here and magical guiding has seemed to happen. even though i focused it in daylight i really had to wind the guide scope focus a lot before stars showing. when i calibrate snr was about 20, now im guiding as i do some increasing exposure time tests its about 13 to 14. i didn't recalibrate when i sequenced m51 though. 

when the test subs are done, i'll try and do a proper hour maybe two until clouds on m51, dithering (gonna guess at a number for now) full calibration frames, and see how it looks compared to my previous best effort (mirror lens lol)....

ill post some screenshots tomorroasd in case any insights can be gleaned, but im a happy chappy so far
 

subs look crap. will try re calibrating gudining before i try a proper go at m51

Edited April 6 by TiffsAndAstro

[TiffsAndAstro]

ok so looking at my longer sub guide test shots, im hoping the guiding drops were wind and/or focus related. I focused it in the afternoon and it was way, way out when i tried guiding. i focused it more but possibly not enough. Also clouds.

i did manage to get 13x60sec (both guided? lol) of m51 and cigar galaxy.

my previous best image of m51 was 2 hours on a £10 40 year old 200mm (cropped in

)

13x60sec seems a decent start with my new stuff - just a quick stretch. 

 

[TiffsAndAstro]

14 hours ago, WolfieGlos said:

Yes, you should be able to unscrew it separately from the front element.

I can only seem to unscrew it and the front element comes away with the hood. Also the inside of the front element was dirty.

Front of the front element also needs a clean but I cant reach it down the front of the dew shield.

The threads look a bit rusty and janky too.

Edited April 7 by TiffsAndAstro

[TiffsAndAstro]

Bodes and cigar also 13x60sec

I'm guessing there's some tilt in this and m51 above, maybe and/or coma.

Will try a proper 2 or 3 hours on one target tonight, clouds permitting.

 

Though now I've seen it,  I will have to try and image the smile face at the of markarians chain 😁

Edited April 7 by TiffsAndAstro

[AstroNebulee]

15 hours ago, TiffsAndAstro said:

Does the dew shield actually detach from this? is it non detachable on later models? cos all mine seems to do is unscrew with the front element.

i don't want to try and slide it with too much force....

My dew sheild pulled off and had a felt strip attached to the scope. Will take a photo when I'm home. 

I wouldn't bother cleaning the element unless it's really dirty, you'd be surprised how much dirt doesn't bother the image. 

Lee 

[AstroNebulee]

2 hours ago, TiffsAndAstro said:

ok so looking at my longer sub guide test shots, im hoping the guiding drops were wind and/or focus related. I focused it in the afternoon and it was way, way out when i tried guiding. i focused it more but possibly not enough. Also clouds.

i did manage to get 13x60sec (both guided? lol) of m51 and cigar galaxy.

my previous best image of m51 was 2 hours on a £10 40 year old 200mm (cropped in

)

13x60sec seems a decent start with my new stuff - just a quick stretch. 

 

The stars look good in all the corners and no back focus issues I can see. 

It was really windy out ladt night when I was trying for the milky-way with dslr, so I'm not sure where you are but the wind will play havoc with guiding unless really sheltered. I found the 72ed was better on bigger targets and never really bothered with to many galaxies. I did do M31, M33, M51 and M81&82. But found it was at the limit. 

Lee 

Edited April 7 by AstroNebulee

[AstroNebulee]

11 minutes ago, TiffsAndAstro said:

Bodes and cigar also 13x60sec

I'm guessing there's some tilt in this and m51 above, maybe and/or coma.

Will try a proper 2 or 3 hours on one target tonight, clouds permitting.

 

 

It's looking good. Though not M51 above its NGC3077 I think. 👍

Lee 

[WolfieGlos]

24 minutes ago, TiffsAndAstro said:

I can only seem to unscrew it and the front element comes away with the hood. Also the inside of the front element was dirty.

Front of the front element also needs a clean but I cant reach it down the front of the dew shield.

The threads look a bit rusty and janky too.

Here's mine.

I did have to hold onto the "black plastic" on the end of the front element and essentially twist them in opposite directions to loosen it, and it was a little tight, but the dew shield definitely comes away.

I

[TiffsAndAstro]

2 minutes ago, WolfieGlos said:

Here's mine.

I did have to hold onto the "black plastic" on the end of the front element and essentially twist them in opposite directions to loosen it, and it was a little tight, but the dew shield definitely comes away.

I

I'm guessing mine is rusted so both parts unscrew rather than just the lens hood. Will have another go in a while with this pic as reference.

 

Also, Ty so much for this and your other replies, you have no idea how much I appreciate it all.