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GeoC

Star Adventurer polar scope light mod

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GeoC    17

As people have pointed out in other threads, the polar scope light does not attach to the dovetail bar. This means that when the mount is fully loaded you can't make final polar adjustments without shining a torch down the polar axis.

My solution is to cut two notches out of a plastic pipe (the dovetail gap is 2.0cm), and glue the light to it. It can then sit permanently in place.

I left the tube a bit long because the light is often too bright - shifting it further away gives a better illumination.

 

 

 

01.jpg

02.jpg

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Ryan_86    36

Im having the same problem, mine came with a plastic extension piece that connects to the mount side of the illuminator. This has 4 notches which just fits in gap of bracket. 

Ryan

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SteveNickolls    726

Yes, my SA came with an adapter too that connects the illuminator to the bracket the trouble is this is a very loose fit and it easily dislodges. All can be secured however with some judicious velcro :-)

Cheers,
Steve

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Ryan_86    36

I did wonder how long it will stay in the dovetail. I haven't tried it yet with adaptor. So.would do you do, wrap Velcro around the adaptor is it Steve?

Cheers 

Ryan

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SteveNickolls    726
3 hours ago, Ryan_86 said:

So.would do you do, wrap Velcro around the adaptor is it Steve?

Hi Ryan,

I used the sticky backed Velcro and placed short strips of the loops along the bracket near the centre point and around the adapter. I then used two short strips of the opposite type of Velcro (hooks) (but keeping the backing still on it) to secure to the Velcro on the bracket and adapter. I hope this makes sense. Good luck!

Cheers,
Steve

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Ryan_86    36

Hi Steve, that's a neat idea. I think Skywatcher come up short in this atea. Never still, it's an amazing bit of kit that I can't wait to use this (Hopefully more often than not) 

My 1st outing was a successful 1, I gathered 2min exposures if the Cygnus area which was amazing after processing. Using a canon 600D and a 18mm -135 lens @18mm.

Can I ask What you are using to image? I'm going to zoom in at 135mm next time and see what kind of exposure I can achieve. Further down the line I will be attaching a Zenithstar 61mm, can't wait.

Cheers,

Ryan

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SteveNickolls    726

Hi Ryan,

Until I got the SA mount this spring I was imaging using Alt-Az equipment (a SkyWatcher Synscan mount and either a 102mm Startravel f/4.9 refractor/Canon 600D or the camera and lenses). I could get 60-70 seconds exposures quite well depending on field rotation but always wanted to push the exposure time.

The SA has been little short of a revelation and I'm sure you will be pleased with yours. I have carefully been trying out longer FL lenses to see what exposures can be had and I am now faced with a 'glass ceiling' created by the local light pollution, the limiting magnitude here is around 4.3 in the suburbs of Nottingham. I have a number of lenses, the kit Canon EFS-18-55mm f/3.5-5.6, a Canon EF 75-300mm f/4.5-5.6 II USM a Canon EF 85mm f/1.8 and most recently a Samyang 135mm f/2 ED UMC. The jewel is the Samyang lens, very capable fully open.

I recently reviewed my log of imaging sessions with the SA to see what exposure times the mount has been able to deliver. At 300mm I've had 180 second exposures at f/5.6 ISO 400 with no star trailing. When I polar align I now do this when Polaris is at a marked division on the reticle to make alignment as precise as possible and take guessing out the process. I use BYEOS to image and at other FL's I have placed the cursor over a star and found no star movement over successive exposures, so at 135mm the SA tracking has been rock steady over 8 minutes. If I had no light pollution I could take very long exposures, as it is I have to cut exposures short.

Here is an image of the area around Sadr taken using the SA mount and Canon 600D plus Samyang 135mm lens at f/2 from x60 forty five second light frames at ISO 400 plus x20 dark frames and x50 flat and bias frames. I use DSS to stack and StarTools to process. Using the lens at f/2 and local light pollution levels restricted me to 45 second shots.

19_9_17_CYGNUS_Final_4.thumb.jpg.1d18451672f87121bb78143c49dbaf4a.jpg

On holiday earlier this year in Cornwall I was able to increase exposure time to 180 seconds using the same combination and at ISO 1600. This image is made from eight 180 second light frames and x20 dark frames and x50 flat and bias frames. The exif temperature data showed a steady 15 degrees throughout the imaging session.

NAN_Completed.thumb.jpg.021550c01f564ac25375acc36a0b3106.jpg

Good luck with your imaging Ryan.

Best regards,
Steve

P.S. The WO Zenithstar looks a lovely instrument, light enough for the SA to carry. I think at 360mm FL you would be looking into guiding to get the best out of it.

Edited by SteveNickolls
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Ryan_86    36

Hi Steve, amazing images I must say especially the one taken from Cornwall. If only you had dark skies permanently. I'm quite fortunate, I live not  to far from the Brecon Beacons, so a 45 minute drive places me under some of the best skies within the U.K. 

I'm totally new to astroimaging and processing so am finding my way slowly but surely. I plan on using what I have until I feel ready to add to my set up. Regarding guiding, is there a particular lightweight setup people common use on the Star Adventurer?  I have a 200p dob and have always planned on starting my astrophotgraphy journey. I suppose it's natural to progress onto bigger (more expensive set ups ), probably when my family have grown, I have retired and my mortgage is paid off haha.

Anyway here is my 1st attempt using the Star Adventurer. I used a Canon 600F (unmoded) 18-135mm lens @ 18mm, iso800, 18x120sec lights, x10 darks, no flats or bias. Stacked in DSS, processed in PS. I was told there is a method to help make the dust lanes pop but haven't tried yet. Here is the jpeg.

Cheers

Ryan

MilkWay-Usk-Res-PS'd-JPG.jpg

Edited by Ryan_86
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Ryan_86    36

Me again Steve, can i ask. With the 600D, enabling mirror lock means I have to leave the mirror up for the same amount of time as the exposure, before taking the image. This means it's taking me twice as long to complete am imaging session. Is tgere any way around this?

Cheers

Ryan

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Davey-T    9,022

Nice image, lot's of videos on Y'Tube on processing the Milkyway.

Mirror lock shouldn't affect the exposure length, auto noise reduction doubles the exposure length, make sure it's disabled.

Dave

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Ryan_86    36

Thanks Dave. I have auto noisereduction disabled. Using the intervalometer, when it starts an exposure the mirror locks up and stays like it for 2mins, then When the intervalometer starts a new exposure thats when the sensor opens. So it's taking me 4 minutes to complete a 2 min exposure. (2min mirror lockup then 2 min sensor open). Cheers

Ryan

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Waldemar    267

Did you try to not use the mirror lock? Not necessary with longer exposures. The little tremble of the mirror is too short to make a difference. 

Edited by Waldemar
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Ryan_86    36

No I've always enabled mirror lock. If it doesn't effect long exposures I will definitely turn it off. Thanks for that.

Regards

Ryan

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SteveNickolls    726

Hi Ryan,

Sorry not to reply sooner (I have been at the Nottingham Beer and Cider Festival and...) but it seems you are now settled over the mirror lock issue etc. I do like your image using the SA. You are very fortunate living close-ish to very dark skies. As regards lightweight set ups it's really down to what suits the individual. Personally I have used just my camera and lenses on the mount as I don't want to go the route of auto-guiding at the longer FL's of say a WO Xenithstar 61 for example. Finding good lenses that admit lots of light do help the cause and I can recommend the Samyang 135mm f/2 ED UMC lens in that regard. I'm hoping to experiment with filters in the future as it is the local light pollution that is holding back exposure times now.

Best regards,
Steve

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melsmore    34
11 hours ago, Ryan_86 said:

Thanks Dave. I have auto noisereduction disabled. Using the intervalometer, when it starts an exposure the mirror locks up and stays like it for 2mins, then When the intervalometer starts a new exposure thats when the sensor opens. So it's taking me 4 minutes to complete a 2 min exposure. (2min mirror lockup then 2 min sensor open). Cheers

Ryan

Hi Ryan, I don't know for sure if it is the same for your Camera (I've just had a look at the 600D manual online and it would appear to be so - see page 122), but on the Canon 350D I use Bulb,Mirrorlock and the self-timer, the exposure starts two seconds after the mirrorlock fires. I use an MC-36b and set the exposure time to 62 seconds, with interval set to 7 seconds. Then with bulb, mirrorlock and self-timer enabled, the exposure starts two seconds after the mirror lock fires and I get exposures of 60 seconds. The  7 second interval gives my old slow camera enough time to write the image to the CF card. I found that using the mirror lockup on the 350D does help, but the 600D is a much better camera ....

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Ryan_86    36

Beer and cider festival eh, sounds fun Steve. Yeah I think I'm going to go down the Zenithstar/guiding route when I feel ready and my wallet allows me to. Cheers pal.

Melsmore, that's brilliant and thanks for the helpful information. I have just checked page 122 and you are spot on. I just tested it and it works a treat. I didn't realise I had changed the self timer settings. I need bit of a refresher course before my next outing I think. I tend to give the camera 4 seconds to write the image even though 2 seconds is plenty on a 2min exposure, I like to think I am going easy on the camera haha.

Thanks again both, I would be capturing half the data otherwise. 

Kind Regards

Ryan

Edited by Ryan_86
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