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130 p ds


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It depends if you want it as an imaging only scope or want to look through it, the design throws the focus point further out but the compomise is a long focus tube to accomodate the use of an eyepiece you could shorten it but would need various extension tubes when viewing.

Alan

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If we are talking about when viewing, you either need to slice a bit off the end of the drawtube, or , use a lower profile 1.25" adapter, or use eyepieces that have a focal point that is further below the eyepiece "shoulder" such as TV plossls.

I think I have seen a low profile 1.25" adapter for the Skywatcher focusers somewhere - I'll have a look for it.

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What mods are best to do on this scope to get the best from it? I think the focus tube needs shortening for a start

Hi

Our Rob (Uranium) has done a number of tweaks on his and he gets brilliant images! You may not need to do anything especially if you're not imaging with it. The collimation was well out on mine when I got it. Adjusting the secondary is a pain - I think Bob's Knobs (or equivalent) are recommended. Other than that I've not really done anything to it though I'm sure it can be improved... Adding an autofocuser is a good idea. I fitted the cheap Skywatcher one. It isn't strictly an 'auto' focuser but it does enable you to get tight focus without having to have contact with the knobs. It also holds the focus very well. I've read that adding the SW coma corrector/reducer does cause problems with focus tube ingress. However, I'm using a GSO coma corrector (no reducer) which doesn't cause that problem. It has increased back focus and allows a filter drawer to be included in front of a dslr :). The possible downside to the GSO is a slight increase in focal length (maybe by 10% - from 650 to 715mm) and a corresponding reduction in imaging pixel scale which you may not want. Balancing the 130pds on the mount can be problematic. I've attached a 1kg weight to the mirror end of mine. Something I've noticed is that the finder bracket can easily come a bit loose - probably could be fixed with some threadlock or a mod. Also the tube metal seems quite thin and allows finder bracket flex though it takes some effort to cause that (my 150pds has a backing plate). I've a plan to bolt my guide scope directly to the tube rings when I get around to it!

I suppose flocking etc. could be done. Oh, if long exposure imaging, you might need to cover the mirror end if you are somewhere where there's a lot of stray light.

Can't think of anything else...

Louise

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I have recently acquired mine and find it fine in stock form for imaging.

I will no doubt flock it in due course but nothing else needs to be done really.

The focus tube does protrude a little way into the light path but nothing major. It depends what you want from it really.

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Hi Jules, I had the same thoughts about shortening the focuser tube to prevent it protruding into the light path, seems like a valid thing to do. Also blackening the focuser tube and sticking a bit of flock opposite the focuser should help.

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Hi

Our Rob (Uranium) has done a number of tweaks on his and he gets brilliant images! You may not need to do anything especially if you're not imaging with it. The collimation was well out on mine when I got it. Adjusting the secondary is a pain - I think Bob's Knobs (or equivalent) are recommended. Other than that I've not really done anything to it though I'm sure it can be improved... Adding an autofocuser is a good idea. I fitted the cheap Skywatcher one. It isn't strictly an 'auto' focuser but it does enable you to get tight focus without having to have contact with the knobs. It also holds the focus very well. I've read that adding the SW coma corrector/reducer does cause problems with focus tube ingress. However, I'm using a GSO coma corrector (no reducer) which doesn't cause that problem. It has increased back focus and allows a filter drawer to be included in front of a dslr :). The possible downside to the GSO is a slight increase in focal length (maybe by 10% - from 650 to 715mm) and a corresponding reduction in imaging pixel scale which you may not want. Balancing the 130pds on the mount can be problematic. I've attached a 1kg weight to the mirror end of mine. Something I've noticed is that the finder bracket can easily come a bit loose - probably could be fixed with some threadlock or a mod. Also the tube metal seems quite thin and allows finder bracket flex though it takes some effort to cause that (my 150pds has a backing plate). I've a plan to bolt my guide scope directly to the tube rings when I get around to it!

I suppose flocking etc. could be done. Oh, if long exposure imaging, you might need to cover the mirror end if you are somewhere where there's a lot of stray light.

Can't think of anything else...

Louise

Following a pm from Kalasinman, I think I may have to post a correction re: the gso cc and focal length. TBH the info that's out there isn't clear... GSO themselves just have a picture of it - no info! Now some sources quote a 'magnification factor' of 1.1 e.g. http://agenaastro.com/gso-2-coma-corrector.html Others refer to a 10% increase in focal ratio rather than focal length. I've always assumed an increase in focal length but I could be wrong. It could be that there is only a very small increase in effective focal length. It's probably best to discount my warning about pixel scale as a red herring :embarassed: But if anyone knows the absolute correct GSO cc specification (or has measured it before and after), I'd be interested to know! I think this is only really a concern for imagers.

Louise

Louise

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The problem with shortening the draw tube on the 130PDS is that you can only safely take off around 10mm.

If you take off more than this then the draw tube can disconnect from the guide bearings, which are widely spaced on this focuser... the same issue occurs with the 150PDS.

This draw tube intrusion is more of a problem with both scopes when used for imaging in conjunction with the SW Coma corrector.

For Imaging use with the SW Coma corrector it is better to move the primary mirror up a bit to move the focal plane further out of the focuser... but this will then require a short extension for eyepiece/visual use.

Keep happy.

Sandy. :grin:

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Are you hoping to image with it?

The major change ive made to mine is to mount the coma corrector inside the drawtube and turn it into an all-threaded affair, which means I have to rack the focuser out further to get focus. The distance depends on the corrector im using - the skywatcher takes the focus point inwards slightly, the baader normally leaves the drawtube clear of the primary. It can be adjusted slightly by pushing the primary up the tube a few mm using the collimation screws (that pushes the focus point out slightly), not an ideal solution though becuase I prefer to have a bit of compression on my primary mirror springs.

But for viewing, I dont think you really need to do anything with it.

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will be doing some very basic imaging.....moon with dslr and x1.5 barlow fitted to nosepiece, this should give me a fair image scale on a full moon.

Thinking about using the spc900 on Lunar with this scope just for fun, and will be having a go at video imaging with it

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The 130pds is a very accomplished little scope out of the box, and massively underestimated. I have little advice to add to the above, but hope you enjoy using it.

Am hoping to get back into all this soon!

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Cheers Chris, I hope the observatory has come in handy. I will be very time limited so will be sticking to visual, and maybe some lunar photography. If you could message me some scope / dslr lens ideas that'd be good.

PS: Sorry to butt in on the thread.

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will be doing some very basic imaging.....moon with dslr and x1.5 barlow fitted to nosepiece, this should give me a fair image scale on a full moon.

Thinking about using the spc900 on Lunar with this scope just for fun, and will be having a go at video imaging with it

If its just basic stuff and youre keeping the imaging train fairly light - then no major tweaks required mate. Some people get picky over "nibbles" been taken out of star halos by the drawtube in long exposures (it never bothered me personally, and ive seen worse from refractors), it wont affect lunar imaging one bit... just go for it! :)

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Try and find yourself one of these Jules http://www.scopesnskies.com/prod/astro-engineering/astro-camera-adaptor/AC696-2inch%20to%20camera/DSLR.html and in my personal experience your better off not using a barlow when imaging with a DSLR. The low profile adapter can plug straight in to the focuser draw tube which should hopefully require a bit more outward focus.

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Forgot to say... possibly one of the best lunar images I have ever seen when using an optical aid to help with a DSLR's magnification was the use of a 17mm hyperion although I can't off the top of my head remember what scope that was in ??

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These were my first images with a tiny Skyhawk 1145p and 5 quid Logitech webcam with cmos sensor.

attachicon.gif215453_10150550678650487_8051297_n.jpg

attachicon.gif215453_10150550678635487_463018_n.jpg

Andy, to say they were done with a skyhawk, thay are very good

Okay, i will leave well alone and just add the focus motor

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Thanks nightfisher. The Skyhawk 1145p has a cheap plastic focus tube and I remember mine was oval rather than round, also back then I had no idea about collimation. I would think you'd get some superb lunar images with a stock 130pds so, as you mentioned, just enjoy using it for a while and let the mods come later. You may find that the money you save gets put aside for a dedicated camera of some variety ;)

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  • 5 months later...

Hi, After some basic playing around with my 130PDS on a camera tripod I've decided I must get a proper tripod / mount. Budget is low at this point - I've found a used NexStar SLT  Tripod/Mount/Motor and Controller in my budget - and I have the L shape Dovetail for the SW Star Adventurer - would a combination of these work together? Failing that any advice for under £150? GoTo would be great, I plan to do astrophotography to. - does the GoTo cause any issue with photography?

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Forget the nexstar slt. You would require an EQ mount for any kind of astro imaging beyond a webcam. The 130PDS should sit ok on an EQ3-2 mount and you could get some short exposures with just a single RA motor. Dual motors with guide port or GOTO is necessary for longer exposures but then this will show any weakness in the capabilities of the mount and you'll then be wishing you'd got an EQ5 or above.

 

With your budget your best putting up a wanted advert. I sold a mint EQ5 with dual motors for £150 no so long back which would have suited you perfectly. The HC on the dual motors can easily be modded with an ST4 socket for guided imaging and the mount would easily hold the 130PDS.

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21 minutes ago, spaceboy said:

Forget the nexstar slt. You would require an EQ mount for any kind of astro imaging beyond a webcam. The 130PDS should sit ok on an EQ3-2 mount and you could get some short exposures with just a single RA motor. Dual motors with guide port or GOTO is necessary for longer exposures but then this will show any weakness in the capabilities of the mount and you'll then be wishing you'd got an EQ5 or above.

 

With your budget your best putting up a wanted advert. I sold a mint EQ5 with dual motors for £150 no so long back which would have suited you perfectly. The HC on the dual motors can easily be modded with an ST4 socket for guided imaging and the mount would easily hold the 130PDS.

I'll keep an eye out for an EQ5. I really want to use my DSLR, which was the main reason for getting this particular scope. I  didn't really follow you last bit about modded with an ST4 - I have so much to learn. Thanks.

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