Knighty2112

13 minutes ago, rwilkey said:

Hi Gus, in my opinion the Semi-APO filter will serve your purposes better for reducing CA, I used to have one and it is quite good, but got rid of it when I bought an ED refractor.

Thanks Robin. Plan to use the filter on the first three 'fracs listed in my signature. Don't need it for my ED 80mm obviously, as the CA in that is almost none existent.  

Hi all. Leaning towards getting either a Baader Semi-APO filter, or their Contrast Booster 1.25"  filter. Both roughly similar prices, but wondered which of the two are best; the Contrast Booster gets good reviews, but the APO filter is more neutral when reducing the CA in refractors so leaning towards that more, but just wondered what other members thoughts are on this if you own one or the other. 

Cheers,

Gus  

Got a nice Lunt wedge with filters from Moonshane that got delivered yesterday by the postie. Had first light with it yesterday, but nothing much to see on the sun. Nice and sunny here today again, so going to have a peak again to see if I can see any solar activity again soon!  

Glad it all went well for you Jules. Enjoy the new scope!  

Never got it. A bidding frenzy at the end pushed it up too high. 

11 minutes ago, Skyline said:

And there is still time to bid for it

Yeah, got a bid on it. Fingers crossed!  

39 minutes ago, Chris Lock said:

Picked up this slightly rare find, David Hind Optical are auctioning off Celestron stock on Fleaby. These haven't been in production for years, but this one is certainly brand spanking new so must have been sitting in a box for years in a warehouse perhaps? 

I've never seen one for sale second hand, it's a Celestron OMNI ED102 XLT f/8.8 refractor. I've never named a scope before but for some reason I've been compelled to name it 'Midnight'.

Also needed to pick up a mount for it, so this classic Black dual drive HEQ5 arrived today....can't wait to test both the scope and mount out but there was plenty of thick cloud in the box.

Nice scope Chris. Seriously tempted by one of these!  

2 hours ago, John said:

Nice !. I like the dark blue / white colour scheme

It will be interesting to compare the Omni 120 with your Startravel 120.

Thanks, they do go well together. Yes, that is what I really want to compare and see which gives a better view. In theory the Omni 120 should give better views with the XLT coating, and the longer focul length too, but await a chance to test them side by side on the Skytee 2 mount together to test this. 

New addition of a Celestron Omni 120mm XLT f8.3 to my small family of 'fracs. Still awaiting a proper first light with it due to the weather, but ready and waiting to go none the less. Photographed here with my Altair Astro 102mm f11.  

I'll have to make sure I avoid this EP. 

28 minutes ago, Louis D said:

I'm no optical expert, but that diagram seems to show the exact opposite of what is common knowledge, that prism diagonals shorten the path length over a mirror diagonal.  I'm still working out what is going on.  The angles of refraction seem correct.  The converging beam is actually made to diverge somewhat within the prism, lengthening its path while in the glass.  I always thought just the opposite was happening and accounted for the shortened path length.

After looking at it again I see what you mean! Is there an optics expert in the house?  

23 minutes ago, Stu said:

I must say it does hurt a little when chaps and chappesses complain about LP and actually what they mean is the little ornate village lamp about 200 yards down the road  

Wish that was the only thing that created my LP!  

3 hours ago, YKSE said:

Just find a correct light path schematic for mirror and prism diagonals. Peter and Stu's understanding was correct, that prism reflects too, the shorter light path in prism is achieved by bending the lights closer to each other than straight reflection in mirror diagonal.

 

OK, I see. Make sense now. Thanks!  

Quite a few mods there. Well done.  Can't say I've had any issues with any of the above really on my tripod, the only mod I did fit to my Az3 tripod mount head was a counterweight to allow better control when near zenith, especially with heavier EP's fitted. Due to LP I usually use the tripod in the lowest height possible to dodge the glare from street lamps on the road behind my house, or on the path in front of it, so stability has never been an issue for mine really. 

1 hour ago, Mak the Night said:

Interestingly, 90° Amici prisms can work well for astronomy and I often use one for lunar viewing. 45° prism diagonals are more for terrestrial use.

Somebody needs to tell Skywatcher about this then, as they supply quite a few of their telescopes with a 45 degree diagonal, ones which are clearly designed for astronomical rather than terrestrial use.

Of course one of the first upgrades I got for my Skywatcher Startravel 120mm f5 'frac was get a good 90 degree diagonal.  

1 hour ago, parallaxerr said:

Hi Knighty, the wrap is Carbon fibre effect vinyl from eBay. Not sure which seller I used but there's loads on there selling it. 

Thanks. I saw some on eBay last night, so may order up some to do my dew shield.  

1 hour ago, parallaxerr said:

ST120 added to the frac stable. Fitted the standard dual speed crayford from the ED80 and wrapped & flocked the dew shield, looking forward to first light

I like the wrapping on the dew shield. I may wrap mine up too, as it matches the dark body of the scope too. Got the full inside of my scope fully flocked, even inside my Crayford focuser tube, so no stray light bouncing about in my ST120! Where did you get the wrapping from? 

My Skywatcher Startravel 120mm f5 frac, with my new addition in my collection of my Altair Astro Starwave 102mm achromatic f11. Still awaiting a decent first light with it due to work and weather, but views so far have been cracking!  

I'm assuming your 45 degree diagonal is a standard prism type one supplied with the scope? Check to make sure the prism is not loose, or is able to move at all in its housing as I had an old stock Celestron prism diagonal that used to move about slightly and cause similar issues. 

Yeah, I'm buying a second hand 20mm Televue plossl too. And then just to propel myself even further down that long slippery slope I went and pushed the button on a new 14mm Baader Morpheus EP! Yikes! I need counselling! Hehe!  

Sorry, the Chris I thought you meant isn't in fact the Chris I meant in my post. Oops!  

Hi and welcome back. Chris is still around on here. I actually bought a scope from him earlier this year and went to his house to pick it up. I'm sure you'll run into him again here as well again.

Enjoy your time on the forum, and a big hi from the UK!  

22 minutes ago, Stu said:

If you are using any form of GPC or Barlow then I don't think you will see much vignetting on the 32mm Plossls. The Barlow narrows the light path so it doesn't hit the aperture stop of the Binoviewer as much/at all. Pretty sure that's right anyway  

Yeah, need to use the WO 2x nosepiece ordered separately to achieve focus, so in reality my 32mm EPs become 16mm. Would be nice to get a wider view though, so may still consider perhaps lopping some off the tube of the ST120 perhaps to do that. I'll wait and see how the new Altair 102mm f11 frac coming next week works with them first before I make any firm commitment one way or the other.  

When I put the binoviewer in to my diagonal, which has a compression ring, in only insert it up to the shoulder of where it slopes inwards, that way it is always on a a straight part of the neck of the binoviewers. 

7 minutes ago, Mak the Night said:

I have used a pair of 32mm BCO's in my WO bino's and not noticed any vignetting. That goes for the 25mm orthoscopic pair too.

 

Good to know.

Do you need to use the 2x Barlow nosepiece to achieve focus to in your scope?