Trentend

Gear arrives Thursday (OVNI-B). Can’t wait to try out! Weather looks clear also as things stand...

Thanks Peter, looks like the filters aren’t going to be cheap. I see the Chroma 5nm 2” is almost double the cost of a 6nm Astronomik. Is the performance difference likely to be so great? Looks like I need to do more research before pulling the trigger...

PVS7 with high end tube due to arrive soon 😀from OVNI. 55mm and televue 67mm converter on order. What filters/size would you recommend? I’m thinking Astronimik 6nm ha based on quick research. I’ll be doing viewing from light polluted city back garden in my 18” dob. If I venture out with a handheld set up, e.g. x3 magnifier, can I use the same size or is that 2” only?

Tried the “legendary” RKE 28mm eyepieces on the moon last night. Not sure if I’m doing something wrong but no floating effect. Actually found them tricky to use with precise eye position required. Went straight back to the panoptics for a more comfortable view. Should I persevere? Perhaps need to be at a dark site?

Hi Stuy, the mirror is by Oldham Optical and F3.9. Unfortunately with the virus restrictions I’ve been unable to take it out to the dark sky site. But took a peak at the moon last night from the back garden and it was great. Very stable image pretty much straight away with minimal cooling and just the fan on. Was a doddle to collimate and pretty sharp on all 3 powers with the binoviewer. Viewing chair arrived today so looking forward to trying that out.

Any advice on a cover to limit the amount of dust and creepy crawlies getting onto the primary mirror? Thinking of some form of microfibre cloth under the wooden Mirror cover then surrounding the whole thing (base and truss arms but not OTA) with a large bin bag? There are a number of access holes in the rocker box so never going to be completely air tight. Also, what about a grab handle on the end of the OTA when I’m navigating from one position to another (at the moment just grabbing the end of the scope near the spider vanes)?

A few starters for ten.

First, I hope everyone is keeping safe and well from the virus. Finally picked up my new pride and joy last weekend after much saving of pennies, research on this forum and time in the field. Settled on an 18” Lukehurst ultra portable 2 having previously progressed (with varying degrees of success) from an 8” skywatcher to an Orion Optics VX12 and finally settling on an 18” truss dobsonian figuring that’s was big as I could go without a shed redesign, larger car and new back! Service from David Lukehurst has been fantastic. Highly knowledgeable, quick to respond to questions and happy to customise the set up for me. He was also more than happy to contact Russ Lederman to get help maximising the set up for a binoviewer and Serge from Astrodevices fitting a Nexus DSC (I had the pleasure of meeting Serge back at the IAS show in October which seems like an age ago). My brief being as follows: Main interest DSOs having discovered some great darks skies within an hour of my home address Binoviewing only Some portability (single person set up) Object guidance capability given the relatively short viewing windows north of the border Spec as follows: Feather-touch focuser to take the heavy weight of my kit Nexus DSC Dew heater for the secondary Fan for the primary Tracer battery Glatter and tublug for collimation Binotron 27, filterswitch and powerswitch Wheelbarrow handles for movement Panoptic 24mm In a very brief break between clouds last night I managed to get a quick peek at both Venus and M42 from a very heavily light polluted back garden. Venus was fantastic. Much larger and clearer than I’m used to. Like comparing a peach to a pea. Clear and steady having allowed the mirror to cool for an hour or so and with the fan on. M42 was a revelation. Can’t wait to get some filters In the filter switch sometime down the line, but plenty to keep me busy in the coming months before that. Pictures to follow. Will also be looking for some advice please on a suitable/lightweight observing chair, replacement wingnuts for the truss (I keep dropping the ones I have) and storage options to protect the mirror when in the shed. Can’t wait to get the kit set up and out to the local dark skies!

Looking forward to it tomorrow also. A long trip down from Edinburgh!

Have recently ordered a new dob from David Lukehurst (next 3 months will pass very slowly...) and need to finalise where to place the Nexus DSC unit. Looks like I have two options, either on a separate stalk or some form of ball joint mount near the eyepiece. Any experiences / thoughts on these?

Unboxed my new toy today and have a few questions: The focuser is fitted with a brake system (thumb screw A in the photo below). How do I use this? Do I back right off and then adjust until there is a little tension on the draw tube (I’ll be using a heavy binoviewer). Or do I get tension via the two grub screws (B) or a bit of both? I believe the other grub screws should be left and not adjusted (C to F). Thanks Thanks

Are there likely to be vendor discounts on the day? Looking to purchase a feathertouch focuser.

I will try a repeat of this tonight in my smaller 8 inch skywatcher (that works a treat on all settings and has never been collimated).

Too excited to wait for a test this evening (I so want this to work as have £££ ready for related kit that I’ve been holding off for months) so tried in my lunch break. Interesting results. The laser centred nicely in the donut on the primary with the hotec only. When I put the binoviewer in place and swapped one of the eyepieces for the hotec with the focuser fully in, the dot was about 1-1.5 inches away from the donut 😳😳😳 . When I then moved the focuser fully out there was definitely some drift, not much (around 2-3mm I’d say) but you could feel a little play, even with the various screws tightened up. So definitely need to try a new focuser. Guess what I don’t understand is how the dot can be so far out in the first place??

Eddgie suspects the weight of the binoviewer is causing the focuser to sag a little when fully extended (it is very heavy with a filter switch, two eps, ocs and power switch) and has suggested I try placing the laser first in the focuser on its own and then repeat with the laser in the binoviewer when fully extended to see if the dot on the primary moves. Will try tonight and report back.

I left a 3cm extension tube in between the ocs and power switch (see photo) as this seemed to do the trick with the 8inch skywatcher. Will try removing it for the vx212 to see if it makes any difference (Rob, not sure if you have this on yours?).

Apologies yes an F4 so appreciate smaller margin for error. Presume this is more critical the higher the magnification (fine on low power, stars shine nice, bright and pin sharp but not if medium or high).

I have a denkmeier OCS A45 which I believe should address this?

Thanks both. Potential school boy error. Have removed the slack/play (there was at least 5mm) by tightening the two adjustments screws (yellow arrows). The fine focuser (red arrow) doesn’t work and never has so still want to replace the unit. Have a free evening so going to reacquaint myself with the astrobaby collimation guide... One thing I always notice when using my Hotech to align the secondary is I have to apply a lot of pressure to get the laser in the donut ring on the primary. Suggests the secondary still isn’t in the right position perhaps.

Looking to upgrade the focuser on my scope to either a moonlite or Baader diamond steeltrack. I use the scope with a denkmeier binoviewer and 24mm panoptics - have crisp views at low power but can’t focus on the medium and high. Previously thought this was poor collimation (and it may still be) but when I had a look through it the other night I noticed a significant amount of sag with the medium and higher settings as the focuser travel out is much greater. Wonder if this explains the poor views? I need to replace the focuser as it’s a bit battered and the fine tuning mechanism doesn’t really work. Any thoughts on the best one to get and what accessories such as fitting plates etc would I need (I have previously used the Baader clicklock mechanism so leaning towards that). Really hope I can get this scope to work as it’s so easy to set up and transport.

Enjoying some great views of the moon this week through the VX12 on low power (binoviewers and 24mm panoptics). But still not as clear as hoped for on middle and higher power. When observing the moon at mid and high I notice if I move my eyes towards the bottom of the eyepiece and look up (rather than central looking straight ahead) the view is sharper. Does this suggest the secondary isn’t centred in the viewer correctly? Current position in the photo below. Also unable to properly resolve stars in the middle and high setting (but fine low). When I try and focus the top part of any star almost resolves clearly but a tail appears towards the bottom. A bit like a badminton shuttlecock pointing upwards (if that makes sense)? Have an ocs45 fitted so not sure if this is coma related (I don’t think it should). Cavalry arriving in the next week or so from the local Astronomy club to take a look, but any thoughts before then appreciated.

You’re right thanks Vx12l seems like the sensible route based on my original requirements. Must stop drinking and surfing for scopes...

All of my viewing will be visual using the binoviewer. Would that work with a paracorr? What’s putting me off the 5.3 is the size, which is too temptingly similar to the 14inch...

Really appreciate the advice from everyone. Looking at the weight/size there doesn’t appear to be much in the 12L and 14(!), although the latter retails for circa £700 more, so that rules it out (unless I wait for something used). Very keen on the 12 F4 (that is super light) but need to find out more about these paracorrs - what they do, is there an impact on magnification, field of view, would I need a type 1 or 2 etc... Presume given I have panoptics the eyepieces should be able to cope in a faster version? Will I have any focusing issues using a binoviewer?...

Looking to upgrade from my cheap but effective 8 inch skywatcher reflector on an eq mount (which I find a pain in the ar*e to transport) to a more lightweight/portable 12inch dobsonian with greater aperture that will give a real wow factor on DSOs at local dark sites. Will be used for visual only and budget is up to £2k (a one off purchase with no £££ for anything else - honest). Will be used with a denkmeier standard binoviewer, power switch and pair of 24mm panoptics (I love this set up in the current scope but still find a lot of the DSOs just faint fuzzy blobs). Nearly pulled the trigger on a second hand skywatcher 10 inch flextube goto, but not convinced the visuals will be that different to my current set up. I also had a go lifting a 12 inch flextube but found that too heavy / cumbersome (back hurt for a few days just lifting in and out the car once). Portability / quick set up essential. Not interested in a truss at this stage - nights here in Scotland too unpredictable so want something I can set up in 5-10mins and be using pretty much straight away, albeit at low power as the scope cools down. Been hunting for weeks on the internet. Can’t see anything from Meade, Skywatcher, Explore Scientific that fit the bill and some of the more bespoke companies are too expensive. Then stumbled across the Orion Optics UK site, the lightweight VX12 and their neat dobsonian mount. Interested to hear people’s views on a few matters: The company seem a little marmite - either very good (great optics / portability) or very bad (question marks over mirror performance claims, general quality and customer service lacking including some scare stories). Should I be concerned? Next, have priced up for a 12 or 12l scope, mount, tube rings, trunion mount and friction brake. Would I need anything else to get going? Finally any views on the 12 (F4) v 12L (F5.3)? The former is shorter, a little lighter and perhaps more portable, but don’t think I’d find the 12L too big and would this ultimately be cheaper (no parracor?) and more forgiving? 14 inch is going to be over budget. Thanks