Gogleddgazer

Hi JP and welcome to the astro back hole! You'll find no end of helpful advice and guidance here which will hopefully keep you headed in the right direction towards some even more exciting and rewarding views. Enjoy the oddessey!

J

Thank you all for your inputs. I am investigating options to get the refractor serviced, RVO have the facilities and I have also tried to raise Es Reid who has come up in a number of threads/fora as something of a refractor fettling/collimation guru.  Fingers crossed. Once it is sorted the next question will be how to keep the tube dry with all the imaging gear attached in a ROR obsy!

On checking over my rig today I've discovered some fungal growth on the inner parts of the main objective cell in my APO triplet.  Suggestions from the SGL HIVE-mind for short term amelioration measures and perhaps more crucially recommendations/contact details for UK-based technicians who can disassemble, clean and re-collimate the OTA.  I am pretty practical but don't believe that I have the wherewithal to do a proper job on my own.  Thanks in advance.

J

Thanks for the replies chaps, the first 2 suggestions I had already discovered while researching how to get to a solution that would work with my existing equipment, while the third is but one of many options I could pursue by purchasing an alternative focus motor setup.

Cheers

J

Hi Folks,

I wonder if anyone can advise.  I have a Celestron focus motor for SCT that for the most part is controlled via computer as part of an imaging set up.  However, on occassions I want to do visual only work, but don't want to be tied to a laptop/PC interface.  I know that the focus motor can be driven using a Celestron handset via celestron mounts, but I have neither - my mount is a Skywatcher.  Is anyone aware of an alternate focus motor controller (like Hitecasto perhaps or the ZWO one) that will succsessfully drive the Celestron focusser directly?  I can't be the first to have run into this problem, but there seems a paucity of information about how to do this.  Thanks in anticipation

J

Hello to the SGL hive mind....

I have recently acquired a C9.25, 0.63 reducer and associated celestron OAG. All the research I have done to date flags the 174MM mini as the guide cam of choice due to the big sensor taking advantage of the bigger prism star field - it also (of course) carries a hefty price tag. Currently I am making do with an Altair GPcam3 290c which is a horrible compromise on many fronts, but has worked moderately well to date as I get to grips with longer FL AP guiding with an OAG.  

There seem few alternate choices that fit the form factor of the 174MM which seems necessary to achieve focus (I can't get "hockey puck" form cameras close enough to get focus when the reducer is in place).  

Given the "ZWO proce premium" I deliberately stepped away from their ecosystem and so am not restricted by ASI air related requirements. 

290M sensor cameras might be an obvious choice, but the QHY 5III 200 has caught my eye as a potentially viable alternative. However there seems a paucity of real world commentary about it as a guide camera in all the usual fora. Has anyone here got any experience of using it. I would welcome their views. Similarly I am open to all suggestions as how best to optimise my set up without breaking the bank and going down the 174MM mini route.

Thanks in anticipation 

J

Since moving across to NINA I always warm my camera as per Ady's post above. Simple enough to do while closing up/derigging other elements so doesn't add time to any imaging session. To my mind it makes sense to do such things gradually and under control. Whether that is better or worse than simply switching it off and allowing things to equalise naturally I am not sure, although I would imagine that the latter has a less even sensor temperature curve than when gradually reducing cooling.

4 hours ago, ollypenrice said:

A very good Eagle, especially since it was flying so close to the ground! 😁

I think it would stand more contrast in processing. You can use a standard contrast slider or, if you have a program with Curves, you could fix the bottom of the curve where it is and lift the curve above that. This will avoid boosting the noise.

On any Ha nebulosity you can, if you have Photoshop, go to Adjustments-Selective Colour and lower the cyans in red (top slider to the left.) This is often spectacularly successful in boosting Ha emission.

Olly

Thanks Olly, high praise indeed coming from you - I think I got lucky with the seeing and a host of other things besides. Looks like I need to spend more time honing and refining my processing skills! Something for the many many cloudy nights here in N Wales. 😄

Yes it is low on the horizon where i am, only about 25° above at it's highest at the moment

I have been wrestling with AP with very mixed results for about 12 months and so was inordinately excited to make out the shadowy outline of the pillars of creation in the subs on my first attempt at M16 earlier this week. Being colour blind adds a further degree of complexity to my processing efforts beyond those everyone struggles with. Despite all that, I am here to learn so would welcome any input my fellow SGLers can offer to help me improve things. 

TS Photoline 130 APO, full spectrum molded Canon 70d, astronomik UHC and L2 ir/uv filters

70x120s guided subs (dithered every 3), plus darks, flats and bias frames

Stacked in DSS, processed in GIMP

Cheers

J

Makes perfect sense, and really useful food for thought to add to my current mix.  Looking at your cardinal points my obsy alignment wrt North is very similar to yours, albeit the long axis runs about 30 degrees west of North.  I'll have to consider whether staggering them either side of the centre line reaps any real benefits for the more northern one.   

What a great thread and comprehensive documentation of your build. Thanks for taking the time to put it together. It is proving really valuable for me as i am couple of months behind you but working towards a similar 2 pier roll off roof observstory. I am intrigued to know more about how you settled on pier placements and what led you to seemingly offset one from the centreline, or is that just an optical illusion from a couple of your photos?

Great description and now added to my list of things to hunt down. The composite is a really good way to communicate the relative scales of these doubles. Thanks for taking the time to put it together.

J

1 hour ago, jacko61 said:

Rother Valley Optics own brand 12v Dew Heaters are very good. Come with both RCA and 5.5x2.1mm plugs and their own voltage controller.

RVO Heater Bands With Integrated Controller - Rother Valley Optics Ltd

Graeme

I got some of these recently and they are (imho) excellent, particularly given their flexibility wrt connection options

John

4 hours ago, vlaiv said:

Wrong reason to choose such ota.

TS 130 APO is capable of getting you "really close" to your targets - as close as you can go with current cameras and their pixel sizes (in fact - it is likely that you'll be oversampling with about half of current cameras even with that scope).

Good reason to go for 8" OTA is to speed up your capture - but in order to do that - you need to set your working resolution.

Do you have any idea what working resolution you want to image at? Do you have idea of what your mount and skies are capable of?

Thanks Vlalv, time for me to get into the technical maths and understand the things you talk about better so I can make a more informed decision. Every day is a school day! At least your post gives me some steers to do more targeted research, so thanks for taking the time to reply.

4 hours ago, ollypenrice said:

Are you sure that you will really obtain more DS detail from a scope of this focal length than with your 130 refractor? I wouldn't bank on it. You will need very good, stable seeing and very good tracking accuracy.

I've found no significant difference between the final detail caught with a TEC140 at a metre FL and that caught with a 14 inch catadioptric at 2.4 metres FL (on a mount running at around 0.3"RMS.)

The Vixen would obviously give you a bigger image but would that bigger image hold up at 100% and, if it didn't, would it be any better than an image shot at lower nominal resolution? I wrote an article on this very comparison for Astronomy Now and concluded that I was limited not by FL but by seeing. My site is pretty good.

Pixels are now getting so small that the rationale behind long focal length is thrown into doubt.

Jeremy is right that the figure on this scope is finalized by having a thicker aluminium coat around the edge of the mirror, which does have implications long term. However, I think the main question is, Will this really give you more detail?

Olly

Thanks Olly, really helpful additional food for thought and to be honest it adds a lot of weight to the argument for me to persevere with what I have rather than adding another OTA to the collection. 

Thanks to both of us for your insights, just the kind of input I was looking for to help inform my decision 

Hi Folks, I am toying with the idea of taking the plunge on a long FL 8" OTA for getting up closer to DSO than my Tak 76DS and TS Photoline 130 APO afford and wondered if anyone with experience of the above Vixen could offer their thoughts.  It will be mounted on an AZ-EQ6 which should suffice for the potentially long exposures that seem necessary with such a scope. I've read a variety of online reviews but would particularly welcome members thoughts on the utility of the Vixen primarily for AP, but potentially also for occassional dedicated visual work. Thanks in advance

J

1 hour ago, cajen2 said:

Indeed, but not at nearly four times the price of the dob.....

The Celstron Starsense Explorer LT114  set me back £200, so I'd welcome a link to the vendor who is selling a dob for £50. 🤣

I'll add my 10 pence worth to say Starsense Explorer is a simple and very effective means of finding things - I got it with a Celestron 114 reflector this time last year. The app is smple and quick to set up and very easy to use. Audio descriptions of what you are looking at and lots of other information to help build your knowledge. 

Thanks Martin, that sounds the kind of jumping off point I need. I'll look into it

Knocks my efforts into the dark ages! Lovely image, I think it'll be a while before I build up the courage to post any of my efforts. 😄

What a great, thought provoking thread. I am at the start of my imaging oddessy and really struggle to get anything that resembles the brilliant images one sees here. Getting to grips with what the processes do is for me the first task as I don't want to become too mired in generating "artistic" and visually striking images. I know authentic is a bit of a misnomer, but I feel that less is more given what you actually see when looking upwards. Looking forward to getting to understand and use the software more effectively than I am managing ATM!

Starsense Explorer LT was where I started a year ago and I think it is a great and painless entry into stargazing. Really simple and quick to set up, light weight so easy to move if buildimg/tree dodging required to reveal clear losing of sight to targets and remarkably accurate in getting you pointed at exactly the right bit of sky.  Limitations of an inexpensive set up allowed for, i think it is a brilliant system for starting out.

Welcome to SGL and congrats on a great choice of OTA - lots of incredible things to capture through that.