fwm891

Picking up on Sara's point about WO's I have just got a ZS 73 with the Flat 73A 1x field flattener. It's a 430mm fl at f5.9 and I've just been 'playing' with it on a star adventurer with my Nikon 800E

I've attached a 180s sub, 1250 iso with a 300% inset from the top left corner. I know it's on a star Adventurer mount so not the best. This is at it's standard back focus position and I'm just playing with the adjusted to see what difference small changes make...

Try not to take your background so dark as your loosing a lot of fine detail - great start

5 hours ago, Rusted said:

Why not roll off onto the lawn parallel with the fence?
I'd also suggest enough clearance behind the obs. to reach in for litter, maintenance or painting.
Or, make it so close it won't matter but without using the fence for structure.
Putting the obs. so near to the gap beside your house will force some odd manoeuvres with lengthy or bulky objects.
Nor do you want to build so high that you block the light to your neighbour's window.
If they normally have that window open they will be able to hear every sound you make or your mounting slewing. Or vice versa!
External visibility will be high in your present situation through the diagonal gap to more distant homes.
If south is across the rear face of your home then the further away you move the more western sky you will reach.
I would be moving further down the garden for several of the reasons I have mentioned.

Hi Rusted,

Firstly the roof will be running parallel to the fence line (no other option) due to lack of space.

The obs will be 300mm from the fence and with the wall height when the obs is open at 1220mm (4ft) it will be easy enough to brush leaves etc away to keep the gap free of debris. Also at only 2000mm long I will be able to push a broom through the gap from outside.

The fence is 6ft high the obs will be about 6ft 6" to 6ft 9" at the top of the ridge (the eves will actually be below the fence.

As to positioning and horizons - take a look at the photo (taken at approx. mount height): I have no north view until I get near the zenith. To the east I have trees that top out at about 50°, to the south I have a small dip in the tree line and to the west my own property is in the way. Believe me I have positioned the obs in the only place I can to get any benefit from the restricted panorama I have. There is a gap between my neighbour and my house which gives me an area of sky to the north west.

If I move east to open the western sky up a little I loose my southern 'dip', If I go west any further I won't be able to go past the meridian when exposing at lower latitudes.

My skies are Bortle 4 and although I have a few street lights around none thankfully shine into the obs position and all are on short posts and well shielded.

As to noise my neighbour is a classical guitarist and practices well into the early hours...

Still waiting for the CEM60 at the mo to finalise measurements but finally able to start placement of pegs to locate the corners of the build. Also shown is a section through the proposed wall/floor/foundation area.

I built the model with a square (2000mm) base, that has now changed and will be 2000mm (L) x 1700mm (W). Fixed wall height circa 1220mm, sitting on treated wooden sleepers which in turn sit on blockwork foundations.

Another change I'm looking at is to make the roof run-off rails detachable so they don't encroach on a paved seating area when not in use. I did this once before and the rails will slot into metal brackets at the end of the building.

Francis

On ‎23‎/‎05‎/‎2019 at 21:46, groberts said:

I'm planning to use Sharpcap for Polar alignment, which gets good reviews, using a Starlight Express Lodestar X2 mono guide camera, combined with a William Optics 200mm FL x 50mm guide scope, which I calculate provides a FOV of 1.85 x 1.38 degrees. I've been using this set-up successfully with PHD2 for sometime.

Given the above parameters + before proceeding further with Sharpcap I wanted to confirm: 

1. Will the pixel size of 8.6 x 8.3 nm, which is not square, work OK with Sharpcap and plate solving, which I understand is an integral part of the polar alignment routine? 
2. Will the installed ASCOM driver for this camera used with PHD2 be OK with Sharpcap or do I need something else - if so which one?

Thanks, Graham

Graham, Perhaps I've miss read this but surely you'll use your main optics to do your alignment with SharpCap (or any other software). If your guidescope isn't perfectly aligned with the main scope then although its adequate for guiding it will introduce errors when calibrating your PA?

Hi, I've just installed one on my Edge HD8. I down loaded and installed the software from the links on the FLO product page (I used the newest dated option of the ascom driver). After installing the software I re-booted my laptop (Win 10) Then connected the focuser to the laptop and opened the Celestron software. Clicked on connect, and then calibrate - the software took the focuser through it's paces running the full focus travel in and out, then returned the focuser to the position it started in.

I then checked and connected to the focuser via SG Pro to make sure - worked fine.

I connected a 12VDC - 1 Amp supply to the focuser and a USB 2.0 lead to the laptop.

Links from FLO product page:

Celestron Focuser Utility Program (.exe file)  

Focuser ASCOM driver (Directory)  

First a big thanks to FLO (ordered yesterday, arrived this morning - fitted👍 ).

Simple. For once I followed the instructions and everything went well. From removing the old rubber focuser adjustment knob and flange to fitting the motorised focuser. All required tools were in the box although I found the cross head screwdriver a bit short so used one of my own. I was expecting the shaft grub/locking screw (socket headed) to tighten sooner than it did but that really was the only bit giving me any concerns.

I downloaded and installed the software from FLO's product page before connecting the focuser and re-booted the laptop. I'll be using this with a non-Celestron mount so opted for the Ascom driver (newest dated). Plugged in a 12VDC supply and USB lead to the laptop, opened the Celestron software, connected and hit calibrate. Calibration took a few minutes as the focuser drove from one extreme to the other and back to it's original position.

I then played sending it to different numbered positions. More seriously I looked a the backlash settings and ended up with a '5' setting. The white indicator on the focuser makes watching for instant motion very easy.

So need to try this in anger at some stage...

I'll update once I have a chance.

Your RA trace is 'reasonable' but to me needs some adjustments to your scope's balance, PA etc. 

Can't tell from your post images what guider settings your using so any comments are guesswork.

Personally I'd drill the holes for your bolts then a little bag of ready mixed fine sand and cement - spread the sand/cement mix, drop your bolts through and align everything then when the cement dries just snug the bolts up a little. You could use tile grout instead, again let it dry and then tighten things down.

Steve, Do you know what the component(s) is/are with the CEM60's. Is it a modification?

2 hours ago, BillyBoy said:

Any CEM60 in that little lot..? ?

Well that's two of us on the wait list anyway

Seal the floor - YES

2 minutes ago, Stub Mandrel said:

I have more finders than scopes.

Hmm, I must need a new scope...

Should be easy to find one then....

? Pleased for those waiting for EC mounts but...

Quote

 

I've been watching the iOptron CEM60 ad on the TS site. Yesterday it started by saying they were 6 days from a delivery, but the end of the day it said 23 days...

I did actually look at the "drawer runner" variant. I looked at the time to take the roof out sideways as the obsy will be rectangular (slightly) narrower one way. I've chosen the twin rails so I can run the roof past the end wall opening a little more sky to the east. I'm still thinking about putting an angled end to the roof above the door but the extra complications in construction and covering out weigh any real/percieved benefit.

Thanks for all the comments - keep em coming...

Well the model has progressed if nothing else...

Please excuse the panel pin axles, and the brace round the wrong way and... (anything else)

8 hours ago, JamesF said:

But the Photoline 72ED might.  It's all so complicated!

You need another scope to cut out complicated decision making...?

On ‎26‎/‎04‎/‎2019 at 11:29, RolandKol said:

And did I understand it correctly,

35mm extension tube is needed for DSLR even if FF is used? 

No, the Flat 73A is set to 11.4 (on the WO scale - probably mm but not sure?) then the 48mm T camera adapter. Total. If your using a cooled camera (CCD or CMOS) then some adapter will be needed to make up the difference between a dslr and short back focal plane cameras.

My pic's above were without the flattener in place - Han Solo has a flattener.

Mine with guide scope. Flat 73A and D5100 on Star Adventurer

14 hours ago, JamesF said:

But where are you going to get the 11.5mm apo to go inside the model?

I have a lathe and some small lenses...

31 minutes ago, Gina said:

I did my model in SketchUp!

I have to say I hate Sketch-up. Never got on with it even the basics...

Decided to try building a model at 10th scale - nowhere near finished, braces to add, sleepers, cladding, etc., etc...

58 minutes ago, Knight of Clear Skies said:

I doubt my polar alignment was good enough for 5 minutes at 135mm pointing south, but the longer exposure makes it easier to see any misbehaviour from the mount.

If your testing something the set-up must be as tight as possible otherwise the test is pointless. Even if you are intentionally off-setting your PA, off-set it a good amount so you can clearly see errors.

39 minutes ago, Knight of Clear Skies said:

What kind of star trails did you get though please? Did you get any seagull shapes?

They were curved but no bright spots along the length - sorry dumped them.

3 minutes ago, JamesF said:

Given that only the RA axis is driven, if there's periodic error and that's the only problem, shouldn't the trails be straight rather than jagged?  Or perhaps only deflect in one direction?

Hi James - If it is a serious error and the drive wheel is a little eccentric then there may be a speed variation causing the brighter patches...?