chemistorge

Hi All, 

I recently bought myself a little SW MAK102. While doing this I though it might be nice to use my ASI120MM-S camera with it for mono planetary imaging (just for fun!). To this end I though I could do with a  filter wheel, so I searched for 3D printable one. I choose this one:  https://www.thingiverse.com/thing:1292900 . It printed fine but I had to reprint the carousel several times to get the filter holes correctly sized. Also the model has female threads on both sides with no adaptor. 

Time when on and I thought why not motorise it! I looked online and found a git hub (https://github.com/Blueshawk/Rayz-indi-wheel) with Arduino code compatible with Xagyl filter wheel drivers and instructions to modify cheap manual filter wheels. This looked good until I tried the code, it was very buggy with INDI and the serial latency was poor. 

Fast Forward: 

I decided to design a motorised filter wheel from scratch and also completely rewrite the arduino code and I am happy to say it works completely with INDI (Kstars) and ASCOM (tested with sharp cap).  The functions are limited to moving filters and set offsets only, but what else do you need. Additionally there are buttons on the wheel to manually move filters (although no feedback) . 

The filter wheel in the videos and pictures is my prototype. I have made slight modifications in the 3d cad files to improve the design.  There are two designs for the bottom, either M42 for T2 connection to scope or M48 for connection via coma corrector.  The filter box is bolted with M3 bolts and nuts and the circuitry lid uses M3 bolts that are threaded into plastic holes.  The circuitry holder fits the Arduino Nano, Motor driver board and 28BYJ-48 motor and Hall Sensor.

See GitHub for files and Code https://github.com/chemistorge/Arduino-Motorised-Filter-Wheel-Xagyl-compatible-ASCOM-and-INDI-. 

With indi drivers, you have to save configuration after setting offsets otherwise it resets them when you next connect. You can also use a serial monitor to talk to the wheel.. see code for commands.

I will be adding more to Git hub as I get time.

Video with ASCOM and SharpCap:

Video with INDI: 

22 hours ago, alacant said:

Much better:)

You've still gone very heavy handed on the choice of ROIs though. Go easy on the contrast. That is almost certainly where your unevenness originates.

For second (an subsequent) AutoDevs, it's important to try different ROIs. Try the core only, one of the arms, a group of bright stars, a group dim stars including or not the galaxy... The possibilities are endless. Don't worry if you don't get it right first time. The beauty of st is that your data is always linear. Do your processing in any order.

In the end, at last we've a viable alternative to the ancient levels and curves approach where your data was manipulated as a series of non linear files produced as a result of isolated unrelated procedures. Of course, if you're happier with the latter and it produces better images for you, stick with it.

Cheers

 

EDIT: even if you've overdone it, there are a couple of 'rescue' things you can do:

 

But it's just as easy to wind back to an earler stage in the processing and redo it from there. your data remains linear.

 

Ah thank you, I didn't realise you can go back, I will keep persisting, thank you for all your help.

On 26/08/2021 at 17:35, alacant said:

Hi

This with the latest ST v1.8.511.

Apart from wipe using synthetic bias and flats, I stuck as close to the default values as possible. It seems that maybe the flat frames are not correcting the field too well and there are vertical bands which new dark frames may help with. Both succumbed to Wipe however.

Not definitive by any means. Yours has more detail and colour, but as I thought, there is more galaxy to be had. 

HTH anyway.

 

Hi, You must be a wizard with Startools, I find it very difficult especially the wipe module, also I still don't know how to your the autodev ROI. this is my best effort on the same data set straight out of startools (5 attempts to replicate yours). I can't workout how you get such a smooth none-blotchy image.

I do like ST8, just got this result in 5 mins from old data on the Veil Nubula.

1 hour ago, alacant said:

Hi

This with the latest ST v1.8.511.

Apart from wipe using synthetic bias and flats, I stuck as close to the default values as possible. It seems that maybe the flat frames are not correcting the field too well and there are vertical bands which new dark frames may help with. Both succumbed to Wipe however.

Not definitive by any means. Yours has more detail and colour, but as I thought, there is more galaxy to be had. 

HTH anyway.

 

Thank you, I have tried again and your result is similar to mine, although I think I need to work on star colour. I have just re check my stack and found that I used 2 min darks from my library not 3 min darks. I am going to try again on the new moon as the moon glow was pretty bad. Thank you for all your help. I am only using ST 1.7, I have just download 1.8 and going to give it ago.

1 hour ago, alacant said:

Refractors in general I believe. Certainly our 72ed and other camera lenses. The mask will get you close, but the final tweak is best done by a human. 

We find the opposite. I'd say that the second development ROi in AutoDev being chosen wrongly. 

Post the stack if you like.

Cheers.

Here is the stack, the moon glow gradient is very prominent. Autosave.fits Thank you.

@alacant thank you, I focused using a 3D Bahtnov mask, but maybe that doesn't work for this lens I will try manual focus on screen (Thank you for the tip). I am still trying to get the hang of processing, I have lots of data on various targets but struggle with processing, I find startools makes my images very noisy (usually the wipe module), So I stick with photoshop, but I am still trying to find the best work flow.

Hi All, 

I obtained a Tair 3 off ebay a few months ago and I finally got around to using it. Here is Andromeda (300mm, f5.6, 45x180', 40 flats and 40 darks, ASI294MC, 5 degrees, Full Moon, Bortle 6.7). I processed the image in startools and finished with camera raw in photoshop. I am not a good image processor but I don't think it is bad especially as it was full moon and I only used a IR cut filter. During processing I did have to remove violet halos around stars, maybe I need to stop down to f6.7. 

Wide angle CCTV camera lens can be found on eBay, I don't know what thread is on the sv105, but worth a look. You can buy C-mount lens and I have seen a 1.25" to C-mount adaptors. The main issue is going to be back focus, do you know what the flange to sensor distance is for the SV105?

@Rodd I did the processing in Startools trial version as a test and got that result, but I couldn't save so screenshot instead.

@Seelive Thank you for that, I am using DSS and do use kappa-sigma, I didn't realise it got rid  of them.

@nephilim I didn't guide because I get good tracking with 120 sec subs. I use around 40 darks and 40 flats, but I forgot to turn on manual dithering in Ekos, it causes issues if you try and guide with manual dithering set, so I turn it off (and forget to turn back on when not guiding). I do need more practise at processing. Only just got all my equipment working well together (ASI294mc, Astroberry (kstars/ekos), SW130p (modded with dual crayford electronic forcuser) and SW eq5 (AstroEQ mod).  

Ah, does that get rid of them?

My first attempt back in Nov 2017 of Orion.

and a screenshot (I lost the original processed file and haven’t reprocessed the data yet) of my effort last February.

Hi,

While taking my first go at part of the veil nebula, I noticed that I was throwing out 10 % + subs to satellite streaks. (106x 120s).

What is other people’s experience of streaks? Is it getting worse?

FYI, The 150p model will fit a 130p scope if scaled by 89%.

No use to me, but excellent design.

Hi All, 

My new project is a DIY version of this product. I have focus/aperture by wire lens for my Canon camera and I would like to use my ASI294mc with them especially  my 50 mm, 24 mm primes and  also my 250 mm zoom lens. 

I started with the following 3d printed adaptor (here) as a base. I modified it to enable pogo pins to fit and make contact with the pads on the lens.  I am now waiting for the small circuit board to adapt the pogo pins to a 2.54 mm header for ease of connection. 

Once I receive the circuit board I will be able to start writing the arduino code to interface with the lens. I have found the protocol online. As I teach arduino programming to students at a college, the program should be no problem. 

I plan the following specs:

1) Works with EF and EF-S (currently 3d model only fits EF as I need to chop a bit off.)

2) Be able to set aperture with two buttons, setting to be displayed on 0.9 inch LCD screen.

3) Be able to focus: 1 button for near focus, one for infinite focus, +/- 10 steps, +/- 1 step. (possibly include a routine that works out how many steps from near to far focus and then display on screen to enable more precise refocusing in subsequent sessions). 

I will update this page as  I progress. The adaptor will fit all astrocams with 17.5 mm back focus.

Thank you perfect, I have a 130P so I will adjust and see if I can get away with outside on my Ender 3.

Hi Bill, Is the flange designed to sit inside the scope or on the outside? 

Just coming back from a week in North Devon (Bortle Class 2.3). While I saw the Milky Way with my naked eyes for the first time in six months, my attempts at astrophotography were very mixed.

At Home my imaging rig works well (Near London Bortle Class 6.4). My rig is a 130p, ASI294mc, Astroberry on Pi 4.

The night started off a bit cloudy so polar alignment was stop start. I finally got a good polar alignment of < 1 arc min. I did notice that the  latitude and azimuth adjustments were switched in ekos which was strange (didn’t get that at home). (11.30 pm)

While the clouds cleared I spent  time setting up my Canon 80D with 24 mm F2.8 lens for wide field milky was shot. For some reason I couldn’t  get focus, in fact I couldn’t see stars very well through the View finder or with a test shot….strange. So I increased my iOS and exposure and decreased aperture, still no improvement…..take camera back inside….idiot I had left a 850nm IR Pass filter on. Set up went well from there….(12.00am).

Back to main scope, set to two star alignment. Scope goes the wrong way…very strange. Humm I had previously had this when manually moving the mount with a hand controller without Ekos connected (this upsets the tracking that ekos has, namely it alters the parking position). Did the fix, which is to close down kstar/ekos without parking which resets the parked position to Polaris. Still no joy. At this point I went around in circles checking all cables the motor connections. In the process of this my USB DIY power module had the ports come unglued (only hot glue), so I had to unscrew the lid and hold while I plugged the cables in. (1 a.m.)

At this point I was getting very frustrated and tired (system works prefect at home). I then glanced at the clock on the raspberry pi, the date and time were incorrect! There was no obvious way to set the time. 
 

Turns out the Raspberry Pi doesn’t have an internal clock that runs during power down, it either updates on boot from internet, GPS or manual. 
 

All my problems with my mount were down to incorrect date and time, only a problems as I had no internet and I didn’t know it was an issue. By this time it was getting on for 2 am and I had to take down my rig as I was with my family and could stay up any longer. 
 

The rest of the week was wall to wall cloud. So no images on my asi294 in dark skies (sad).. but now I know more for next time….

Anybody else had a similar story of errors…..?

Hi Marvin, Did you also move the focuser and spider down the tube? I moved mine 3 cm down which solved all the back focus issues for prime focus without moving mirror.

The Dual speed focuser is very good, completely rock solid. I have a motor attached for auto focus and it work great. It was the best up grade to my scope.

Hi, Around 2 years ago I got fed up with having a scope with a horrible plastic focuser but good optics….namely the sky watcher 130p. I had managed to score a Crawford focuser from Astro buy and sell which I intended to fit. As I only had the one scope it took me a while to gather the courage to perform open heart surgery on my one and only scope!

Here is my journey:
 

First I found a website (Here) to calculate the intersection size between the tube and focuser to get a cut out template. This was stuck on the tube 90 degrees around and 30 mm closer than the original focuser hole.

I then used a 3 mm drill bit to drill a “dotted line”.

I then used a hand held fine jigsaw blade to join the dots.

To smooth cut out to the line I used a grinding disk on a drill to go round the hole until it was perfect, after which I drilled the relevant mounting holes. The focuser and spider locations were 30 mm closer to the primary mirror than previous which has allowed prime focus with easy.

I have been using the scope for the last 2 years with no problems at all. Just after I finished this project I noticed that Skywatcher had started doing  the 130pds (duh!, but it was more fun DIY!).

Simply: heavy duty Velcro.

To power my canon 40d (and more recently 80d), I just put a dc-dc buck converter (£2) (Link) in a box with 2.1 mm jacks for input/ outputs and set the output voltage to 7.6 v. Using a canon fake battery power cable with 2.1 mm jack. I can then either use a mains 12v, 3a PSU, or 12v battery to power the camera all night long. This set up has worked for over a year with no problems.