silentrunning

Managed to grab 5 x 5 mins in R, G and B of the supernova in M101. I would say it was about m11. 

Green box shows location before it went bang! 

Yep that's it! 👍

I was imaging M108 last night and managed to get 3x5 mins in L,RG and B before the clouds arrived. This was with a 12" GSO RC and a QYH163M. 

Looking up this object I was surprised to see that a supernova had been discovered a few days ago and I managed to locate it in my data.

SN reference - https://www.wis-tns.org/object/2023dbc

I've designed and printed both a 5 and 7 position 2" filter wheel using my Ender 3 pro. For the motors I use small Nema 17's that are controlled by an Arduino UNO with a CNC shield that holds up to 4 stepper motor controllers. I have used the one arduino with the shield to control RA and DEC on a 3D printed German Equatorial plus a focuser and a filter wheel. I wrote the firmware for the controller to emulate Skywatcher firmware on the RA and DEC motors and filter wheel and focuser on the other two motors. Having written ASCOM drivers for everything it connects seamlessly with all the usual control and acquisition packages. 

I've used the whole set up  with a QHY163 camera and a Samyang lens. I wouldn't trust 3D printed components to take the weight of the camera etc so my camera on this setup is held in place - as is the Samyang 135 lens -  with rings that I designed and 3D printed.

One problem I came across is that PLA seems to let through certain wavelengths of light so it is crucial to paint the filter wheels. I used Black 3 but this left an awful sooty deposit and I got a much better result using mat black spray paint.

Here's a clip of the mount during development - It's absolutely silent now as I moved from A4988s to trinamic 2209 controllers, massive improvement, incredibly quiet and amazing microstep resolution. 

I also printed various worm gears including gyroid ones - as shown in the second clip. In the end I went over to a belt driven system that improved things enormously as PLA gears tend be just to rough even at the smallest layer heights. 

I will see if I have any photo's of the filter wheels.

Good luck. Let us know how it goes. 

John

Here's a pic of some of the other components. It's all disconnected at the moment as I work on other things. This shows the  ring system, the 2 filter wheels, a glare shield for the Samyang and a mount plate all 3d printed. Also a handy carousel holder. 

All examples straight out the box with no additional processing and default parameters.

During the processing of some data on M45 I ran Starnet 2 to create a starmask and got this incredible result which has had no additional colour processing.

I guess it shows how the brain fills in the stars with the color of the blue nebulosity as the images are otherwise identical just one with and one without the neb!!!

It is a fantastic book Mark. I can't imagine you being disappointed. 

I actually contacted Prof Kaler after having finished a second reading of it which I started almost straight after I first finished it! So much wonderful information and beautifully written. He wrote some very kind replies to me. 

Based on this book I bought this book of his  https://www.amazon.co.uk/gp/product/0716750759/ref=dbs_a_def_rwt_hsch_vapi_taft_p1_i7 and I can say it's just as astonishing. It maybe getting on a bit but there is nothing in it which has fundamentally changed.

"Stars and their Spectra" by James Kaler is the best book I have read on the mechanisms behind stars and their evolution. It contains next to no equations but digs in very deep and is one of the most readable books I have ever picked up. I paid £29 for the hard cover so I've no idea why it is currently £160 on Amazon.  Maybe it's popped out of print for awhile. 

Here's my Amazon review of it.

----

As an amateur astrophotogragher looking for additional pursuits related to astronomy I have been toying with the idea of a buying a diffraction grating to attempt some very basic spectroscopy of the stars. Looking into this subject I came across this book by Kaler which appears to be well received and offered at a good price for a substantive hard back.

Once started I could not put this book down and read it word for word over a couple of weeks. It is beautifully descriptive, written in a refreshingly warm style in contrast to so many text books that though detailed mathematically are very cold and feel almost unattached to their subject matter.

After a general introduction Kaler offers a description of how observational astronomy can be used to derive the physical properties of stars and then gives a superb account of the atomic processes that give rise to continuous, emission and absorption spectra and why and when these spectra can appear in combination.

After a description of prismatic and diffraction based hardware the book starts in earnest to explain the spectral sequence, initially giving an extensive account of the history and different systems that have emerged over time and how these have been distilled down to today's system OBAFGKMLT.

The HR diagram and the MK system of luminosity is described in detail and then the book starts in earnest by allocating an individual chapter to each star type starting at M and making its way through 300 odd pages to type O. Each chapter is absolutely engrossing due the authors passionate style of writing.

Beyond type O the author continues in the same vein to describe planetary nebulas, protoplanery systems, white dwarfs, neutron stars and many other exotic types. Nova and supernova are described in detail and the book concludes with 40 pages or so dedicated to the subject of the live cycle of different mass stars which beautifully draws on all the details of the previous chapters to give the best description of the life of a star I have read.

This book has essentially no equations but is clearly written by someone who is profoundly knowledgeable and besotted by the stars.

In summary a wonderfully detailed yet ever so readable book that I highly recommend.

-----

https://www.amazon.co.uk/gp/product/0521899540/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

It hasn't got WiFi. The PC running Octaprint connects to the printer via the USB cable.

I learnt to design stuff with Freecad and then switched to Fusion 360 which is also free and a stunning design environment.

I was using Cura as a slicer but have switched to PuraSlicer.

I don't use the SD card, I have Octaprint running as a server on my Windows 10 PC which talks to the Ender 3 via it's USB port.

Got into 3D printing a few weeks ago and have completely immersed myself in it.

After doing loads of research I bought the Creality Ender 3 Pro and it's superb. Not a lot of difference to the one you are looking at and with the upgrades mentioned I would consider it a great buy.

Superb Carol. Great processing. 

Well I've never used an SLR before for anything but one turned up yesterday. 🙂 

It was a stunning evening last night and the comet was perfectly placed for viewing from my back garden but unfortunately not accessible from the Obsy.

Having recently purchased a Samyang 135mm F2 lens that is currently bolted to the mount in the Obsy I decided to splurge on a Canon SLR so I could potentially get into 'normal' photography and make more use of the lens. Anyway after a few hours reading the manual - the camera seems to have more functions than the space shuttle - and a quick look at the settings some people have been using to capture the comet I pointed it at the comet and grabbed some 20 second frames using the standard zoom lens that came with it.

It proved hard to focus and the lens is clearly not of a quality we astrobods would hope for but it was nevertheless exciting to see the comet on the cameras screen. I also had a go at light 'painting', during a 20 second exposure I shone a torch around the back garden and that seemed to work really well as well. So all told I'm pretty pleased with this first stab at using an SLR.

This is 20s at f5.6 ISO 800.

I found this a tricky object to process as well.

If you do a Google search for NGC6888 thousands of images come back very few of which appear 'right' to me or give me something to aim for. Strange object.

After a mad 2 or 3 weeks getting to grips with a new hobby 3D printing (or rather and adjunct to astronomy!) I managed to build a couple of adapters that have allowed me to get to focus with the new Samyang 135mm F2 lens bolted onto a SX filter wheel and a QHY11 Camera. A couple of nights ago I got to run the lens in and out on an adjustable adapter I had made and once I felt I was bang on that elusive 44mm I quickly printed off a non adjustable more sturdy adapter giving the same lens to chip distance. 

This is 10 x 10min exposures binning at 1x1 in Ha. Hopefully get some O and S to add to it when the weather improves.

The full resolution image can be found here

Superb image Carol, hope you get the Samyang back in action ASAP.

4 hours ago, Adreneline said:

Glad you've got it nailed. Is this image cropped at all? The aspect ratio looks almost like 16:9.

What was the final spacing between the sensor and the lens end plate? Was it bang on 44mm?

Adrian

Hi Adrian

Yes this imaged was cropped as I did a meridian flip half way through and didn't bother centering on the previous images. The full field of the frames obtained before the flip is shown below. I just adjusted the distance until I got the flattest frame so I assume I'm at the quoted 44mm for this lens.

and the corners via the AberrationInspector script in Pixinsight....

I'm not used to WF imaging and was surprised at the under sampling of the stars, something I don't have to worry about with my usual setup using a 12" GSO RC. I registered using drizzle and got a massive improvement..

Well the adjustable adapter allowed me to get the QHY11 near to if not bang on the focal plane of the lens. The field on this image is so much flatter than with the previous adapter.

Well it's built, appears to work and is now in situ! It maintains the Canon bayonet on the lens. Outside of the canon connector is an external thread of 58mm diameter 1mm pitch that threads into an equivalent female thread built into the custom FW adapter. This eats into the space available for the screws that connect the flange to the FW so I had to print my own tiny screws with 2mm heads!!! I can now achieve minute, <0.05mm adjustments to the lens to chip distance and hopefully get close to the ideal 44mm. Next clear night I'll have a play and see what effects this distance has on the various out field aberrations.

Finally got my hands on one of these lenses. Been a lot of work learning a new hobby 3D printing to get the FFD down towards the optimal 44mm. I've built adapters for both sides of the SX FW I have. One connects the Lens to the FW, actually bringing the lens into the FW slightly and an adapter for the QHY11 Dew Heater and camera connector on the other side. This one actually mounts inside the wheel although it's all very tight in there, just a 1mm flange and no screws to hold it in place.

After reading this excellent thread I am probably going to go ahead and build an adapter that removes the Canon bayonet completely and will connect directly to the FW,a bit like the one FLO are now selling for the ATIK FW. I might even try to build in adjustable shim ring so I can get bang on the 44mm rather than either side of it. 

This is a single frame and essentially first light I obtained before the clouds rolled in the other night. I'm not sure what to expect at the very periphery of the field at f2 but I have significant aberrations in the outer 3rd of the image, especially one side which makes me think that image tilt is definitely part of the equation. Wether getting closer to the ideal 44mm will smooth things out across the field will have to wait and see. Pleased with progress so far.

No processing other than a stretch.

4 minutes ago, fozzybear said:

Found this on their website

Our 1.25" filters have a M28.5 male (and M28.5 front female) thread / our 2" filters have a M48 male (and M48 front female) thread

Both thread sizes come with our proprietary pitch - which is not the same for the female and male threads.
This is our own proprietary "emergency solution" for uniting a world were manufacturers all over the world copy from each other - to the point that there are almost a dozen different pitches in use for male and female threads. Traditionally US-companies used to do a UNF-based pitch and the rest of the world went for metric threads - but these do vary from 0.5 to 0.75.

For this reason it does not make sense to publish our non standard pitch because our pitch is made to cope with all existing metric and US-pitch standards - and as said - our solution has evolved from sheer necessity. It is a mixture of a queer pitch and under-/over-dimensioning . We will not want to declare this as a standard and get bashed up for it. It works for us and is a result of 20 years adaptation to fit our filters onto all crazy threads we have seen. And inspite of this - every now and then there comes another "dragonboat-eyepiece" were even our filters may not fit

Thanks fozzy bear that clears things up!

What a strange stance for Baader to take. I understand their reasoning for producing something that presumably fits as many non-standard bits of kit as possible but not telling us what they pitched for in the the end is crazy- sorry for the pun!

12 minutes ago, fozzybear said:

Baader Planetarium of Germany use a slightly different thread pitch (which they do not specify, but which is a little less than 0.75mm) for their M48-threaded products. This was selected based on their measurements of hundreds of other M48 threaded accessories on the market, and which they believed would therefore increase the chances of their products being compatible with the largest number of non-Baader items.

Struff! What a can of worms astronomy gear is! Thanks.

Anyone know the thrread pitch of standard 2" filters in particular Baader 2" filters?

Thanks in advance.

On 19/06/2020 at 15:40, badgerchap said:

Welcome to 3D printing! Such a joy seeing your creations emerging upon the build plate before your very eyes! 

 

I'm impressed with the thread pitch you managed from an FDM printer, that's great going! I have a resin printer that can perhaps go a smidge smaller on a very, very good day, but would be a lot less rugged than what you'll have produced. Great work. Might have to get myself an Ender too.....  

Your right it's mesmerising watching this thing!!!..