Stub Mandrel

I caught a Jellyfish earlier in the month.

Also, the Leo Triplet:

I put a quick process in the 130P-DS thread, but I've done a lot more work on this now:

On 22/02/2021 at 01:30, Trucker360 said:

so, im a noob...... how do i get to most of these settings. like the noise thingy...

And like magic, here is the manual:

450D Manual Download

On 22/02/2021 at 13:29, wobblewing said:

I had no issue at all with the error induced from pushing the platform following a circle profile by using a linear leadscrew.  As you can see the motion is as good as linear through its entire travel, so a fixed speed across it (without varying across its travel according to position) worked out fine.

In principle, it out to be reasonably simple to implement RA-only guiding. With good polar alignment 60 second exposures with a ~60" fl should be achievable. That could be fun!

Excellent!

Bunch of Monkeys 🙂 and a beehive!

I added some blue data to my HSO image to bring out the reflection component of this nebula.

On 02/02/2021 at 17:22, John78 said:

Is anyone using a QSI 683wsg camera with a Skywatcher coma corrector - I have one on the way (camera) and I forsee back-focus issues,  The Skywatcher CC has M48 threads, if I use the M48->T2 M42 adapter to screw on the end of the CC to then screw into the camera I effectively add 7.3mm to the total distance because I cannot screw the adapter down to be flush with the flange.

So the question is - is the 55mm measured from the flange, or the very back of the threads on the CC, there appears to be no optical drawing I can find for the CC?

The camera with T2 adapter has a backfocus distance of 1.98", so i'll be out at 57.6mm before including filters etc...  I suspect the solution is a custom M48 adapter plate close to the correct thickness to screw the CC straight into, that or turn 3mm+ off the end of the CC in the lathe 🥶

The S/W coma corrector is designed to give the correct performance when the flange (i.e. the flat surface at the bottom of the 48mm is exactly 55mm from the sensor.  This works well with custom M48 to Nikon/Canon fit adaptors.

What you probably need is to discard the T-mount nosepiece which is too long to use and instead use suitable adaptors between the CC and the body of the camera.

QSI can probably tell you what to use.

This is how I use mine with ZWO kit: M48 - M42 adaptor, followed by various combinations of various M42 spacing rings and my filter wheel to make up a about 50mm, leaving about 6mm for the camera backfocus. The extra length allows for shortening of the light path by 1mm due to refraction in the filter wheel.

I've just upgraded to version 1.9, a long process with my cronky broadband and was a bit disappointed to find it just hangs when I try to import FITs.

Rather than going through it all again to install the beta, I think I will wait until the next release before using the stacking as it seems a bit short on options compared to DSS at the moment.

If  stacking can be refined, FITs added and a direct paste only into selected channels (the various workarounds are infuriatingly non-intuitive compared to other imaging packages) it will certainly replace photoshop and maybe DSS for me, but it isn't quite there yet. I hope these things are sorted soon.

A few versions here:

https://www.thingiverse.com/search?q=footprint+moon&type=things&sort=relevant

The original:

https://www.thingiverse.com/thing:266725

Note it is Buzz Aldrin's footprint although some people claim it's Neil Armstrong's

22 hours ago, jjfabien said:

Good day. I have just installed DSS 4.2.5 (I worked with the 4.2.4 previously) and I am now experiencing banding! Most images come out with circular banding. I don't understand where it comes from. Images were taken from a Nikon D750. Any idea how to solve this issue?

Kind regards
 

Circular banding usually means stretching at too low a bit depth. Are you using JPEGs instead of RAW for your images or flats?

On 26/01/2021 at 13:30, Daf1983 said:

Would the 80ed not need a focal reducer to make it quick enough for imaging? This would bring the focal length to 510mm (with 0.85 reducer which most use), which is not that much longer than the 72ed. I'm not disagreeing with you by the way, just trying to get my head around both optiins😁

I've had a play on the field of view simulators, and while the 80ed is probably better for more targets, I felt there wasn't much in it(assuming you use a focal reducer)

Bear in mind the ED72 will need a flattener as well so if used with the SW flattener the relative lengths remain the same.

I have no trouble imaging small, faint DSOs at F8, personally I don't find that aperture makes as huge a difference as I would expect, but it's affected a lot by other aspects of your setup too.

<edit> I should make it clear the primary reason for a 'reducer' is its role as a field flattener and improving star shapes - changes in focal length are a 'side effect'.

On 24/01/2021 at 12:00, happy-kat said:

Thought you had startools as well, could use the compose module to combine then save as tiff output

I never got the hang of startools or pixinsight. I have an aversion to packages with non-standard interfaces.

ED72 is a much shorter focal length, making the ED80 more of an all-rounder. I suggest using the field of view simulators in Stellarium to look at how they suit different targets.

Bear in mind though that if you go for a dedicated astro camera in future it will probably have a smaller sensor, especially if you want to stick with 1.25" filters

I have a scope made with the lens from the obsolete ED66 that is superb as a wide field scope and is same focal length as the ED72 (400mm) there are some hints the ED72 may not be quite as sharp being a faster scope than ED80/ED66, but personally I doubt it's noticeable under most circumstances. The ED66 complements my 130PDS which is similar Fl to the ED80 with the coma corrector (590 vs 600mm).

I also have a 1200mm scope for small DSOs and planets, and various wider camera lenses.

Of all of them I think ~600mm (130p-DS/ED80) is a 'sweet spot' in terms of price/performance and flexibility of targets, but that's only my view.

A good combo might be ED72 and a 130P-DS for not a huge amount more than an 80ED alone.

My latest 130P-DS image:

I think taking a step at a time is sensible, I feel that in many ways it makes the journey more rewarding.

But I would go straight to a scope that will serve your needs long term. The ED80 should tack for a minute or longer if you have good PA and the mount is well adjusted.

The step to guiding is relatively cheap if you already have a suitable laptop, so you pr4obably won't take too long before moving forwards.

On 23/01/2021 at 00:50, Jamgood said:

I was just amazed I could capture anything! Blew me away.

I bet that did 🙂

I've had a brilliant idea...

I'll just keep PS2 for combining images then edit them in something else...

This is from September 2015, but I just uploaded it to YouTube, I hope folks find it interesting.

Not sure I ever shared this 🙂

This is fitted with a cheap eyepiece/erecting prism and minolta t-mount adaptor I found in a bargain bin decades ago before discovering astro.

HI,

On 28/09/2020 at 11:48, dazza1639 said:

These are my first go at HOO, and I struggled a bit with how to combine channels in Affinity, it's not as straight forward as pasing the mono images into each channel like photoshop, but once I got the hang of the new workflow and the differences with masks, I think I prefer it.

I have just bought Affinity Photo, but I am completely unable to work out how to combine three mono images into an RGB one, despite searching their forum.

You obviously have cracked this problem - could you explain of give me a link to the solution!

Many thanks.

(My 20 year-old copy of PhotoPaint you select combine channels and assign one image to each channel - it's as simple as that! - it also lets you split images with one click - RGB, CMYK etc.)

On 17/01/2021 at 08:45, Ouroboros said:

There is and I find it works tolerably well. I use a 450D and see banding with that. The amount varies session to session, and I have never been able to pin down the conditions in which it occurs.  I didn’t find taking darks reduced banding. I also have a pathological dislike of taking darks when I could be taking lights. My time imaging under the stars is little  enough without wasting a huge fraction of it taking pictures of nothing. So I take more subs and dither.

You don't need to take darks for every session. Before modding it for cooling, I took three sets of darks for each exposure length I used with my 450D - one set each for warm evenings >10C, cool 0-10C and cold <0C.

Their impact on image quality was dramatic.

Even to get a set of 12 5-minute darks is only an hour, which could be at the end of an imaging session while you pack up and get ready for bed, and you don't have to repeat it.

10 hours ago, JamesF said:

I'd be 93, but if I've not gone out in a blaze of glory well before then I'm going to be quite disappointed

James

Live life at a moderate pace, die in middle age...

11 hours ago, Chriske said:

But I think it"s time to leave this thread. Although it is a eq. platform, it has nothing to do with the original post.
Sorry Neil...🥴

Not at all Chris, your mount adds to the body of knowledge and is nicely executed although the 'rustic' tripod made me do a double take!