Stub Mandrel

4 minutes ago, Whistlin Bob said:

Yeah- it didn't show up so much in the editor at full resolution but stuck out in the jpeg like a sore thumb. It does leave quite a few artefacts behind, but they're easily dealt with if you take a bit more care than I did!

In Photoshop there's a 'healing Brush' which sometimes does a smoother job.

Went over to join about ten stalwarts from the Rosliston Club, hoping to do a bit of outreach, but we only got a handful of the public.

A few very brief clear spells let me focus with my ASI120MC on the Bresser (Lidl special!) Decided not to use a barlow due to tricky conditions.

We missed first contact as it was clouded out for several minutes so Mercury was well on the disc by the time we first saw/imaged it.

Over the next hour, lost of brief appearances.

Then a small but tall tree interfered for most of us while we got about 15 minutes of clear! I got a good run of video just after this.

Nearly everyone packed up in the face of thick, dark cloud and light rain, but Andy (who had a Daystar) persisted and I swapped over to my C90 Mak and DSLR and eventually skies cleared again. A few folks who had stayed in the hope of a sighting saw good views on my camera and Andy's Daystar and I got some whole-disc pictures.

I packed up and spent a good while chatting interspersed with looks at the daystar including seeing my first prominence.

Neither Registax nor Autostakkert wanted to stack the images, so I manually stacked the ten best scoring. Unlike 2016 I had flats, which seem to be even more critical for solar than DSOs!

Added some synthetic colour:

18 hours ago, Whistlin Bob said:

Been playing with Starnet++ on a Western Veil I took with the 130pds a few weeks ago. Starless and less starry versions below. Kit- 130pds, HEQ5, Cooled 550d, Quadband Filter, 26x 6mins with Flats, Darks and Bias. Uploading it here I can see I need to spend more time on the background of the star-less one- still quite pleased though  

 

 

There's a sort of repeated 'fish scale' pattern at the top of the Starless one, was that the clone stamp? Still, I want a play with this 🙂

Quick and dirty go at your helix, Gradient Exterminator to colour balance, curves to tidy up the background then Noel's space noise reduction action.

Try Astromedia for small front-silvered mirrors:

http://www.astromediashop.co.uk/Components.html

22 x 15.5 for £2.45 + postage.

The top of the T2 hole may need some manual tidying up.

21 minutes ago, zfedoran said:

If you have the dexterity to successfully debayer a sensor, then maybe take a look at building the Cam86 (which has a 16 bit ADC with a real CCD sensor). You don't even need to sacrifice a camera to get the sensor, you can buy old new stock (about $10-20 per sensor).

 

 

Too many projects, too little time, at least for the present...

2 hours ago, zfedoran said:

I imagine it would work since it is older. If you do try it out, the trick is to get started with a small scrape, just enough to lift a few CFA pixels. Then apply the tape, pressing firmly, then peal back slowly. You'll need to take a lot of care to ensure the static cling of the tape doesn't make it jump somewhere you didn't intend (like the gold wires).

Take a look here: https://www.cloudynights.com/topic/486810-thinking-about-removing-the-cfa-from-my-20d-thoughts/

 

Just a side note though, I've done this on two canon 20d's and honestly, it isn't worth the effort. The camera is quite dated and really annoying to work with software wise. Other than that, it also suffers from an outdated ADC process that introduces noise.

True, I haven't used the 10D since getting a 450D; being 12 rather than 14 bits probably loses more signal than debayering gains.

Still it might be fun to try.

8 hours ago, zfedoran said:

I was hoping that the sensor would be old enough to work with the scotch tape method (I've done a Canon 20D, which was super easy thanks to the CFA coming off with tape),

Cool - I have an old 10D do you think that would work on it?

8 hours ago, WanderingEye said:

Well, I am not sure what the scale is on the EQ8 encoder, but what I do know is that the amount of backlash does NOT register on the encoder when I move, so it’s not enough to show there, but not sure how small the increments are in there.... 😀

Edit: just found this, the resolution of the encoder, so does that mean that the backlash is less than 1.2 arc-mins, as it does not register..??

17624 Counts/Rev., approx. 1.2 arc-minutes

Arc minutes are what you need for GOTO, arc seconds are 1/60  the size and what you need for guiding.

Backlash in DEC shoudl be as small as you can get it, but totally eliminating it isn't as important as it being consistent - if it is reasonably small and consistent PHD2 will be able to work it out empirically and compensate for it.

Yes, a lot of astro cameras have an 'ST4' output that has four signals which operate the four guide directions.

@steppenwolf's   (Steve Richards) book 'Making Every Photon Count' explains how to modify the switches in a non-goto controller and set this up.

Well you got an excellent pair of images out of it, even if they are upside down 😉

Your basic understanding is correct.

Some people let the polar alignment be slightly out, as that tends to mean most corrections are in the same direction, minimising backlash (mostly an issue in DEC as guiding in RA is usually an issue of varying drive speed but not direction).

My own experience is that the better the PA I get, the better the guiding.

The clever bit is that the software measures the relative brightnesses of all the pixels in the star and uses these to average out the centre, this can be done accurately to a  surprisingly small fraction of a pixel. This allows quite small, short-focal length scopes to be used as guiders and still allow tracking well enough for much longer scopes.

Software wise I use PHD2, I now get consistent results, with the actual accuracy usually determined by the transparency and seeing. This meant 'tuning' the mount and experimenting with different guiding algorithms to see which worked best with my setup.

I think I can be safe in saying that what works with me may not work as well for someone else as you need to match the way the software works to the hardware  - we are asking the scope to point with an accuracy to shooting a bullet through the earth into a target the size of a football field, so tiny differences in setup mean measurable differnces in how teh rig reacts to guiding.

Good news is that the number of choices is reduced by the ability of guiding software to learn how your rig reacts so you just need to experiment with a few algorithms and they will do tehir own fine tuning.

9 hours ago, wxsatuser said:

The trunk is the dark bit in the middle, turn it 90degrees clockwise.

Ah, Now I see the elephant!

Well I've still used both on this iteration, but with greater care, sacrificing a bit of detail for greater smoothness. It is only 17 subs, so noise is an issue.

What do the 'panel' think?

(Edit - I masked in the old bright stars as they had posterised a bit, they are now bigger, but softer and more natural looking).

21 hours ago, stash_old said:

People are confusing ASCOM with actual "client software" that does something.

If ASCOM was 'just' a protocol or architecture like TCP or USB I'd agree but it isn't, you need the platform which is a discrete lump of software for it to work.

21 hours ago, carastro said:

This is what I am seeing if I blow it up.  It's not noise it's like Jpeg artifacts.

I have blown up one of the areas bottom left. 

Carole 

Usually means I used Noel's Deep Space Noise Reduction followed by Astra Image's Denoise ; must take care to use on OR the other..

Just now, carastro said:

The image itse'f without zooming looks good, but it doesn't look good to me either when I try to zoom in on it.  Are you sure you uploaded the right file?  Looks more like a jpeg to me.

Carole 

I think it's just a bit noisy and colour blotchy being only 1 1/2 hours data?

But criticism is useful... How about this?

This is a screen grab at my end:

2 hours ago, tooth_dr said:

Neil what do you do when you upload the image. It is quite pixelated when I click on it. 

Most odd, it looks fine here - one pixel per pixel, if you know what I mean!

It's just a standard PNG, at half APSC-size (I used super-pixel mode).

4 hours ago, alterelektroniker said:

Alternately, google for Glob Top Adhesive-Sealants.

I want a tube of ANYTHING called Glob Top. I don't care what it does.

Taken on my third outing with an Optolong L-Enhance filter, used with a modified, cooled canon 450D, home built ED 66 scope and HEQ5 mount. 17 x 5-minute subs.

2 hours ago, don4l said:

That's excellent.  The bit that I find hardest is matching the backgrounds - and you have nailed that.

 

It's the final fiddle with gamma and black point that does that.

12 hours ago, tomato said:

A great result, what software did you use to stitch them together, APP by any chance?

Thanks, I did it manually in Photoshop: match a star, set it as centre of the image and rotate, then adjust gamma and black point until they pretty much match.

Might be better if I processed the two images the same, the Soul is sharper but shows less detail.

I've made my first attempt at a mosaic with pictures of the Heart and Soul nebulas taken this month using the L-enhance filter: