fwm891

@Anthonyexmouth I imaged the comet with a Celestron RASA 8 at f2 with an ASI294MC Pro cooled to -20°C. Processed in PI. Image is cropped to remove stacking edges

Animation made up from the one hour track last night

Compilation of 60 x 60 sec subs aligned on the comet in PI. All processing in PI. Also a star aligned image using the same subs to show it's movement.

Clear again so again tried an object (M44 - Beehive) that I can't remember ever shooting before and M97 / M108 pairing, a couple I've not looked at for some time.

Hi Tony, I've just tried this in PS CS3.

What I've done:

Opened your image

duplicated the layer and made the blend method screen

Applied 1st levels adjustment layer - lightly

Applied 2nd levels adjustment layer - again lightly

Applied 3rd levels adjustment layer - again lightly (Better to gradually apply levels and keep the noise down)

Applied Hue Sat adjustment layer

Applied a colour balance adjustment layer

Applied a curves adjustment layer - tiny shadows adjustment

Then tweaked the upper levels adjustment layer for mid tones.

Flattened and saved as small tiff

Francis

M13 The Great Hercules 26-3-20 -proc.tif

Tried imaging the Leo Trio. Not been to this area for some time - quite a change.

Image is built up of 27 subs, equal mixing of: 120, 300 and 600 second subs.

Captured with SGPro, processed in APP (stacking and calibration) PI (colour work) and a levels tweak in PS CS3. 

1 hour ago, alan potts said:

A really nice image Francis, could maybe use a tad more saturation in my view.

Alan,

For you @alan potts with a bit more saturation (as far as I dare)

Francis

Finally got the dark, flat and flat/dark calibration frames for this image. This has allowed me to do a less severe crop taking away  just the stacking artefacts.

Final processing carried out in APP (calibration and stacking), PI for background correction (DBE, ABE SCNR etc) and a final levels check in PS CS3.

Hope you like.

Both images with William Optics ZS 73 + Flat 73 A x1 flattener. Nikon 800E (no filters) on an iOptron CEM25P guided (PHD2) via 9x50 finder guider (asi 120mm)

Shot as RAW frames and processed in PI and PS CS3. M101 had 16x 180s subs, M51 had 14x 120s subs.

Both frames have been cropped

Sixteen sub frames 60 and 120 seconds mixed. Stacking on the comet head in PS-CS3

Fan shaped flair on the stars caused by cables

1 minute ago, Mark at Beaufort said:

Nice photo Francis - hope you are keeping well. 

Thanks Mark - I hope you and yours are too 🙂

I've combined the previous nights data with last nights ( now totalling: 3hrs 40 mins ). I still have no darks, flats etc for calibration but I pleased with what's there at present - hope you like

Processed in PI and tweaked in PS and back to PI...

Nice one Brian 👌

10 hours ago, astro mick said:

Hi Francis.

Well done on the capture of these Galaxies.It looks a bit noisey to me and calibration frames would defo improve the overall image.The Galaxies seem to be a bit overexposed,with blown out cores,however you proberbly know this.

Still a nice capture.

Mick.

Thanks Mick, Yes pushed really hard in PS and definitely needs more subs long and short. I'll try processing through APP that seems to deal with noise better. 

Process in APP and PS. Less noise but background dust has gone. More data needed...

This image set was captured on March 15th but only just got round to processing the subs.

Subs: 6x 120s, 5x 300s and 5x 600s combined in PI and finished off in PS CS3.
Taken on March 15th 2020
Celestron RASA 8 and ASI 294 MC Pro @ -20°C, IDAS NB-1 filter.
iOptron CEM60 mount.
No dark, flats or bias frames shot.

7 hours ago, Osprey said:

Should I try for 1/8 or 1/16 steps?  I think the 4988 boards I have will do 1/8...not sure of the 1/16, will have to research that one.

 

And so I understand right, you're advocating adding gearing to reduce this even further?

Only if you can't increase the stepper pulses by finer micro steps

Noticed these while walking the dog this evening. Quite strong colour (I have added a little saturation too)

They had faded a bit by the time I got back and grabbed a camera but still a good display - best I've seen both sides of the Sun for years.

7 hours ago, Osprey said:

@fwm891 Getting back to the calculations....

I bought a NEMA 17 high torque motor with 11.9 mm diameter 20T pulleys.

According to the math you've shared with me, here is what I come up with:

86,164.0905 seconds per sidereal day

86,164.0905 / 360 deg = 239.344696 seconds per 1 deg.

239.344696 sec/deg divided by 60 sec = 3.989078 min/deg

The stepper motor is 400 steps per revolution @ .9 deg / rev.  I want to micro-step it down to 1/4 ……….

 

Bill

Bill, I think this is where you're getting confused:

Your motor gives 0.9° per step. You want to micro step x4 steps = 0.225° per step. OK with that? your reducing the step size so the angular movement per micro step will also be reduced.

Divide 360° / 0.225° = 1600 steps per 360° rotation of the motor.

Your Horse shoe is 1219.2 diameter giving 3830.22976... circumference

Your pully is 11.9 diameter giving 37.38495... circumference 

Your motor needs to turn 102.453788... times per sidereal day

Total micro steps 102.453788 x 1600 = 163,926.061583.... in a sidereal day

There are approx. 86,164 seconds per sidereal day (ignoring decimals)

Therefore you motor needs to run at 1.9025 steps per second to drive your 1219.2mm horse shoe at sidereal rate.

I think you've got timing and distance measurements crossed. 

At approx. 2 steps per second that will appear jerky in an eyepiece so you may want to either increase the micro stepping rate, or add a reduction gear to increase the number of steps per second.

Old movies used 16 frames per second as a minimum rate as below that rate visual persistence showed flicker.  Hence why its common now to use 25, 30 and higher rates to smooth out motion.

I hope that helps

Francis

9 minutes ago, Z3roCool said:

A C9.25 Edge HD would be great as recommended above. That with a sturdy EQ Mount. Then for Wider Field with the same scope, could get HyperStar. Best of both worlds? Couple of good cameras - I would be in heaven!

Problem there is that you have to re-collimate both ways when you add/remove the secondary assembly.

The observatory stayed closed due to wind last night but it gave me another chance to use the ASI 294MC Pro with my 70-200mm f2.8 Nikon lens with an IDAS NB-1 filter.

Orion was shot at the bottom end of the range at 70mm the others at circa 100mm. exposures ranged from 30s to 180s. quite a few subs were lost to clouds but I was pleased with the CEM25P mount's tracking. All subs were unguided which given the windy conditions I felt was good. I need to shoot some calibration subs for these images at some stage.

The image of IC1805, IC1848 plus 2017 T2 (Panstarrs) had 60s and 180s subs. The others were 30 and 60secoonds.

The grouping of IC405, IC410, M36, M37 and M38 is probably my favourite for the night.

Both above were slightly cropped but the Orion image is full frame.

Superb Martin - one of the best images I've seen posted for a long time (even mine!) ✅

Images of the eccentric added

I've been playing and come up with an adapter allowing me to fit my Nikon lenses to my ASI294MC Pro cooled camera body.

The adapter is based around a Nikon lens to Canon body adapter (it was in my kit box doing nothing !). This is fitted into an aluminium body (main body in photo) with 6x 2mm metric machine screws. The 294 has a 42mm male T thread, I've used this to fit the camera body to a small aluminium insert which slides into the main body of the adapter. I've threaded the front of the insert to take 48mm filters.

To allow the lenses to be changed easily I have inserted an eccentric cam to depress the release lever - operated by the brass lever on top of the adapter.

The main body has a slip ring/clamp arrangement to allow the whole adapter/lens/camera combo to rotate for framing. I've etched (scratched!) 10° markings around the main body to act as an aid when framing.

Currently fitted to a shortish Vixen bar but this will be altered so when using longer lenses to front of the lens will be supported to reduce loading on the adapter/lens mount.

Photo of the adapter with the 294 and a 24-85mm Nikon lens. Also a section through the adapter (not exactly as built I made a couple of minor changes as the machining progressed. An image of the rosette nebula from it's first light session last night.

It needs a few tweaks but it works.

Images of the eccentric and adapter/294 with IDAS NB-1 filter in place

I've been making an adapter to fit Nikon lenses to my ASI294MC Pro (uncooled test) and last night cleared for a short while to get a few test frames with this set-up.

Mount iOptron CEM25P (Unguided) also unbalanced as the original counterweight was way too heavy so shot with no CW.

Lens Nikon 24-85 f2.8 zoom (D series)

Camera: ASI294MC Pro (uncooled) for test.

Filter used: IDAS NB-1 filter

Processing: APP for stacking, PI and PS for colour.

I should have got out earlier for the Orion frames (2x 60s) as it was disappearing into my gutters so switched to the rosette and the Heart & Soul areas where I had a little more imaging time.

Rosette: Lens set at 50mm but heavy crop for final frame

Orion: Lens set to 24mm again heavy crop

H&S: Lens set to 50mm and cropped.

I like to tinker with bits like adapters so when I came this morning to test my latest gadget to link my Nikon lenses to my ASI294 MC Pro I couldn't quite believe my screen images - there was this round object where a round object shouldn't be?

Quick check: stars in focus, aircraft moving across FoV, clouds passing (fast) and it's still there! I had the camera and 24-85mm lens mounted on a bean bag on the window sill with the lens leaning on the double glazing pointing up at about 45°. I'd pushed the gain up to about 500 in SharpCap(3.2) with 3 sec exposures to avoid too much trailing. I took a couple of snapshots to plate solve later then tried SharpCap's live stack to see if I could reduce the noise around this mystery object.

That's when the penny dropped (plonker) that mystery object was a water droplet hanging under the gutter and catching a local street lamp...

It wasn't moving with the star background but with the short single frames that wouldn't show. It was only viewing the livestack that things began to register (no pun intended)...