david_taurus83

Excellent! Even with a 150 Esprit it's small! Which outer shell is everybody referring to? I can see 2 🙂

47 minutes ago, Annehouw said:

Here is something that you can try: If you are using the native ZWO driver in PHD, change to the ASCOM driver.

I had the same observation as you and changing the driver changed typical snr from 20 or so to well above 100.  What I noticed in the guide frame is that there were fewer stars to choose from, but the star shapes were much smoother. 

I tried that and it made no difference initially. Using the ZWO driver you can still select 16 bit mode. Whichever you choose though, you need to input the correct ADU value in the Saturation by ADU box, so 255 for 8 bit mode or 65535 for 16 bit mode otherwise I find it was selecting staurated stars or incorrectly displaying the red SAT warning on non saturated stars. After changing to a low gain of 10, it worked perfectly last night despite seeing conditions. Even when high haze came in around 2am it carried on at around 0.6" RMS no problems. It was up there with my old AZEQ6 for performance last night.

53 minutes ago, kirkster501 said:

Yes true.  But don't make the mistake, on a rig that had previously been guiding well, that if you get a bad guide graph one night that you have to make wholesale changes.  I have learned this one the hard way.  After years of trial and error and me thinking that I know better,  I've found the defaults are indeed very good choices.

I agree, there are perhaps too many things the user can change. I wonder if in the Guiding Assistant they could employ an algorithm to determine the best gain and exposure to select a suitable star for your given sky conditions?

47 minutes ago, happy-kat said:

It's common for cameras to have dead pixels so don't be surprised to also see dots of red and blue etc around the image.

F22 is a very small aperture so even at 30 seconds won't let a lot of light through but expected it could be noisy.

F22 makes sense as I dont think the kit lens goes down to F2.2!

You would make it more sensitive. The idea is that you make 1 large pixel out of 4 (2×2)  so all the photons that hit that super pixel add to its charge and increase brightness. This works in a CCD better than a CMOS. You might be better to resample in post processing software. I tried binning an ASI1600 and I had a lot of blocky stars. Resampling in Pixinsight gave better results.

Here is a screenshot of my initial guiding. Look how rough the SNR graph with an average value of 50. This was a star PHD selected.

I then lowered the gain and let PHD select another star. Much better performance all round and the star profile stays nice and steady.

34 minutes ago, kirkster501 said:

You can drive yourself mad obsessing over the guide graph.  Very often it is just the seeing that night.

Possibly a lot of times, if you dont change settings but I dont think the seeing improved for me tonight as I changed gain. I'm used to seeing a SNR of 20 or so but I regularly see screenshots of other folks PHD screen with high SNR values. I'm starting to convince myself that low gain with this camera is forcing PHD to select better stars and therefore high SNR.

At 30 seconds the light from that window should swamp the sensor so I'm guessing your ISO was very low?

I know I shouldn't dwell on it but I've been doing a lot of graph watching lately. I've been kind of cheating recently and selecting saturated stars, not too saturated, just with slightly flat tops on the profile. SNR on these are up to 200 or so and the guiding graph always smoothed out. I've typically always used a high gain setting of around 80 or so and letting PHD select a star, it always tends to select a low SNR faint star and and watching the profile, the star wobbles and waves and naturally the centroid moves about and the mount follows suit. Typical guiding of around 1.3" RMS with some large peak to peak errors. Tonight I've experimented and dropped the gain down to 10 and let PHD select a star. Its selected a nice bright unsaturated star with SNR of 250 and the centroid stays exactly in the same spot and my guiding error dropping to 0.6" RMS. There is a lot of vertical banding now I'm guessing due to low gain but I'm not bothered. This has got me thinking. Are the problems we think we have with guiding actually to do with the mounts or a particular setting like above in PHD?

Do you have all the bits that came with the 1600? If so you should have everything. Camera and FW is 26.5mm, the 21mm spacer and the 16.5mm M48 to M42 spacer with the M48 to M42 adapter on the scope side should enable you to thread onto the reducer. That gives you 64mm. Add some of those thin nylon shims and you should be about bang on.

£400 for a lump of steel! I'd be looking for threaded steel bar for a shaft and use nuts to hold weights in place!

Good polar alignment is one thing but it has more of an effect on long exposures. The stars in your image have a streak which looks like a sharp deviation so could be wind, cable swinging about, backlash etc. Neq6 is generally a good mount though so 60s exposure at that focal length should be achievable. Is the mount new?

I've tried to recreate an image similar to your but cant. My cr2 files are set to open in their raw format but nowhere near as bright as yours. Yours looks like a mono image with noise. below left is an uncalibrated cr2 file with half saturated sensor and right is debayered with unlinked stretch.

Snap! It was my birthday yesterday as well. Also celebrated with some cider and an imaging session 🙂

Use hand controller and setup in Alt-Az mode. No need to polar align then.

I started with APT and still use it from time to time. Mainly using NINA now, primarily for its auto focus routine as I think APT is lacking in that department. NINA has a good sequence routine and will happily slew to target, platesolve, centre, image, dither, autofocus as often as you want (x number of frames, x number of minutes, or if HFR values of stars increase etc) auto meridian flip etc. Oh, and its FREE!

Belt looks stretched. Too tight?

@Knight of Clear Skies

Sharpcap. I used to have a Polemaster and both give near similar results. If anything, I think Sharpcap is a bit more accurate and you only have to rotate the mount once where Polemaster is more fiddly, more steps involved and more user input needed. Also, grossly overpriced given the availability of Sharpcap for £10.

31 minutes ago, stash_old said:

Never said it did - ASPS settings wizard calculates the FL from the info you put in from the Astrometry.net solve - "Pixel Scale" - Step 5 then give a new FL. 🙂

Bottom line it works!

No, I'm sure it used to say it. I've seen it! Just wondering if theres a setting I'm missing somewhere!

Where does it say on Astrometry the focal length? I'm sure it used to as it solved some of my 200p images as 1018mm, that's why I remember!

5 minutes ago, vineyard said:

Ah ok, thanks. The original image is so clean, I just had to chuckle seeing my hack at it!  Cheers & stay safe, Vin

Hi Vin. I got a similar result with my DSLR and 3 hours worth. I think this one needs dark skies. One for a star party I think.

^^^ This. Once you've calibrated your lights, then debayer them all. (Optional, but after debayering I load them all into Blink to have a look for bad ones and discard as needed.) Then pick one to align all the rest to, then integrate. I used to use the LVA tutorial and it's similar to the book but I dont bother using the drizzle or normalisation routines as they take soooooo long unless you've got a supercomputer!

No, not all the way in. If you can get roughly 1m from the glass to the camera body and you have an inch either way to play with you should be fine.

I see now. On the adapter you got today, can you unscrew the 1.25" adapter on the end and insert the 2" section. You might be able to use that. You can use it as it is but with the 1.25" barrel you are restricting the amount of light that can get to the camera, if you see what I mean. You would end up with dark corners and edges.