david_taurus83

What camera is it? Those dots look like their on the sensor. 

Just now, Stuart1971 said:

Yes, so the Min figure shown is the one I need to alway be above 0….correct…

Yes, it will be, or should be always. When you take a light you should never have a min value of 0. You'll have your bias signal in there as well. The offset value is added to this so even dead pixels will have a value above 0. So when you subtract a flat dark or dark you should never create 0 value pixels in your image because the offset keeps it above the threshold.

2 minutes ago, Stuart1971 said:

Yes, just eying the histogram, I have now learnt about the reading the statistics instead….this gain and offset lark is all me to me after years of using a CCD and not having to know about it…

Yes, keep an eye on the numbers in the statistics. It will tell you the mean reading as well as the max, 65k on a star for example, and the min, your bias number. 

Does it feel much looser now when the clutches are undone and your trying to balance? Mine is stiff brand new out of the box so balance is a bit of a guessing game.

29 minutes ago, oymd said:

@wimvb

Can I please check. 
 

Is this the final correct sequence at the bottom?

Bearing, then 2 smooth rings then clutch?

I'd imagine the bearing runs between the 2 washers.

Did NINA say they had a min value of 0 or just eyeing the histogram?

13 minutes ago, alacant said:

Haven't tried with a 6d but with modern sensors, there isn't need to take bias or dark flat frames. Subtraction of the median works fine. E.g. on a 700d, this value is 2048 (round to the nearest power of 2). Use this value on your light and flat frames and away you go.

In fact this method is recommended and implemented in the latest version of Siril.

Worth a try?

Cheers

That suggestion started a bit of a debate on another thread!

Are you sure that's what's blocking the axis from turning though? Even with a rusty bearing I'd have thought it would still turn albeit be very rough and stiff.

Don't these have a low gain mode and a high gain mode? Where the likes of the ZWO version automatically switches to the higher mode at a certain gain value?

6 minutes ago, oymd said:

THIS ONE GOES FIRST:

Right?

 

I'd order a new bearing if it was me. Good quality SKF

11 minutes ago, ONIKKINEN said:

I was curious about this conversation about darks being not helpful with Canon DSLRs, and i admit i never thought about it or measured my own darks when i shot with a 550D. I took some test darks and found that a 1s dark has a median ADU of 2049 while a 600s one has a median ADU of 2047? So it seems Canon is doing something to make all dark signal be somewhere around 2048 ADUs regardless of exposure time.

The bias is 2047. The Canons have very low thermal noise in general but if imaging in warm weather it does become more apparent. 

20 minutes ago, Grant93 said:

 

Any reason you don't use an IDAS in the lens? Just asking because I had some weird purple and green reflections when using my IDAS in the Samy135mm, but not when using the ZS61. Never found an answer for it, always just assumed the lens was just too fast for it.

Sorry, should have been more clear. The D2 clip in for Canon 6D was discontinued when I tried to order one, so the closest I could get in terms of bandpass was the L Pro. I have a 2" D2 which I use with my scope.

Very limited for choice with a 6D. Personally I use an Optolong L Pro clip in if using a lens. If using a scope I use my IDAS D2.

Don't need darks with the 6D. It has low noise and very low thermal noise. I used to take temperature controlled darks (peltier cool box) and found they did very little to the end result. As vlaiv has said, just use a master bias for your flats and lights. Dithering also helps. I've had my best results with my 6D on the end of a scope, never had much luck with lenses apart from a Samyang 135. Always used a filter. 

2 minutes ago, Astro Noodles said:

Dithering would require guiding. I'm not at that stage yet. 🙂

If you use a goto mount and use APT then you don't need guiding to dither. APT will dither for you.

Been discussed recently actually. I start rambling on a bit about Eqmod but the info is there about using the USB port on the mount. You need to download the Prolific driver from Skywatcher and set baud rate to something different. Perhaps its your laptop that's playing up though?

https://stargazerslounge.com/topic/388361-controlling-eq6r-using-usb/

44 minutes ago, Starflyer said:

Isn't the skywatcher flattener/reducer threaded to takes filters on the end that goes into the focuser?

Don't think so. Think they have an M54 or M56 thread that goes directly onto the focuser. They do a nosepiece that you can use but with the 72ED I don't think there's enough inward focus to fit the nosepiece.

5 minutes ago, Spen21_10 said:

Didn’t know that existed looks like an ideal option for my set up. I’m guessing it will work with all 48mm/2” filters as I’m looking  at purchasing a L-extreme sometime? Currently have the baader uhc-s which came with second hand 72ed but haven’t had chance to try yet cause couldn’t attach. Thank you so much for your advice much appreciated

Yes, all 2"/48mm filters.

The Baader Protective T ring allows you to insert 2" filters into the T ring itself. I have one and use it that way myself.

https://www.firstlightoptics.com/adapters/baader-protective-t-ring-for-canon-eos.html

34 minutes ago, StevieDvd said:

I was synching mount to software before ever using Platesolving - that's different from the Platesolve synch to mount contolling software. What platesolver are you using?

Usually ASTAP from within NINA. I had the same issue 3 years ago with my first AZEQ6. If the mount/Eqmod thinks its too far away from a platesolved position, it refuses to sync the coords to Eqmod, though the imaging software keeps platesolving until its on target. I suspect APT and NINA just issue a slew command in milliseconds in both RA and Dec to reposition based on platesolving results, despite what the mount thinks. Otherwise there would be an eternal conflict?

I've never seen B1950. Sometimes NINA asks on startup to sync location from mount to NINA or vice versa. Pretty sure I have both running on JNOW.

20 minutes ago, scotty38 said:

I'm not 100% sure i understand what you mean here but if EQMOD has the correct coordinates set up and NINA is platesolving ok then things should be good. There are plenty of settings in EQMOD for the Meridian limits etc as well as in NINA. If I use Cartes du Ciel to "test" by slewing to appropriate targets it will cause my mount to flip or not as the case may be. When NINA is running it works there too.

Having said that, using GSServer instead of EQMOD CdC would not flip correctly despite all my fiddling with it. I discovered this the hard way using it with NINA one night night and wondering why guiding had failed. A pier crash was the reason so I went back to EQMOD and it's been fine since.

If I slew from home position all the way round to celestial equator, eg for PHD calibration, I ask Nina to platesolve and sync to the mount. That's where I get an error saying Eqmod rejected the sync as it thinks it's too far away from where the mount is pointing. So even though NINA or APT for that matter can centre on a target, I have found the platesolved coords differ with what coords are in Eqmod. Thats an entirely different topic anyway. I will give the non Eqmod method a go and see how it works out.

2 minutes ago, ONIKKINEN said:

No EQMOD at all, correct. There is a small skywatcher widget on desktop after connecting though. It has N/S, E/W and slew speed buttons and nothing more.

But its not necessary since NINA and PHD2 (and the handcontroller) have full control of the mount.

Thanks for this. I will look into it. Just to be clear, is this the Skywatcher Synscan Pro app in Windows you use or just a widget that pops up like Eqmod?

Eqmod usually doesn't sync platesolved coords for me despite NINA getting a target bang on centre. It's not bothered me too much but I always wonder if this is why I have struggled with meridian flips. Both my first and current AZEQ6 always rejected syncing.

I've just gone back through my messages as I asked a Tak owner this question. He spoke to an optical engineer who suggested it was mild pinching of the optics. So given you were imaging in a colder than usual climate, that may explain your issue. Here's some Tak FSQ85 examples:

34 minutes ago, dieg00 said:

Hmm I see. Did you also experience the direction being different on each star? I am asking because if it were retaining clips, wouldn't the direction of the spikes be on the same directions (of the clips)?

I didn't take particular note of the orientation as I just considered it an artifact of the scope, like how diffraction spikes are to a Newtonian. But I did notice the Takahashi scopes artifacts do change direction around the field of view. I know I've seen an explanation somewhere.🤔