RolandKol

This is RolandKol Dairy:

Linear Fit Clipping stacking started on Monday at 10:30...

2013 Light subs in total. (Lucky, as I have all master Calibration subs.)

Question N1: how long it going to take? - My guess: 5 hours probably... (PC is quite slow... Need a new one...)
Question N2: some subs were a bit cloudy... How many will get rejected by Pix script? - My guess: around 300 probably... (I need a DYI cloud sensor to save HDD space for sure.... will google about it again) 

18 minutes ago, Marmo720 said:

Yes, thought that might be issue so I will retake a new set of bias, darks and dark flats today before the rains come in and see if that makes a difference. 

The M51 data I attached are from clear night without clouds. 

Just check your very first dark taken during a daytime...
In my case, - if camera is on the scope, darks are not completely dark even if the whole rig is covered and etc.

Also,

I think it is worth to mention, - if I recall correctly, Mo did Darks and Bias via APT on Windows,

Lights and Flats, - via EKOS/Kstars on the RaspberryPi.

14 hours ago, Marmo720 said:

58 x 0.3sec bias 

Also, try to take more of them... 100 - 150.

And what about DarkFlats.... Have you managed to collect them?

I just stretched the initial "Autosave.fits" file to show as example for audience. No crop.

This one is autostreched on pix without any background adjustments:

The second, -  Background Subtracted only:

The third, - Background Divided and Normlised, later Subtracted.

I would say, - not perfect, but good enough....
 

P.S.
Mo, is this one the same, -  from the cloudy night?

Asking, as on my Office PC, - after background extraction it looks even better than at home .

33 minutes ago, DaveL59 said:

I've generally dried silica sachets on a tray in the oven, didn't know you could zap em in the microwave, interesting tho they used to say it wasn't good to run a microwave empty and it'd be pretty much empty with only a small amount of dessicant in  there, surely?

It will take around 30sec... 

1 hour ago, carastro said:

Thanks Guys, Well I changed the dessicant.  

Thanks for your generous offer David, but I have about 4 spare tablets.

I left the dehumidifier on in the obsy for a couple of days and tried the camera again, and all those weird swirls have disappeared.

I do however have one stubborn swirl at the bottom, so perhaps it needs a bit more drying out.

Thanks for your help, I will know what to look for in future, or perhaps I should make a point of routinely changing my  dessicant every so often.

Carole 

Glad to see you are getting it back to normal

As per desiccants, - in case you will run out of them

They can be dried in the microwave and used again

Thanks guys for the compliments
But I am not yet happy, - especially with the stars... 
Will try to re-process next week....
Plus, few clear nights are in the forecast for this weekend... maybe I will end up with 4k of subs to play with  (insane...)

Sadly my new Ha filter is not yet delivered

Hi guys...

I am struggling to image in LRGB from my location due to the Light Pollution....
Bortle 8-9... London....
So I decided to go for a short exposures (15 and 30sec) and gain 200 to reduce noise and influence of LP.

Ended up with around 2k subs (62.4GB of data) to Blink/Stack and etc...

I thought my PC gonna die... 

At the end, almost half of the images went to the Bin  

And sadly, I lost most of the Green Channel due to the clouds.... 

You can see the result below...  Heavily cropped due to the LP artifacts.

Not sure if I want to go through all of that again  

But if you have any suggestions how to optimise the exposure/gain settings, - Would be very grateful.

2k of images to blink is not a joke!

Data: L 435x15sec, R 337x30sec, G 69x30sec, B 298x30sec.

130PDS+SW CC +ASI1600MM + Baader LRGB

P.S.

How do people get that "brownish" background colour?
I tried to add a bit of Red without any acceptable results...

P.P.S.

Did something wrong to the stars... 
 

Hi hi,

I would suggest to keep Flats longer than 0.3sec with ASI1600, and just in case, take around 40 subs per filter.
ADU 30k (+-2k should be ok).

I used gain 200 this night, and tried to do Flats on the sky using white T-Shirt...  Was made to place 3 of them bent in a half (6 layers) to get Flats longer than 0.3s on Luminance and ~30k ADU value....
If you use bias subs, these also should be done at 0.3sec or a bit longer (0.31 - 0.32), - and if you want to get perfect results, avoid bias, take darkflats instead.

Hi Guys,

Another M57.
I had some CC spacing problems and suffered from heavy coma.

This one was the test image after some corrections been done, - only R and G filters 30min each at 30sec (blue failed to autofocus after SGP upgrade... ).

I have stacked them as l was curious if l can get any colour from 2 channels only

Hope to add some data some day.

Hi guys,

I been struggling to get a perfect spacing on my Skywatcher 130PDS + ZWO ASi1600MM + ZWO EFW + Skywatcher Coma Correcter.

I do get quite good spacing using Baader derlings, but anyway some stars at the corners are a bit "coma damaged". I want to get it perfect during the summer.

I am thinking to try a Variable Locking Extension, but not sure which will fit

At the moment I am looking at these two, -

1 ) T2 Variable Locking Extension Ring

2) M48 Variable Locking

Would be happy to get an advice on which one would fit without any additional adapters.

If you have any other suggestions, I am more than happy to see them

Kind regards,

Hi Mate,

you will also need Canon adapter to connect the DSLR to the coma corrector Carole mentioned,

something like https://www.firstlightoptics.com/adapters/skywatcher-dslr-m48-ring-adapter.html

As per HEQ5, - it will be ok for 150PDS and close to the weight limits, but it will not fit for 200PDS, you will need NEQ6 as minimum for it.

As per Canon, - crop sensor will do the job, - I have not tried full frame as they are more expensive.

Ignore Barlow, - it is not used in Astrophotography (at least with DSLR).

You cannot calculate back focus easily as it is related to the camera you use, with Canon it is 55mm, the ring in the link will get you to the correct distance to get in the focus.

You will also need a Bahtinov Mask, to get a focus correctly.

Once you get your second hand Canon, - remember, batteries do not like to work in the cold... especially the used ones... So get more of them or,  - check for the power adapter to feed camera during the session.

Something like this https://www.ebay.co.uk/itm/AC-Power-Adapter-ACK-E8-DR-E8-Battery-coupler-kit-for-Canon-EOS-550D-EOS-600D/391307738791?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D226064%26meid%3D6384728fcc8f4ee5847adfceca3bf1c3%26pid%3D100005%26rk%3D1%26rkt%3D12%26mehot%3Dsb%26sd%3D164137136423%26itm%3D391307738791%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWeb&_trksid=p2047675.c100005.m1851

Just keep in mind, these adapters are model specific, - be careful.

I thought a lot about it...

I woud stay between 2 options: Horizon vs Hypercam, - as 383L will be quite old and not so reliable...

Both with 36mm Filters due to backfocus...

On another hand, you can wait for ASI1600 + 31mm filters...

I do not think you will lose in quality with any of them as they use the same panasonic sensor, - just the different amount of £££ can be used for joy as the different sizes of filters are needed....

17 hours ago, Stub Mandrel said:

Some people have criticism of the SW CC, but it needs no spacers to work with a T-adaptor and DSLR, and if used with the ASI1600 there are two spacers supplied that give the correct spacing; unlike other types it seems to be relatively insensitive to spacing anyway. Some people get reflections of bright stars, but I've found that only Sadr and Alnitak are bright enough to cause a visible 'ghost' image and was easily able to correct it.

And here are a couple of works (some in progress) from last night:

 

I am in the list of people who were not able to get a correct spacing with SW CC+ASI1600MM on 130PDS...
Standard ZWO rings were very close, but coma was present... With delrin spacers managed to reduce it, but not completely...

I guess, it also depends how primary is colimated... Full in or Full out and etc... Not yet figured out...

On 28/03/2020 at 10:12, edarter said:

All working now, thanks for the tips! Took a bit of getting my head round it but eventually got there using a frame from the previous nights imaging session to line up in the same spot last night. Very happy! 

Nice

Just in case, - maybe you will find it handy, you can save your Frame/Target details in the Object list on APT, so next session simply select your object from the list and use Goto++.

55 minutes ago, edarter said:

So are both Stellarium and NINA sending control commands to the mount? 

Hi Ed,

It's is a bit different...

Imaging software like APT or NINA do not control the mount directly.

The real control is done, in your case, by EQMOD, which is the main software which controls the mount, it is the main engine, the rest are the steering wheels, breaks and etc.....

EQMOD calculates how fast mount has to rotate and into which direction, current position and etc and etc.

Software like APT and NINA and even Stellarium, can send commands to EQMOD to change the position/target, - and EQMOD does the rest.

Platesolving software (any), usually interacts with imaging software, which almost immediately passes the command/coordinates to EQMOD and to Stellarium, but only EQMOD does the rest (adjusts the position and etc), Stelarium will show the result based on the data from EQMOD.

In other words, - if you managed to make EQMOD to control your mount, don't forget about it, read and learn more about it, as it is the backbone of the whole  system you building around.

P.S.

And yes, platesolving works as you described. It is a VERY handy tool in our hobby.

As I can see you even have DYI newtonian, so you probably know about the cone error and etc. 
Platesovling, removes all that headache... Once meridian flip is done, - if mount missed the target due to the cone error, - platesolving will adjust the targeting.

All up to date Imaging software has Automeridian flip option, but it will not work if that option is not enabled/ticked on the EQMOD.

Also, if you keep camera on the rig, you can do several sessions on the same target with almost ideal framing, APT and NINA both have options to record/save Framing coordinates, which you can re-use next session for re-targeting with the help of platesolving. 

However, there are different ways imaging software "speaks" to EQMOD, for example, in order for Platesolving to work on SGP imaging software, EQMOD has to be set to work in the "Dialog Based" mode.

For APT, if I recall it correctly as have not used it for a while, EQMOD has to be in the "Append on Sync" mode.

1 hour ago, happy-kat said:

Hi

@RolandKol did you ever try that test please?

hmmm,

nope... 
I got Samyang 135mm F2 for a very nice  price and piggybacked it on my SW 130PDS... 
So Evoguide was always busy... :(

I cannot recall the article or forum thread, but I do remember someone like @vlaiv explaining, - color has no effect on Flats.
@vlaiv, if it was not you, - my apologies.

23 hours ago, tooth_dr said:

Darks last a whole season so no issues there, do it once and it’s done 👍🏼. Flats - if you are setting up each night I’m not sure how much benefit it would be to setup just to taken them.  My scope and camera does not move between sessions so flats last me several sessions or longer. 

Have you tried darker paper? Grey or dark blue?
I never tried myself, - but it should help... I think...
 

3 hours ago, Marmo720 said:

Edit: Now that everything is working well - the clouds have decided to take over. No clear skies for over a week and half according to Yr   

Plenty of time to clean the glass!
Once cleaned, do some flats to check if that major one has gone away....
I do recall you had it previously and it was on the sensor....

P.S.

Happy to see, things have much improved and you actually are very close to create the nice and clean image

Happy new year!
just curious @Barns, any luck?

I hope you have managed to sort it out

2 hours ago, JamesF said:

I managed to use another 50cm today, printing a grommet for the new cable for my rain gauge.

So there's still about a metre and a half left.  It's become a challenge now, to find useful things to print that will get me as close to using all of the remaining filament as possible

James

Bag clips are quite good for leftovers !)

53 minutes ago, Marmo720 said:

Is it still under exposed? Even with the iPad and lightbox at maximum brightness and with just 1 white paper, I could only get the combined histogram at about 50%. I will try to do the flats manually and aim for 75% peak. 

At least if the new histogram are less under exposed then we are heading in right direction...

if histogram was around 50%, that will do the job, - but simply make more of them... not 5 but 50.

1 hour ago, Marmo720 said:

 

I had a quick go in between rain showers to take some flats with the lightbox and iPad using white papers. I aimed for about 75% on the histogram and used ISO800. Each flat was taken 5 times so you will see 5x5 flat attempts. 

Hopefully this is useful in diagnosing a potential solution. Clear ish skies tonight so will try with lights too 

https://we.tl/t-0s7e1vQpx3?src=dnl

result is even more insteresting...
have you moved your camera since the last sesion?

P.S. stacked iPad+LightBox with 1 sheet only.

Flat still looks underexposed...
Next time use Full ligh on the lightbox and 2 or Max 3 sheets.
if it was already on full power, stay with one sheet and increase exposure a bit.

Light box RGB histogram channels were concentrated in one  peak nicely, - iPad was spread. I would stick to the lightbox.