bomberbaz

I can honestly say I am not looking to change anything either in or out just now.

I have a couple in my frac eyepiece box that are very rarely used but they fit a gap and its a gap that occasionally needs filling.

Another thing is both cost me less than £100.

Probably my dob, although I am growing quite fond of my giant bins.

That said, off out with the ED100 later tonight as long as clouds play ball. Last decent chance until September really. 

Lee's beat us all to it, it definitely is the speed buttons.

FWIW I used to slew around with 8, 9 zooms along too fast with quite an over run then fine tune at 3.

Also the mount needs final adjustment from two directions which are always always the same way (see note below), the mount itself will tell you this. So it is always a good idea to try to get past your target by around a half degree in the required direction.

NOTE: I can't tell you which exactly as I can't remember but it seems to vary in it's "apparent" direction compared to the handset (phone) depending on which star your aligning on but you will soon get the hang of it. 

1 hour ago, Olli said:

I tried a two star alignment in at the start of the session and it was way off but I haven’t tried it after it got a bit better at aligning.  At the moment the Star I choose is Arcturus and I then tried Polaris as my second star not sure if these are good choices. I did use a compass on my phone last night to Try and be accurate but I’ll try and get a physical one. ( they are fun to use anyway) I will have a look into Thor illuminated eyepieces and will make sure to close the thread once I figure this out… hopefully. Thanks

If you want best accuracy, you are better looking for stars which are either side of N/S and also the further apart the better. Also preferably above I think it is 30 degrees Alt in height too. 

With that in mind Arcturus is fine but a better star as second would be capella or if it's later on and it has dropped low down then either of pollux or castor.

Vega is only just below 30 and gives a better spread. Just check stellarium (other apps are available) to see what height the stars are at.

Just got my ZWO mains power connection, so it's running the AZ GTi, ZWO Air, 224mc guide and 183mc cooling at 0 degrees taking darks. It is giving a steady 12.1V and currently drawing 0.9A. 

I think it will be fine at that and from here on will slowly build a darks library at 60, 120, 180 and 300 at zero and -10C. I think I will do 64 of each as a minimum. 

I was worried the voltage might not be enough for tracking but 12.1, yeh be alright that.

Just done a quick unprocessed stack of 20 frames with UHC only(top) & 20 frames with astronomik L2 only bottom. (I did stretch the top UHC one a small amount as it was very dark)

I forgot to mark up star but top left it stands out a mile. Very bloated in top picture, nice red star in bottom one.

It is a visual use one I was trying to give a dual life (could always double stack with L2) but anyway, back to r3esults.

From what I see below it appears the star (T cep) which is a pulsating variable is bloating and something is getting past the UHC to cause the bloating. IR I suspect. 

Simple question, I thought a UHC filter would also cut UV and IR, is that not the case?

It is a standard televue uhc bandmate

Good idea and thanks for the explanation. I shall look into emulating this idea if it works for you and sack the bias files as seemingly they are of little use.

1 hour ago, AstroNebulee said:

I generally do 30 of each. My flats and flat darks are done at the end of every session and don't take long to do. I don't use bias frames. 

I have reused my master dark files I've built in a library since getting my camera in January so only used about 3 times 😂, regarding the degradation, is it because the osc can change a bit over a  long period of time, so say take darks once a year maybe? Someone with better knowledge will be along shortly. 

Cheers 

Lee 

Query this Lee as I know you use the ZWO ASI Air like me. The system allows taking of light, dark, bias and flats in the autorun section. Where is the button for (or how do you take) dark flats.

I understand them but still cannot fathom how to do it using the ZWO system as it calculates the exposure and gain for flats for each time used, how do you replicate or am I missing something?  (probably the latter)

cheers

steve

stunning that, simply stunning. 

I am absolutely sure this has been asked before but given how systems and equipment evolve constantly, thought it worth asking again.

I am going to build a library of darks and bias to save time, seeing as the camera is cooled, it is a simple (although tedious) task to be done during the daytime. 

My queries are firstly how many would you do? I have read in several places that 30 of any averaged stills is generally enough and I am happy to take that as a maximum point.

However when I get down to the 3 and 5 minute darks, we are getting to a serious amount of data, in this case 30 subs give 1'30" at 3 minutes and over 2'30" at 5.  This seems like over kill to me so what is anyone's rule of thumb. (I realise people will have their own methods, I am trying to find my own starting point)

Next the master dark or bias created during first use. Is it ok to keep reusing these? I have also read these can degrade over time although I don't understand how this can happen but it is still what I have read.

Cheers all

Steve

10 hours ago, Louis D said:

It comes down to profitability.  The absolute profit on a $3000 motorized focuser is much larger than on a $400 manual focuser, so you concentrate on the former since the labor involved is similar for both.  GM and Ford have done the same with vehicles.  All US manufacturing is of high profitability full size pick-up trucks and SUVs.  Most of the smaller vehicles are made outside of the US to take advantage of lower labor costs.  Apparently, MoonLite didn't want to shift production out of the US to cut costs on manual focusers, so they stopped making them altogether.

glad I got mine when I did, had it for around 5 years now and still going strong.

late to the party here but I use a moonlight on my 14" dob and have some seriously heavy glass to put in it.

However I didn't know they had ceased production. Don't know why as it is a sterling piece of equipment. 

2 minutes ago, AstroNebulee said:

I'm not sure how much amps the dew straps will consume being connected to the osc, they are quite thirsty things the dew straps. I think the USB ports on the back of osc are mainly for guidecamera, electronic filter wheels and focusers, things that don't draw much amps, it may prove too much along with cooling the osc and being powered through the AAP. I may be wrong though. 

With my 294 mc pro I wouldn't want to connect dew straps to my camera, much better to use a separate USB Hub as you do. This is just my opinion 😊

Good point actually, max draw of USB 2 is only 0.5A.

32 minutes ago, LaurenceT said:

Nice setup, I think I'm having power issues in that the power bank/Asiair connection seems to die suddenly, I think the power bank is dropping from 12v.

What power tank are you  using there?

This little fella here is my power option Lawrence:

Celestron Lithium 13.2 Ah LiFePO4 Powertank Pro | First Light Optics

Tested it with everything running including cooling at still getting a steady 12.6V input and 12.4V from the two ports in use. 

Just had a data clearout, didn't realise just how much I had (239GB). 

To be honest none of it was really good as it was learning material but I got my best efforts and saved them before dumping the data it came from. 

Bear in mind the longest amount of main RGB data is about an hour as I was initially trying to see how far I could get off lower amounts of data.

Going forwards I shall be taking more and also using UV/IR and UHC filters as appropriate.

Double Cluster

M82, too much red left in.

M81,82. Was actually quite pleased with this although not sure if there was an issue with my darks & bias files here.

California Nebula. Very over processed but only had 25 minutes data.

Anyway I promised a picture of the new rig once mods have been applied. The camera as you can see is a pro version, the ZWO 183MC pro. I have the powertank straps to the centre pillar and finally I have added an additional counterweight as the one wasn't enough. 

Guestimate of total weight around 4kg inc weights.

Do you use a cooled camera, only ask cos my 183 pro has 2x USB plugs on back that could be utilised.

I actually have a home made, 6" dew shield I put onto the imaging scope, I do need a tape for my guide tbf.

Hello guys, back in the game. My 183mc pro camera arrived today. I had to change vendor for first time in years, covid apparently still causing delays but I couldn't wait.

Should get my uv/ir cut filter tomorrow but if conditions are ok I will do some broadband subs tonight of the IRIS and if time allows the Soul nebula.

Cheers

Steve

Hello all.

Just starting out in spectroscopy, the learning curve is steep but not as daunting as I first feared.

I am currently watching a huge number of video's from Rspec as I think their software seems the most user friendly for a novice such as I. The video are in a very simple guide format so this is most pleasing to me as I am ok but not brilliant with tech.

The recommendation is to start out with A stars for their well defined and identifiable profile and I know there are plenty. But is there a resource for all stars that is readily available.

Ideally I would be hoping for one with spectral data accompanying the stars referenced so I can cross reference all my own data with known reliable data.

It's all quite exciting this, my grating should be with me just in time for the next lack of clear skies. 🙄

regards

steve

48 minutes ago, vlaiv said:

Was there ever such thing as astrophotography in simple terms? (or is it just me )

Depends on how you want to use it for mono purposes. I'll give you some examples:

1. You want to use color camera for "mono" purposes - size of pixel is the least of your concerns

2. Say you want to use it for Ha - then only red is really sensitive in Ha. In terms of resolution - pixel size will be effective 4.8um (it will be able to resolve as if pixel is 4.8um large), but as far as sensitivity goes - pixel is still 2.4um in size

3. Maybe you want to use it for OIII - things get complicated here as both green and blue pixels are sensitive in this wavelength - but to a different degree.

4. You want to bin your data 2x2 to actually get mono image (there are better ways to do this) - pixel size as far as both sampling and sensitivity go - will be 4.8um but effective QE will smaller than any of individual components.

5. You want to use some sort of duo band filter that captures both Ha and OIII at the same time - things get progressively complex here - so no easy way to describe what is going on.

In the end - I'd like to point out that with OSC - pixel size is never really that pixel size (unless you do bayer drizzle)

Ever wish you hadn't asked a question 🤣

Actually thanks a lot vlaiv, I had not given consideration to HA and OIII data capture but glad you pointed all this out for when I get around to imaging again. 

I actually want to try capturing some data in mono for sampling spectroscopy and it is the data capture method that needs testing as much as the actual data before i even think to commit to purchasing a dedicated mono camera. 

I am really not sure what I am doing but getting there albeit very slowly. 

Come to think of it, I never did check if the rspec software automatically converts colour to mono, doh!. More research needed.

Cheers

Steve

Seen it for last two nights but toniight was best views. 

Not getting great resolution but then I am only using my g&g 60mm frac. 

Best two picturesattached. The phone eyepiece efforts were blurry and smeared.

Just checking my understanding here of colour to mono! 

The zwo 183mc has a 2.4 pixel in RGGB, if I want to use it for mono purposes it it then 2x2 giving a pixel size of 4.8?

Is this correct and in simple terms what is the net effect please!

TIA

Steve

Not sure if this has alrready been reported but for those who might have missed it 🤔

https://bgr.com/science/a-4-billion-year-old-comet-80-miles-wide-is-headed-toward-earth/

7 hours ago, RayWUK said:

A few updates to my rig in the last week or so. Firstly the ASI AIR firmware updated to the latest Version (1.9), Secondly I sold my Star Adventurer so had to find a substitute for the 1kg counterbalance weight i was using on the the AZ-GTI in the form of a 32mm length of 40mm Dia. steel bar with a 6mm hole in the centre to bolt on the end of the counterbalance rod. Lastly and most excitingly a new ASI533MC Pro camera to replace the Canon 600D.

I had to re-balance the RA and Dec axis using the method shown on here a few pages back.

First night out with the new rig to night, polar aligned, focused and guiding on M81 within 15mins, the ASIAIR is brilliant and a real game changer in this respect. Managed and hour of imaging before i had to call it a night as i have an early start in the morning. Guiding was below 1.0" for most of the session and the previews of the images look promising. 

Here's a sample 30sec sub from the ASIAIR. Hoping to find time to process them tomorrow. 

well done ray, can you screen shot your guide settings and also what were your subbing times please? Look like 30 seconds and did you dither?

4 hours ago, AstroNebulee said:

Hopefully your camera arrives soon Steve. I did have the zwo 1.25inch one and did the same as you are going to do by putting it in the adaptor ring and up close to the sensor. I did go for the 2 inch version eventually to cut out the vignetting I got on my 294mc pro and it seemed the rotator was as good a place to fit the filter and seen it done by @StarlightHunter

I'm pleased to hear the astronomy bug has bitten again, I believe we all go through losing mojo for it at some stage. The shorter evenings really get me. 

Lee 

 

I am currently looking at spectroscopy as a summer pastime to continue my astronomy exploits.

Incredibly interesting although quite involved but I won't hijack this thread. I hope to start a new one soon once I get things going.

Steve