Leti Theobald

Hi,

I'm currently planning to go into Mono and I have my eyes on a ZWO 2600MM.

I'm now choosing my new set of filters and I can't decide which ones to get. They will need to be 56mm as I have the filter wheel already but currently between:

• Antlia 3mn / 4.5 mn / 7mn
• Baader 6.5mn
• Optolong 6.5mn
• ZWO 7mn

I know Antlia is probably the best out of these but will the 7mn Antlia be good? Or do I need the 3mn?

I'm trying not to expend a ridiculous amount of money but at the same time I want something I can be very happy with my images and not want to change filters anytime soon.

Current Equipment:

• WO Zenistar 73
• WO Field Flattener
• ZWO Mini Guide Cam
• WO Mini scope
• ZWO 7 x 36mm filter wheel
• Bortle 6 skies

Thanks,

Leti

oh no, I'll have a look

58 minutes ago, scotty38 said:

My view would be go 2" if you think you may go FF at some time. If not then 36mm should be just fine. I currently use 36mm on my 294m but I went 36mm just in case I bought a 2600 sized sensor.....

Thank you. Am I correct to say I need the 36mm unmounted filters? Also, any suggestions on Brand. I've always used Optolong on my current OSC camera but I know they are not the best of them.

27 minutes ago, teoria_del_big_bang said:

I also was a bit worried when going to APS-C format and at the time already had 36mm filter wheel and filters and worried I would need 2". But so long as you do not place extra spacers in between camera and filter wheel (other than what is needed to connect them) you should be fine.

The cost to step up from 36mm to 2" is quite considerable, especially when buying good quality filters. Also ideally you will probably want a 7 position filter wheel (so you can have all the SHO and LRGB filters without changing) and this is also an extra cost and adds extra weight to the train.

So as said already unless you see yourself going to FF anytime soon then from my experience 36mm should be fine. 

Steve 

Thank you. Am I correct to say I need the 36mm unmounted filters? Also, any suggestions on Brand. I've always used Optolong on my current OSC camera but I know they are not the best of them.

Hi, I've just decided to take my first step into mono astrophotography and wondering if the cost for a the 2" filters are worth or would I not notice any difference by getting the 36mm filters.

I will be using the ZWO filter wheel and ZWO 2600MM camera

I haven't bought anything yet so just trying to budget my expenses

Also, if anyone has recommendations of what brand filters to get that would be great - I was thinking Optolong but unsure if they are good enough

4 hours ago, alacant said:

Hi

Add an INDI server and you have a complete imaging system for the Mac; all three run natively.

https://indilib.org/get-indi/download-mac.html

Or... Perhaps to begin with and as the heq5 has a guide port, keep it simple by connecting the mount directly to the 120 using the ST4 cable and use PHD2 to guide 'on camera'.

HTH

Hi HTH,

is this the link to use it in Kstars? I’m completely new to guiding and using a laptop for imaging but really interested to know the best system to use. And do you know any simple and good tutorials for it? It’s all a bit mind boggling!

3 minutes ago, newbie alert said:

Just seen this part

Assume it be the same as windows but not 100%

I thought it would as it says that ASCOM can be used on a Mac but for the life of me I can’t find a way to make it work, haven’t been able to download it at all. I’ve managed to connect the camera do PHD2 fine but I should get the cable for the mount tomorrow and might attempt using EQMac for the mount and see what happens!

otherwise I will have a go at with Kstars and Ekos , otherwise INDIGO 1, hopefully one will work. 
macs make everything more complicated but Im going to persist with it!
 

11 minutes ago, newbie alert said:

Hi Leti... You be better off pulse guiding so not using the ST4 connection...

You will need the ascom platform driver and the drivers for your guide cam installed regardless of how you guide

benefits to pulse guiding are that you only have to calibrate once, with ST4 you have to calibrate every time on every target and after a flip.. plus if you bring up the drift align tool it will tell you where you're pointed so helps with calibration on equator 

 

Thank you so much, I thought that might be the case but just wanted to make sure. So I guess off to download more things and try to understand how they work 😲

Hello all,

I have decided to start guiding so I can get longer exposures. 
my current set up is:

HEQ5 Mount

WO Zenistar 73

50mm WO Guidescope 

ZWO Asiar Mini 120mm

Canon 600d Astromodified 

Please bear in mind I use a Mac computer which I know makes some stuff a bit awkward 

I have downloaded PHD2 is just starting set up. The questions are what else do I need?

- Can I use the St4 connection between the camera and mount to do the guiding or do I really need ASCOM and connect the mount to my laptop? 
- will I need any other software? 
- if I use ASCOM do I only install the drive for the mount or do I need anything for the camera?

I bought a cable to connect the mount straight to a USB for my laptop but hasn’t arrived yet.

thank you so much

Leti

1 hour ago, michael8554 said:

Hi Leti

To my eyes the stars appear to be elongated everywhere in the whole image.

Since the exposure was 90 seconds I'd say it's RA tracking. or Polar Alignment error.

Is that elongation in RA or Dec or both ?

Try a short exposure and stretch it, to see if it's the mount or the optics.

Michael

It looks to be in both Ra and Dec. I tried a shorter 60 seconds exposure. It was still there but less severe.  I think I will just realign tonight and start again, hopefully it was just me doing some dodgy polar alignment last night!

1 hour ago, newbie alert said:

Seen them like that using a OAG and guidecam, just needed a slight spacing adjustment...

With my William optics 80 I had to use a adapter to produce the correct spacing...

Are you using a reducer?

I’m using the William Optics Adjustable Flattener 73A for ZS73 and I also have a Optolong filter 

Just wondering if this has happened to any of you and what would have caused so I don’t do it again.

Tonight whilst trying to image the M35 all my stars look like the below. I only did a 90 second exposure, which I usually do without an issue. Could this just be some bad polar alignment on my part? I’m not using any guiding just a HQE5 mount and a WO Zenistar 73 with a canon EOS. 
 

Any ideas? 

At the moment considering the below but of course happy with different suggestions:

1)

William Optics Z 73III / William Optics 50mm Guidescope with 1.25” RotoLock / ZWO ASI 120mm Mini USB Mono Camera / William Optics Adjustable Flattener 73 A / M48 t ring

2)

William Optics Z 81 APO/ William Optics 50mm Guidescope with 1.25” RotoLock / ZWO ASI 120mm Mini USB Mono Camera / William Optics Adjustable Flat6A III 0.8x Reducer/ M48 t ring (does the extra cost make a lot of difference?)

3)

Sky-Watcher Evostar 80ED DS- Pro / Sky- Watcher Evoguide 50ED Guidescope & ZWD ASI120mm Mini Bundle / Sky Watcher Field Flattener for EvoGuide 50ED / M48 t ring

Hello all, I know this is a tricky question but would like to know your opinion on which Telescope to get. 

What will it be used for? Astrophotography, mainly DSOs and Nebulas but I would like it to also be able to use it to photograph planets sometimes - but won’t be used a lot for it.

Budget? Up to £1k

Weight? Not too heavy as I’d like to be able to move it around as it currently stays inside and I take it out at night to photograph 

Where? Mainly my backyard in a Bortle 5 location 

Type? Refractor unless you want to convince me otherwise

Current gear which I don’t want to change:

Mount - HEQ5

Camera - Canon EOS 400d Astromodified, however I would like a telescope that would also work with a astro camera in the future.

im currently looking at:

William Optics Zenithstar 81 APO
William Optics Zenithstar 73 APO III

William Optics RedCat 51 APO

Sky-Watcher Evostar 80 DS-PRO ED

But open to any suggestions! 

11 hours ago, Elp said:

In the absence of applied flats I've done this in around 30 minutes manually (the flats issue is still present but reduced), no painting as sometimes you need to paint out dust motes and stuff like the streak on the top LHS, image would help with a crop (i've left it so you can see the full frame) and more integration time to reduce average noise level and improve signal:

 

Thank you, maybe my flats are making it worse

21 minutes ago, ONIKKINEN said:

The method of taking the flats you mentioned sounds ok to me. Only thing to make sure is that there is no screen flicker with the laptop (probably not a problem) and if there is the exposure needs to be long enough to even the flicker out but you can just add more interlayers with t-shirts or printer paper or something like that in that case (if the screen flickers try to make the automatic exposure at least 1/2s, that should even everything out).

The mechanical accuracy and stability of everything between the lens cell and the camera sensor are what make or break flats, and just looking at the scope i would assume the focuser to be the weak link here. If the focuser can wobble from one side of the sky to the next it also means the vignetting profile changes, so flats become impossible to match to lights. Its a problem even with good scopes sometimes, the focuser really needs to be much better than just ok to be reliable for astrophotography so this might not be something you can fix easily. Looks like it might have a tension adjuster? If it does, tension it so that you can only barely move the focuser in and out to make it more stable.

Thank you, I will try again using your tips!

30 minutes ago, ONIKKINEN said:

No flats could work better than badly working flats, try without the flats?

Also you will need to crop the image to a size that is inside the ring this way but you may have needed to do that anyway because of the field curvature (also the image is slightly out of focus on the red channel and completely out of focus on the green/blue channel because of chromatic aberration but not much you could do about this)

I’m sure I can still do some work on my focus, still learning how to get it spot on! 
Without flats didn’t look that great either. Do you have any tips on how to take them?

31 minutes ago, ONIKKINEN said:

2 main reasons for the ring. The first is that you are using a 1.25'' filter with an APS-C sized camera, so there is severe vignetting. You need bigger filters for APS-C sized chips to get less vignetting.

The second, and what is the bigger issue here, is that your flats have not worked. Looks like dust donuts are still visible so flats are not working, and the ring artifact would be also gone had flats worked.

How did you take the flats? Did you take them immediately after imaging, or better yet during imaging without first moving the camera or touching anything on the scope in any way. And also, how is the focuser on the scope, if it cant keep the camera sturdily in all orientations you will never have proper flats.

Thank you!

My telescope only fits 1.25" lens so I'm a bit stuck with that for now.

For the flats, I took just after imaging - my current technique is white shirt with an elastic band to hold it tight and a laptop screen on max brightness white screen. Camera on AV at the same ISO.

The camera feels quite sturdy but it's not an amazing telescope, I know I will have to upgrade soon

23 minutes ago, City9Town0 said:

Is it visible in the single un-corrected frames? Does it move slightly over time such as light from a street lamp entering?

it could be light from somewhere, I can't quite think where - might trial another from a different side of the garden and see if it changes

r_bkg_pp_lights_stacked.fitAnd Siril stacked file also attached

Stacked Tif image attachedStacker Horsehead.tif

This is a single frame stretched 

This is a histogram super stretched picture without the filter . So still there. This is just the Astro modified camera with loads of light pollution 

Hi everyone. Would someone be able to help me with an issue I’m having with my subs - I had a friend also stack it for me in case it was my stacking but had the same issue. 
This is what my image looks like - there is a colour ring around it. I’m using the below gear:

Skyways 80050 telescope - 80 mm aperture and 500 mm focal length

Canon EOS 600d Astromodified 

Skywatcher HEQ5 Mount

Optolong L-eNhance Tri Band Deep Sky Filter 1.25

T Ring adaptor 

ISO 800 and 100” exposure (around 60 frames)  

we stacked both using bias, darks and flats and also with just lights and the result is the same

Thank you so much!

Looks awesome 😊