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Post by davy on Dec 23, 2017 10:10:49 GMT
I'm looking to start using filters,, light pollution is becoming worse for some reason around carol's area and although I have seen some led type lights getting fitted else where ,,I still have the orange glow to contend with.
With a bit of reading behind me, I decided that the narrow band filters may help cut this down a lot,, dilemma now is. What nm range is best suited for me in my cloudy, rainy environment,, Don't get a lot of imaging time
Do I go for expensive 7nm range or the wide narrow band filters that are cheaper Help 😀
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Post by davy on Dec 23, 2017 10:29:58 GMT
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Post by Dragon Man on Dec 23, 2017 10:59:11 GMT
Can't help davy, sorry mate. I know nothing about all that Narrow Band stuff or nm numbers.
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Post by davy on Dec 23, 2017 13:44:04 GMT
Been reading up on it,, it may just come down to cost verses amount if days I get out,, no point paying out about £400 for a couple of weeks a year use
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Post by howie1 on Dec 24, 2017 0:59:55 GMT
davy,
ChrisV may be able to answer your question better than me. He and I have been dabbling in AP rather than EAA. He longer than me, and I am certainly more technophobic than he. Learning to guide has for me been a PITA! And more cables! And more software! And more stuff to buy like batteries and inverters and ... !!!
Why AP for me, and filters too? For the very reason you are thinking filters and LP but for EAA davy! I was sick of driving for over an hour on a good weather report to get away from severe LP at my home, only to find the forecast is wrong. And when its nice weather, the Moon LP is up!
So I decided to forget about EAA and for 9 months now I have been trying to learn guiding, and the effect of filters etc at my home. Yes, weather has been bad and windy and misty and all the rest, and definitely crap for EAA ... but I've been on the learning curve and here's what I have learnt. It all applies to you as we have very similar kit.
I've bought an Optolong L Pro LP filter. It's broadband (BB) Light Pollution (LP) filter. And also bought a narrowband (NB) OIII filter. And given both several cracks. Here's the go ...
1. Broadband LP filters will double the length you have to take each exposure. You have to get REALLY precise with PA or you'll get fuzzy shots cos you've doubled length of exposures. You will have to learn to guide ... end of story! So ... you'll double your setup time. You'll have more cables. You'll have more costs crop up ... eg another battery and invertor to cope with laptop using more power for the guidecam (or if you buy power cables and adapters and plastic boxes to protect the power cable and plugs from outside dew ... well the cost just keep going).
2. The Moon, and the old lighting using bulbs and tubes were in a specific frequency band hence LP filters could handle it. Filter out that spectrum but still let photons of other frequencies (our objects of interest) through to the sensor. But my local club had an info session and petition on LED lighting. LP filters and NB filters will not work on LED LP. LED is at very white IE across all the spectrum (or nearly all). So beware ... neither broadband nor narrowband filters will fix your LP if your area is getting more and more LED lighting. Which is why astronomers are so upset by LED.
3. Narrowband OIII, Ha etc filters quadruple the length to take each exposure! Because they are blocking so much light! This means you will definitely have to guide! With even longer exposure times (now at least quadruple what you are used to doing in order to see anything for EAA) comes not only the fact that you'll have to learn guiding etc, but also that the guider is going to crack up heaps of times. Why? The mount reaches its limits! My (and your) 200p newt is 85% of the HEQ5 PRO carrying capacity but only 45% of my CGEM DX carrying capacity. Guiding cracks up at least 50% of the time on the HEQ5 when guiding for 5 minutes and very few times on the beefier CGEM DX. As well as running that particular image, it is just a right Royal PITA constantly worrying, checking, restarting and researching the hundreds of settings and pieces of advice on the net to try to fix it up! Our HEQ5 PRO's are really only designed to get 300 sec + exposures using an ED80+DSLR+guidecam. It guides fine with that lightweight on it. Put heavier stuff on and you immediately get problems. Even on the (for me) very expensive CGEM DX, the 200p is pretty unusable. It loves the ED80 cos that's about 15% of the CGEM carrying capacity.
Summarising for your needs davy .... do not go Narrow Band for Light Pollution for EAA. Waaaaaay too long exposures are needed for EAA IMO. If you are going to try filter, then get Broad Band LP filter to handle LP for EAA. Most NSN broadcasters use the IDAS LP2. Seems to work a treat on Moon and non-LED LP. BTW I hate my Optolong L-Pro. But, just remember when get a LP filter then you are going to have to double exp time. That will show up your mounts limitations very quickly, and extremely likely you'd most likely think of the cheaper otpion of getting autoguider and scope. You may get away with it ... or you may find another expensive shopping list results!
Cheers Howie
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Post by davy on Dec 24, 2017 4:40:54 GMT
Cheers Howie,, I new in my heart I was stepping up a notch giving filters a go,, the exposure time I had a rough idea I needed more of, now the bit i was guessing at is real-time video narrow band astronomy,, using a watec 902h 1/2" mono sensor,, this is a very sensitive camera very near ir spec,
I'm hoping using this camera will give me a shorter exposure time on each of my channels in narrow band,,,
Guiding.. I was hoping not to do but had it in my plans and would use the zwo asi178mc.with Orion mini guider finder
Mount wise,, stripped down heq5,, remove pier extension and twin saddle, control via skywatcher wifi.
Scope,, skywatcher ed80 with skywatcher 0.85 focal reducer/flatner
Power wise,, run from car cigarette lighter and new power junction box I have to put in,, split charging system to a 12v 22amp golf cart battery.twin 12v cigarette sockets and usb with volt enter.
Kit wise nothing much I don't have these days,, could set up an observatory and kit it out to the max,, been building up my kit for seven years lol.
Observatory will have to become a reality and spoke to Carol and if I do what I'm told I can get one,,, now that's the only problem,,,, me doing what I'm told ain't going to happen 😇.
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Post by davy on Dec 24, 2017 5:17:24 GMT
Howie. The step towards narrow band video is a two fold experiment for me.
First is, can it be done in my climate, bad seeing and weather and can it be done the way I envisage it in my head,,, everyone knows some of my ideas ,, well most go against the norm,, but in my defence I've had a good few successes.
2nd part can I cross the video/astrophotography barrier more,, I started in astrophotography first and got a lot of knowledge from my mate Steve, and a lot if my thinking of how I can do VA comes from ap. I still believe in this principle.
Live viewing, fast wide field scope, high frame rate with a sensitive camera and capturing as many photons as possible,, Now we have the how It's the method How long can I expose before the data degrades,, what is the sweet spot for video astronomy capture in seconds,, same principle as ap ,, not long enough = not enough detail,,, too long and you can blow out an image. So I believe cleaning up an image using filters,, now this could be done via lrgb ir narrow band , my plans are to skip lrgb and get data from narrow band,, now I may need to step back and capture on lrgb as well,, I just don't know yet.
Like ap the technique will require a fair bit of post processing but I have took steps in that area already by buying Steve Richards book ,, dark art or magic bullet and it definitely is an asset in my current thinking.
I can imagine folk looking at this post and saying,,, nutter,,, and they may and probably are right but I don't follow the crowds when it comes to astronomy I like doing it my way and it pushes the brain,,I've seen and heard of a lot of folk leaving the hobby due to hitting a brick wall and I believe it's because they followed a path others were on,, Tried it and didn't like it,, buying my qhy 5 camera,, jumped in because the in crowd said it was a brilliant camera,, my backside,, what a piece if junk compared an old Samsung scb.
I believe VA is on a roundabout just now with current cameras but getting to where we were 4 years a go. Use a sensitive camera,, cool it,, and control it's integration via software,, clean up the image ,, why are we going round and round beats me. Now lock me up and throw away the key to my padded cell 😂
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Post by davy on Dec 25, 2017 23:21:10 GMT
Just one my first narrow band filter from skies the limit 1.25 o3 filter £18
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Post by davy on Dec 26, 2017 10:27:18 GMT
Been doing a fair amount of reading and watching utube videos on filters and I think the best route try is lrgb with hydrogen alpha,, still unsure on the hydrogen alpha spectrum to go for , 7nm ,12nm or a wider one ,, next purchase will be lrgb or just the and use the ha filter as the luminosity filter,,,
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Dec 27, 2017 18:00:38 GMT
I use the Orion Extra Narrowband filter set and a Lodestar X2M camera. The whole set is 7nm. If you have a filter wheel or a slide, you can do your alignment and polar alignment without a filter. Lately, I haven't been guiding, though I have in the past. To reduce the wires, I mounted a powered 6 port hub with two charging ports on the scope and bought some short USB cables. It keeps everything pretty localized and I can just plug everything into the hub. So the only wires I have coming off the top are the power wire for the hub and the USB 3 cable from the hub to the computer. Here's some images I've posted on this site: astrovideoforum.proboards.com/thread/1993/lodestar-x2-session?page=1&scrollTo=19120My Astrobin Narrowband: www.astrobin.com/users/Robrj/collections/382/I use Starlight Live with the Lodestar. It allows you to capture to separate channels. For a more realistic color, you can capture H-alpha to red and O-III to green and blue. S-II is more limited in where it will show up. OPT sells a tri-color narrowband set that includes H-Alpha, O-III and H-Beta. It's supposed to be more RGB like, so you get the benefits of narrowband with the look of RGB. I think H-Beta is assigned to blue, O-III to green and H-Alpha to red. It does have a couple of disadvantages as were already pointed out. Plus, you're capturing to each channel so coupled with the long exposure plus doing it for each channel, it can take a 2 to 3 times as long.
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Post by davy on Dec 27, 2017 18:48:22 GMT
Cheers Rob,, so better going for the 7nm on h alpha
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Post by ChrisV on Dec 28, 2017 3:45:21 GMT
+1. I've used a 7nm h-alpha (baader narrow band set) on a zwo mini filter wheel. You'll be blown away by the detail that comes up. For the nice h-alpha objects it doesn't blow out exposure times too much. But I haven't used filters add much as Rob.
AP nutters go narrower. I think I remember reading that 12nm width ain't as good. I didn't use guiding with h-alpha. 15-30sec subs. But that was targets like omega nebula
Edit: those narrow band shots are great Rob.
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Post by ChrisV on Dec 28, 2017 5:11:29 GMT
These are back from September. ASI290MM -80mm refractor. Stacked & processed in sharpcap M16 16x 10sec Omega Neb 12x 20sec The beauty is that these were done with half moon. I got the Baaders as they are parfocal - so easy to setup and focus with the UV/IR, then switch to the h-alpha and shoot.
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Post by ChrisV on Dec 28, 2017 5:15:55 GMT
And as a comparison, here's the Omega taken with the UV/IR filter on the same night. Same total time (240sec) but half the sub length 24x 10sec
I could pull out a lot more of the nebulosity with the h-alpha as it hammers the background (using the histogram stretch in sharpcap)
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Dec 28, 2017 6:24:45 GMT
Wow!
So doubling your exposure will get you a reasonable live view?
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Post by Dragon Man on Dec 28, 2017 8:57:00 GMT
NIIIIIIIIIIIIIIIICE!!!!
Even the last pic, with less exposure time, is really good. Well done Chris, and good examples.
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Post by davy on Dec 28, 2017 8:57:01 GMT
Nice comparison Chris,i was hoping to get some decent video with the watec being mono and squeezing out more detail, but no menu to change integration , can alter the frame rate but nothing much after that,,so I will hammer on using the zwo 178, the status sensor is pretty good so hopefully I can get some decent stuff done, Need to get more tests done on the az gti mount,, get the alignment done right and test the tracking,, if it's not up to it will switch to eq3 pro and then heq5.
I want to keep exposure low so I'm doing more live viewing rather than it feeling astrophotography,, how is the experience Chris, do you feel it's still video
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Post by ChrisV on Dec 28, 2017 21:20:54 GMT
20sec subs (for me) is still video. But not for all.
I started with longer 30-60sec subs at low gain but dropping sub length and increasing gain didn't hurt.
Might be about time to do a broadcast. I think those shots I posted were from a cloud interrupted broadcast. I'll have a look and see what h-alpha targets are around - rosette ... and try a few different sub lengths.
I haven't been doing much video lately. Mostly trying to get a handle on AP. Mount is too big to drag out for video. I'm still mucking around building the portable arduino mount for video. Was hoping to really get into it over christmas but have been sick as a dog. Must have been a dodgy prawn at my brothers place on boxing day.
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Post by ChrisV on Dec 28, 2017 21:23:17 GMT
NIIIIIIIIIIIIIIIICE!!!! Even the last pic, with less exposure time, is really good. Well done Chris, and good examples. The last pic isn't h-alpha. It's just uv/ir as a comparison to show how the h-alpha let's you pull out detail
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Post by ChrisV on Dec 28, 2017 21:25:15 GMT
Nice comparison Chris,i was hoping to get some decent video with the watec being mono and squeezing out more detail, but no menu to change integration , can alter the frame rate but nothing much after that,,so I will hammer on using the zwo 178, the status sensor is pretty good so hopefully I can get some decent stuff done, Need to get more tests done on the az gti mount,, get the alignment done right and test the tracking,, if it's not up to it will switch to eq3 pro and then heq5. I want to keep exposure low so I'm doing more live viewing rather than it feeling astrophotography,, how is the experience Chris, do you feel it's still video The watec is worth a go !! Or is your 178 a mono - that would be really good. Or even if it's colour ? Is the 178 the one with great IR sensitivity ?
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