Which nebulas?

[jetstream]

12 minutes ago, John said:

here is a slight danger here that we are talking you into spending as much as your scope has cost on a filter and your first 2 inch eyepiece

Thing is he needs them to see what he wants to see. A 1.25" OIII will work with the 25mm but with a small TFOV.

Not sure what to say!

Edited February 10, 2021 by jetstream

[Deadlake]

11 minutes ago, jetstream said:

My 2 truss dobs came with filter slides, that also function as focuser baffles. I leave them in the scopes, 2 each. The fracs have them screwed into the 42mm LVW when needed.Sure be nice to have a wheel system for the fracs.

Filter slides/wheels are almost a must IMHO.

Wheels work with 1.25” filters, unless you go for electric versions. Slides seem a better way to go..

[John]

10 minutes ago, jetstream said:

Thing is he needs them to see what he wants to see. A 1.25" OIII will work with the 25mm but with a small TFOV.

Not sure what to say!

I agree Gerry.

I just thought I ought to sound a little note of caution.

 

[Deadlake]

8 minutes ago, jetstream said:

Thing is he needs them to see what he wants to see. A 1.25" OIII will work with the 25mm but with a small TFOV.

Not sure what to say!

It’s an engineering problem....

[Tiny Clanger]

3 hours ago, Kon said:

I am a beginner in the hobby but totally fascinated by the smudgy nebulas. I own an 8" Dob and I am at bortle 4 skies. I have only owned my telescope since December and as we all know the weather has not played ball. With the predicted clear skies this week and the new moon, I was wondering which nebulas you suggest for me. I have good seeing on all directions. In the limited viewing time we had so far, I have managed to see the Owl Nebula (M97), Crab nebula  (M1), The Cat's Eye Nebula (NGC 6543), Eskimo Nebula (NGC 2392), M42. (I have seen several clusters and galaxies) but I am after nebula suggestions. I have no filters so I am after targets that can show as is. Are there any targets that I 'must see' during Feb? Fingers crossed for clear skies this week.

While you save up for  all those exotic filters I don't need to know about (because if I did,  I might feel I need one, which I don't) here's a few web pages and a free PDF which might help you :

https://www.cambridge.org/turnleft/seasonal_skies_january-march

https://www.constellation-guide.com/constellations-by-month/february-constellations/

https://www.astroleague.org/al/obsclubs/caldwell/cldwlist.html

https://las-astro.org.uk/docs/Loughton_List_v2_0.pdf

Heather

 

[jetstream]

2 hours ago, Tiny Clanger said:

While you save up for  all those exotic filters I don't need to know about (because if I did,  I might feel I need one, which I don't)

Give us a while Heather, we'll work on you as well to get one

Seriously though, if someone is interested in seeing nebula one of the mentioned filters is a must IMHO.  AND 😀 seeing as you stopped by in this thread you must be interested.

[Kon]

7 hours ago, Tiny Clanger said:

While you save up for  all those exotic filters I don't need to know about (because if I did,  I might feel I need one, which I don't) here's a few web pages and a free PDF which might help you :

https://www.cambridge.org/turnleft/seasonal_skies_january-march

https://www.constellation-guide.com/constellations-by-month/february-constellations/

https://www.astroleague.org/al/obsclubs/caldwell/cldwlist.html

https://las-astro.org.uk/docs/Loughton_List_v2_0.pdf

Heather

 

Thank you for the links. I will try compose a list for tonight. My head is all mingled with the options and the excellent suggestions above.

[Kon]

10 hours ago, John said:

For quite a while an Astronomik O-III was my only deep sky filter and it did a great job. The UHC enhances what you can already see. The O-III can show you stuff that is otherwise practically invisible.

I think this piece of information is extremely useful to me. The fact I can access nebulas that are not visible then the OIII makes sense since my viewing is pretty good from my skies (could be darker but i don suffer much).

[Kon]

9 hours ago, John said:

There is a slight danger here that we are talking you into spending as much as your scope has cost on a filter and your first 2 inch eyepiece

Hahaha...or ouch in my pocket! I realise that the accessories are adding up more than the scope quite quickly.💸

[Kon]

9 hours ago, jetstream said:

Thing is he needs them to see what he wants to see. A 1.25" OIII will work with the 25mm but with a small TFOV.

Can you explain more please? Sorry a beginner and I do not understand the technicalities of putting a filter. I have not noticed a difference in FOV using my 1.25" moon filter with my EPs or am I missing something with the UHC/OIII?

[jetstream]

4 hours ago, Kon said:

Can you explain more please? Sorry a beginner and I do not understand the technicalities of putting a filter. I have not noticed a difference in FOV using my 1.25" moon filter with my EPs or am I missing something with the UHC/OIII?

You can buy the 1.25" filter and use your 25mm Super plossl more cost effectively. If you are really interested in viewing nebula, have access to dark skies and can afford it a 2" set up is the way to go.

The 2" set up has a much wider TFOV.

[jetstream]

Heres the difference-I used a 25mm TV fs dia for calc and APM UFF

25mm-21.2/1200x57.3= 1 deg

30mm  38/1200x57.3= 1.8 deg TFOV

This is a big difference IMHO.

 

[jetstream]

4 hours ago, Kon said:

Can you explain more please?

If you buy the right stuff you can always sell it and get at least 2/3 of your money back. Did you email Astronomik for band pass?

[Kon]

35 minutes ago, jetstream said:

Did you email Astronomik for band pass?

I did. Once I have a reply, I will post it here.

Doing some more reading and the +/- of each filter, I am considering to get both a UHC and OIII now....

[jetstream]

2 minutes ago, Kon said:

I did. Once I have a reply, I will post it here.

Doing some more reading and the +/- of each filter, I am considering to get both a UHC and OIII now....

What did you read? Theres a lot of " UHC is better than an OIII on this object" or the "emission lines primarily dictate the use of the OIII" etc etc.

Both are nice to have for sure but to start with I think maximum contrast is the way to go. A widefield eyepiece is an excellent addition and would make sure I got one before 2 filters. Just my 2 cents.

[Kon]

5 minutes ago, jetstream said:

What did you read? Theres a lot of " UHC is better than an OIII on this object" or the "emission lines primarily dictate the use of the OIII" etc etc.

Both are nice to have for sure but to start with I think maximum contrast is the way to go. A widefield eyepiece is an excellent addition and would make sure I got one before 2 filters. Just my 2 cents.

I read some targets benefit more  from one than the other. Too much information out there is not so good some times...Ok, I think I will go with the advise of your experiences and go for an OIII only for now and see how it performs. 

[jetstream]

3 minutes ago, Kon said:

I read some targets benefit more  from one than the other. Too much information out there is not so good some times...Ok, I think I will go with the advise of your experiences and go for an OIII only for now and see how it performs. 

👍

There are reasons... I've found that early success with observing these faint objects and with maximum contrast develops and enhances ones "object recognition ability". I use the technique of repeated viewing of the same object, over and over really does develop ability. I've done it for years and still do it now.

They make UHC's every day...no rush IMHO.

[Deadlake]

I've ordered one of these:

https://www.firstlightoptics.com/filter-wheels/manual-5-position-filter-wheel.html

I'll also get a 2" version as well.

My thoughts are the 1.25" filters will be for planets, whereas 2" will be for nebulae etc. I did look at the Baader UFC (slides) as well but add £36 per filter, plus the slide holder of £45. When a 5 filter wheel is around £60-70. Only issue might be back focus, will see where I get to with the 1.25" wheel first and report back.

I really will not mix planet/DSO viewing and the cost of slide outs (possible dew issues) is a lot more.

OIII looks interesting, looking at prices as a lot of products are creeping up in price.

 

 

 

Edited February 10, 2021 by Deadlake

[jetstream]

13 minutes ago, Deadlake said:

OIII looks interesting, looking at prices as a lot of products are creeping up in price.

Glad I bought when I did.

[Deadlake]

Looking up, according to Starman:
 

The TeleVue BandMate II filters are current since 2018.  Their older Band Mate filters were wider in bandwidth and discontinued several years ago.

TeleVue BandMate II filters are made by Astronomik, but, as you note, the TV Nebustar (their UHC filter) passes no red, while the Astronomik does have an output in the red at the H-α wavelength.

The DGM NPB (their UHC filter) passes a very broad swath of wavelengths in the red, so stars appear red.  

@jetstream is it worth paying the extra for no red with Televue?

[jetstream]

@Deadlake Nope!

If you have a tight Astronomik UHC, I would not get the TV. I just wanted to try the TV filters because I needed to fill the other dobs slide instead of switching. My Lumicom UHC is extremely good, which speaks highly for the TV Nebustar.

The NPB is an unusual filter-tight, dark, passes red but gives VG views? I cant quite figure this on out. I called Dan McShane before and after the purchase-he owns DGM-and told him my thoughts-his filters is vg which he really appreciated, good guy Dan is.

Btw- a colleague has a spectral analyzer- he is also a vendor- and he embraced the idea of testing the TV filters for free and under the condition I don't pay for them if they are too wide, down on transmission etc. He called me and said "Ger these are extremely good filters".

Sorry for the long story but for me red isn't an issue but I do like the TV which gives a different perspective on things.Save your money IMHO.

[jetstream]

@Deadlake BUT... 😀

A mandatory, must have planetary lunar filter is the Baader single polarizer...forget the rest. My best seeing is right at dusk and some of my very best views of Jupiter and the moon has been with this filter. I do get better views in darkness at times but this filter opens up many opportunities.

Forget the rest...IMHO Including the Baader NEO.

[Deadlake]

1 minute ago, jetstream said:

@Deadlake BUT... 😀

A mandatory, must have planetary lunar filter is the Baader single polarizer...forget the rest. My best seeing is right at dusk and some of my very best views of Jupiter and the moon has been with this filter. I do get better views in darkness at times but this filter opens up many opportunities.

Forget the rest...IMHO Including the Baader NEO.

Interesting for the moon I have a polarising one, change the amount by rotating it. I'll look at the Baader ones.

Any filter suggestions for Jupiter?

[jetstream]

2 minutes ago, Deadlake said:

Interesting for the moon I have a polarising one, change the amount by rotating it. I'll look at the Baader ones.

Any filter suggestions for Jupiter?

The Baader single polarizer is the only one that does much (for me).

BUT...😀

I do have a technique. Interested?

[Deadlake]

3 minutes ago, jetstream said:

The Baader single polarizer is the only one that does much (for me).

BUT...😀

I do have a technique. Interested?

ok, you've got me.