Is this a good Guide Scope combo?

[open dock]

https://agenaastro.com/clearance-2nd-zwo-30mm-f-4-mini-guide-scope-for-asi-cameras-30120-cln-1292.html

https://agenaastro.com/zwo-asi120mm-mini-cmos-monochrome-astronomy-imaging-camera.html

[kindred reef]

Pretty good

[noble marlin]

It'll work, this tool will help in deciding whether your imaging train and guiding setup are very compatible:
http://astronomy.tools/calculators/guidescope_suitability
If you don't know what to put, your guidecam has a pixel size of 3.75 and the guidescope is obviously 120mm.

You obviously want to be as close to 1:1 ratio as possible, though you can get away with something like 1:5. I run my setup at a 1:1.75 and get consistently round stars.

[kindred reef]

I got 1.35, good enough?

[noble marlin]

1:1.35 is plenty fine, you essentially want your guiding to match your typical atmospheric seeing. One of many reasons why high focal length imaging is so much more difficult.

[kindred reef]

alright then

[open dock]

I got a high number how would I get it smaller?

[open dock]

Should I get a bigger mini telescope? Because the one above gave me 2.87

But I found another mini scope that’s around the same price and brings it to 1.97 I know that’s still high but it’s in my budget

[noble marlin]

What focal length is your main imaging scope? I can probably suggest something specific based on that.

Odds are your guidescope would need to be longer, still want to keep a low focal ratio though since guiding required short exposures.

[open dock]

I have a sharpstar with 275mm

[noble marlin]

What camera are you pairing with it, roughly 3µm pixel size?

You could get away with that small guidescope, though the classic 50mm F4 guidescope might be a better choice (40% more FL), brings it down to roughly 1:1.7 which is plenty on a good polar alignment / tracking. Plus you're very much future proofed if you decide to get something a bit longer.

[open dock]

What about this ? https://www.svbony.com/sv106/

[open dock]

I want to pair it with the camera in the link at the top the 120MM

[noble marlin]

Asking about your main camera, but the SV106 is more than adequate.

If you'd like, when I get a moment, I can show a comparison of my 30mm F4 vs a 80mm F5 - same guide camera as you - on my CG5 imaging at 448mm / 2.4µm. The difference becomes negligible when you get below 1:2 in most cases.

[open dock]

My main camera is a ZWO 585mc, sorry in school 🏫 trying to respond when I can 😕

But the SV106 works?

Should I get the 60 or 50mm version? I assume 60

[noble marlin]

The 60mm gives you 1:1.6, which is more than fine, I'd say that is your best choice, though the 50mm should be fine too, it'll be a difference of 10%.

[open dock]

Okay thank you 🙏

Would you recommend either of these?

[noble marlin]

No problem, and honestly, I have zero experience with dual band filters, you'd be best asking someone else. Best of luck!

[dreamy ember]

zwo duoband filter has really bad halos and rather wide bandpass

im not too sure about the sv bony one

optolong probably has the best

[open dock]

But Optolong are so expensive 😵

And I’ll cross ZWO off

[dreamy ember]

it’s worth it, if you think it’s too much buy a uv/ir cut

i got mine used for 110

[open dock]

Does that do the same thing?

What mm is good for a filter?

[dreamy ember]

no, uv/ir cut just cuts out infrared and keeps all visible light but duoband filters cut out everything except Ha Oiii and sometimes Hb. Look at the graphs that are with the filters and it shows what they isolate

[dreamy ember]

it just depends what you want

[open dock]

What are the differences between a UV/IR vs Dual Band? Just that a UV one keeps all light and cuts infrared?

[dreamy ember]

.

[open dock]

When taking photos do you usually just want HA and Oiii or all? Sorry it’s my first time trying to get a filter

[tawdry notch]

Only in nebulae, in Galaxies a dualband filter is not good

[dreamy ember]

most emission nebulae have mostly Ha and Oiii in them so isolating those helps you collect as much useful light as possible

but yes for galaxies and stuff you’d want a uv/ir cut

[open dock]

So the IR/UV is a better multipurpose filter?

[dreamy ember]

and like dark nebulae are good for broadband

[dreamy ember]

technically yes but duoband excels a lot more than the uv/ir cut in certain targets

what bottle are you

[open dock]

High 5/6

[dreamy ember]

so duoband will help in emission nebulae to cut out some of the light pollution too

[tawdry notch]

Like MeLlamoKeepo said, the UV/IR cut, only removes non visible light, it helps with sharpness and star bloat, a dualband filter will do better at nebulae as the signal coming through can only be what the nebula produces, a UV/IR cut can be used on both, Dualband are only really good at Emission/Planetary nebulae

[dreamy ember]

since it’s isolating ha and oiii wavelengths and rejecting the rest

[tawdry notch]

Tbf B5-6 is better than most, but a Dualband filter will still significantly improve the signal, a UV/IR cut basically doesnt do anything in terms of light pollution

[dreamy ember]

in fact with my l enhance it is reflective when you look at it, that’s because it’s blocking out a lot of the visible light and therefore reflects it back at you but if you were pointed at an ha or oiii regret it would collect all of those photons

but yes uv/ir cut wouldn’t do a lot for light pollution, i would recommend having both so that you can shoot any target

[open dock]

Which should I get first?

[tawdry notch]

Personally UV/IR cut will do better, what cam do u use?

[open dock]

585mc

[dreamy ember]

it just depends what you want to image

[tawdry notch]

Oh yeah then definitely a UV/IR cut

Tbf yeah, if you only wanted to shoot nebulae then a dualband filter all the way, but if you wanted both now, then UV/IR cut

[dreamy ember]

i go strictly for emission nebulae so i went for the l enhance but if you want galaxies and dark nebulae and stuff too then definitely uv/ir

[open dock]

What UV/IR filters do you guys recommend?

[dreamy ember]

do your research and look it up on youtube

[tawdry notch]

From FLO?

FirstLightOptics?

[dreamy ember]

you’re basically looking for something that doesn’t have any star halos

[tawdry notch]

UV/IR cuts dont produce halos luckily lol

[open dock]

🤷🏽‍♂️

[dreamy ember]

really? i’ve seen some that have i thought

[tawdry notch]

Nah, probably a CLS or UHC filter, UV/IR cuts dont get them unless you bought some "uv/ir cut" from amazon for 5usd then maybe XD

[dreamy ember]

anyways just find some that people recommend and get good reviews and you’ll be alright

[dreamy ember]

lol

[tawdry notch]

Heres the one i use, make sure you do your research on the thread size you need for the filter, would be a shame if you purchased it and doesnt fit lol

https://www.firstlightoptics.com/astro-essentials-filters/astro-essentials-uvir-cut-filter-125-2.html

Can confirm it doesnt have halos incase im wrong about the UV/IR cuts having halos, i need to research that ngl

[dreamy ember]

if you buy a 1.25” it just screws into the 11mm spacer that comes on the camera

you should have a t2 to 1.25” adapter

that came with your camera

[open dock]

Mine isn’t cooled so it doesn’t come with that

[dreamy ember]

i’m looking for one myself so i’ll check it out

oh

[dreamy ember]

you using a scope?

[open dock]

I’m still trying to figure out if I need a filter drawer or not and than what spacers to get but it’s confusing

[dreamy ember]

if so you could do something with that or zwo filter drawer

but ideally you want the filter as close to the camera as possible to reduce vignetting

[open dock]

Is this one better than the Optolong one?

[open dock]

Say I got the filter drawer what spacers would I need to help it attach and get to 55mm? Because the threads are confusing and what I’ve struggled understanding

[dreamy ember]

not sure, how long is the drawer?

hmm your camera didn’t come with many spacers

[open dock]

21mm

[dreamy ember]

ok so 21mm +11mm is 31mm

so you’re missing 24mm

make sure the threads and everything line up though

[open dock]

What threads go with which?

[dreamy ember]

not sure, look at the product description

[open dock]

Where did you get 11?

[dreamy ember]

there’s a spacer on the camera already

i think it’s 11

[open dock]

Is it 17.5?

[dreamy ember]

yeah so 17.5

24+17.5

41.5

need 13.5

so just find an adapter for that and it should be ok

but again do your own research

[open dock]

Okay thank you

[open dock]

This one I think works

[dreamy ember]

you would be at 58ish then

i’m not too good about reaching focus like this so if someone else could say if that would be close enough that would help

i have a roki and mine just kinda worked lol

[open dock]

21 + 17.5 =38.5?

[dreamy ember]

didn’t measure it at all

[dreamy ember]

oh i thought the zwo was 26

then yeah that should work

[open dock]

Here I think it says 17.5

And than the drawer will be 21

[dreamy ember]

yeah that’s good then