Zwo recommendation

[SpaceFish]

Hi All,

I am about to purchase a SW Skymax 127 (woohoo, happy dance and cloudy skies etc) but need some advice, as usual.

I am looking to use it as a mix of mostly visual but moving into planetary (with a hint of DSO if I can find any that fit in the FOV) AP. I (think) I have narrowed it down to the ZWO ASI120MC Colour, ZWO ASI120MC-S Colour or the ZWO ASI224MC.

So here are the questions,

1. Is it worth going for the usb 3 120 over the usb 2, I know you will get more frames but is it worth the extra £50~. 
2. With this scope, will I notice much difference between the 120MC-S and the 224? (I have a decently spec'd laptop i7, 8GB ram, SSD, usb 3 etc so should get the most from both)
3. If I go for the 224, it recommends an IR filter, I wont be able to afford that right away, and not really sure I understand it anyway. What will I be able to image without it, and what will improve with the filter? A sub question I suppose, what should I be looking for in an IR filter when I buy one?
4. Also open to suggestions on other cams but my hard limit is about £250

As always, thanks for any and all advice.

SpaceFish.

[Demonperformer]

From memory the 224 has a bigger chip so more DSOs will be available to you. But DSOs tend to need longer exposures so you would then need to think about the cooled version -out of your price range. 

The 120 does not need an ir filterror because it is already built in. Unless you specifically want to image in the Ir bands, you will needto block it or it will interfere with the image you get on the chip (think noise).

HTH

[wimvb]

FLO's website has a field of view calculator for both cameras

https://www.firstlightoptics.com/zwo-cameras/zwo-asi120mc-s-usb-3-colour-camera.html

https://astronomy.tools/calculators/embedded_field_of_view/?telescope[]=185&telescope[]=50&telescope[]=40&telescope[]=117&telescope[]=14&camera[]=7&solar_system=jupiter&quick_select=telescope

Both models have the same fov. When it first came out, the 224 was highly praised as a planetary camera. But check out this forum and astrobin.com for images taken with either camera.

Personally, I would choose a usb3 model over a usb2. Faster download at high frame rates, and fewer dropped frames.

Both are very limited at DSO imaging due to the small chip size. But that doesn't mean you can't have fun trying. 

[London_David]

The ASI224 is actually excellent for DSO EEA since it is one of the most sensitive colour cameras you can get, allowing you to stack short exposures. Of course, angle of view does depend on your scope, so it is a great idea to check out what you will see on astronomy.tools as suggested. 

You could get a TSOptics 0.5 focal reducer for £50 and get down to about f/6 @750mm on your skymax which would be great for galaxies. I just gave someone exactly that as a gift this Christmas (for an 8” sct 2000mm @f/11, going to 1000mm @ f5.5 ish) and it we had it working a treat.

If you’re interested, over on Cloudy Nights EEA forum there is a lot of great examples taken with the asi224 on short exposures. There is a guy there called AstroJedi who posts a lot with the asi224, you can just search the forum for the camera. Here is his asi224 flicker stream: https://www.flickr.com/photos/147842817@N06/albums/72157674749494795

I wouldn’t worry about an IR filter too much. For some dso (galaxies) it’s better without. If you feel the need it’s an easy accesory later. If you don’t have a lot of experience, I suspect you’ll not know the difference. 

If you’re interested in planetary then you definitely want to go for the usb3. You can get away with low frame rates on dso but planets are bright and the faster frame rate allows you to shorten exposure to get luckier with fractions of a second of good seeing. The short version is that usb3 can allow you to have crisper views on nights of poor seeing.

If I was looking to buy a colour camera in your budget range I would only be looking at the asi224 or the new asi385. The 385 is very similar to the 224, only with a large chip — making it more expensive.

So to answer your specific questions...

1. Yes
2. Yes - the 224 will make your life a bit easier. 
3. You can image everything and with out an ir filter. Some people even spend lots of money removing the IR filter from their dslr to make it better for use in astronomy! With a filter on certain objects will have a little more detail. In a good IR filter you want clear transmission on every other wavelength except IR. most filters are shown with a graph of transmission lines. You want a high mark on the ir wavelengths and zero on all others. The Baader brand of filters are good quality and not too expensive. The even cheaper ZWO ones are probably fine too. You can get fancy Japanese made filters for  more than the cost of the camera too, but as I said... if you’re new to this I’d be surprised if you can tell the difference. I wouldn’t bother or worry about it until you know exactly why you think you need one. 
4. Look at the ASI385 since it will give you a bit of a wider view with the same level of detail but the actual sensing performance should be very similar. 

If your hard Budget cap is 250 go for the ASI224 — it’s is a great little camera!

 

[SpaceFish]

Wow as always that is some pretty in depth and comprehensive advice. I hadn't even thought of the reducer but now will be adding one to the list of future things to look in to.

In the mean time i've settled on, in no small part, due to the advice above to go for the 224. When I finally get everything and am up and running you can all expect lots more slightly dodgy pictures and some more advice  

Thanks.