What should I expect with a Mono Cam but no LRGB & Narrow Band filters

[keramos]

Hello Everyone,

I'm about to delve into the world of DSO imaging, well not immediately but with a month or so once I've got all my gear sorted.

Telescope: WO Red Cat 51
ASI Air
ZWO Finder and ASI120MM mini USB 2

Main camera (as of now)..
1) Nikon DSLR - D3300, this is an unmodified camera
2) ASI 174 MM USB 3 Mono

I was wondering what I should expect in terms of results with the ASI174MM i.e. don't have filter wheel or LRGB+NB filters

Given that I've maxed out my budget and will take me a while to get filter wheel+ filter lens & Cooled camera.

What should be my expectations given my current kit?

Lastly, if I do take images with ASI174MM without any filter wheel etc, do folks add colour in post processing (as done with solar)?

With DSLR that is unmodified I believe relatively decent images can obtained but without finer details (as per Making every photon count).

Any examples around for both ASI Mono and DSLR?

Thanks in advance.

[Spongey]

Looks like a nice setup you're getting!

The ASI 174MM isn't particularly suited to deep sky astrophotography, as it has no cooling. However, you can expect to get somewhat reasonable results out of it if you wanted to use it for DSO imaging.

You are better off using your DSLR with the RedCat, as you will get a much larger FOV, and the pixel size is more suited to the focal length of the scope.

With no filters in front of the ASI 174MM, you will always get a soft image with the RedCat. This is because (standard) refractive optics cannot focus infra-red and ultra-violet light at the same time as the visible spectrum. Looking at the QE graph, there is decent response in the ASI 174MM in both UV and particularly in IR, which will lead to a soft image. The minimum requirement for a sharp image with this camera in your setup would be a UV/IR cut filter (only about £20). 

The ASI 174MM is however a fantastic planetary camera, and would do well as a autoguiding camera too, although I notice that you have the 1200MM for that already.

Typically, colour is not added to monochrome DSO images, but you are of course free to experiment!

[keramos]

Hi Spongey,

Thanks for the reply, I haven't bought the ASI120MM as yet and already have UV/IR cut filter.

I did think about using the ASI174MM as guiding camera and only use DSLR, but wasn't sure what to expect from DSLR which is unmodified (until I read Steve Richards book, pretty good read I must say)

If I don't invest the £145 in ASI120MM, then is there any filters I can invest in to use with DSLR which might be helpful given DSLR is unmodified for Astro usage.

Aspiration is to get ZWO EWF+Filter+ ASI1600MM pro when funds become available.

 

[MarkAR]

Personally I would stick with the DSLR for practice and save up for a better cooled camera. If you get a CMOS OSC then the Optolong L-Xtreme would be a good filter for NB.

[Spongey]

It is true that your ASI174 will have a greater response to Ha and other deep red wavelengths compared to your DSLR, but if you are just starting out then you can't go wrong with with a DSLR to begin with. You can still get great results with an unmodified, unfiltered DSLR, and there are plenty of broadband targets that wouldn't particularly benefit from increased response anyway. I currently use a stock Canon 6D while I am saving for a cooled mono cam, feel free to check my post history to see what sort of images are achievable! 

I agree with MarkAR in that you'd be better suited to save the money from the ASI 120MM, use the ASI 174MM as a guide camera, and stick with the DSLR as a primary imaging camera for now. You could of course try imaging with the ASI 174MM too, if you feel like it. 

There are various filters that you can use with a DSLR. A common example would be a light pollution clip-in filter. What is your sky like?

 

[keramos]

Thanks MarkAR & Spongey,

Where I live its approx Bortle 5 but more like 6 however where I plan to image is Bortle 4.

[keramos]

I need to research Mono vs OSC, looks like OSC have up'd the game seen some vids on QHY268C (expensiveeee!) and lots of ZWO OSC capability.

oh well by the time I save up there will be something new in market.

[rickwayne]

You can pick up a used Ha filter somewhere and get started right away. You don't have to have a filter wheel, the ZWO cameras let you mount a filter easily.

With just Ha you can do things like this, or this, or this.