First Planetary/Lunar Camera

[TiTanecd]

Hello community

I want some help on choosing a planetary/lunar camera for my XT8G and 130EQ (for wider views). They are 203/1200 -  f/l 5.9 and 130/650 - f/l5.

I was looking at ASI120MM, ASI120MC and QHY-5L-M (and the MC to compare).

I think the first thing to ask is which of these will suit a f/l5.9 and 5? I've seen posts on the optimal pixel per arc second. I'm still early on, so this will apply more for when I do guiding next year sometime.

Secondly, I found that my Logitech HD-3000 doesn't have the dynamic range as a dedicated camera does, some pictures taken with a ASI120MM look to be able to have dark shadows and evenly bright open areas. Is this down to that fact? 

Thirdly, practicality. Going mono means filters (and filter wheels if you want to get jupiter with out it rotating too much), if you want colour. I've seen MM vs MC on Jupiter and you can see the crispness with a LRGB image done with a mono, over the colour one. But I don't see myself atm doing that, as I think that requires lots of time and practice. But I don't want to get say the MC than and then my Lunar images will lack with the dynamic range of colour or guiding capabilities in the future.

So I'm stuck with Mono or Colour & ASI or QHY.

ASI: Has pros like it comes with a nice lens for large area shots and might handle heat better.

QHY: Has the lightweight compact feature and can achieve greater inward focus if need be.

I'd like any help I can get, as I have to order from the UK (ZWO's online store if I go with them) to South Africa, with a currency of like R11 - $1 ($340.00 for Mono incl shipping).

[bobmoss]

I recently went through the same thing and had a really hard time deciding what to buy. I literally took about 2 months to decide.

In the end I went for the ASI120MM. I wanted it mainly as a guide camera so sensitivity was important.

I went for the mono rather than colour as I decided I wanted the best possible image quality and didn't want to get the colour version and then always be wondering if I could have had slightly better images if I had only bought the mono! The timing was good for me as I'm now getting a filter wheel and filters as a Christmas present.

I also prefer the design of the ASI over the QHY as it seems more pratical.

And lastly, the support in the ZWO forums seem good (and they answered a question I sent them via email quickly).

[riklaunim]

Note that shadows on Moon will be black and not gray from refracted/reflected light, so dynamic range won't help there much (unless you want an extreme dynamic range to catch Earthshine alongside Sunshine - then you need logarithmic response or multi-frame HDR).

Smaller pixels on those cameras prefer f/15 and around, but some planets can take even f/20 (in general bit less than you would use for 5.6 pixels in DMK21* and alike cameras). Filter aren't that bad. Aside of color imaging of some planets you can easily shoot moon in IR, Venus in UV and IR etc. Classical LRGB imaging of planets is very hard due to atmospheric dispersion. The planet would have to be really high on the sky or you would need an atmospheric dispersion corrector. IR-RGB is easier to do, can give big improvement over RGB if the conditions aren't optimal but it also changes colors a bit.

[D4N]

Remember that the mono camera has a clear glass window so you will want to use a filter of some sort or the IR light will give you focus issues. I always have a filter in place even when making mono images unless I'm guiding.

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[riklaunim]

Remember that the mono camera has a clear glass window so you will want to use a filter of some sort or the IR light will give you focus issues. I always have a filter in place even when making mono images unless I'm guiding.

When doing planetary/lunary images there always is some sort of a filter, best for given objects. Unfiltered imaging isn't something done often (and focus problems will be caused by dispersion).

[TiTanecd]

Note that shadows on Moon will be black and not gray from refracted/reflected light, so dynamic range won't help there much (unless you want an extreme dynamic range to catch Earthshine alongside Sunshine - then you need logarithmic response or multi-frame HDR).

Dynamic range might not be the right word, more like different areas have a clearer differentiation of colour. Up to now mine seem to have a wasted out look, and requires PS to darken the shadows. I feel its the webcam not keeping the dark areas dark, without effecting the lighter areas.

An example of what I called Dynamic range is like the photos astroavani takes. There is a difference between, White, Gray and Black.

eg: http://stargazerslounge.com/topic/229054-catena-davy-yes-catena-muller-maybe/#entry2470076  

Remember that the mono camera has a clear glass window so you will want to use a filter of some sort or the IR light will give you focus issues. I always have a filter in place even when making mono images unless I'm guiding.

Do you mean like an IR-Cut filter or IR-Pass?

Smaller pixels on those cameras prefer f/15 and around, but some planets can take even f/20

So a 2x or 3x barlow would actually help to get my 5 to 10/15? F/5 Looses quality?

I was thinking of the ASI Mono, and even shooting IR shots with it for the beginning and Lunar, until I got the hang of it. Then getting filters and wheel.

[riklaunim]

Dynamic range might not be the right word, more like different areas have a clearer differentiation of colour. Up to now mine seem to have a wasted out look, and requires PS to darken the shadows. I feel its the webcam not keeping the dark areas dark, without effecting the lighter areas.

Shades of gray Low gain and all good dedicated cameras will handle moon easily in IR.

 

Do you mean like an IR-Cut filter or IR-Pass?

IR-Cut is the "L" filter, which isn't much usable with mono camera. IR-passing filter is very good for lunar imaging.

 

So a 2x or 3x barlow would actually help to get my 5 to 10/15? F/5 Looses quality?

 

I was thinking of the ASI Mono, and even shooting IR shots with it for the beginning and Lunar, until I got the hang of it. Then getting filters and wheel.

f/5 would be below telescope resolving power. For lunar imaging it's usually better to shot bit below the limit to avid light diffraction effects, while for planets you would want to max out as much resolution as your aperture can give.

[TiTanecd]

Thanx for all the help. Makes it easier to piece things together, as some sources assume you know a certain amount of knowledge when explaining things.

My telescope has a 0.57sec resolving power.

1. ASI120 : Resolution: 0.64"/pixel

2. ASI120 + 2x Barlow: Resolution: 0.32"/pixel (f/11.8)

3. ASI120 + 3x Barlow: Resolution: 0.21"/pixel (f/17.7)

So number 2 would be good for lunar and 3 good for planets, generally.

Also I assume we shoot at the highest resolution the camera has (eg 1280x960, or 640x480 with 2x2 binning).

Tx again.

[D4N]

Shoot at the lowest resolution that will fit the subject on the chip, this will increase frame rate. For lunar or solar this tends to be max resolution but for planetary there isn't much point imaging lots of black. I've never needed to use the binning.

Remember that a 2x Barlow isn't necessarily 2x when imaging, it all depends on the distance to the sensor. I have a 2.25x Barlow and just add more spacers if I want to increase the image scale.

The filter you use will depend on what your target is. For solar I use a continuum filter, for planetary or lunar I will use colour filters.

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[TiTanecd]

Tx alot, learning this all for the first time

Need to learn the basics from an imaging perspective now also.

[TiTanecd]

Ordered the ASI120MM and 3x barlow for a xmas present for myself

Clear skies is the only other gift I want.

[D4N]

Nice, I'm sure you will be happy with the image quality, it's a big step up from a webcam.

TSED70Q, iOptron Smart EQ pro, ASI-120MM, Finepix S5 pro.

[TiTanecd]

Yay! Got my camera, 2 days before. USA to Cape Town 5 days including SA holding it for 2 days over the weekend.

Only thing is the clouds have rolled in and heavy mist for next 3 days followed by 65km winds for a week... hope it clears soon, just want to get testing.

It did give me the chance to test out settings inside, like the USBTraffic, AutoAlign, etc so not all bad.

Got a focal reducer and Meade 3x Barlow also.