QHY5l-ii mono or colour and gama electronics

[acarleton]

Hi all

i am looking to get the QHY5l-ii autoguider to enable me to take longer exposures of DSO's but i also wanted to use it as a planetary imager. my question is, should i get the mono or the colour? what are the pros and cons? why is the mono more expensive? if i get the mono then i will have to buy additional filters to pull together a colour image of the planets. Finally, has anyone bought off gama electronics before? seems like a guy who set up a website and is selling these cameras, i wanted to make sure it is on the up and up.

i am looking to get it this weekend so any help would be appreciated.

[pluto]

I got my QHY5L-II colour from Gama for the same reasons you cite. The mono would have been better for guiding but it is handy having the colour for quick planetary/lunar/solar imaging. Plus I never really had a problem guiding with the colour anyway though I was using a guidescope and not an OAG.

If you do get the mono you will need to get filters, and probably a filter wheel, if you want to do colour images of planets etc.

Gama was good to deal with, Theo is very knowledgeable about the products he sells.

[acarleton]

Thanks Hugh

Why is the mono better for guiding? and i don't get why it would be more expensive, it seems counter intuitive

Thanks

[wasyoungonce]

Well the colour uses a bayer matrix (http://www.opticstar.com/Run/Astronomy/Astro-Editorial-Articles-General.asp?p=0_10_19_1_6_200_40) laid on top of a mono sensor using RGB to make one pixel.

Mono, each pixel records a value thus by sensitivity alone the mono should be 3x more sensitive given same pixel matrix. Thus a mono is more sensitive for finding guide stars.

When guiding you don't require colour information just mono pixels.

But if you want to use your guide camera as a planetary camera, then you will need filters, where as for a colour camera does not. There is a whole lot more to it than this suffice to say this is a start.

[acarleton]

is sensitivity mainly of concern when dealing with guiding? given that planets are fairly bright then they don't need a high sensitivity, i am assuming. also if i lay RGB filtered mono images ontop of each other, am i going to get a greater resolution, picking up finer detail than the colour version?

Thanks for the help

[wasyoungonce]

Sensitivity is key for guiding, finding guide stars, expecially with off axis guiders. I don't think (never have) guiding is necessary for planetary imaging.

Resolution is better with a mono sensor as guide software can detect a 1 pixel change and a colour pixel is RGB where in a mono = 1 pixel.

[traveller]

As Brendan said, the colour model has less sensitivty due to the bayer matrix.
This is the link to the QHY website.
I am looking at a colour one as I am after planetary imaging first and guiding second.
Cheers,
Bo

[scagman]

Hi Acarleton,

Can't add to the mono/color debate, but big :thumbsup: up for gama electronics.
Very helpfull if you have any questions or problems.

Cheers

[acarleton]

But wouldn't the mono be better for planetary as well or are you not wanting to get filters