what is the best guidecam for OAG's ?

[Northernlight]

Hi all,

I use an OAG with my 2 scopes which are 400mm & 1000mm Fl. I'm looking for a new guide cam recommendation and my old lodestar is getting a bit old now and struggles finding stars.  Traditionally, i  believe IMX174 based guiders were considered the best due to their larger sensor size. I just wondered if this was still the case as these are also quite old sensors now.

Are there any newer modern guiders with a similar size sensor or are the older IMX174's still considered the best choice for acquiring more guide stars ?

 

Cheers,

Rich. 

[Skipper Billy]

Many years ago I tried all sorts of guide cameras and eventually settled on the orginal Lodestar.

Like you, after a few years later I felt the need for an upgrade and tried a few options from ZWO etc but the best performer - by far - was the new Lodestar.

https://www.firstlightoptics.com/starlight-xpress-cameras/starlight-xpress-mono-lodestar-pro.html

 

[Elp]

My 290MM works perfectly fine at 1000mm FL. A larger sensor size won't hurt.

[ONIKKINEN]

The new-ish 220MM is very good. I use mine at 1018mm focal length f/5 with an OAG and it just works, even through a semi-narrowband filter (Antlia triband RGB - 3x 30-40nm passes).

Guide star SNR is usually in the hundreds, sometimes in the thousands so there is plenty of SNR to spare for slower scopes. Highly recommended, much better than my previous 120MM.

[Northernlight]

Is there a way to work out the suitability for the best camera ?  My main imaging rig will comes in at 0.78" resolution :-

I am using an OAG and the 2 cameras i'm considering are the ASI174MM mini or the ASI200MM mini

ASI174MM = 1.21" resolution with OAG

ASI220MM = 0.83" resolution with OAG

So the ASI220 will be the closest match to my main imaging rig, but the ASI174 will have a much wider FOV and more stars for the MultiStar guiding, which is likely better for the harmonic mount i've ordered.

[Elp]

The size of your OAG prism also makes a difference to how many stars it'll see. Also read up on long FL guiding with a HD mount, some manufacturers don't recommend around or over 1000mm FL for whatever reason, haven't tried mine yet at that FL.

[michael8554]

The PHD2 developers only consider guidescope/guidecam arcsecs/pixel.

Up to about 3 (which your suggestions are in) is okay, it gets worse as you get larger, the 6.5 with those tiny guidescopes is pushing it.

So you can afford to Bin both those cameras to improve star capture.

Michael

[skybadger]

I run at 2000mm on a lodestar 8um pixels binned X2 using an oag. Typical exposures 2.5 secs and guiding .5"

Sometimes it's hard to find a star but rarely.