ZWO ASI120MM advice

[DaveHKent]

I'm considering getting the ZWO ASI120MM camera after reading a few positive reviews. I'd been thinking of going for the Orion Starshoot solar system imager, but this sounds far better (and more expensive) as it says it can be used for some deep sky stuff too.

What is the difference between the mono and the colour versions? (web link for spec). Obviously one is only in black and white, however that is more expensive. In my limited knowledge, colour sounds better. Do you generally get a crisper picture going monochrome and using a filter wheel? Will the difference be that much.

My scope is the Celestron NexStar SLT 90. I understand the tracking motor on these is not generally smooth enough for DSO work. Does anyone know what the maximum exposure I might be able to set on this is?

[lensman57]

I'm considering getting the ZWO ASI120MM camera after reading a few positive reviews. I'd been thinking of going for the Orion Starshoot solar system imager, but this sounds far better (and more expensive) as it says it can be used for some deep sky stuff too.

What is the difference between the mono and the colour versions? (web link for spec). Obviously one is only in black and white, however that is more expensive. In my limited knowledge, colour sounds better. Do you generally get a crisper picture going monochrome and using a filter wheel? Will the difference be that much.

My scope is the Celestron NexStar SLT 90. I understand the tracking motor on these is not generally smooth enough for DSO work. Does anyone know what the maximum exposure I might be able to set on this is?

Hi,

I have the ASI 120 MC and some other brand of cameras, it is a very good camera. I don't know anything about the Orion Star Shoot. The mono camera is a lot more sensitive to light than the colour version by up to 30%. All CCD chips are mono, the colour version has a Bayer Matrix array on top of the chip, one red, one blue and two greens. The signal from the colour chip is processed by onboard chip or by software to decode the signal, Debayerd, then you will have colour image. The Bayer matrix is what causes the reduction in sensitivity since the light falling on the chip is divided into the colour bits. If you buy the mono version you can still have colour but you will need to do what is called an LR GB, image sequence. For this you will need a decent set of LRGB imaging filters, From £100.00~ £200.00, a filter wheel either manual or driven to house and move the filters into position and all this costs money. A decent manual filter wheel can cost uo £90.00, a driven one up to £400.00. Your scope should be fine with a colour camera, ASI is quite sensitive for a colour camera, but do your research before making a decision.

Regards,

A.G

[Zakalwe]

My scope is the Celestron NexStar SLT 90. I understand the tracking motor on these is not generally smooth enough for DSO work. Does anyone know what the maximum exposure I might be able to set on this is?

Its a f13 scope mounted on an alt-az mount. Thats about as bad as it gets for DSO work. You want something with a fast focal ratio mounted on a German Equatorial for DSO work as you need to track the heavens. An alt az scope will give field rotation on long exposure.

Planetary/lunar work is different, and your scope would be great for this.

[DaveHKent]

Cheers for the advice. I suspected as much for DSO

[Twisted Lip]

Hi,

I have the ASI 120 MC and some other brand of cameras, it is a very good camera. I don't know anything about the Orion Star Shoot. The mono camera is a lot more sensitive to light than the colour version by up to 30%. All CCD chips are mono, the colour version has a Bayer Matrix array on top of the chip, one red, one blue and two greens. The signal from the colour chip is processed by onboard chip or by software to decode the signal, Debayerd, then you will have colour image. The Bayer matrix is what causes the reduction in sensitivity since the light falling on the chip is divided into the colour bits. If you buy the mono version you can still have colour but you will need to do what is called an LR GB, image sequence. For this you will need a decent set of LRGB imaging filters, From £100.00~ £200.00, a filter wheel either manual or driven to house and move the filters into position and all this costs money. A decent manual filter wheel can cost uo £90.00, a driven one up to £400.00. Your scope should be fine with a colour camera, ASI is quite sensitive for a colour camera, but do your research before making a decision.

Regards,

A.G

I've read a load of books and material on the web over many years and have never heard it described as straightforwardly as that! Top top description!

I do have the Orion starshoot and although my efforts with it have never actually been that good (to get decent images with it you need a bit of aperture and slower f/r and for this i only have Dobs so can't perform any kind of longer exposure), I have seen some very very good examples of planetary work.