Planetary camera choice?

[souls33k3r]

Hi guys,

I was hoping that someone with planetary imaging might help me decide on which planetary camera i should go for.

I'm not looking at mono because i want to try and stay away from filters as much as possible and someone told me you have to be really quick with the colour channels to capture them. Plus it's a bit more money.

So the next obvious choices for me are the ZWO ASI224MC, ASI290MC & 185MC.

My scope is an EdgeHD 8" and i do indeed have a TeleVue Powermate 2.5x.

Thanks

[Guest]

ZWO ASI120MC has worked really well for me :-)

David

[SkyBound]

+1 for the ASI120MC,  or the MC-S which is the USB 3.0 version

[PeterCPC]

224 but it will need an IR cut filter whereas the 120 comes with one fitted.

Peter

[D4N]

I would suggest that the 178mc is better for planetary than the ones you listed, smaller pixels, higher resolution and 14 bit instead of 12.

This spec list from ZWO may help.

[CraigT82]

A common rule of thumb to get yourself sampling correctly is to go for a camera that has a pixel size which gives you a resolution of about 1/3 to 1/2 of the dawes limit of your scope (when calculating the resolution you should take into account the image amplifier you'll be using).   

C8 has a Dawes limit of 0.58".  ASI120, 185 and 224 all have 3.75 micron pixels.  When used with the C8 and 2.5x powermate you'll be sampling a about 0.15" per pixel, so about 1/4 of the dawes limit, so You'll be oversampling with this set up (which is not a deal breaker really).  If you swapped the 2.5x powermate for a 2x one you'll be bang on sampling wise. 

Generally, oversampling means you'll be sacrificing frame rates as the small pixels aren't sensitive enough (image will be too dim) and you'll need to increase exposure times. Undersampling is where you'd pixels wont be small enough to capture the finest detail that's on offer.

Whichever camera you go for you'll need a decent laptop with USB3 and ideally an SSD to get the most from it.

 

[vlaiv]

I vote for ASI224, with focal ratio of about f/18-f20, so x2 powermate

It has the least read noise.

[souls33k3r]

cheers for your response guys, 224MC is looking like a much better contender. 

I'm not looking to spend money on the cool version just the normally cheaper version for planetary imaging.

I'll also be looking in to purchasing the ZWO ADC.

In reality, all what i expect is the images for not to be blurry and grainy but smooth and clear.

The price difference in all 224, 290 and 185 isn't much really so i don't mind spending extra £30 for it. 

[D4N]

Yeh the cooled version is pricey, I've got a 178MC that I've built my own cooler for and found it makes a huge difference to the noise levels although I also have to use a dew heater to stop it icing up he glass.

[ronin]

From your options I would go for the 185 - reason bigger sensor. The 224 is 4.8x3.6, the 185 is 7.3x4.6. But the 185 loses out on the number of pixels - if relevant.

My choice would have been the 178 at 7.4x5.0 and 6.4M pixels and smaller ones for planets.

[souls33k3r]

11 hours ago, CraigT82 said:

A common rule of thumb to get yourself sampling correctly is to go for a camera that has a pixel size which gives you a resolution of about 1/3 to 1/2 of the dawes limit of your scope (when calculating the resolution you should take into account the image amplifier you'll be using).   

C8 has a Dawes limit of 0.58".  ASI120, 185 and 224 all have 3.75 micron pixels.  When used with the C8 and 2.5x powermate you'll be sampling a about 0.15" per pixel, so about 1/4 of the dawes limit, so You'll be oversampling with this set up (which is not a deal breaker really).  If you swapped the 2.5x powermate for a 2x one you'll be bang on sampling wise. 

Generally, oversampling means you'll be sacrificing frame rates as the small pixels aren't sensitive enough (image will be too dim) and you'll need to increase exposure times. Undersampling is where you'd pixels wont be small enough to capture the finest detail that's on offer.

Whichever camera you go for you'll need a decent laptop with USB3 and ideally an SSD to get the most from it.

 

Craig, mate i seriously do appreciate you sharing this very vital information. Never did quite understood the dawes limit but now i have.

One thing i did notice with the 224mc is if i bin it with 2x2, i'd ne just slightly over half of the dawes limit. Would that still be ok?

[PeterCPC]

IMO you don't want to bin planetary images.

Peter

[knobby]

Is your laptop USB 3 ? Ideally you want to capture as many frames in as short a time possible .

Another vote here for the ASI 224mc.

[souls33k3r]

22 minutes ago, PeterCPC said:

IMO you don't want to bin planetary images.

Peter

Oh ok, didn't know that either but at least i was thinking along the correct path

10 minutes ago, knobby said:

Is your laptop USB 3 ? Ideally you want to capture as many frames in as short a time possible .

Another vote here for the ASI 224mc.

No mate, unfortunately it isn't but i can buy an express card and make my laptop a USB3 compatible. Is that really a game changer? I know i'll be pouring money into a technology which my laptop natively doesn't have.

[RayD]

I have a ZWO ASI290MC for planetary and it's been excellent.  TBH I think depending on your requirements for sampling and budget, any one of the ZWO range is reliable and represents pretty good value for money.

[CraigT82]

If you're going to go for the ASI224Mc, or any of the newer generation of cameras with USB3, you will definitely need a USB3 computer to take advantage of the high frame rates they offer.  Saying that though they should work perfectly well in the meantime with USB2, just with slower frame rates.

There's a fair bit of variation in chip sizes for these current crop of ZWO cameras, you my want to think about one of the bigger sensor ones if you plan on doing some lunar imaging too, you'll be able to get more of the surface in and image (and fewer panels for lunar mosaics).  Something worth considering as the planets are gonna be pretty low for the next few years and really not at their best.

Here's an image to show the relative sensor sizes of the current range:

 

 

[souls33k3r]

2 minutes ago, CraigT82 said:

If you're going to go for the ASI224Mc, or any of the newer generation of cameras with USB3, you will definitely need a USB3 computer to take advantage of the high frame rates they offer.  Saying that though they should work perfectly well in the meantime with USB2, just with slower frame rates.

There's a fair bit of variation in chip sizes for these current crop of ZWO cameras, you my want to think about one of the bigger sensor ones if you plan on doing some lunar imaging too, you'll be able to get more of the surface in and image (and fewer panels for lunar mosaics).  Something worth considering as the planets are gonna be pretty low for the next few years and really not at their best.

Here's an image to show the relative sensor sizes of the current range:

 

 

Cheers Craig, that's really helpful. I did however checked this on the astronomy.tools website as well. So many things to consider and yet there isn't one that is just perfect for one setup. At least they're keeping true to this hobby by making ones life difficult  USB2 will have to do for now but like i said i do have my eyes set on a USB3 express card which i'll have to buy sooner rather than later.

 

2 hours ago, RayD said:

I have a ZWO ASI290MC for planetary and it's been excellent.  TBH I think depending on your requirements for sampling and budget, any one of the ZWO range is reliable and represents pretty good value for money.

Cheers RayD, i really am torn right now ... all three that i have chosen are good in their own respect. not sure if i should look for a different brand?

[Astrosurf]

I hope I don't confuse you more, but I love my 120MC! But I know it isn't the best camera for planetary.

Alexxx

[RayD]

2 hours ago, souls33k3r said:

Cheers RayD, i really am torn right now ... all three that i have chosen are good in their own respect. not sure if i should look for a different brand?

Yes definitely look at others. QHY I believe are also reasonably good. I think many have recommended ZWO as for a long while they really specialised in planetary cameras and have only very recently ventured in to the DSO market. They are very good at the price mark so I wouldn't discount any of them.

i actually have a 120MM also which I use for guiding and both are great for what they are used for.

As someone else noted to get the very best from them you need USB3 but they will run happily on 2, and when you consider that they are about the only ones using USB3, I wouldn't see it as a real deal breaker. 

Hope you get some great images with whichever one you choose