Suggestion for planetary/lunar camera with DSO setup

[Richard_]

Whilst I'm well versed in DSO, I don't have any real experience in lunar or planetary imaging. I don't have the space or budget to buy another telescope, so I'm looking for a suitable camera to compliment my DSO setup. My setup is as follows:

• WO 120mm refractor (780mm FL @ f/6.5)
• Skywatcher EQ6-R
• Use of a x2 barlow (turns into 1,560mm FL @ f/13) (item link to FLO)

From what I've read, the pixel size of the camera should be between 1/5th or 1/7th times the f-ratio of your system, depending on seeing conditions. So with my barlow in place, I should be looking for a pixel size between 1.85um and 2.60um. Looking at the recent offersing from QHY, ZWO and Player One, many of them offer pixel sizes of 2.90um which is close enough to my range. I'm using a Windows PC to control so I'm not stuck by particular brand ecosystems. To keep price down, I'd prefer to stick with colour cameras to avoid purchasing a filter wheel and RGB filters. I've grouped the cameras by sensor as follows:

• IMX585 (2.90um pixel size)
  • Player One Uranus-C (£399)
  • QHY5III585C (£368)
  • ZWO ASI585MC (£382)
• IMX662 (2.90um pixel size)
  • Player One Mars-C II (£200)
  • ZWO ASI662MC (£199)
• IMX664 (2.90um pixel size)
  • Player One Neptune 664C (£280)
  • ZWO ASI664MC (£329)
• IMX678 (2.00um pixel size)
  • QHY5III678C (£249)
  • ZWO ASI678MC (£299)

One thing that's clear is that the ASI585MC has been a well received and popular camera. Heck, I know of it because people are taking good images of DSO with it. This camera sensor category also happens to be the most expensive on the list!

• Is the difference in performance between the IMX585 and other sensors on the list night and day (if you'll parden the pun)? With the release of the IMX585, should I negate the other cameras on the list?
• Are there any sensors on the list which should be ignored straight away?
• Is it realistic to use the barlow I linked above or should I really consider something like the TeleVue Powermate?
• Below are some FOV's I made using the above cameras (ZWO version) - would this offer acceptable views or do I really need a bit more FL?

 

[Fegato]

I'm no expert either, although I have shot the moon and planets. I have an older ZWO ASI290MC with 2.9um pixels which did an OK job. I think my problems were normally related to seeing...  having the perfect set up for planetary is all very well, but if the seeing is crap, then it's hard to get any sort of result! My F/10 wasn't quite enough either, and my barlow was too powerful (made it F/22.5).

I think a rule of thumb is to aim for a focal ratio of 5x your pixel size. So with the 2.9 - about F/15. So your F/13 sounds pretty good. 

I think the 585 is more expensive because the sensor size is  larger? That might be good for moon work, but won't give you anything on the planets. That's the problem with having one set up for lunar and planetary, the size difference is massive (unless you just want to do ultra close-ups of the moon). I've tended to use my larger sensor ASI294MC Pro for moon pics and compromised on resolution. 

Must admit, I like the look of that 2um pixel camera - might work well with my 8 Edge HD at F/10. But then again, that seeing....

 

 

[Richard_]

20 hours ago, Fegato said:

I'm no expert either, although I have shot the moon and planets. I have an older ZWO ASI290MC with 2.9um pixels which did an OK job. I think my problems were normally related to seeing...  having the perfect set up for planetary is all very well, but if the seeing is crap, then it's hard to get any sort of result! My F/10 wasn't quite enough either, and my barlow was too powerful (made it F/22.5).

I think a rule of thumb is to aim for a focal ratio of 5x your pixel size. So with the 2.9 - about F/15. So your F/13 sounds pretty good. 

I think the 585 is more expensive because the sensor size is  larger? That might be good for moon work, but won't give you anything on the planets. That's the problem with having one set up for lunar and planetary, the size difference is massive (unless you just want to do ultra close-ups of the moon). I've tended to use my larger sensor ASI294MC Pro for moon pics and compromised on resolution. 

Must admit, I like the look of that 2um pixel camera - might work well with my 8 Edge HD at F/10. But then again, that seeing....

 

 

Thanks Fegato. I shoot in mono, so I suppose I could try my QHY268M on the moon with a reduced ROI and go for a smaller sensor for planetary.

My seeing conditions are not amazing. My FWHM is anywhere from 2" up to 5". Does that mean planetary is a no go?

[Fegato]

The planets are very small and you're trying to pick up much greater detail/resolution than you'd expect to with DSO work. In poor seeing you see them wobble about all over the place. On the other hand they are very bright - so obviously exposures are very short, you shoot video and use "lucky imaging" to pick the best frames. I found I just had to use a pretty small % of the frames when seeing was poor, and my results were mediocre.

But really, I haven't put nearly enough effort in to it. I'm sure if you persevere with it, some nights you'll get good seeing or periods of it, and you can definitely get good results in the UK, as you'll see by others work.

[Elp]

The ones I've used are the 224 and 485 both OSC. The 485 was useful in that I could also use it for DSO even though it's uncooled (if you know you know), the larger sensor size is also of benefit if you wish to capture Jupiter and it's four main resolvable moons in one shot if they're in an almost horizontal line (at a tilt) which I've done, the large sensor will also be of benefit on the moon (and white light solar, though mono would be better in this regard). But, if imaging planets I still use the 224, it's popular for a reason and it's NIR capability can help when using an IR pass filter to get more stable surface detail, a larger sensor you can ROI (region of interest) to crop the sensor so you can get a smaller image/video resolution and a faster frame rate of capture (another reason the 224 is popular).

[Astronomist]

Another option that might be worth a look is the new ASI676MC - it has 2μm pixels but offers a bigger sensor area than the 678, which may be useful for lunar. it is quite a bit more expensive though, and I suppose there is always a small risk associated with buying a product that is new on the market.

On 19/05/2024 at 22:54, Richard_ said:

With the release of the IMX585, should I negate the other cameras on the list?

No! At the current level of technology there isn't a lot to choose between the newer cameras; something else will almost always be the limiting factor (I have no idea if this is true in DSO imaging as well). Best to go with whichever is the best match to your scope / use case in terms of pixel and sensor size.

[Richard_]

3 hours ago, Fegato said:

The planets are very small and you're trying to pick up much greater detail/resolution than you'd expect to with DSO work. In poor seeing you see them wobble about all over the place. On the other hand they are very bright - so obviously exposures are very short, you shoot video and use "lucky imaging" to pick the best frames. I found I just had to use a pretty small % of the frames when seeing was poor, and my results were mediocre.

But really, I haven't put nearly enough effort in to it. I'm sure if you persevere with it, some nights you'll get good seeing or periods of it, and you can definitely get good results in the UK, as you'll see by others work.

That's right, I tried lunar once or twice which was using video and then stacked the best x% of frames. It sounds like even with poor seeing, you get the odd pocket of good seeing so maybe not all is lost!

 

3 hours ago, Elp said:

The ones I've used are the 224 and 485 both OSC. The 485 was useful in that I could also use it for DSO even though it's uncooled (if you know you know), the larger sensor size is also of benefit if you wish to capture Jupiter and it's four main resolvable moons in one shot if they're in an almost horizontal line (at a tilt) which I've done, the large sensor will also be of benefit on the moon (and white light solar, though mono would be better in this regard). But, if imaging planets I still use the 224, it's popular for a reason and it's NIR capability can help when using an IR pass filter to get more stable surface detail, a larger sensor you can ROI (region of interest) to crop the sensor so you can get a smaller image/video resolution and a faster frame rate of capture (another reason the 224 is popular).

Thanks for the suggestion of the 224. I don't mind going for a larger sensor if it means I get the best of all worlds (reduce ROI for planets, use max ROI for lunar). I initially ruled this camera our out as the pixel size of 3.75um was a bit higher than the rule of thumb suggests for my setup. How does mismatching of pixel size work with planetary, is it like over/under sampling with DSO? Or does it just lead to pixelation or loss or resolution?

 

3 hours ago, Astronomist said:

Another option that might be worth a look is the new ASI676MC - it has 2μm pixels but offers a bigger sensor area than the 678, which may be useful for lunar. it is quite a bit more expensive though, and I suppose there is always a small risk associated with buying a product that is new on the market.

No! At the current level of technology there isn't a lot to choose between the newer cameras; something else will almost always be the limiting factor (I have no idea if this is true in DSO imaging as well). Best to go with whichever is the best match to your scope / use case in terms of pixel and sensor size.

Interesting choice! I'm not sure how I missed this one out. Price wise, at £349 this isn't the most expensive on the list (the ASI585MC is £382). I'm not fazed by a square sensor as I started out DSO with the ASI533MC, and I think a square crop is perfect for framing of planets. What's the real world implication of choosing a smaller pixel size for planetary?

The reason I asked about sensor technology is due to some amazing introductions to the DSO world. As an example, the IMX 571 (as used in ASI2600, QHY268) is a crop sized sensor and is an amazing sensor compared with previous generations. Very little dark current, no amp glow, no challenging flat frames, so spending a few extra quid on this sensor over a previous generation is a no-brainer. I was curious to know if a similar phenomena had happened in the planetary world which would help narrow down my search

[bosun21]

The 585 is a great camera for planetary imaging with the ROI I was capturing at about 180fps. It's good for lunar with the larger sensor allowing a larger surface area of the moon to be imaged. It also has good IR sensitivity for when using an IR pass filter. While the seeing and the Jetstream being constant sources of irritation and hindrance I am now well and truly hooked on planetary imaging and EAA. I started off planetary imaging last year with a 150 Maksutov and the ASI585MC. I was capturing at f12 which is under the recommended f14.5 for my 2.9 pixel size. I captured this image on my second ever attempt coming from being a 100% visual observer.

I now added a ASI462MC which is even better in the near IR however the 585 wins in my assessment.

Edited May 21 by bosun21

[Elp]

3 hours ago, Richard_ said:

Or does it just lead to pixelation or loss or resolution?

Think it's a resolution thing, but quality of details will also be dictated by aperture and quality of seeing.