ZWO/Player One IMX 585 Sensor Image Showcase

[Space Cowboy]

3 hours ago, PeterC65 said:

It will be good to hear how you get on with the QHY variant of the IMX585.

Where did you buy it from? I can't find a UK based supplier.

 

I've ordered it from Bernard at modern astronomy. He's making up an order from QHY at the moment.

https://www.modernastronomy.com/shop/cameras/lunar-planetary/qhy-lunar-planetary/qhy5iii585c-colour-camera/

Thanks for your comment on CN. 😉

Edited March 13, 2023 by Space Cowboy

[Richard Wesson]

On 16/02/2023 at 19:46, PeterC65 said:

I bought the Player One version after much deliberation. I have mixed feelings as to whether it was the right decision, meaning there probably isn't much in it.

The passive cooling feature probably doesn't take more than a few degrees off the temperature. My camera temperature is usually not much above the ambient temperature, even when it's outside in the cold. I'm not sure what the situation would be for the ZWO version.

My main reason for choosing the Player One version was because it switches to High Conversion Gain mode at a gain of x180 rather than x250, and since Low Conversion Gain mode isn't much use I thought this would be an advantage. As it happens I mostly use a gain of x400. The gain of my camera will go up to x800, although x650 is the maximum practical gain. I've heard that the gain of the ZWO version doesn't go quite as high, so together with the higher LCG / HCG switching point, it may have a smaller usable gain range.

Another plus for the Player One model is the hexagonal shape which makes orientating the sensor very easy (not to be underestimated).

I've had need of support from Player One and they were great so I wouldn't worry about that. There are a lot more people using the ZWO version though and so you are more likely to be able to get advice.

The other thing to consider is whether you ever plan to add more of the ZWO infrastructure, as the ASIair computers will only work with ZWO cameras. I use my Player One version perfectly happily with SharpCap, but via USB.

 

Well, have gone for it and ordered the Player One Uranus which only took a week to arrive!

Coming from a DSLR, and being a newbie to asto cams (except for guiding) I am curious as to why you have chosen a gain of 400 as I thought lowest noise etc was at gain 180? Thanks. 

 

[PeterC65]

4 hours ago, Richard Wesson said:

I am curious as to why you have chosen a gain of 400 as I thought lowest noise etc was at gain 180?

I was expecting to use a gain of 180 too. The read noise falls substantially at 180 (as the sensor switches from LCG to HCG mode), but read noise continues to fall as gain increases, so 180 isn't the point of lowest read noise. Instead it's the best compromise between a low read noise and all of the other parameters, which worsen with increased gain.

However, in practice I found that 400 gain gives the best result for me for DSOs. I worked this out by observing M33 at gains of 180, 200, 250, ... 800, capturing a snapshot of the result after stacking 20 frames at 4s exposure with the histogram auto stretched, then comparing the snapshots side by side. It's hard to compare the live results I find. Changing the gain by 50 makes only a small difference so 350 and 450 also work well, but I find that at lower gains the target is fainter so I can't see so much detail, and at higher gains there is too much background noise.

As well as the 400 gain, I almost always use a 4s exposure for DSOs, sometimes 8s. This is partly because I want a close to live experience and partly because I use an AZ mount and so more than 15s will show star trails. It may be that with longer exposure times a lower gain might be better.

I do use the 180 gain when observing the Moon and planets though, as they are bright so don't need the higher gain. I wind down the exposure until just below the white clipping point. I've still not had much luck observing the planets via EEVA, so I just capture frames for subsequent post processing (AP), but I've had some success observing the Moon with an IR pass filter to reduce atmospheric wobble and the cameras auto white balance enabled to sort out the colour.

I also stick with a fastish scope setup (<F7) for DSOs. Whereas for the Moon and planets I switch to around F12.

 

[JonHigh]

Hi all. As a fellow ZWO ASI585mc user, I’ve been reading this post with interest and thought I share a couple of my own DSO images taken with this “planetary” camera. 
Most 25 sec subs at 252 gain on my Evolux 82ed with the .9 Flattener/reducer mounted on HEQ5 rowan belt mod. 
I have used lower gain settings but I have found 210 to 310 seems to works the best. Will try 180 or 400 next time out. Considering getting a 533 pro and keeping the 585 for planetary on the SkyMax. Although I am tempted to get a OAG for it and try it out on DSO livestacking /AP? Or side-by-side with another scope for guiding?! Lol

 

 

 

 

Edited March 27, 2023 by JonHigh

[licho52]

I wouldn't go to 533 from this camera, completely not worth it.

[JonHigh]

On 24/03/2023 at 01:36, licho52 said:

I wouldn't go to 533 from this camera, completely not worth it.

Oh. As I’m looking for a cooled camera, may I ask what you would recommend please?

I would like to stay with ZWO

[Adam J]

1 hour ago, JonHigh said:

Oh. As I’m looking for a cooled camera, may I ask what you would recommend please?

I would like to stay with ZWO

The 533 is worth it as an upgrade twice the sensor area and larger pixels makes it more sensitive and with a wider FOV, it is usable over a large range of focal lengths. 

The 294mc is a tricky camera to calibrate

The 2600 is in a totally different price league. 

Adam 

[JonHigh]

2 hours ago, Adam J said:

The 533 is worth it as an upgrade twice the sensor area and larger pixels makes it more sensitive and with a wider FOV, it is usable over a large range of focal lengths. 

The 294mc is a tricky camera to calibrate

The 2600 is in a totally different price league. 

Adam 

Hi Adam, thanks for your input. Was looking at the 294 but you’re right, the 2600 is over and above unless that unknown relative leaves me something. 😂  Don’t get me wrong, I really like the ASI585 but I believe getting a cooled camera is the way to go for serious DS photography for now. So a 533 is still on the cards! I would like to know why licho52 says it’s not worth going from 585 to 533? 

Edited March 27, 2023 by JonHigh

[Adam J]

1 hour ago, JonHigh said:

Hi Adam, thanks for your input. Was looking at the 294 but you’re right, the 2600 is over and above unless that unknown relative leaves me something. 😂  Don’t get me wrong, really like the ASI585 but I believe getting a cooled camera is the way to go for DS photography for now. So a 533 is still on the cards! 

Consider a mono 533, you will not regret it. You can build up filters over time. 

Adam 

[PeterC65]

1 hour ago, JonHigh said:

I would like to know why licho52 says it’s not worth going from 585 to 533? 

I can't answer for @licho52, but as I see it, the 585 has better resolution than the 533 across its longer side (3840 pixels vs 3008 pixels) and the size of that longer side is almost the same (11.2mm vs 11.31mm). The 533 is just twice as wide (but still less in resolution per mm). Since the images will always be viewed on a rectangular screen, usually a landscape orientated one, it makes sense to utilise all of the screen real-estate and the 585 is an exact match for a 4K screen. QE and read noise are better for the 585 and bit depth is better for the 533.

 

[bosun21]

On 19/12/2022 at 09:00, PeterC65 said:

AP isn't my thing but I've been playing with image processing software recently (I've settled on Affinity Photo and Topaz DeNoise AI) so here are a few post processed live stacks that have come out well I think.

The Flame and Horsehead Nebulae ...

M33 ...

M35 and its neighbour NGC2158 ...

M42 of course ...

M52 and the Bubble Nebula, NGC7635, which now looks like a bubble ...

M81 and M82, one of my favourites ...

Caroline's Rose Cluster, NGC7789, which has recently become a new favourite ...

 

Great captures Peter, I’m impressed. I can see that your very gradually being enticed into the astrophotography world. Proceed with caution and a hefty overdraft arrangement 😂.

[licho52]

533 is often misunderstood, it has a few things going for it, like lowish (but not low by any means!) price and clean sensor that doesn't need much calibration and hides hideous corners from cheap optics well because it barely covers the middle of the image circle.  That said a tiny square sensor is absolute anathema to serious photography.

The 585MC at its cheap price is absolutely amazing.  It does tiny sensor right - gives you less area but it's actual usable area to make a worthwhile picture with proper format.  It doesn't really need cooling.  After you exhaust the 585MC, step up to 2600MC.  If you think it's expensive, ok, wait with the upgrade.

[nicoscy]

585 is also quite sensitive to longer wavelengths if of interest, much more so than the 533...

[PeterC65]

10 hours ago, bosun21 said:

Great captures Peter, I’m impressed. I can see that your very gradually being enticed into the astrophotography world. Proceed with caution and a hefty overdraft arrangement 😂.

AP isn't for me. I don't have the inclination to learn about proper post processing and much prefer the real time experience of visual and the close to real time of EEVA.

 

[bosun21]

28 minutes ago, PeterC65 said:

AP isn't for me. I don't have the inclination to learn about proper post processing and much prefer the real time experience of visual and the close to real time of EEVA.

 

I agree with you on this. I am going to do a bit of EAA with my new Starfield and my 12” dobsonian. There’s a guy on YouTube doing EAA with his 8” and 12” dobsonian getting good results.

[Adam J]

2 hours ago, nicoscy said:

585 is also quite sensitive to longer wavelengths if of interest, much more so than the 533...

So I just did the calculation for this and got the 533 as being 30% more sensitive than the 585 at SII wavelengths, SII being the longest wavelength of real interest for the stated application of DSO imaging. 

Adam 

[nicoscy]

Hi Alan,

Kindly elaborate as I may be wrong on this, but the 585MC appears more sensitive than the 533MC. If I am wrong, always willing to receive some education!

 

[Adam J]

18 minutes ago, nicoscy said:

Hi Alan,

Kindly elaborate as I may be wrong on this, but the 585MC appears more sensitive than the 533MC. If I am wrong, always willing to receive some education!

 

Sensitivity is made of of three factors:

1) Quantum Efficiency (QE) @ SII

2) Noise (e-)

3) Pixel Area (P)

Lets forget the effect of cooling an assume we are doing short exposures <60 seconds so that cooling is not a big factor. We will set gain so that we are left with at least 10 stops of dynamic range in each case (so gain = 300)

In that case:

S = (QE * P) / e-

For the 533:

QE = 0.8 * 0.75 (red) = 0.6

e- = 1.2

P = 3.75^2 = 14.06

So  S = 7.03

For the 585:

QE = 0.91 * 0.76 (red) = 0.69

e- = 1.1

P = 2.9^2 = 8.41

So S = 5.28

S (533) / S (585)  =  1.33 

So a 33% higher sensitivity for the 533 in comparison to the 585 at  672nm (SII). 

Essentially you are forgetting the effect of larger pixels on sensitivity. 

 

Adam 

 

 

 

 

Edited March 28, 2023 by Adam J

[nicoscy]

Thank you for the calculations! Makes sense!

[nicoscy]

Must make an excel sheet for that!

[licho52]

On 28/03/2023 at 11:26, nicoscy said:

Thank you for the calculations! Makes sense!

I think it's not that simple.  What matters most is QE which in 585 is higher and noise which is a bit higher per area in 585.  The rest is sampling which can be taken care of by binning or otherwise resampling in postprocessing.  I wouldn't take pixel size as a detriment for AP, in fact in some cases it can be an advantage.

For example, smaller pixel size in 585MC can be attractive in wide-field APOs (like Redcat) where it lowers the sampling from 3.13 to 2.2, but also in certain applications like shooting small planetary nebulas and globular clusters with mid-FL OTAs like the ever popular f/4 Newtonians.  Excellent for lucky imaging techniques too.

I am a big fan of such amazing affordable sensor.  I wish they were available when I was starting out.

PS

I used to own 533MC so I know that camera well and now I own a 585MC as my 3rd camera in addition to 2600MM/MC combo.

Edited March 29, 2023 by licho52

[nicoscy]

I have both the 585 and 533, but chose the 585 for a particular scope to sample as best as possible given my seeing conditions. So, binning would undersample quite a but in my case.

Expecting a 8" f4 newt, reduced by 0.95 to match with this sensor solely for galaxies, PNs and small clusters. Excluding M31 and M33, all other galaxies fit in nicely on the 585, thank you!

 

[Adam J]

21 hours ago, licho52 said:

I think it's not that simple.  What matters most is QE which in 585 is higher and noise which is a bit higher per area in 585.  The rest is sampling which can be taken care of by binning or otherwise resampling in postprocessing.  I wouldn't take pixel size as a detriment for AP, in fact in some cases it can be an advantage.

For example, smaller pixel size in 585MC can be attractive in wide-field APOs (like Redcat) where it lowers the sampling from 3.13 to 2.2, but also in certain applications like shooting small planetary nebulas and globular clusters with mid-FL OTAs like the ever popular f/4 Newtonians.  Excellent for lucky imaging techniques too.

I am a big fan of such amazing affordable sensor.  I wish they were available when I was starting out.

PS

I used to own 533MC so I know that camera well and now I own a 585MC as my 3rd camera in addition to 2600MM/MC combo.

 

I have to disagree, the Rayleigh limit for a 50mm aperture is 2.7um. 

So you wont get 2.2 arc seconds per pixel even if that is the raw sampling. 

In terms of resampling you end up at 5.8um pixels in 2x2 and that is actually going to leave you under sampled so its not really an option and you are better off with the 533 at 3.13um per pixels. 

At longer focal lengths and apertures the 585 may well be a superior sensor for galaxy imaging.  The issue with putting it on a wide field scope is that you would be putting a tiny little sensor on a wide short focal length scope just wont make use of the large flat field and makes very little sense. You would be better off with a larger sensor and a longer focal length then binning it as you would have a faster system with the same FOV. 

Actually such a sensor is avaliable https://www.firstlightoptics.com/zwo-cameras/zwo-asi-482mc-usb-30-colour-camera.html

You can see the effect the binning on the form of a quad bayer matrix has had on the read noise. (Same sensor as the slightly older 485 but in quad baryer to get 5.8um pixels). 

Adam

 

Edited March 30, 2023 by Adam J

[Adam J]

6 minutes ago, Adam J said:

I have to disagree, the Rayleigh limit for a 50mm aperture is 2.7um. 

So you wont get 2.2 arc seconds per pixel even if that is the raw sampling. 

In terms of resampling you end up at 5.8um pixels in 2x2 and that is actually going to leave you under sampled so its not really an option and you are better off with the 533 at 3.13um per pixels. 

At longer focal lengths and apertures the 585 may well be a superior sensor for galaxy imaging.  The issue with putting it on a wide field scope is that you would be putting a tiny little sensor on a wide short focal length scope just wont make use of the large flat field and makes very little sense. You would be better off with a larger sensor and a longer focal length then binning it as you would have a faster system with the same FOV. 

Adam

 

 

Ignore, double posted.

Edited March 30, 2023 by Adam J

[JonHigh]

HI all, 

Been reading this and it would seem to me that if I was to get a cooled camera, I might be better off taking a deep breath and buying the 2600 for my EvoLux 82 and skipping the 533 entirely. I would keep the 585 for my SkyMax 150 as it does seem to work very nicely on it thank you very much.. (Shame they don't produce the 585 as a Pro option as it seems to be such a versatile camera. LOL)

But hang on, wouldn't I be cropping a lot of the image using the 2600 for things like smaller galaxies, clusters and nebulas? So the 533 would be more advantageous on my Evolux  (with the reducer attached - 477mm at F5.8) to fill the sensor rather than cropping possibly heavily from a larger sensor?  Ahhhh..... Does this make sense or have I got this wrong? 

Incidentally the square formats doesn't bother me particularly as it reminds me of the medium format cameras I used to use back in the day!

 

 

Edited March 31, 2023 by JonHigh