In the market for new CMOS camera.

[kirkster501]

Thinking of getting a new camera.

I want it to be a CMOS one since I believe that is the strategic direction of imaging.

I want to be able to use it for widefield on my FSQ (no reducer) but also on my Meade 14" so I need it to have an OAG.  A big chip so I could bin 2x2 everything on the SCT.

Appreciate your thoughts please.

 

[Adam J]

2 minutes ago, kirkster501 said:

Thinking of getting a new camera.

I want it to be a CMOS one since I believe that is the strategic direction of imaging.

I want to be able to use it for widefield on my FSQ (no reducer) but also on my Meade 14" so I need it to have an OAG.  A big chip so I could bin 2x2 everything on the SCT.

Appreciate your thoughts please.

 

Whats your price limit?

[sloz1664]

Just a thought, can you bin cmos chips ?

Steve

[johninderby]

7 minutes ago, sloz1664 said:

Just a thought, can you bin cmos chips ?

Steve

Some info from Altair on binning.

https://cameras.altairastro.com/2017/09/15/how-does-binning-work-with-cmos-cameras/

[vlaiv]

2 minutes ago, sloz1664 said:

Just a thought, can you bin cmos chips ?

Steve

Sure you can - in pretty much the same way you can also bin CCD

CCD on the other hand can be binned in the way CMOS sensor can't. CCD supports hardware binning that CMOS sensors do not support. But both can be binned in software. Difference between the two comes from read noise. CMOS sensors have quite a bit lower read noise (in general) and therefore suffer less from it's effects on software binning.

42 minutes ago, kirkster501 said:

Thinking of getting a new camera.

I want it to be a CMOS one since I believe that is the strategic direction of imaging.

I want to be able to use it for widefield on my FSQ (no reducer) but also on my Meade 14" so I need it to have an OAG.  A big chip so I could bin 2x2 everything on the SCT.

Appreciate your thoughts please.

 

At the moment, if you are looking for mono sensor, ASI1600 (and other cameras based on Panasonic chip) are biggest options. There are a few very interested options by QHY still being developed - I believe the price will be quite high compared to current CMOS offerings, have a look here:

https://www.qhyccd.com/index.php?m=content&c=index&a=lists&catid=123

Or, better, here is excerpt from the bottom of the page:

Check out last two entries. I wonder what the read noise will be like.

[ollypenrice]

It's frustrating that the big chips are colour at the moment.

I can't say I've been convinced by the full frame colour data I've seen. Odd colour balance (very odd), large stars...  I don't think CMOS is quite there yet, myself.

Olly

[Gina]

+1 for the ZWO ASI1600MM-Cool

[kirkster501]

The ASI1600 is top of mind......  I will investigate this further.

[Dragon_Astro]

How about one of the Altair 183 mono/colour?

 

[newbie alert]

Once the cmos have cured the ampglow prob that some suffer, any Micro lensing that some suffer from and the huge files that's needed to store the data( a friend used a terabyte on 1 image) then I'd be interested as yes it will be the future..

[tomato]

I can’t see the data storage capacity required coming down anytime soon on CMOS cameras, lots of pixels times lots of subs equals lots of data.

[kirkster501]

TBH I am in no rush for this and can wait.  But I'm thinking ahead about what to buy.  Yes the micro lensing is a bit of a concern. I'm not bothered about file sizes and data storage.  Once the image is processed the calibrated lights can be offloaded onto a bulk external hard drive and they cost peanuts nowadays.

A QSI 583 or 683 is still an option and they come up used quite a lot.  But not sure they are the right way to go in 2019 and I'd like to move into a world of faster exposures and more of them.  Especially with the Long Focal ratio SCT 14".

Happy for a sanity check on my thinking folks......

[Dragon_Astro]

What length exposures were you thinking with a CMOS?

[newbie alert]

But not sure they are the right way to go in 2019 and I'd like to move into a world of faster exposures and more of them.  Especially with the Long Focal ratio SCT14".

Long focal length and small pixels.. not sure on that one..sorry but don't know anyone that deepsky images with a 14 that I could ask!

[tomato]

On my rather brief experience with CMOS mono cameras (ASI 178) to date on small galaxy imaging with an Esprit 150, I have been impressed with the detail captured with relatively short integration times.

I have noted however, that the images captured so far seem to have a distinct hue, I have found it difficult to replicate the palette usually displayed with CCD images of the same target. However, this could be down to my mediocre processing skills.

[Adam J]

5 hours ago, ollypenrice said:

It's frustrating that the big chips are colour at the moment.

I can't say I've been convinced by the full frame colour data I've seen. Odd colour balance (very odd), large stars...  I don't think CMOS is quite there yet, myself.

Olly

Not sure how CMOS technology could result in large stars unless someone is using it incorrectly, i.e like you would use a CCD sensor.

[ollypenrice]

On DS imaging I wouldn't bank on the 14 inch Meade beating your TEC 140. My money would go the other way.

Olly

[ollypenrice]

Just now, Adam J said:

Not sure how CMOS technology could result in large stars unless someone is using it incorrectly, i.e like you would use a CCD sensor.

Microlensing effects would be my guess. The chips are not manufactured with astronomy in mind. What is there to do incorrectly once you've focused?

Olly

[Adam J]

Just now, ollypenrice said:

Microlensing effects would be my guess. The chips are not manufactured with astronomy in mind. What is there to do incorrectly once you've focused?

Olly

Micro lensing would show a pattern as opposed to just larger stars and CCDs also have micro-lenses, my guess would be something more along the lines of too high a gain setting.  Would be interesting if you could post an example.

[ollypenrice]

6 minutes ago, Adam J said:

Micro lensing would show a pattern as opposed to just larger stars and CCDs also have micro-lenses, my guess would be something more along the lines of too high a gain setting.  Would be interesting if you could post an example.

I only host the cameras in question, I don't operate them.

I'm very suspicious of all the numbers beloved of imaging theorists. By a country mile the best camera I use is the numbers-catastrophic Atik 11000 but I honestly believe it does things that the numbers don't talk about. Star control and star colour are tremendous - as it seems to me.

Olly

[vlaiv]

6 hours ago, ollypenrice said:

It's frustrating that the big chips are colour at the moment.

I can't say I've been convinced by the full frame colour data I've seen. Odd colour balance (very odd), large stars...  I don't think CMOS is quite there yet, myself.

Olly

There could be a number of reasons for your observations - not saying that it is certainly the case, but I'll list them anyway:

- Large stars: Most people don't realize that when using OSC cameras they are in fact sampling at two time lower sampling rate than pixel size would suggest. After that, interpolation of sorts is used to "fill in the gaps" unless super pixel debayering is used, or more exotic - splitting of sampling matrices into separate subs. This means that you are artificially "increasing resolution" (trying to present image at twice sampling rate by effectively rescaling subs). That, coupled with the fact that OSC sensors have smaller pixels which in it self can lead to oversampling, means that stars will be "bigger" when viewed 1:1. Not CMOS fault - but rather due to way they are used.

- I would throw in fact that CMOS sensors are cheaper than CCD and because of this more people opt for such cameras that can't afford precision mounts, but that might be moot point given that you have experience with hosted gear and I suspect that mounts used in such setups won't be average "consumer" level.

On the matter of color - there is big difference in how mono + LRGB and OSC handle color. Just look at filter response curves. This however does not mean that one of those is "true" color. Both can and should be color calibrated and suitable transform found to represent true star color as neither will do that "out of the box". What I suspect is happening is that you are used to the way mono+LRGB renders color (without calibration) and it has become "de facto" color standard on how images should look like. If you take OSC color rendition - it will look wrong (in comparison to what you are used to). It is in fact the case that neither are rendering proper color without color calibration. If you do color calibration on both - you should get same colors (or very close colors - depends on camera/filter gamut compared to display device gamut) in both.

[ollypenrice]

9 hours ago, vlaiv said:

There could be a number of reasons for your observations - not saying that it is certainly the case, but I'll list them anyway:

- Large stars: Most people don't realize that when using OSC cameras they are in fact sampling at two time lower sampling rate than pixel size would suggest. After that, interpolation of sorts is used to "fill in the gaps" unless super pixel debayering is used, or more exotic - splitting of sampling matrices into separate subs. This means that you are artificially "increasing resolution" (trying to present image at twice sampling rate by effectively rescaling subs). That, coupled with the fact that OSC sensors have smaller pixels which in it self can lead to oversampling, means that stars will be "bigger" when viewed 1:1. Not CMOS fault - but rather due to way they are used.

- I would throw in fact that CMOS sensors are cheaper than CCD and because of this more people opt for such cameras that can't afford precision mounts, but that might be moot point given that you have experience with hosted gear and I suspect that mounts used in such setups won't be average "consumer" level.

On the matter of color - there is big difference in how mono + LRGB and OSC handle color. Just look at filter response curves. This however does not mean that one of those is "true" color. Both can and should be color calibrated and suitable transform found to represent true star color as neither will do that "out of the box". What I suspect is happening is that you are used to the way mono+LRGB renders color (without calibration) and it has become "de facto" color standard on how images should look like. If you take OSC color rendition - it will look wrong (in comparison to what you are used to). It is in fact the case that neither are rendering proper color without color calibration. If you do color calibration on both - you should get same colors (or very close colors - depends on camera/filter gamut compared to display device gamut) in both.

I've used OSC and mono CCD from the same model of camera and never found much difference in colour but the CMOS colour data I've seen strikes me as problematic.

Olly

[Stub Mandrel]

 

13 hours ago, newbie alert said:

 the huge files that's needed to store the data( a friend used a terabyte on 1 image) then I'd be interested as yes it will be the future..

I think this must be because the ease of CMOS imaging tempts people to tackle ever more challenging images.

Even with short exposures I rarely manage more than 4GB of data in a night with a DSLR, which produces similar file sizes.

[Stub Mandrel]

11 hours ago, Adam J said:

Micro lensing would show a pattern as opposed to just larger stars and CCDs also have micro-lenses, my guess would be something more along the lines of too high a gain setting.  Would be interesting if you could post an example.

There are some startling examples on Cloudy Nights - patterns of circles radiation out from stars. They seem to be associated with a combination of filter spacing and micro-lenses.

[cuivenion]

13 hours ago, newbie alert said:

Once the cmos have cured the ampglow prob that some suffer, any Micro lensing that some suffer from and the huge files that's needed to store the data( a friend used a terabyte on 1 image) then I'd be interested as yes it will be the future..

I've never quite understood why the 'amp glow' issue has never been sorted. DSLR's use cmos and it hasn't been an issue with them for years. 

Do Canon/Nikon mess with the RAW file to get rid of the amp glow?