What would I gain?

[assouptro]

Hi Starpeople!

I have been enjoying this fascinating hobby/obsession for over 14 years now 

Initially I resisted upgrading to a CCD camera for the first 10 years persevering with different DSLR cameras as they became affordable enough on the secondhand market to justify ripping them to pieces to modify them for astrophotography.

I did eventually dip my toe in the world of cooled CCD cameras buying a second hand Atik 314L+, old tech with a tiny sensor compared to my full frame Canon 6D but WOW! I was blown away by the difference in my (tiny) imaging abilities and couldn’t go back to DSLR unless trying for starscape milky way shots.

I went on to buy a Atik 460 and a 490 as they popped up at decent prices, filter wheels and eventually a set of 1.25” astrodon filters to avoid the dreaded Oiii halos.

I have really enjoyed using these cameras and it’s only the North West UK weather that stops me taking any opportunity to capture photons from billions of miles away! 

However after recently purchasing another ancient CCD “antique”namely an Atik 383L+ there have been a lack of clear skies and I found myself perusing forums and YouTube etc to satisfy my “Astro itch”only to discover it appears I am desperately behind the curve! It seems I should have sold all my CCD cameras whilst they were worth something, investing instead in CMOS technology!

 

Apparently, it’s the only way forward?

Looking at the second hand market it’s obvious there has been a shift.

I am curious though, 

Would the move to a modern CMOS camera be a subtle improvement? Or would it be a significant change as it was moving from DSLR to CCD?

I recently had a short window in the clouds and got to test the 383 sensor in broadband and it left me wondering..

If I can capture an image like this in less than 3 hours with one of the notoriously noisiest Kodak chips using an average ed100 scope (revelation Astro Ed100, not a colour corrected triplet) what would I benefit by buying a newer CMOS camera? 
 

(5 min subs rgb 45,60,70min respectively)

Just wondering?

Bryan

[tomato]

I think it is all a matter of degrees. One of the key debates ongoing is how close a state of the art OSC CMOS is to mono and LRGB. I don’t think moving from a mono CCD to a CMOS mono would be as big a leap as the move from uncooled DSLR to cooled CCD.

The mono KAF8300 with filters is still capable of producing excellent images, it hasn’t suddenly dipped in performance just because the next generation of CMOS sensors  has arrived. It may just need a bit more effort than the CMOS equivalent, and the longer exposures make more demands on the mount, but if you are on a limited budget  then I would rejoice at the great deals  that can be had on used CCD cameras.

The technology on optical sensors is moving along, so I don’t think it will be long before there is another new, improved CMOS camera in the mix.

[ollypenrice]

All those CCD images posted 'out there' still exist. Have they all been demoted by new and better CMOS images? It's news to me if they have...

Olly

[vlaiv]

1 hour ago, assouptro said:

Would the move to a modern CMOS camera be a subtle improvement? Or would it be a significant change as it was moving from DSLR to CCD?

Depends what you see as subtle / significant.

There is simple way to compare the two - QE.

All other things are pretty much "tie" in the right hands, but you can't optimize for QE - it is either there or not.

I'll go by new prices - and find comparable camera on CMOS side. At FLO - 383+ is around ~£2000

For same amount of money you can get Altair Astro 26M APS-C. You get larger sensor - with QE above 90% while KAF8300 peaks below 60% - that is 50% improvement in QE - and consequently - you would get the same image in 2/3 of the time - judging by just that one parameter.

Not to mention that you get larger sensor - APS-C sized vs 4/3 one of KAF8300 - and sensor size is speed when paired with appropriate telescope.

If you captured above image in less than 3 hours - would it be subtle or significant improvement to get the same image in 2h or less?

[assouptro]

1 hour ago, tomato said:

I think it is all a matter of degrees. One of the key debates ongoing is how close a state of the art OSC CMOS is to mono and LRGB. I don’t think moving from a mono CCD to a CMOS mono would be as big a leap as the move from uncooled DSLR to cooled CCD.

The mono KAF8300 with filters is still capable of producing excellent images, it hasn’t suddenly dipped in performance just because the next generation of CMOS sensors  has arrived. It may just need a bit more effort than the CMOS equivalent, and the longer exposures make more demands on the mount, but if you are on a limited budget  then I would rejoice at the great deals  that can be had on used CCD cameras.

The technology on optical sensors is moving along, so I don’t think it will be long before there is another new, improved CMOS camera in the mix.

Thanks for the input tomato 

One thing that bothers me with regards OSC Cmos is this…

As my 100ed isn’t a triplet and therefore focuses rgb at different points, wouldn’t I end up with some sort of bloat?
would I be forced to upgrade my telescope to take advantage?

cheers

Bryan  

[assouptro]

46 minutes ago, ollypenrice said:

All those CCD images posted 'out there' still exist. Have they all been demoted by new and better CMOS images? It's news to me if they have...

Olly

Thanks for taking the time to add your thoughts Olly 

I agree, I have seen so many incredibly inspirational CCD images as well as some equivalent CMOS images

It’s just that I took a decade to commit to the change to CCD.
Once I did, I wished I had done it sooner and as I don’t know how many more decades I have left, I l guess I’m looking for reassurance that I don’t end up regretting delaying the next “evolutionary” change?

cheers 

Bryan 

[assouptro]

29 minutes ago, vlaiv said:

Depends what you see as subtle / significant.

There is simple way to compare the two - QE.

All other things are pretty much "tie" in the right hands, but you can't optimize for QE - it is either there or not.

I'll go by new prices - and find comparable camera on CMOS side. At FLO - 383+ is around ~£2000

For same amount of money you can get Altair Astro 26M APS-C. You get larger sensor - with QE above 90% while KAF8300 peaks below 60% - that is 50% improvement in QE - and consequently - you would get the same image in 2/3 of the time - judging by just that one parameter.

Not to mention that you get larger sensor - APS-C sized vs 4/3 one of KAF8300 - and sensor size is speed when paired with appropriate telescope.

If you captured above image in less than 3 hours - would it be subtle or significant improvement to get the same image in 2h or less?

Thanks Vlaiv for adding your thoughts.

Although you have presented a fair and reasoned comparison, there are a few factors that do influence me at present.

The CCD Kaf383 can be bought for less than £600 second hand, I’m not sure why? Which is one of the reasons for asking the initial question. 

If I was to upgrade to a 26mp APS-C camera, I would have to either choose OSC which might not work well with my doublet, or invest in a new carousel for my filter wheel and a full set of filters so that cost difference has now become quite significant. 
 

I guess it’s the real term cost v real term advantage that I’m wrestling with? 
 

I guess if I had an unlimited budget I’d be jumping on the bandwagon and trying out a new CMOS camera myself! 
 

Thanks 

Bryan 

[vlaiv]

2 minutes ago, assouptro said:

The CCD Kaf383 can be bought for less than £600 second hand, I’m not sure why?

I guess that most people don't have gear to fully utilize CCD sensor like Kaf8300. It has very high read noise and therefore requires long exposure times. 10-20 minutes long.

People have issues when needing to guide for 20 minutes per sub.

It is simply much easier to switch to CMOS that you can use with say 2-3 minute exposures - or x5-6 shorter ones (Kaf8300 has about 9e of read noise, while modern CMOS often has less than 2e).

You don't have to go for APS-C sized sensor. You can go for say 294mm type camera. That will be both cheaper and allow you to use your filters and will provide higher QE (and shorter subs).

There is also convenience when operating CMOS vs CCD camera that is in line with modern life style. Who has the time and patience to wait for multi second sub download when they can have multiple FPS live previews

I'm not saying that you should switch - if 383L+ camera is working for you - then sure - CMOS will work a bit better, but question is - can you justify the cost.

 

[newbie alert]

You  probably already had a cmos sensor in  your dslr...  so the gain with a dedicated cmos or ccd is the cooling..

The kaf sensor is a classic, still can produce awesome images, just because the market for cmos dictated the rise in production didn't cause the older sensors to simply switch off, they never just stopped working...

Ccd and cmos both have pro's and con's...  so depending on what suits your style .. if you're enjoying ccd then what's needed to change?  Have you seen better m45 images with cmos? If yes it could be for a few other reasons than just the chip.. 

I'd be pleased as punch if that was my image, hope that you are

With the 8300 sensor it likes a decent power behind it, -20 cooling and with narrowband decent length exposures depending on your skies

[The Lazy Astronomer]

My take on it is to ask the following question: are you looking change your camera anyway?

If yes, then sure, go for a newer generation CMOS, for all the reasons mentioned above.

If no, then your money is probably better off in your pocket (or spent elsewhere!). I don't think there's really anything in it in terms of the final image quality when it comes to CMOS vs CCD these days - I see fantastic results with both.

The CMOS might make it easier on the mount, and be a bit faster than a CCD, but if you're getting results you're happy with - in a timeframe you're happy with - is it worth the £2k or so to buy a new CMOS?

[assouptro]

33 minutes ago, vlaiv said:

CMOS will work a bit better,

Thanks Vlaiv

that kinda answers my question 

Although I probably will be looking for something like the 294mm in the classified ads so I can “dip my toe” 😊

cheers 

Bryan 

[assouptro]

22 minutes ago, newbie alert said:

You  probably already had a cmos sensor in  your dslr...  so the gain with a dedicated cmos or ccd is the cooling..

The kaf sensor is a classic, still can produce awesome images, just because the market for cmos dictated the rise in production didn't cause the older sensors to simply switch off, they never just stopped working...

Ccd and cmos both have pro's and con's...  so depending on what suits your style .. if you're enjoying ccd then what's needed to change?  Have you seen better m45 images with cmos? If yes it could be for a few other reasons than just the chip.. 

I'd be pleased as punch if that was my image, hope that you are

With the 8300 sensor it likes a decent power behind it, -20 cooling and with narrowband decent length exposures depending on your skies

Thanks for the kind comment newbie 

Yeah, it’s my best m45 to date and I was pleased to achieve it in such a short time too which is what got me thinking as CMOS users generally rave about the speed!

Cheers 

Bryan 

[assouptro]

29 minutes ago, The Lazy Astronomer said:

is it worth the £2k or so to buy a new CMOS?

Thanks Lazy! 
I don’t think I’ll be parting with my hard earned money just yet.

I’ll probably pick one up for £500-£800 second hand when they bring out the new 3D version !

Cheers 

Bryan 

 

[DaveS]

I'm caught in a similar situation, just at a slightly more ruinous price point, with my G3 16200. When I spec'd my big rig it was the best option, but things have moved on rapidly and the new QHY 600 mono or 410 OSC are serious contenders. However (And it is a BIG however) not only is a QHY 600 £4100, but I would need a new wheel, and worse (MUCH worse) because the 16200 sensor is "only" APS-H I thought I could get away with 2" mounted filters not taking into account that a) 50mm unmounted Chroma were the same price as 2" mounted and b) the G3 wheel would take 50mm unmounted as well as 2" mounted. Dur... *slaps head*

The QHY 410 OSC might be an option if I only wanted to image in RGB.

Edited November 19, 2021 by DaveS
Typos!

[assouptro]

10 minutes ago, DaveS said:

I'm caught in a similar situation, just at a slightly more ruinous price point, with my G3 16200. When I spec'd my big rig it was the best option, but things have moved on rapidly and the new QHY 600 mono or 410 OSC are serious contenders. However (And it is a BIG however) not only is a QHY 600 £4100, but I would need a new wheel, and worse (MUCH worse) because the 16200 sensor is "only" APS-H I thought I could get away with 2" mounted filters not taking into account that a) 50mm unmounted Chroma were the same price as 2" mounted and b) the G3 wheel would take 50mm unmounted as well as 2" mounted. Dur... *slaps head*

The QHY 410 OSC might be an option if I only wanted to image in RGB.

Geez! 
I thought I had a problem!! 😖

[assouptro]

19 minutes ago, DaveS said:

not taking into account that a) 50mm unmounted Chroma were the same price as 2" mounted and b) the G3 wheel would take 50mm unmounted as well as 2" mounted.

That’s rough! 

[DaveS]

Yep, showing not merely a degree of stupidity, but a postgraduate degree of stupidity. I kick myself most every day over it.

Ah well, at least it's saved me from spending even more money that I haven't got (Gotta think positive ).

A QHY410C (Not to be confused with the QHY411) may be a realistic possibility down the line.

Edited November 19, 2021 by DaveS

[assouptro]

2 minutes ago, DaveS said:

Yep, showing not merely a degree of stupidity, but a postgraduate degree of stupidity. I kick myself most every day over it.

Ah well, at least it's saved me from spending even more money that I haven't got (Gotta think positive ).

A QHY410 (Not to be confused with the QHY411) may be a realistic possibility down the line.

I guess, if if wasn’t for the forums and streaming channels etc you’d be happy with your purchases and be imaging with a smile on your face looking forward to the next 20-30min sub to download

Sometimes you’ve just gotta put blinkers on, process the data, and enjoy the amazing results that you and your kit are capable of! 😊

[DaveS]

TBH I'm pretty happy with the 16200, and the DDM 85 has no trouble with 10-20 min subs, just an itchy hankering after something "better", for a given value of "better".

[Allinthehead]

4 hours ago, assouptro said:

what would I benefit by buying a newer CMOS camera? 

The answer to this surely is that it depends on which Cmos camera you would buy.

The Imx 571/455 mono cmos sensors would be vastly superior to your ccd and your images would reflect that, however the cost difference is not insignificant, especially when you factor in filters etc. 

I think the ccd vs cmos "debate" makes no sense. It's much more fruitful to debate the merits of one sensor vs another while considering your own imaging location and equipment.

[assouptro]

30 minutes ago, DaveS said:

just an itchy hankering after something "better", for a given value of "better".

Thanks Dave 

I couldn’t have put it better

I feel validated.

I don’t know if all hobby’s are like this, as it is my main interest.

But the next step always just out of reach? 
 

Cheers 

Bryan 

[assouptro]

14 minutes ago, Allinthehead said:

vastly superior to your ccd and your images would reflect that

Thanks for chipping in

I didn’t want to start a cmos v ccd thread, I just wanted to try and quantify the next move and understand what I could have gained in that image if using CMOS 

Using the term  “vastly superior” is a bold statement and I only have my own experience to go on and to me that point of time was the swap from dslr to ccd, it literally blew me away! 

Although my Canon 6D was a lot better than my Canon 350D it wasn’t vastly superior 

I don’t know what your journey has involved and what equipment you have used so maybe you are using that term in a different context? 

However if your Avatar is an example of what is possible with a CMOS camera in a similar amount of time then that is what I would consider vastly superior

Cheers 

Bryan 

[GalaxyGael]

The IMX571 and related sensors, particularly in mono will be objectively superior to the CCD up to APS-C size, in almost all respects we encounter in typical imaging situations.

Depending on your preferences for images and your location, moving to current gen CMOS will at least reduce sub exposure time or overall integration time. Since the sensor will not change in size, you can still sacrifice some sensor area using your smaller filters for now in mono captures and the sensor area is available to you if and when you can upgrade to larger filters. The beneficial chip performance, QE, noise profiles etc will be there for you in either case.

It could be a longer term purchase/upgrade if you went the OSC route, and the camera capability is there if you ever upgrade your scope to a well color corrected triplet APO (or reflector, depending on preference). 

One great example using IMX571-similar chips is the ZWO ASI 533MC Pro. It has the 50k full well cap., natively 14-bit (using IMX533) which can be scaled to approximate 16 bit chip once you are pulling in several tens of subs, and is only 1 inch diagonal with a square-shaped chip. It is much cheaper than the ASI2600 variants, but same pixel size and almost as good, suits small and large filters. Comes in at about 1k EUR, over half the price of the 2600MC Pro.

 

[Allinthehead]

13 hours ago, assouptro said:

have my own experience to go on and to me that point of time was the swap from dslr to ccd, it literally blew me away! 

@tooth_dr went from an 8300 to an imx571 mono so I would think he would be able to guide you.

13 hours ago, assouptro said:

However if your Avatar is an example of what is possible with a CMOS camera in a similar amount of time then that is what I would consider vastly superior

That image was captured in 4.5 hrs with Osc Imx571 under bortle 4 skies with an F/3.3 instrument. What are your skies like?

[assouptro]

1 hour ago, Allinthehead said:

That image was captured in 4.5 hrs with Osc Imx571 under bortle 4 skies with an F/3.3 instrument. What are your skies like?

Thanks for the info 

It’s a beautiful image! And in such a short time! 
what were the length of your subs? And what was the 3.3 instrument? 

My sky is around Borte 5/6 I’m in the suburbs of a small city (Lancaster) 

I guess you can only work with the tools you have! 
 

Thanks again 

Bryan