Colour CCD?

[Astrosurf]

And the 071: https://www.astrobin.com/gear/59635/zwo-asi071mc-cool/

Which specs of the two would you say were better? I'm hopeless at the techie stuff!

[wimvb]

The asi071has 4 x as much pixel area. Even though it has fewer pixels, it still has a larger sensor = larger fov. You might want to check out what that means for your setup (scope & intended targets), by using a fov calculator (there's one on flo's site).

Larger pixels also means higher full well and larger dynamic range. But probably also higher dark noise. Qhy have been addressing amp glow issues. Asi have published dark current data and I believe even a dark frame.

Asi has 14 bit output, which helps in using that full well/dynamic range. Qhy is 10/12 bit, just as most dslr models.

There is a price difference, but if you can afford it, and the amp glow is managable, I think the asi is a better buy, just because of the sensor and pixel size.

Just my € 0.02

Btw, do you have access to a dark site? Under light polluted skies mono ccd/cmos with filters may be a better option.

[Astrosurf]

Wow, thanks! Great info.  I can get to reasonably dark sites so that wouldn't be a problem. The Rollright Stones near Chipping Norton is one. I'll send a letter to Santa for next Xmas!

[iapa]

On 29/03/2017 at 00:19, ollypenrice said:

We humans are trichromats, having three kinds of colour receptors in the eye. I did come across this rather splendid sentence on the net, though...

There is no currently peer reviewed scholarly work that has confirmed the existence of a functional human tetrachromat though they are suspected to exist.

Oh to be a tetrachromat!!

lly

ah, but which wavelengths would you choose?

[iapa]

On 29/03/2017 at 11:28, LightBucket said:

Well we no longer talking about colour CCD cameras, you guys have lost me.......so I'm off....

stick around -

1. the thread will return to subject

2.these diversion can be amusing, and/or informative. Often both.

Remember that imaging does involve how light is perceived as well as how to capture it.

[Guest]

I hope you find the advice you need among the wide range of subjects discussed in this post :-)

I imaged with an OSC (QHY8) for about 5 years and found it extremely easy to use, process (colour balance was easy to fix), and my OSC shots are still my best RGB images to date :-)

My decision to go for an OSC in the first place was based on our sky conditions. The need for extended periods of clear in a night or worse, hoping for 2 or 3 nights of periodic clear skies is what I have found so tiring about mono - but the results are undoubtedly better with Ha, Oiii and Sii - (and one day with LRGB no doubt once I get enough clear skies to finish a good image)

So my advice would be to go for an OSC without a doubt - it was less hassle and took less time than my experience so far with mono LRGB imaging.

Hope that helps :-)
David

[DaveS]

Where I could see the ASI071 OSC really scoring is as part of a holiday / travel rig with a DSLR lens (Or even a Star 70 'scope) and eg a Star Adventurer. If I wasn't already over-stretched I'd be looking to buy one myself.

A mono version would be *very* interesting.

[The Admiral]

And now it looks as though ZWO are bringing out a FF OSC camera .

I'm reading this thread with interest because OSC does have certain advantages, though I can clearly see the advantages of mono too! As a DSLR (well, mirrorless actually) user, if I ever went for a dedicated camera I'm not sure which I'd go for either. For me it would be great if the camera came with an LCD and on-board processor with appropriate firmware, so as to be used as a self-contained unit. But I guess I'm a distinct minority here .

Ian

[Helen]

Interesting discussion.....  Just as everyone know Olly is firmly in the mono camp, most people probably know I'm mostly in the OSC camp   I've recently got a mono ASI1600 (to double as large field solar cam).  I have spent a few night now, in less than ideal conditions (scudding cloud) trying it out.  I don't know whether I'm just lazy (may well be the case!), but OSC seems so much simpler - focus and run.  (Although I was interested to see Olly talking about leaving focus the same between coloured subs - might experiment with the best compromise).  One set of flats etc and if you lose a few subs you still have an image, with the quality just increasing as more subs come in.  One stacking and processing run etc  I know that ultimately I would get a better image with every element of the mono process implemented to its best, but...  And then there are comets, how do get a good colour image with filters??  I'm thinking of running double rig again, so that I can choose between colour and mono depending on condition, what I want to image, and how I feel.

Like Ian, I would love a set up which merges the benefits of a DSLR/mirrorless with CCD.  I've just started doing some widefield astro with a Sony 6500 and the convenience of just needing a camera and tripod is lovely!

Horses for courses I think.

Helen

[The Admiral]

16 minutes ago, Helen said:

I would love a set up which merges the benefits of a DSLR/mirrorless with CCD.  I've just started doing some widefield astro with a Sony 6500 and the convenience of just needing a camera and tripod is lovely!

Horses for courses I think.

Helen

Probably getting a bit OT now, but I suppose an intermediate stage would be a micro-PC strapped to the OTA/tripod, with an in-built LCD screen, or at least a reliable wi-fi connection to a tablet. It all adds to the complexity of course, and needs to withstand the vicissitudes of our weather. Unless one is in the happy position of operating from an obsy, in which case simplicity can go to the wall anyway!

Ian

[iapa]

24 minutes ago, Helen said:

Interesting discussion.....  Just as everyone know Olly is firmly in the mono camp, most people probably know I'm mostly in the OSC camp   I've recently got a mono ASI1600 (to double as large field solar cam).  I have spent a few night now, in less than ideal conditions (scudding cloud) trying it out.  I don't know whether I'm just lazy (may well be the case!), but OSC seems so much simpler - focus and run.  (Although I was interested to see Olly talking about leaving focus the same between coloured subs - might experiment with the best compromise).  One set of flats etc and if you lose a few subs you still have an image, with the quality just increasing as more subs come in.  One stacking and processing run etc  I know that ultimately I would get a better image with every element of the mono process implemented to its best, but...  And then there are comets, how do get a good colour image with filters??  I'm thinking of running double rig again, so that I can choose between colour and mono depending on condition, what I want to image, and how I feel.

Like Ian, I would love a set up which merges the benefits of a DSLR/mirrorless with CCD.  I've just started doing some widefield astro with a Sony 6500 and the convenience of just needing a camera and tripod is lovely!

Horses for courses I think.

Helen

Just moved to the ASI1600MM-C as well, from modded DSLR, with a view to adding a second OTA and the OSC camera later.

The time involved getting a set of data seems much greater...... and a lot of faff, multiple sets of flats. 

OK, based on a single night where I managed 14 each of LRGB - at 5s exposure. Duh - misread exposure in SGPro when creating the profile. 

Wonder if I am better running through L,then R etc. or run L,R,G,B, then take another set to maximise data captured on any night. It would work the EFW hard though - changing between every exposure

[iapa]

7 minutes ago, The Admiral said:

Probably getting a bit OT now, but I suppose an intermediate stage would be a micro-PC strapped to the OTA/tripod, with an in-built LCD screen, or at least a reliable wi-fi connection to a tablet. It all adds to the complexity of course, and needs to withstand the vicissitudes of our weather. Unless one is in the happy position of operating from an obsy, in which case simplicity can go to the wall anyway!

Ian

you mean like this?

https://www.amazon.co.uk/d/Desktop-PCs/Bben-Windows-Officially-Licenced-Multimedia-Computer-Bluetooth/B01M61HVJC/ref=sr_1_1?ie=UTF8&qid=1493389069&sr=8-1&keywords=bben

Cost £135

Ran as set the other night using SGPro.

Plate solved, and guided with PHD2 for a while easily.

[iapa]

The USB 3 hub you can see was an addition after the event, i.e. just put on today.

The mess is unpacking after a weeks holiday away with two rigs.

I installed, ASI camera driver, and Toupsky then ASCOM 6.3, the drivers for mount, EFW and ASI1600.

SGPro, StellariumScope and Stellarium

PHD2.

The only real issue was Stellarium as, although I had turned off the satellite and Iridium flare options, it reenabled these where I started Stellarium again despite saving the config.

 

[The Admiral]

19 minutes ago, iapa said:

you mean like this?

https://www.amazon.co.uk/d/Desktop-PCs/Bben-Windows-Officially-Licenced-Multimedia-Computer-Bluetooth/B01M61HVJC/ref=sr_1_1?ie=UTF8&qid=1493389069&sr=8-1&keywords=bben

Cost £135

Ran as set the other night using SGPro.

Plate solved, and guided with PHD2 for a while easily.

Probably, if I can work out what's what . I was wondering about the number of USB ports but I guess the hub has given you enough. These devices are getting mighty small! So do you communicate via USB or wi-fi? By the time all the software and OS is on the system, how much free capacity is available for storing images, or are they sent to a remote device via USB?

Ian

[iapa]

19 minutes ago, The Admiral said:

Probably, if I can work out what's what . I was wondering about the number of USB ports but I guess the hub has given you enough. These devices are getting mighty small! So do you communicate via USB or wi-fi? By the time all the software and OS is on the system, how much free capacity is available for storing images, or are they sent to a remote device via USB?

Ian

I can't give you all the info

The USB hub wasn't used

Above the USB hub is the stick PC - it has 1 x USB3, and 1 x USB2. HDMI connector is stick forward.

Am just doing a 'hardware' review article on setup and use.

See                    stick PC for imaging and control                 

 

[iapa]

21 minutes ago, The Admiral said:

Probably, if I can work out what's what . I was wondering about the number of USB ports but I guess the hub has given you enough. These devices are getting mighty small! So do you communicate via USB or wi-fi? By the time all the software and OS is on the system, how much free capacity is available for storing images, or are they sent to a remote device via USB?

Ian

USB 3 port to ASI - it has two USB ports which I used for the guide camera and the EFW; basically because of the length of the cables supplied.

The USB2 port on the stick PC had the hand controller plugged in.

[iapa]

5 minutes ago, iapa said:

USB 3 port to ASI - it has two USB ports which I used for the guide camera and the EFW; basically because of the length of the cables supplied.

The USB2 port on the stick PC had the hand controller plugged in.

Before we get clobbered for deviation, should probably continue in new topic stick PC for imaging and control

[Guest]

I've been really impressed with the responses to this post.

Everyone has responded with great enthusiasm but most importantly good advice....and they've done it calmly without descending into an OSC/Mono slugfest LOL!

Should serve as a great post for others in the future to help them make up their mind.

I'm sure the moderators will be along shortly to move the other off topic discussions to a more suitable location :-) 

Great work all!

David

[Alien 13]

For me personally it would be OSC, why would I pay £1000s for a set of 3 nm filters so I could throw most of the light away. I would think mono plus filters would struggle with Comets and Meteors too.

Alan

[Stub Mandrel]

On 28/03/2017 at 11:27, LightBucket said:

I have a question, as OSC CCD cameras are built for Astro use, why do they put a Bayer matrix in front that consists of 2 green 1 red and 1 blue filter..?.seems stupid to me when they could surely just use one of each colour, or am I being stupid and does it have to be in multiples of 2....  in which case could it not be a pattern of six and have two of each...just a thought

A pattern of four is the usual requirement. It would make sense to have a LRGB or an RRGB matrix. Or even IR+RGB

Of course the software would need to catch up.

[Adam J]

On 29/03/2017 at 00:19, ollypenrice said:

We humans are trichromats, having three kinds of colour receptors in the eye. I did come across this rather splendid sentence on the net, though...

There is no currently peer reviewed scholarly work that has confirmed the existence of a functional human tetrachromat though they are suspected to exist.

Oh to be a tetrachromat!!

lly

Interestingly though not all people are sensitive to exactly the same range of wavelengths there are people who see further into the IR / UV than others (20 - 50nm or so) though they still have three colour receptors.

[The Admiral]

On 28/03/2017 at 11:27, LightBucket said:

I have a question, as OSC CCD cameras are built for Astro use, why do they put a Bayer matrix in front that consists of 2 green 1 red and 1 blue filter..?.seems stupid to me when they could surely just use one of each colour, or am I being stupid and does it have to be in multiples of 2....  in which case could it not be a pattern of six and have two of each...just a thought

As Neil has said, and of course the sensors used in these cameras are made primarily for the conventional photography sector where the Bayer array more closely matches the colour response of the human eye. And with manufacturing scale comes economy, so I do wonder whether mono versions of the ASI071CC or the new ASI094CC will ever see the light of day (or should that be night ). I don't know how readily sensor manufacturers can make available their chips without the colour filter array, as it's a critical component of the sensor which is precisely aligned with the underlying pixels. It's not as though it's a lift-off filter.

Ian

[The Admiral]

11 hours ago, Alien 13 said:

For me personally it would be OSC, why would I pay £1000s for a set of 3 nm filters so I could throw most of the light away. I would think mono plus filters would struggle with Comets and Meteors too.

Alan

I've always assumed, rightly or wrongly, that when it comes to narrow band imaging one is not throwing light away because there is only  that light to be imaged. Or at least, mainly the case (note the steps backwards here!). Prepared to be corrected on that one. I guess it will only apply to nebulae which are emitting because of excitation, rather than reflected starlight. With other sources I'd certainly agree a lot of light would be discarded. But if your sky background is high it might be your only choice. But one isn't obliged to go down the NB route, one could just do LRGB, and that I guess is the conundrum, LRGB with a mono camera, or OSC. Hmm, difficult that, unless NB is weighing in heavily.

Ian

[DaveS]

For NB targets you're not throwing light away since the light you want is the emission line which is passed in 95% or so even by a 3nm filter.

For LRGB the dichroic filters are far more selective than the dye filters in colour CCDs.

[ollypenrice]

2 hours ago, DaveS said:

 

For LRGB the dichroic filters are far more selective than the dye filters in colour CCDs.

Yes, this is a good point. 

Olly