Yep I know, which camera......

[rickwayne]

Your wife doesn't "borrow" your gear for her own astroimaging? Lucky!

[scotty38]

Haha no, she's happy to have a look at something if I show her but beyond that she has no real interest in it.

 

I mean, don't get me wrong, she is in wonder of the night sky, she just is not that keen getting cold to do it....

Edited February 1, 2021 by scotty38

[ollypenrice]

2 minutes ago, scotty38 said:

Haha no, she's happy to have a look at something if I show her but beyond that she has no real interest in it.

 

I mean, don't get me wrong, she is in wonder of the night sky, she just is not that keen getting cold to do it....

My wife says that in winter it's too cold and in summer it's too late!

Olly

[scotty38]

2 minutes ago, ollypenrice said:

My wife says that in winter it's too cold and in summer it's too late!

Olly

Too cold where you are? We have spent many holidays in the south of France and it's never been too cold, admittedly never in winter but even then there is no comparison with what we have here 🤣

[callisto]

2 minutes ago, scotty38 said:

Too cold where you are?

yous lot in the southern parts don't know what cold is 🤣

[ollypenrice]

1 minute ago, scotty38 said:

Too cold where you are? We have spent many holidays in the south of France and it's never been too cold, admittedly never in winter but even then there is no comparison with what we have here 🤣

I bet it's colder here than in Lincs by night. 3000 feet up, continental climate... We are in the Dept of the High Alps, after all. We'd see minus 12C routinely in the past with a coldest of minus 19C and we could get 80cm of snow overnight. In the last six or seven years it's warmed up considerably but we did see minus 10 last week along with some snow. This was a couple of weeks ago, looking down from the observatories.

Olly

 

[callisto]

2 minutes ago, ollypenrice said:

coldest of minus 19C

Did not realise it was that warm 😁

[ollypenrice]

Just now, callisto said:

Did not realise it was that warm 😁

You lowlanders.!!! 🤣

Olly

PS To ensure that it never snows again, just buy a 4WD. It worked for us!

[rickwayne]

One word for all of you mamby-pamby types who think you know what winter is: Wisconsin.

[The Lazy Astronomer]

4 hours ago, scotty38 said:

I ordered the 294...... Please don't tell my wife

 It's a great camera, you won't be disappointed!

[scotty38]

1 hour ago, ollypenrice said:

I bet it's colder here than in Lincs by night. 3000 feet up, continental climate... We are in the Dept of the High Alps, after all. We'd see minus 12C routinely in the past with a coldest of minus 19C and we could get 80cm of snow overnight. In the last six or seven years it's warmed up considerably but we did see minus 10 last week along with some snow. This was a couple of weeks ago, looking down from the observatories.

Olly

 

Ah ok fair enough. I guess I should have taken more notice of your avatar rather than imagine you sitting on a beach sipping a martini 😂

[ollypenrice]

2 hours ago, rickwayne said:

One word for all of you mamby-pamby types who think you know what winter is: Wisconsin.

Yeah, but it's uninhabited, right?

🤣lly

[smr]

I have been dithering over a dedicated cooled Mono or dedicated OSC for some time now. I feel like I have read and watched thousands of articles / videos comparing the benefits of both as well as studying astrophotography images and asking lots of questions on the topic. I've never had a harder decision to make when it comes to buying something for a hobby I have.

Overall when you see the images of LRGB and Narrowband they are better resolution with much more detail than a typical gallery of OSC images, and I do love pure narrowband images. The stars also appear smaller in Mono images.

Just when I'm leaning towards Mono+EFW+Filters I'll see spectacular data and images from imagers with OSCs, for example the work @Allinthehead has done with his OSCs, and most notably of all, for me, the Horsehead and Flame Nebula image which is a result of the 2600MC Pro (OSC) and Tak 160 combination, although in favourable skies and with a skilled imager it has to be said. But, it shows what can be done with the kit. That kit isn't cheap though, both items will cost a total of around £5k.

It's perhaps not a fair comparison, in that I've surely not seen every Horsehead image there is, but it's the best image of this DSO that I have seen thus far and it happens to be OSC. I'm not biased one way or another at all.

I'm so close to buying my first dedicated astronomy camera and basically it's a choice between Cameras of the same sensor, the 2600MC or 2600MM (or the QHY version). Cost doesn't really factor into it for me because if I went for Mono I'd be happy enough taking Mono images to begin with, and it wouldn't be too long before I'd buy the EFW and Filters, I can't afford to buy all in one go.

It's just weighing all this up, do I go for an OSC and then when I can afford to buy a fast scope like the RASA f/2 or a Takahashi, or do I go for Mono+EFW+Filters and image with my current scope at f/5.9

I could always upgrade to a faster scope a year or so later.

I'm an IT and Computer Engineer so I don't mind the computer work and technical challenges, in fact I enjoy it, so I would probably enjoy Mono in the sense that it's more technical than OSC / more things to get working together to achieve an image. Having said that there's also another good reason for going for OSCs though - fast lenses. 

Using the Canon 200mm 2.8 or Samyang 135mm 2.8 with a 2600MC Pro would be superb I think for those really nice wide widefield images.

I do feel a little put off by some comments I've read by imagers who seem quite annoyed at the clouds and weather patterns we have here in the UK - when trying to image a target and having the data collected for L,R,G but then not being able to complete B before the target has moved into an obstructed position after a consecutive run of cloudy nights, and it's a matter of waiting another year for the target to come around.

Like I said, difficult decision. 

[tomato]

I agree 100% on the conclusions made about mono vs OSC on the same sensor, but you have to seriously consider the latest CMOS OSC sensors, given the superb NB and RGB images that have been posted recently (admittedly from good skies and by expert imagers).

Of course, this all conquering sensor is now available in mono.😉

[gorann]

7 hours ago, ollypenrice said:

My argument over mono versus OSC versus time goes like this: Lum = R+G+B per pixel, simultaneously. You cannot shoot this with an OSC camera, you can only shoot R or G or B per pixel. Now the OSC filters don't have hard cutoffs so this is slightly overstating the case since the green OSC filter, in particular, overlaps into R and B.  Still, the total photon count per unit time is very considerably higher in L than in RGB or OSC.  Sticking to the simplified version where colour collects 1/3 luminance we can make this comparison in 'luminance units:'

1st hour:  mono in R, 1/3.  OSC 1/3

2nd hour: mono in G ,1/3.  OSC 1/3

3rd hour: mono in B, 1/3.   OSC 1/3

4th hour: mono in L, 3/3.     OSC 1/3

Add this up and mono scores 6/3 while OSC only scores 4/3.  While shooting equal amounts of LRGB makes processing easier, it would be perfectly possible to add another hour's lum in mono, taking us to 9/3 while OSC only advances in a further hour to  5/3. And so on...  Some targets can be shot with a hugely extended luminance run, some cannot. Faint stuff like tidal tails, IFN etc can have way more luminance than RGB bot colourful targets do need a higher percentage rgb.  On top of this you can, with CCD, gain further time by binning colour 2x2. Binning with CMOS is something I haven't tried and don't fully understand.

And then, should you want to do pure NB, you will certainly want mono.

But  I don't argue in favour of mono CCD over OSC just on the basis of the arguments above but on experience of both and, the fainter the object, the more the real world advantage of mono became evident. On M42 there was nothing in it. On galaxies the OSC was rather lame.

2nd but: I've been really impressed by CMOS OSC data I've processed and also by dual band filtration of OSC. How does this work in the moon? Not a clue. Perhaps Goran could advise? So I would personally consider an OSC CMOS whereas I would not consider an OSC CCD.

Complexity?  On all our rigs I focus in L and let RGB look after itself. Non parfocality doesn't come, in our cases, from the filters but from the optics and it isn't worth worrying about. With OSC you cannot refocus between colours anyway. You can in mono but personally I usually don't. Nor do I shoot separate flats, except very exceptionally. Luminance flats work for all filters almost invariably. What you can usefully do in mono is shoot lum and blue with the object at its highest.

Olly

Here is a recent example of a OSC CMOS image (ASI2600MC) I took with the IDAS NBX filter (dual band) under the last full moon and a RASA 8 (the sky was soo bright I barely could see Cassiopeia when I did a one star alignment). Totally 4.2 hours of exposures.

Edited February 1, 2021 by gorann

[rickwayne]

7 hours ago, ollypenrice said:

Yeah, but it's uninhabited, right?

🤣lly

SMILE when you say that, son!

Anyway, that's not true. We have cows.

[rickwayne]

WRT the Great Mono vs. OSC Debate, meh. You will be able to do great images either way. At the current state of the art, what really matters is setpoint cooling for noise reduction and consistency. Unless you're pretty far out under one leg or the other of the bell curve, you really won't miss whichever one you decide to eschew.

I will say that personally I'm kind of perversely drawn to mono's greater amount of fiddle-faddle, just as I enjoy shooting old manual-everything lenses for terrestrial work.

I had never even considered not bothering to refocus for the RGB filters. But...of course that make eminent sense! Given my Beverly Hillbillies focusing rig, that would probably add a nontrivial number of RGB light frames to a given imaging session. And if you're not refocusing between the filters, there's no reason not to interleave them, meaning that you don't have to get stuck with just e.g. LRG and have to wait for a year.

[ollypenrice]

10 hours ago, gorann said:

Here is a recent example of a OSC CMOS image (ASI2600MC) I took with the IDAS NBX filter (dual band) under the last full moon and a RASA 8 (the sky was soo bright I barely could see Cassiopeia when I did a one star alignment). Totally 4.2 hours of exposures.

Goran, have you tried comparing/combining pure OSC and dual band-filtered OSC?  Essentially I wonder what, if any, is the 'cost' of the filter in terms of signal. Super image.

Olly

[gorann]

1 hour ago, ollypenrice said:

Goran, have you tried comparing/combining pure OSC and dual band-filtered OSC?  Essentially I wonder what, if any, is the 'cost' of the filter in terms of signal. Super image.

Olly

I just stared doing that. I posted my first attempt yesterday where I added the red (Ha) signal from the NBX dualband filter to an RGB image of M31 collected back in August. I have just bough a second RASA and ASI2600MC for a dual rig where one collects RGB and one HaOiii (or both RGB depending on target). I am just waiting for it to get a bit warmer here (-15°C now) to save my nose and fingers when I set it up.

 

[vlaiv]

Interestingly enough, there is single small change that sensor manufacturers can do that will negate difference between OSC and mono.

Don't know why they don't already do it - I think it would improve daytime photography as well (color rendition and low light performance).

Instead of having RGGB as bayer matrix - we could have RLGB - one of four pixels could be without filter.

[smr]

27 minutes ago, vlaiv said:

Interestingly enough, there is single small change that sensor manufacturers can do that will negate difference between OSC and mono.

Don't know why they don't already do it - I think it would improve daytime photography as well (color rendition and low light performance).

Instead of having RGGB as bayer matrix - we could have RLGB - one of four pixels could be without filter.

That's a good point, I wonder why they don't. 

[gorann]

36 minutes ago, vlaiv said:

Interestingly enough, there is single small change that sensor manufacturers can do that will negate difference between OSC and mono.

Don't know why they don't already do it - I think it would improve daytime photography as well (color rendition and low light performance).

Instead of having RGGB as bayer matrix - we could have RLGB - one of four pixels could be without filter.

Interesting suggestion Valiv. Could it be that they whant that extra green signal since it coinsides with our visual sensitivity? In any case it seems difficult enough to convince the manufacturers to skip adding a bayer mask, so making them change it is probably just a theoretical possibility unless it in some way would enhance daytime photography (would it?).

Edited February 2, 2021 by gorann

[vlaiv]

20 minutes ago, gorann said:

Interesting suggestion Valiv. Could it be that they whant that extra green signal since it coinsides with our visual sensitivity? In any case it seems difficult enough to convince the manufacturers to skip adding a bayer mask, so making them change it is probably just a theoretical possibility unless it in some way would enhance daytime photography (would it?).

I think that reason for having two green as opposed to two blue or red pixel is human eye sensitivity. It also adds to resolution, as we are most sensitive in brightness rather than color change and brightness that we perceive is closely related to shape of green channel.

Lack of mono sensors is tied to economics of scale I believe - it is much more cost efficient to have OSC sensor in consumer cameras and these are driving force behind mass production of the sensors.

I think there would be some benefit to daytime photography from having one G pixel replaced with L. Better color rendition is one, improved low light sensitivity is another.

31 minutes ago, smr said:

That's a good point, I wonder why they don't. 

There has to be some rationale behind using RGGB instead of say RLGB. Not sure what it is, but I doubt that they "simply did not think of that"

[michael.h.f.wilkinson]

Interesting thread. I am looking for my first cooled astro camera, and the ASI294MM Pro is the main contender (although I did consider the ASI183MM Pro earlier on). I already have a ZWO filter wheel (7 position), so should be ready to go. I must say, the uncooled ASI183MC I have (originally bought for planetary and lunar) has been surprisingly good at DSO imaging, clearly more sensitive than the old EOS 550D (modded).

[vlaiv]

15 minutes ago, michael.h.f.wilkinson said:

Interesting thread. I am looking for my first cooled astro camera, and the ASI294MM Pro is the main contender (although I did consider the ASI183MM Pro earlier on). I already have a ZWO filter wheel (7 position), so should be ready to go. I must say, the uncooled ASI183MC I have (originally bought for planetary and lunar) has been surprisingly good at DSO imaging, clearly more sensitive than the old EOS 550D (modded).

How did you find calibration of that ASI183MC - given that it does not have set point cooling and suffers from amp glow?