mono CCD advice please

[glowingturnip]

Hi all,

So I've got a big birthday coming up this year (half a century if you must know), and I think I've gotten permission from the other half to splurge on a CCD plus filters.   Wonder if I could pick you good folks' brains as to which ones to look at.  Criteria I'd want are...

- mono

- set point cooled

- large frame - ideally I'd want a fov similar to my DSLR

- filter wheel

- filters - I think I'd be mostly looking at HaLRGB, I like my pics to be vibrant natural colours, but I'd probably dabble with narrowband too

- OAG would be nice I guess, but certainly not essential

- all-in, around £3k

Any ideas ?

 

Regarding filters, are there such things as par-focal filters so I could run a whole session changing filters automatically without refocusing ?  If not, I suppose I'd have to have an auto focuser on the OTA, it can't be done in camera ?

 

And a silly question - would it make any sense to do my RGB with my DSLR and the Ha and Lum with the CCD or am I just asking for DSLR blotchiness ?  I just can't see myself being particularly thrilled about devoting a whole evening to shooting just blue or green.

 

Cheers

[johnrt]

I would look at the Kodak KAF-8300 CCD based cameraa if you are looking to keep a chip as close to DSLR size as possible. Atik do the 383l+ and others do their version too. You would be able to get camera, wheel and filters for £3k no problem.

Sara @swag72 images with an SBIG camera variant of the same chip, so if you want to see with what is possible have a look at her images.

Can you mix your colour from a DSLR and Lum / Ha from the CCD, yes of course. Would I mix DSLR data & CCD data togther? NO!!

 

[swag72]

20 minutes ago, johnrt said:

....Sara @swag72 images with an SBIG camera variant of the same chip, so if you want to see with what is possible have a look at her images.

I use a QSI and a Moravian  That's the QSI683 and the Moravian G2-8300

[johnrt]

7 minutes ago, swag72 said:

I use a QSI and a Moravian  That's the QSI683 and the Moravian G2-8300

Doh!

[ollypenrice]

Agree with John. The QSI (and Moravian?) bonus with this chip would be that the integral wheel is close enough to the chip to go for the cheaper 1.25 filters.

If you have a mono CCD camera you will want to use a DSLR for colour like Jeremy Clarkson wants to tour the Dolomites in a Nissan Micra rather than a Ferrari F12. Your CCD will be way faster and way better.

It doesn't matter how parfocal your filters are, you will not be able to image for too long without refocusing. It is very sensitive and cooldown affects it throughout the night for most of us. Indeed all the decent filters are parfocal anyway, it is the optics which are not perfectly colour corrected. Any non-parfocality will come from this. In LRGB imaging I focus in L and then tend to scroll LRGB, LRGB with our electric wheels. I do this so that guests get the best chance of a full dataset. Even if there is very slight focal imperfection in one of the colours (and I don't find that there is) it really doesn't much matter. It is the L which must, absolutely, be nailed on focus.

Robotic focus is done at the scope.

Olly

[swag72]

I very much rate the KAF8300 sensor - It is a largish sensor that is in many camera's. The most important thing for me is that it's affordable  I have also used the Sony ICX694 and the larger ICX814 chip........ In comparison to the KAF8300 I think that these sensor are vastly over rated and very much 'bigged up'. The KAF8300 gets some bad press, internet forums saying that it's old technology, that it's noisy and that it's sensitivity in Ha and OII is pretty poor.....

Sadly I listened to all this twaddle and puff and ended up with the wrong chip..... I believed that the KAF8300 would be too much to handle and would be a slouch. Don't you believe it..... in my opinion real estate and chip size beats all other advantages into a tin hat.... and I say this having EXTENSIVELY used all three chips.

So make you mind up on sensor and then decide on a manufacturer. I really rate the QSI. It has an integrated OAG and 8 position filter wheel.... what more could you want? It also works with 1.25" filters as the sensor and the filters are nice and close. The cooling on the QSI is excellent and this was a major consideration for me being in Spain. The Moravian is also a great camera. It doesn't have an OAG, and sadly only a 5 position integrated filter wheel. Again 1.25" filters are fine. The Moravian is as well built as the QSI (they are built like tanks and with a quality feel about them).

Parfocality - Pah!!! Don't believe it for a minute.... none of my RGB Baaders are parfocal and none of my Astrodon narrowband filters are either..... This is probably down to optics more than anything, but so far I've used these filters in about 4 different scopes!! But with an auto focuser this is totally irrelevant anyway

Hope all that helps

[glowingturnip]

Excellent advice all, thanks very much, I'll do my homework and check into all of those carefully.  I'm also shooting in Spain so the cooling is important I guess (I'm usually sitting outside in a deckchair, in shorts, with a beer at the time).  I like the sound of that QSI.

 

39 minutes ago, johnrt said:

Can you mix your colour from a DSLR and Lum / Ha from the CCD, yes of course. Would I mix DSLR data & CCD data togther? NO!!

 

 

7 minutes ago, ollypenrice said:

If you have a mono CCD camera you will want to use a DSLR for colour like Jeremy Clarkson wants to tour the Dolomites in a Nissan Micra rather than a Ferrari F12. Your CCD will be way faster and way better.
 

Hahaha, ok, point taken !   Makes sense nailing the Lum focus (and Ha I guess)  and being less fussy about RGB - good point, something to experiment with.

 

Are there any separate power supply needs or other incidentals I should be looking at ?  And does anyone happen to know if the bundled software runs on XP ?  My field laptop is a hardy old off-the-grid XP machine

The downside of all this of course is that my OTA will start looking distinctly cheap compared to the rest of it...

[ollypenrice]

8 minutes ago, glowingturnip said:

Excellent advice all, thanks very much, I'll do my homework and check into all of those carefully.  I'm also shooting in Spain so the cooling is important I guess (I'm usually sitting outside in a deckchair, in shorts, with a beer at the time).  I like the sound of that QSI.

 

 

Hahaha, ok, point taken !   Makes sense nailing the Lum focus (and Ha I guess)  and being less fussy about RGB - good point, something to experiment with.

 

Are there any separate power supply needs or other incidentals I should be looking at ?  And does anyone happen to know if the bundled software runs on XP ?  My field laptop is a hardy old off-the-grid XP machine

The downside of all this of course is that my OTA will start looking distinctly cheap compared to the rest of it...

You won't find yourself wanting to include the Ha in the scrolling wheel nights. Focus is very critical for that, too, and since you always need a lot it will be on a different night. (Possibly with the moon around to some extent.)

Olly

[glowingturnip]

noted, cheers

[swag72]

20 minutes ago, glowingturnip said:

Excellent advice all, thanks very much, I'll do my homework and check into all of those carefully.  I'm also shooting in Spain so the cooling is important I guess (I'm usually sitting outside in a deckchair, in shorts, with a beer at the time).  I like the sound of that QSI.....

If you're in Spain and anywhere near me, then just give me a shout if you want to see anything in the flesh

[glowingturnip]

thanks for that - we're near Malaga, in the hills inland, a little holiday pad.

[gnomus]

I agree about the KAF 8300.  I own and like the Moravian G2-8300.  It is a heavy camera though.  I also have an Atik 383L - the Moravian plus 10 position wheel is around 800gms heavier than my Atik 383L plus 7 position EFW.  It is one power cable and one USB though.  I have a QSI 690 too, but this is not a KAF 8300.  I mention it only because the QSI is an elegant piece of kit.  If I could justify it, I'd get a QSI 683.  

Personally, I find the bundled software for the Atik and the Moravian a bit clunky.  Once you get the camera, download the trial version of SGP and compare it to the bundled stuff.  

[swag72]

1 hour ago, glowingturnip said:

thanks for that - we're near Malaga, in the hills inland, a little holiday pad.

Ahh.... a little far away

[ollypenrice]

1 hour ago, swag72 said:

If you're in Spain and anywhere near me, then just give me a shout if you want to see anything in the flesh

Sara!!!!!!!

lly

[ollypenrice]

6 minutes ago, swag72 said:

Ahh.... a little far away

I used to cycle out of Malaga airport once or twice a year in my previous life. Some fine hills up there, and good skies.

Olly

[swag72]

1 minute ago, ollypenrice said:

Sara!!!!!!!

lly

 

[gnomus]

1 minute ago, ollypenrice said:

Sara!!!!!!!

lly

Spring is approaching, and Olly is coming into season......

[ollypenrice]

Just now, gnomus said:

Spring is approaching, and Olly is coming into season......

I wish he were. He's coughing like a grampus and sulking between splutters!

Olly

[glowingturnip]

1 hour ago, ollypenrice said:

Sara!!!!!!!

lly

hahaha, I was thinking that too, but being polite !

1 hour ago, ollypenrice said:

I used to cycle out of Malaga airport once or twice a year in my previous life. Some fine hills up there, and good skies.

Olly

probably my hills - Montes de Malaga, nearest town is Casabermeja

[MattJenko]

4 hours ago, ollypenrice said:

In LRGB imaging I focus in L and then tend to scroll LRGB, LRGB with our electric wheels. I do this so that guests get the best chance of a full dataset. Even if there is very slight focal imperfection in one of the colours (and I don't find that there is) it really doesn't much matter. It is the L which must, absolutely, be nailed on focus.

Hadn't really considered this as an approach. Must give it a go.

[glowingturnip]

a question on coma correctors - I have a Baader 2" MPCC on the end of my DSLR at the moment - will that work with a CCD, and will the spacing be right, or do I need to get something else.

I presume the focal plane for a CCD is similar to a DSLR, so given I can get focus with my scope on the DSLR I'll be able to with the CCD too ?

[ollypenrice]

20 minutes ago, glowingturnip said:

a question on coma correctors - I have a Baader 2" MPCC on the end of my DSLR at the moment - will that work with a CCD, and will the spacing be right, or do I need to get something else.

I presume the focal plane for a CCD is similar to a DSLR, so given I can get focus with my scope on the DSLR I'll be able to with the CCD too ?

Unfortunately there is no industry standard for camera flange-to-chip-distance with CCDs so the manufacturers publish this figure on their technical specs. You have to add up the camera chip distance, the thickness of the filterwheel, the thickness of any adapters in the line, and then use further adapters to get the correct spacing from corrector to chip.

Olly

[sloz1664]

34 minutes ago, ollypenrice said:

Unfortunately there is no industry standard for camera flange-to-chip-distance with CCDs so the manufacturers publish this figure on their technical specs. You have to add up the camera chip distance, the thickness of the filterwheel, the thickness of any adapters in the line, and then use further adapters to get the correct spacing from corrector to chip.

Olly

Don't forget to allow for the "filter refractive index" which equates to roughly 1/3rd of the thickness of the filter glass. Why don't filter manufactures state the "FRI" on their products, this astrophotography game is hard enough without having to work in the "dark" (added pun).

Rant over.....

 

Steve

[glowingturnip]

ugh, homework to do then.  Can I assume though that CCDs come with regular T-mounts so I can use my T-adaptor to 2" nosepiece ?

Am I right in thinking the optical train is:  CC - spacers - nosepiece - t-ring - OAG - filters - chip   (the latter three being in the CCD black box)

[ollypenrice]

8 hours ago, glowingturnip said:

ugh, homework to do then.  Can I assume though that CCDs come with regular T-mounts so I can use my T-adaptor to 2" nosepiece ?

Am I right in thinking the optical train is:  CC - spacers - nosepiece - t-ring - OAG - filters - chip   (the latter three being in the CCD black box)

No! If you can lose nosepieces do lose them. They add length and introduce tilt (though I have used them on occasion.)  You are best advised to screw everything together. Yes, a bit of a pain, but you only do it once.

I would be looking at this:

CC - spacers - OAG - filters - chip

I have never built up a Newt imaging rig so don't take this as gospel.

Olly