Exit KAF8300, enter ASI1600MM

[pietervdv]

Evening everyone,

 

Long time without a post, but the last 2 weeks I had some mediocre clear nights to dial in my new CMOS camera, an asi1600MM-cool.

I have sold my long time SBIG ST-8300 to help finance this new toy. This new camera has very low read noise and is nice upgrade from the kaf8300 noise bucket.

Been a bit of a hassle to get everything working as SGP did not seem to like the camera at first, causing all sorts of memory issues. But fortunatly all has been resolved with the latest SGP update.

My 10" Newton astrograph also had its mirrors cleaned this week,  readjusted the corrector - sensor distance and adjusted the detilter for this new cmos camera.

This is what the new imaging train looks like.

I also included the first test shot made with this camera: 3,5 hours made in 5 minute sub frames, Unity gain setting. No darks or flats used yet.

I was very impressed how much detail got registered with only 5 minute subs. Apologies for the non-original target . I am very curious to find out how the camera will perform on the faint Sharpless catalogue objects!

 

Full size can be found here:

http://www.astronomie.be/pieter.vandevelde/rosette-asi 3_5hours.jpg

 

Thanks for taking a look,

Regards,

Pieter

 

 

[alexbb]

Some would argue that the KAF8300 leads to better results and that the noise will drop down after stacking, but after seeing your result... I don't know what one could say more...

I do like very much your Rosette.

Clear skies,

Alex

[RichLD]

Many thanks for this Pieter - I've been considering upgrading from my QHY9 to this camera as the smaller pixels would suit my widefield rig very nicely. Your image has given me the confidence to pull the trigger when funds allow, excellent stuff! 

[pietervdv]

13 hours ago, moise212 said:

Some would argue that the KAF8300 leads to better results and that the noise will drop down after stacking, but after seeing your result... I don't know what one could say more...

I do like very much your Rosette.

Clear skies,

Alex

Thanks!

The advantage of this camera is its very low read noise, downside is an assymetrical ampglow which becomes obvious around the 5 minute mark. But this glow can be calibrated out perfectly with dark frames.

By stacking a large amount of short 5 minute exposures, you can take full advantage of the low read noise. It rivals easily with a multi hour (with 20 minute subs) image from my old st8300.

The asi1600 is "only" a 12 bit camera, but when stacking a large number of frames the dynamic range becomes larger than that.

However, the Rosette is a very bright object, the real test will be on fainter objects.

 

Pieter

[Guest]

Pieter,

AMAZING nice image you did capture, and since I saw your 2nd picture, and now I know that STARLIGHT EXPRESS autoguider connected via USB HUB on ASI1600 CCD

do also work.. 

 

Cheers

 

Martin

 

[LightBucket]

On 17/03/2017 at 20:15, pietervdv said:

Evening everyone,

 

Long time without a post, but the last 2 weeks I had some mediocre clear nights to dial in my new CMOS camera, an asi1600MM-cool.

I have sold my long time SBIG ST-8300 to help finance this new toy. This new camera has very low read noise and is nice upgrade from the kaf8300 noise bucket.

Been a bit of a hassle to get everything working as SGP did not seem to like the camera at first, causing all sorts of memory issues. But fortunatly all has been resolved with the latest SGP update.

My 10" Newton astrograph also had its mirrors cleaned this week,  readjusted the corrector - sensor distance and adjusted the detilter for this new cmos camera.

This is what the new imaging train looks like.

I also included the first test shot made with this camera: 3,5 hours made in 5 minute sub frames, Unity gain setting. No darks or flats used yet.

I was very impressed how much detail got registered with only 5 minute subs. Apologies for the non-original target . I am very curious to find out how the camera will perform on the faint Sharpless catalogue objects!

 

Full size can be found here:

http://www.astronomie.be/pieter.vandevelde/rosette-asi 3_5hours.jpg

 

Thanks for taking a look,

Regards,

Pieter

 

 

Can I ask, sorry for being a little off topic, but where did you get the cable tidy from on the loadstar...? Supeb idea

William

[pietervdv]

1 hour ago, LightBucket said:

Can I ask, sorry for being a little off topic, but where did you get the cable tidy from on the loadstar...? Supeb idea

William

Sure no problem; check here:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p5029_Strain-relief-for-Lodestar-cable---protects-the-connectors.html

The one I got was a 3D printed one. Essential accessory, especially if you are using the st4 autoguider connector on the Lodestar.

 

Pieter

[Adam J]

On 18/03/2017 at 08:57, pietervdv said:

Thanks!

The advantage of this camera is its very low read noise, downside is an assymetrical ampglow which becomes obvious around the 5 minute mark. But this glow can be calibrated out perfectly with dark frames.

By stacking a large amount of short 5 minute exposures, you can take full advantage of the low read noise. It rivals easily with a multi hour (with 20 minute subs) image from my old st8300.

The asi1600 is "only" a 12 bit camera, but when stacking a large number of frames the dynamic range becomes larger than that.

However, the Rosette is a very bright object, the real test will be on fainter objects.

 

Pieter

Nope the dynamic range will stay the same, if something is saturated no amount of stacking will magically replace that clipped data. What you do gain is a little more fidelity / resolution in terms of the number of levels of levels of brightness. But dynamic range is the same.

It is a common error to think that the resolution of the analogue to digital converter controls dynamic range, it only controls the resolution (number of levels) in brightness. Dynamic range is conveyed by the well depth within a single pixel. The bigger the pixels then the greater the dynamic range as they will have larger capacitors attached. CCDs work differently to CMOS and so have a larger dynamic range at a given pixel size.

In summary the dynamic range of the KAF8300 is much much larger than that of the 1600 and would still be much much larger even if the KAF also had a 12bit AD converter. From what I have seen this is still apparent in the images as the KAF8300 still looks to give more contrasty images than the ASI1600. Of course I own neither, its just my impression from the images I see being posted from the two sensor.

Just my opinion. Other factors are also relevant to image quality though.