ASI183 vs ASI1600 for a semi fast refractor and fast lens

[andy123]

Hi! I have a TS 80mm triplet with 0.79x reducer (FL 380mm) f4.75. I also have a Samyang 135mm f2 lens. I'm currently using a full spectrum modified Canon 600D but I'm thinking about upgrading to a mono cooled camera for narrowband imaging. I'm thinking narrowband imaging will allow me to use my equipment more because of strong LP in my area.

Based on my 80mm refractor the CCD calculator (OK seeing) leads me to ASI183 as best match with 1.3 " / pixel  and ASI1600 with 2.06 " / pixel

In reality what is best best match? Thanks!

[groberts]

On the face of it the resolution of the 183 looks like a winner but I've had the 1600 for a while now and can only say it's been very good and fully justified the switch from DSLR to mono, despite all the extra work required the results are worth it.  I'm using the 1600 with a WO GT81 and 0.80 WO focal reducer = FL 382mm & FYI f4.72 . Here's my initial blog on the 1600:

https://watchthisspaceman.wordpress.com/2017/03/28/first-light/

Notwithstanding, I will be interested to see responses on the 183 as it looks very interesting too. 

Good luck, let us know what you get and how it turns out.

Graham

    

[andy123]

Thanks! The ASI1600 has bigger sensor. Will it be demanding to achieve 1.3 " / pixel with my HEQ5?

[geordie85]

I have the qhy version of the 183 and it is very good with minimal noise. Unless of course the image is stretched too far but this can be said for any camera.

I must admit that I haven't successfuly finished an image with it yet due to recently switching scopes. 

[Adam J]

The 183 should do well and you will avoid the weird diffraction effects on bright stars that you get with the 1600. I own a ASI1600mm pro and I do love it. But I image at 650mm focal length so the bigger sensor is more important to me. I think that in terms of focal length once you are under 400mm the 183m becomes a very valid choice and starts to become more desirable in terms of image scale  than the 1600 and certainly a clear winner with the Samyang 135mm. 

I get 0.8 - 0.9 RMS total error consistently on my belt modded HEQ5 pro carrying a much larger 130PDS.  

Adam

 

[andy123]

3 hours ago, Adam J said:

The 183 should do well and you will avoid the weird diffraction effects on bright stars that you get with the 1600. I own a ASI1600mm pro and I do love it. But I image at 650mm focal length so the bigger sensor is more important to me. I think that in terms of focal length once you are under 400mm the 183m becomes a very valid choice and starts to become more desirable in terms of image scale  than the 1600 and certainly a clear winner with the Samyang 135mm. 

I get 0.8 - 0.9 RMS total error consistently on my belt modded HEQ5 pro carrying a much larger 130PDS.  

Adam

 

Thanks. My HEQ5 has the Rowan belt mod. I'm leaning towards the 183 now

[DaveS]

I have both ASI 1600 and 183, which I bought for my 80mm f/4.4. Although it's a good match for resolution I've found getting rid of amp-glow a real pain, and from discussions it looks very finniky about taking Darks. I found it helps if you can do a meridian flip in your subs, so sigma stacking can get rid of the glow.

My preferance now would be for the 1600 and not worry about theoretical resolution, though my next camera will likely be CCD.

[andy123]

2 hours ago, DaveS said:

I have both ASI 1600 and 183, which I bought for my 80mm f/4.4. Although it's a good match for resolution I've found getting rid of amp-glow a real pain, and from discussions it looks very finniky about taking Darks. I found it helps if you can do a meridian flip in your subs, so sigma stacking can get rid of the glow.

My preferance now would be for the 1600 and not worry about theoretical resolution, though my next camera will likely be CCD.

Thanks. I've read several topics on amp glow on the 183. The 1600 is more usable if I chose to use longer focal length in the future.

 

As for the diffraction problems I still have the modified dslr if targets contains bright stars.

[Adam_Jesion]

On 26/08/2018 at 10:30, DaveS said:

I have both ASI 1600 and 183, which I bought for my 80mm f/4.4. Although it's a good match for resolution I've found getting rid of amp-glow a real pain, and from discussions it looks very finniky about taking Darks. I found it helps if you can do a meridian flip in your subs, so sigma stacking can get rid of the glow.

My preferance now would be for the 1600 and not worry about theoretical resolution, though my next camera will likely be CCD.

It's true. I have both of them too. Fighting with the amp glow is discouraging and very frustrating. I use ASI1600 more often.

[newbie alert]

On 26/08/2018 at 09:30, DaveS said:

I have both ASI 1600 and 183, which I bought for my 80mm f/4.4. Although it's a good match for resolution I've found getting rid of amp-glow a real pain, and from discussions it looks very finniky about taking Darks. I found it helps if you can do a meridian flip in your subs, so sigma stacking can get rid of the glow.

My preferance now would be for the 1600 and not worry about theoretical resolution, though my next camera will likely be CCD.

Are you using bias frames Dave?

[DaveS]

Tried using Bias frames, but they made things worse, so used Darks only.