First Light: ZWO ASI178MM High Res CCD

[cshahar]

Hi Everyone:

 

This camera requires good seeing conditions, and a faster frame rate than what my computer is providing. Unfortunately, the USB3 port is being recognized only as a USB2 one by FireCapture, and I haven't been successful in loading the latest driver yet. I also want to get an SSD drive. These two interventions should help the situation significantly. Below is a sample of what I got with a ridiculously low frame rate and average seeing, at the highest resolution possible (3096X2080). I think it has a lot of potential. But it certainly doesn't yet come close to my results with the 174MM at least in terms of sharpness.

 

Thanks,

 

-Charles

[Pete Presland]

That is a good start, despite the issues. 

[michael.h.f.wilkinson]

Nice result, but I think you will need a focal reducer to get the full potential out of the camera in combination with the Quark. The 2.4 micron pixels are optimal around F/12, so with a quark, which easily works at F/30 you are oversampling heavily.

[Davey-T]

Nice image Charles, from memory I think my PGBFly camera has pixels around twice that size and the seeing seems rarely to be good enough to use it without a focal reducer in the f/6 refractor with the Quark, not sure how it computes with your filter.

Dave

[cshahar]

Hi Michael. thank you for the suggestions! Actually, I am using a Quantum filter, but still have to remain at f30. I wanted to get as up close as possible. A reducer would have improved the sharpness no doubt, but would have done so over a wider field. I want to see how far in I can go with a 4-inch refractor, maintaining sharpness, if I improve the frame rate. If that doesn't work, then a reducer is certainly the way to go!

Hi Dave. I am hoping that a faster frame rate will compensate for the seeing conditions, but I could be wrong. Maybe there will be a limit as to what my 4-inch could resolve, and it won't be much further than what I am getting now!

-Charles

[laudropb]

Very promising first light.

[Lowjiber]

Very nice, Charles.  It takes some time to "get to know" a new cam, for sure. 

That cam is pretty fast, and getting USB 3 working will likely help a lot.

The image doesn't look sharpened at all.  Did you try Smart Sharpen very slightly?  Perhaps at something like 0.7 pixels?  I don't see any noise.  It looks nice.

Clear Skies

[David Smith]

Not a bad start Charles. Will be interesting to see how you get on with this camera as I am considering it as an upgrade from my QHY5.

[cshahar]

Thanks again everyone.

Lowjiber, actually I did try to sharpen it, and it shows at 100% view because there is perceivable noise. The issue is really the slow frame rate. If I don't manage to work it out, a reducer is certainly an option. I would like to be able to make significantly large hard copy prints than what I am capable of now.

David, I am curious to know myself. I shall certainly keep this forum updated! Just bought a 500GB SSD. That should help a lot!

-Charles

[michael.h.f.wilkinson]

On 6/18/2016 at 23:44, cshahar said:

Thanks again everyone.

Lowjiber, actually I did try to sharpen it, and it shows at 100% view because there is perceivable noise. The issue is really the slow frame rate. If I don't manage to work it out, a reducer is certainly an option. I would like to be able to make significantly large hard copy prints than what I am capable of now.

David, I am curious to know myself. I shall certainly keep this forum updated! Just bought a 500GB SSD. That should help a lot!

-Charles

I also got myself an external 500 GB SSD (Samsung T1), with which I can have the ASI174MM running at full speed most of the time. Makes all the difference. Regarding a reducer: that is really needed due to the fact that you are working way over the Nyquist sampling rate with 2.4 micron pixels. Reducing focal ratio to roughly F/12 (or perhaps F/16) will capture all the detail in the image, plus increase S/N because more photons are captured at each pixel.

[cshahar]

Thanks Michael. I will definitely keep that in mind!

-Charles