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Contains:  NGC 6207, M 13, Great Cluster in Hercules, NGC 6205
Getting plate-solving status, please wait...
Messier 13 with APO 130 & ZWO1600MMcool, 


Messier 13 with APO 130 & ZWO1600MMcool

Messier 13 with APO 130 & ZWO1600MMcool

Technical card

Resolution: 1280x968

Dates:July 25, 2017

Frames:ZWO new L: 3x300" (gain: 139.00) -15C bin 1x1

Integration: 0.2 hours

Darks: ~12

Flats: ~10

Flat darks: ~100

Avg. Moon age: 2.32 days

Avg. Moon phase: 5.94%

Mean SQM: 21.00

Mean FWHM: 3.00

Temperature: 16.00 job: 1671242

RA center: 16h 41' 41"

DEC center: +36° 27' 25"

Pixel scale: 3.322 arcsec/pixel

Orientation: 80.405 degrees

Field radius: 0.740

Locations: Duc, Prayssas, Lot et Garonne, France


Version D has an added deconvolution to correct from some star elongation.

This is my first and very modest "Luminance" frame using my new setup.
It is only 3 x 5 minutes.

I have done some measurements about the sensor @ gain 139 (supposed unit gain) and -15°C :
Read Noise = 1.67 e-
Dark Current = 0.0088 e-/s
Gain = 0.98 e-/DN
This is perfectly in line with the ZWO specifications.
I have also measured the Read Noise @ maxi gain 300 and found : 1.18 e-

I have attached the field curvature analysis showing that the collimation of the new APO (performed on daylight using an artificial star) can be perfected. On version B and C, you can see that the collimation is almost good at the bottom-center of the sensor. I will need to do the final adjustments.

The processing was done in PI as follow :
- Flat Field Dark Substraction
- Flat Field Integration
- Images Calibration (Dark Substraction and FF correction)
- Cosmetic Correction
- Image Registration
- Image Integration
- Sky Background Correction (DBE)
- Noise Reduction (Demure)
- Nonlinear Image Creation
Final image adjustments performed in Iphoto on Imac (levels adjustements)

Some remarks :
- I have applied the advice from other user of the ASI1600 to do straight dark substraction of dark taken at same integration time and same temperature. I have checked hat the amp glow is fully removed with this approach.
- The Demure noise reduction is very effective with the mono images.



License: None (All rights reserved)


  • Messier 13 with APO 130 & ZWO1600MMcool, 


  • Messier 13 with APO 130 & ZWO1600MMcool, 


  • Messier 13 with APO 130 & ZWO1600MMcool, 


  • Final
    Messier 13 with APO 130 & ZWO1600MMcool, 



Sky plot

Sky plot


Messier 13 with APO 130 & ZWO1600MMcool,