Choosing a security camera

[DaveS]

No OAG needed, it's on the DDM 85 which is encoder guided.

I'll add that I have the camera turned off now, plus I've been round putting black tape over all the LED pilot lights, just in case.

[old_eyes]

34 minutes ago, DaveS said:

I had some light ingress problems which I think might be due to the IR LEDs of my obsy CCTV, after the meridian flip

Before flip

After flip

No calibration, just a brutal linear stretch, but the streak is visible in the stacked subs given a more gentle stretch.

I have a Hoya IR76 on order from EO which I hope will cut off the iR LED emission before the Luminance pass-band.

I used the fits header data from affected frames to see where the scope was pointing at the time.  What were the Alt-Az coordinates? Then, on a cloudy night, I moved the scope to the worst position and eliminated sources one by one. That is when I found it was the security camera.

[Laurin Dave]

33 minutes ago, old_eyes said:

I used the fits header data from affected frames to see where the scope was pointing at the time.  What were the Alt-Az coordinates? Then, on a cloudy night, I moved the scope to the worst position and eliminated sources one by one. That is when I found it was the security camera.

Clever!

[DaveS]

Well, it's not the CCTV camera, since that blasted streak is still there despite turning the camera off. I have no idea any more where it could be coming from.

[old_eyes]

7 hours ago, DaveS said:

Well, it's not the CCTV camera, since that blasted streak is still there despite turning the camera off. I have no idea any more where it could be coming from.

How annoying! No other lights around?

[DaveS]

The most likely other light was coming from the 4-way distribution block which has a neon indicator that I've since covered in black tape. There is also a 12V PSU on the floor that has an illuminated display of voltage. I've covered that with tape too.

When it gets dark enough I will try some ideas to track down the source of the flare.

[old_eyes]

Good luck. It is an exercise in detective work and frustration!

[DaveS]

I found light could get in through the top surface of the camera. but I think I have blacked out all the stray light in the obsy. Trying a two hour run.

[iapa]

I saw this the other day about stray light an focusers: 

 

 

 

[old_eyes]

I solved my problem by buying this camera with starlight capability.

https://www.broadbandbuyer.com/products/37601-dahua-technology-ipc-hdw4231em-ase-0360/

It is a POE device so only one cable, accessible from anywhere by logging into its IP address.

Loads of complex functionality that I have not used yet, but critically you can turn off the IR illumination.

Works well enough for me to see what is going on under starlight.

No evidence of any more light leakage into the imaging train.

Doesn't solve @DaveS problem, but it fixed mine.

[DaveS]

I solved my problems by turning the camera OFF! It will stay off until I have printed a light shield for the camera, though I don't know how effective it will be since I cannot block the cooling vents which is where the light is getting in;.

[old_eyes]

21 hours ago, DaveS said:

I solved my problems by turning the camera OFF! It will stay off until I have printed a light shield for the camera, though I don't know how effective it will be since I cannot block the cooling vents which is where the light is getting in;.

That is a pretty drastic solution for an imager!