AR protect window Zwo 178m And Venus

[neil phillips]

I am thinking about trying a W47 Violet filter for venus in a few weeks time. It does need a IR cut filter. As there is a significant IR leak when using the W47 filter. For Venus

My question is. The ZWO 178M does have a anti reflection UV IR Cut transmission window over the cmoss chip. How effective would this window be in cutting the significant IR leak of the W47Violet filter?

According to Christophe Pellier It does not matter if the IR cut is partially transparent to UV or not. What does matter is how effect the IR cut is.. (His words) 

So i read into that.

1 Will the AR Protective window cut the IR leak of the W47 Filter ?

2 will the UV Cut of the ZWO AR protective window really have no consequence in detecting venus cloud ? 

3 should i just remove the AR protective window from the ZWO178 camera and use a stand alone IR Cut filter in combination with the W47 Violet Filter ?

4 How do you remove the AR Protect window from the ZWO 178 Camera ? I may just get a dedicated UV Venus Filter. But even if i go that route. The removal of the AR Protect window question still stands. 

Its a lot of questions that i am unsure many will know the answer to. But if anyone has any knowledge. Would appreciate sharing ideas. As i do want to at least briefly try imaging venus again.

Looking again at what Christopher says. Apparently there isnt much gain in removing the AR Protect window. 

I may just try a W47 filter with a GSO IR Cut filter i have and see if any cloud is detected

C pelliers venus testing

 

What are the best filters to image Venus? (planetary-astronomy-and-imaging.com)

Edited December 2, 2021 by neil phillips

[symmetal]

2 hours ago, neil phillips said:

4 How do you remove the AR Protect window from the ZWO 178 Camera ? I may just get a dedicated UV Venus Filter. But even if i go that route. The removal of the AR Protect window question still stands. 

The front plate of the camera unscrews. If it's too tight a rubber strap wrench around the 2" nose piece should loosen it.  The sensor is surrounded by a rubber, or possibly neoprene ring, and the protect window sits in a recessed cutout on the front of the ring. When the front plate is screwed on, it pushes the protect window into another recess in the front plate, keeping it in place, and so stopping dust from getting in.

The 178 manual pages 9 and 10 have the response graphs of the AR protect window for the mono camera, and the UV/IR cut protect window for the colour camera which may help.

Alan

Edited December 2, 2021 by symmetal

[neil phillips]

32 minutes ago, symmetal said:

The front plate of the camera unscrews. If it's too tight a rubber strap wrench around the 2" nose piece should loosen it.  The sensor is surrounded by a rubber, or possibly neoprene ring, and the protect window sits in a recessed cutout on the front of the ring. When the front plate is screwed on, it pushes the protect window into another recess in the front plate, keeping it in place, and so stopping dust from getting in.

The 178 manual pages 9 and 10 have the response graphs of the AR protect window for the mono camera, and the UV/IR cut protect window for the colour camera which may help.

Alan

Many thanks Alan. Very helpful information. Much appreciated. It appears only the Colour camera has UV IR cut. in high enough cutoff to be particularly relevant. Not sure what i was reading that made me confuse the two widows. Having a senior moment there i think. Its hardly worth removing the protect window. As its effect will be minimal. As such think i will try a W47 And GSO IR cut filter that i have. 

Edited December 2, 2021 by neil phillips