Back to forums

ASI432mm ring effect

ZWO ASI432MM William Optics Redcat 51 Troubleshooting Artifacts
9 replies•243 views
Nick Grundy avatar
Nick Grundy avatar
Does anyone recognize the issue I'm seeing here? I'm using a Redcat51, UV/IR filter, Daystar Quark Chromosphere, ASI432mm

I've used all of it except the asi432mm previously and never seen this concentric ring issue before

andrea tasselli avatar
andrea tasselli avatar
Newton's rings. You need to tilt slightly the sensor to see them disappear or get another sensor/camera.
Nick Grundy avatar
Nick Grundy avatar
so I need to tilt the camera to remove the issue? (I think I heard of this before with the quark)

it sort of goes against every effort I've made in the past year though. smile

thanks, i'll try it
andrea tasselli avatar
andrea tasselli avatar
Yes. They sell a tilter unit for this camera.
Claudio Tenreiro avatar
Claudio Tenreiro avatar
Hi, Also I understand that the ZWO ASI432MM has a T2 tilter, exactly to reduce Newton rings, I wonder if you purchased as a set.
Best regards and CS!
Nick Grundy avatar
Nick Grundy avatar
Claudio Tenreiro:
Hi, Also I understand that the ZWO ASI432MM has a T2 tilter, exactly to reduce Newton rings, I wonder if you purchased as a set.
Best regards and CS!

It did come with the adapter for this. I had just never needed with any other camera I’ve used with the daystar. Is there anything unique with the 432 that demands it?
Claudio Tenreiro avatar
Claudio Tenreiro avatar
Nick Grundy:
Claudio Tenreiro:
Hi, Also I understand that the ZWO ASI432MM has a T2 tilter, exactly to reduce Newton rings, I wonder if you purchased as a set.
Best regards and CS!

It did come with the adapter for this. I had just never needed with any other camera I’ve used with the daystar. Is there anything unique with the 432 that demands it?

*I suppose that this camera is quite commonly used for the sun, and the problem with Newton rings is well known, particularly with the Quark. Daystar Filters do mention several times this issue and the needs for a tilter. The camera ASI432 is quite suited for the kind of images using the 4.2 Barlow (large pixel size) so I do believe they (ZWO) anticipated the problem and give you the tilter straight away.
Walter Leonhard Schramböck avatar
Walter Leonhard Schramböck avatar
As mentioned: tilt it! Some just use tape or a piece of paper glued to one side of the 1.25" nose-piece to tilt the sensor.
And: making flats is getting more important when tilting the camera to minimize gradients.
Nick Grundy avatar
Nick Grundy avatar
Is there a consensus on the best way to creat flats with the daystar? I’m guessing, but the only method I can think of is to defocus significantly while on target. How else can it be done? (Since I can’t generate my own flat field)
Engaging
Walter Leonhard Schramböck avatar
Walter Leonhard Schramböck avatar
Nick Grundy:
Is there a consensus on the best way to creat flats with the daystar? I’m guessing, but the only method I can think of is to defocus significantly while on target. How else can it be done? (Since I can’t generate my own flat field)

I bought a diffusion-cap from daystar. You also can use something cheaper than this, something that is translucent but not clear. Or you defocus, but if you have massive dustparticles in your optical train this might not be the best way.