New 1600MC Pro Smudges on Sensor

astrozark

Hello everyone,

In October 2018 I bought a 1600MC Pro (brand new still in box with shrink wrap and seal unbroken) from a seller on Astromart.

I have just begun to have the time to use the camera and I have noticed something weird that is on the sensor when I take flats. It is an oily or "wet" looking pattern on the top right of the Flats. Below is an image of 100 stacked, and very stretched Flats. I debayered the Master Flat to really show the pattern. It is also noticeable in the lower left portion of the image. These were sky flats with t-shirt, 15,000 target ADU, 0.11 sec. Oh, and I only use a field flattener and I removed it and just had the camera connected to the scope so that I could rule that piece out and it still showed up.

Master Flat with Smudges.jpg

Upon further investigation I took care to examine the glass cover over the sensor and then the sensor itself and finally I saw it. It is actually on the sensor!! It is hard to see unless you hold it just right but it's there. Below are two images: One that shows a closeup of the sensor with inverted colors to make it easier to see. And one with the Flat overlayed with transparency turned down. It matches

Sensor with inverted colors. Look in the blue area in the corner and there is a very light shade difference which is the pattern.

ASI Sensor.jpg

Here is the same image with the Flat overlayed to show where the pattern lines up.

ASI Sensor Flat Overlay.jpg

It's an oily substance that got on the chip during production or some kind of moisture from cleaning the chips during production?

I have the emails and images from the seller proving the camera was new and the original box never opened.

What should I do?

chad

Hi sir,

Sorry for the problem.

But I have to say, there is no way to solve it directly. It can only be corrected by processing with dark, flat fileds.

When we first received feedback on this problem, we were also very surprised. And think it is caused by us, but after a lot of test, it turns out that the sensor itself is the problem. Different sensor have different pattern, only a small part of the sensors is slight. Most of the sensors are the same as yours. So we asked sensor manufacturers about this problem, they were also surprised. They could repeat, and they are sure it is caused by them. But they did not want to solve it. they said: According to their product standard, this difference of color is within acceptable limits.

You know, for them, we are a very small customer. So there is nothing we can do. There's some speculation: This problem may be caused by manufacturing technology, and it will be very expensive to solve it completely. In addition, most users in other industries do not notice this problem.

So we can do nothing except say sorry to you.

In a word, only one good news, it could be corrected by flat fields, and flat fields are also needed for us. Sorry again.

Thanks

Chad

astrozark

Hi Chad,

I really appreciate the response you gave. So, is it something on the sensor that can be cleaned off? Or is it essentially "baked" into the sensor. I ask because I can actually see this pattern and it looks like it is a dried substance on top of the sensor?

Thanks,

Matt

chad

Hi Matt,

Sorry, the answer is no.

It's inside the sensor. We guess it's near the microlens, you know, for this kind of accurate thing, if there is no special equipment and guidance, disassembly will only lead to damage. So after we broke the two sensors, we gave up. So sorry again.

Thanks

Chad

astrozark

Thanks for getting back.

saguaro

I have a 2-nd generation 1600MC-C (not Pro). If it's any consolation, here is a master flat. I can tell you that it does calibrate out. I've been very happy with my 1600MC-C.

Capture-2019-01-08T19_02_33.jpg

Support@ZWO

saguaro wrote:

I have a 2-nd generation 1600MC-C (not Pro). If it's any consolation, here is a master flat. I can tell you that it does calibrate out. I've been very happy with my 1600MC-C.

Capture-2019-01-08T19_02_33.jpg

Thank you for telling us.