Kubaman wrote:Hi there
my filters are on the proper side of course. The 36mm EFW do not have any holders or fixtures, you just drop the bare filter into the nest and attach by screws with washers. If you look around this forum you'll find out the issue is much more common and some people already sold their cameras due to filter reflection.
The problem is bond in my oppinion as the reflections in the sensor are visible only with specific situation as the filter reflections do. I suspect ZWO/Optolong filters and that's why I asked if ZWO could comment/do the tests with some fine filters for comparison.
I was reccomended ZWO filters so I bought them. I was not aware about the sensor glass reflecting to the filters and back. Now the question is if I should inwest in good filters (not happy of course) or I shoud sell the camera and buy QHY for example.
I redesigned my set up to increase the distance of the filter wheel to the sensor but yet could not tests it due to wheather. But I am pretty sure it'll impact vignetting, and I do not like such perspective. The first of two above pictures is made with 10" Newtonian, second with Canon EF 600 IS L lens. Clearily the issue is between ZWO components - EFW, filters and camera.
Hello there,
I think you may have misunderstood what I meant. The ZWO filters themselves have a correct orientation. So when you place the 36mm unmounted filter into the carousel, you need to be sure you have them oriented correctly. There is a specific side that should face the camera. This is not the case with other brand filters, such as Astrodon, where both sides of the filter are identical.
The glass on the sensor is not AR coated, and buying the QHY version will not do anything to solve this problem. They use the exact same sensors. In fact, I believe they get their sensors from ZWO anyhow. Regardless, the sensors themselves are not AR coated by Panasonic. Liklewise, buying the ATIK with the same sensor will do no good for this issue. The two problems need to be understood correctly (filters in the wrong orientation/coating issue vs sensor glass reflection).
The images you posted show the problem of either improper filter orientation or the lack of coating to the edge of the filter which causes the ringing pattern you see. This can be solved with masks around the filters, or purchasing different filters (i.e. Baader, Astronomik, Astrodon, etc). There is a lengthy thread on CloudyNights about this specific issue. I strongly suggest you read through it all:
https://www.cloudynights.com/topic/600525-flats-issues-with-zwo-filters-and-un-correctable-ring-artifacts/
The image posted by brandxlb shows the microlens reflection issue caused by bright starts and the missing coating on the sensor glass. This is something that either lower exposures or post-processing can resolve. This is not something anyone is going to solve directly, unless Panasonic starts coating the sensors, and since Astronomy is a low-demand hobby, that is not likely to happen. If your heart is set on the 1600, this is something you will need to live with, no matter which company you buy the camera from.