I'm using brand new EFW (7 positions, 36 mm unmounted) for few months and from the beginning encountered an issue with poor filter alignment accuracy. Took me a while to understand why lights not calibrated properly.
The issue explained exactly in following threads:
Tried to open the wheel and tighten all screws as advised in first thread - issue still exists.
Tried to perform init using 'Tool' utility as advised in second thread - issue still exists.
Attaching L channel master flat and calibrated light that demonstrates the issue.
Other filters suffering from same alignment accuracy issues.
I'm trying to resolve the issue with their technical support via email, but without success.
Their latest advise was to configure wheel to work unidirectional, however position offset after rotation still exists.
Just answered them via email. Will update here if any solution will be found.
Unfortunately I have had nothing but rain and clouds for over a month, so I can't even try the unidirectional setting.
If you want to test it in home environment you can test it using following method:
Rotate to problematic filter
Take ~10 flats
Rotate to other filters
Go back to problematic filter
Take another ~10 flats
Stack flats separately
Calibrate one stack with another
If positioning after rotation was identical to initial you will see clean frame, otherwise artifacts will appear.
I'm still trying to resolve the issue with technical support.
Currently waiting while their EFW team investigating the issue.
Asked to return the wheel and receive a refund - spent too much time trying to get things work correctly.
Found their support to be distressingly lacking as well. It is a good example how company lose their customers.
Meanwhile ordered Atik EFW - won't miss warm summer nights with good weather and clear sky because faulty wheel.
Works like a charm.
.I am sorry about this, but I have to tell you even if it is replaced, there will still be the same problem for you, it is a normal tolerance, which is acceptable for us and most of users.
And it has been a long time since the purchase. (3.5 month ago)
We offer a two-year warranty but replacements and returns are not included.
We suggest you sell this filter wheel in your side
THE FILTER WHEEL DOES NOR WORK!!!! Your product is inferior, or defective. Believe me, I will pass this one to ALL I know. My message will be stay away from ZWO because their products are cheap and do not work AS ADVERTISED. That's right, when I bought this camera I was told that the filter wheel would be accurate enough to take flats--I was told by the vendors and by ZWO people on this forum.
Thanks ZWO--for having the worst customer service of any vendor I have used--and I have used A LOT. Cheap Crap. You should be ashamed of yourselves.
Sean--you are not blameless. You are weak and toe the company line. pathetic.