FD-M42 Filter Drawer - Light leakage

mchast

I recently purchased the FD-M42 Filter Drawer and an ASI533MC camera and today I started building my dark and flat's library. I know the 533MC shouldn't need the dark's but I wanted to run through the process. I've found a problem though, there's a bunch of light coming in through the filter drawer. I have re-seated it a few times and still I'm getting some light leakage shown in the ASIAir preview with the histogram stretched. I just wrapped some gaffer's tape around the filter drawer to "fix" it. Is there something else I can do or is this a limitation of filter drawers in general?

Any suggestions would be welcome. Thanks.

Support@ZWO

Could you please share us some pictures to show the light leakage?

monty87

I just recently bought the zwo filter drawer to along with asi533mc and asi2600mc. Last night on my first run, I notices light leak as well and narrowed it down to the filter drawer. Attached is jpg image showing the leak.

monty87

Here is the test image from a dark sub. I also verified it is the filter drawer that was causing the light leak. If I use gaffer tap and some black microfiber cloth to completely cover the filter drawer sides, the light leak stopped.

keramos

monty87

this is a bit concerning, as I ordered mine two weeks ago.

Did you get any feedback from ZWO?

monty87

Unfortunately I have not received any feedback yet. I sent them a support email referencing this post, about a week ago, but have not heard anything yet.

Takhell

This is a bit late for this discussion, but I believe I have the same issue - I started to notice a lot more light noise in my longer exposures (concentrated in the center). I initially just chalked it up to me being a beginner at this. But after going thru the forums, it was noted that this is an issue with this filter drawer. Out of curiosity, I took 2 x 300s darks for comparison. 1 with the drawer in the train (no filter in the drawer) and one without the drawer. Camera is 294MC pro. See the images for the results, but it was a drastic difference. It at the least explains why I'm having such a hard time with post processing anyway. I'm going to try to add some sort of 'seal' around the outside of the main ring (plumbers tape maybe) to see if that helps.

rcolman

I also have light leaks in my filter drawer. Dont they test their own products?

Tech@ZWO

Hi all, we'd like to make an explanation for the whole problem.
After confirming with our devs, the filter holders of M42 filter drawers are designed with lips. Though there are some filter holders in one certain batch are produced without lips, it would not result in the gap like what showed in this post, which means they can be used smoothly and effectively.
The gap occurred in the picture above was just a rare example and was caused by the incompatibility between the filter holders and drawers. We sincerely apologize for the inconvenience it caused if you happen to get the defective one - please contact our dealers or the customer service of ZWO for an exchange.
Please rest assured that the rest filter holders in stock all have the lips.

kelsastro

Hi tech@zow
I got a draw around 12mths ago and have only just got around to stat using it and it has the light leak problem is there anyway of getting a replacement still?

Regards kelsastro

Tech@ZWO

kelsastro
If you buy it from a dealer, please contact dealer. If you buy it from ZWO, please submit this in https://support.astronomy-imaging-camera.com/(attach your invoice and picture of the problem)

FloridaJoe

OR, you can do what I did. I just bought some 2" wide velcro and wrap it around the tray when using it and it keeps any and all light out. I really only need to wrap it when doing dark and bias frames during daylight hours, but I wrap it when doing light frames at night as well just to be sure. I also have a fear of the filter holder & filter falling out of the tray while slewing or the scope positioning with the filter & holder facing downward. No fear with velcro.