Have you Had to Replace your Desiccant?

Dried the desiccant 3 times in the microwave, but now I will replace it with new ones. 

Really nasty to keep the sensor clean. Even polls are clearly visible. You should do it in winter season. I had to clean the sensor more than two dozen times after opening it. The problem you see particles only when you take flats. That means: attaching it to the scope, test, dismantle it, and start from the beginning. I was wearing gloves and worked und a magnifying glas all the time. But you won’t see the tiny particles. 

The only way for me to get the sensor and front glass clean, was to use Scotch adhesive tape to pick up all particles. Blowers, brushes and wet cleaning were not sufficient. Only the tape was able to remove all that dirt. 

Also try to avoid to put the camera upright after cleaning. Only screw on the front cap on the body in vertical position in order to avoid that small particles drop on the sensor again.

Also I had noticed that the screws were over tightened by ZWO. I could almost not remove them. They are also of low quality. They wear off quickly. I have replaced ALL of them by higher quality. Also the screws which attach the EFW to the camera by a millimeter longer ones, since the original screws are way too short, when working without the tilter. They damage the joint. 

Hope that helps.

CS
Rüdiger

I came from ATIK and it was a disaster. After 3 unsuccessful repair attempts in England I had returned the camera and got my money back. The had debris in the sealed argon chamber. Total messed up design. The mechanical shutter disintegrated.
 
QHY might be an alternative to consider. Meanwhile their software is quite usable and they have also a sealed chamber. This would be my choice. Consider the QHY600.

I am in a very humid environment and have given up on the desiccant drying cycle on my ASI6200 cameras.  As suggested on CN, I bring the temp down to 2 degrees over 10 mins and leave it there for 15 mins or so.  Then I lower to -5 slowly over 10 mins and pause then take it down to -10 where I image.   It takes a bit of planning but this sequence usually avoids the dreaded frost.

I’m having a lot of issues with dew on the sensor with my 6200mm. The dew heater doesn’t not help with the dew on the sensor; it only heat the optical window. Cooling down slowly doesn’t help either. I now need an hour before imaging just for the dew to clear.

I have opened the cover a few times and baked my desiccant, but I could never get a completely clean sensor, and the dew issue persists. I have bought a special brush for cleaning 36*24mm sensors and will try to dry the chamber one more time with a hair dryer this weekend.

Yuxuan:
I’m having a lot of issues with dew on the sensor with my 6200mm. The dew heater doesn’t not help with the dew on the sensor; it only heat the optical window. Cooling down slowly doesn’t help either. I now need an hour before imaging just for the dew to clear.

I have opened the cover a few times and baked my desiccant, but I could never get a completely clean sensor, and the dew issue persists. I have bought a special brush for cleaning 36*24mm sensors and will try to dry the chamber one more time with a hair dryer this weekend.

Well, this was my fear.  Basically the design is bogus... Looks like 3+myself out of 8 are hit with this. 

I know Gary Imm has pulled this off, but every 8 months?

Yuxuan:
I’m having a lot of issues with dew on the sensor with my 6200mm. The dew heater doesn’t not help with the dew on the sensor; it only heat the optical window. Cooling down slowly doesn’t help either. I now need an hour before imaging just for the dew to clear.

I have opened the cover a few times and baked my desiccant, but I could never get a completely clean sensor, and the dew issue persists. I have bought a special brush for cleaning 36*24mm sensors and will try to dry the chamber one more time with a hair dryer this weekend.

Well, this was my fear.  Basically the design is bogus... Looks like 3+myself out of 8 are hit with this. 

I know Gary Imm has pulled this off, but every 8 months?

I’ve also learned to accept dust particles on the sensor. Flat frames take care of them very easily and they don’t move over time.

John Dziuba:
I am in a very humid environment and have given up on the desiccant drying cycle on my ASI6200 cameras.  As suggested on CN, I bring the temp down to 2 degrees over 10 mins and leave it there for 15 mins or so.  Then I lower to -5 slowly over 10 mins and pause then take it down to -10 where I image.   It takes a bit of planning but this sequence usually avoids the dreaded frost.

Me too near San Francisco.

I edited my startup script to start at 0 and then to go to -5 in 1 degree steps every 5 minutes.  This programming extravaganza failed miserably.  How slowly do you go from 2 to -5. 

I can reproduce any recipe now that I have the basic programming done. 

Looks like:

Ambient down to 2 over 10m.

Wait 15 m.

2 down to -5 over 7 steps each 5 minutes wait.  (> 10m).

If I make it here, will worry about -10 later.

Very irritating because this worked fine for 10 months.

 I used to do 0 first as well, which worked for a while but then frost began to start at 0. I suspect that as the humidity in the chamber rises (my rig stays covered outside most of the time) it gets more susceptible. So I use 2 now  (even 5 sometimes) and that seems to work. I do it manually so not as precise as your plan. I find the most crucial step is the first. So I try to power up at twilight and just let it sit at 2 for a long time. At least 15 min though.

I also have this issue with my 6200 and I live in a very humid environment. I simply cool to -5 an hour or so before I image.  I’m using Voyager and have tried the various slow cool down options. One thing I noticed is when using ASI V2 SDK in Voyager is that the cooler lowers the temp much slower than the original SDK. Not sure if this helps but it’s no issue to just cool down the cam and wait. 
I have also microwaved the desiccant and yes it’s tough to get the sensor clean. Took me a few tries. 
This issue only happens with humid conditions. In low humidity it’s not an issue. 
This also happened to my older cameras in humid conditions. QSI 583/683 and STL 11k so it’s not a bad design issue. I had to let all of them sit for an hour. What is much easier to do with the old cameras is change or refresh the dessicant although it didn’t seem to make much difference. 
So best practice is to slowly cool and wait.

John Dziuba:

Yuxuan:

John Dziuba:

John Dziuba:
I am in a very humid environment and have given up on the desiccant drying cycle on my ASI6200 cameras.  As suggested on CN, I bring the temp down to 2 degrees over 10 mins and leave it there for 15 mins or so.  Then I lower to -5 slowly over 10 mins and pause then take it down to -10 where I image.   It takes a bit of planning but this sequence usually avoids the dreaded frost.

Me too near San Francisco.

I edited my startup script to start at 0 and then to go to -5 in 1 degree steps every 5 minutes.  This programming extravaganza failed miserably.  How slowly do you go from 2 to -5. 

I can reproduce any recipe now that I have the basic programming done. 

Looks like:

Ambient down to 2 over 10m.

Wait 15 m.

2 down to -5 over 7 steps each 5 minutes wait.  (> 10m).

If I make it here, will worry about -10 later.

Very irritating because this worked fine for 10 months.

 I used to do 0 first as well, which worked for a while but then frost began to start at 0. I suspect that as the humidity in the chamber rises (my rig stays covered outside most of the time) it gets more susceptible. So I use 2 now  (even 5 sometimes) and that seems to work. I do it manually so not as precise as your plan. I find the most crucial step is the first. So I try to power up at twilight and just let it sit at 2 for a long time. At least 15 min though.

John, what is the waiting time before imaging with your procedure? I use NINA to cool to -10 within 10 minutes, and it takes me an hour in total to reach readiness. I wonder if how many steps the sensor takes to reach -10 really matters.

No less than 15 mins and usually about 30 mins.  Like I said, the first step seems to be most important.  After that first pause I rarely get the frost buildup as long as I step down over 10-15 mins.  I hear the QHY is a sealed chamber?  If this truly is not an issue there, I will go that way for the next one.  Regarding Jerry's comment about the "drops" sitting there, I think the spots that appear are actually ice crystals not wet condensation.  When they do appear I take it up to +10 and they disappear quickly.  Then start the cooling process again.  In my experience the flats so not do a good job removing them, because it is not a static feature.  Even if the ice forms and you do nothing, it gradually sublimates away.  So you end up with some frames with the ice n various phases and most without, and they are not on the flats.  So you really have to make sure there is no frost before you capture a frame.

If your procedure only takes 30 minutes, that’s great and I’ll try it next time.

By zooming in a lot, I see that that the frosts affects the image at individual pixel level. This makes me wonder if it’s possible to take care of it in post processing.

Jerry, imaging here in Texas in a humid environment, I have had frost issues with multiple ZWO cameras.  My experience:

- New cameras are typically no problem for at least a year, until the tablets are overwhelmed.
- Dropping the cooling in increments works for a while, but eventually the internal humidity becomes too high even for that.
- Drying the tablets in the microwave works for a while, but doesn't recharge then "like new".  Because of the hassle in changing out the tablets (see below), I always just replace with new ones.
- Replacing the tablets is a pain because of the dust which always will be left behind.  I have found that I need to be pretty aggressive (i.e., pressing hard) in using a new sensor cleaning swap on the inside of the protective cover glass.  Sometimes it takes several cleaning attempts to get glass which will result in usable flats.

I have a temporary setup and I no longer keep my camera outside unless it is in use, which seems to have prolonged the changeout intervals.

This problem has lots of variables, all related to the humidity level and how much exposure that the camera has to it, so each user here will have a different experience.

Bruce Donzanti:

Gary Imm:
Jerry, imaging here in Texas in a humid environment, I have had frost issues with multiple ZWO cameras.  My experience:

- New cameras are typically no problem for at least a year, until the tablets are overwhelmed.
- Dropping the cooling in increments works for a while, but eventually the internal humidity becomes too high even for that.
- Drying the tablets in the microwave works for a while, but doesn't recharge then "like new".  Because of the hassle in changing out the tablets (see below), I always just replace with new ones.
- Replacing the tablets is a pain because of the dust which always will be left behind.  I have found that I need to be pretty aggressive (i.e., pressing hard) in using a new sensor cleaning swap on the inside of the protective cover glass.  Sometimes it takes several cleaning attempts to get glass which will result in usable flats.

I have a temporary setup and I no longer keep my camera outside unless it is in use, which seems to have prolonged the changeout intervals.

This problem has lots of variables, all related to the humidity level and how much exposure that the camera has to it, so each user here will have a different experience.

Hi Gary

This is good info and interesting.  My 6200 went about a year before the dreaded droplets appeared.  What I am doing (as I mentioned earlier in this post) , is I simply turn the dew heater on, let NINA drop the temp to -10 (-5 in the summer) and wait about 1 hour.  That is it and it works fine.  And the humidity in Florida is second to none as I know from living in many cities throughout the US. I know Uwe (also in Florida) does what I do and his also works fine.  I hope it stays this way as I don’t think I have your courage to open it up to replace the tablets and deal with the dust, etc.  I already had to open the back casing of my 2600 to tighten up the circuit board so my plugs would stay installed.  It is really getting ridiculous with these expensive cameras what we have to deal with.  I’ll stop there before I go into a rant.  Thanks again for the info buddy! 

Bruce

Well, I vote that San Francisco (Fog City) has even more humidity. 

I am trying to recover from the shock of learning that not only might I have to open the case but will have to do my field flattening over again.  I have a very flat field. 

I am pretty much at a loss for words but have programmed into my startup script a 50 minute cool down period: 15 minutes to go down to 2 and 35 minutes to go down from there to -5 in 1 deg increments.

If this does not work I am going to run at 0-2 and use software noise reduction as I just cannot face this as a recurrent task, as I was worried about the problem of dust off the desiccant itself... at least my images are clean.

Gary, wonder if you have any opinions on the ATIK ATX 60.  My Vendor would like to sell me one and take the 6200 back in a trade.  Others here are not impressed with that hardware either. 

QHY maybe?  There system does not inspire confidence either:

https://www.manualslib.com/manual/2202560/Qhyccd-Qhy600.html?page=21

A problem you cannot buy your way out of?

2 more things I should have mentioned:
- I use a dew band heater wrapped around the camera and moved up against the filter wheel.  This has definitely helped.  For me it was easy to do, since I need a dew band system anyway and I just added another band.
- I run at -5C in the summer.  I used to push it lower but -5C seems to result in good images and reduce the risk of frost.