ZWO EAF Thoughts?

[JayTee]

Earlier this week I purchased the ZWO EAF along with the ZWO 1.25 5-position EFW both of which will do their duty on all three of my imaging scopes. Primarily on my ES 102 APO with dual speed focuser, my ES 80 APO with dual speed focuser, and my TPO 6RC with dual speed focuser. All my scopes are mainstream as is my EFW, so I foresee not a whole lot difficulties installing and implementing the EAF and EFW. All of this is for my ZWO ASI294MC Pro.

I also just purchased the OptoLong L-eXtreme, and the ZWO UV/IR Cut filters for the EFW. So I'm a bit excited to enter a whole new arena of imaging.

After starting the processing of my M33 data, I realized the image desperately needed Ha data which the L-eXtreme should provide.

Now for the fun part: I shopped around quite a bit looking for the items I needed at the best price. All the usual suspects were searched: Agena Astro, Highpoint Scientific, and Woodland Hill Camera to name a few. I had a difficult time locating the 1.25 L-eXtreme and then finally found it at All-Star Telescope in Edmonton. Well in the process of checking out to buy the filter and saw that shipping was sub $5 and (wait for it) NO tax, it was cheaper than everyone else here in the States. Not only cheaper but 2 times closer to me than the nearest U.S. store. I then promptly ordered all the other gear from them and saved enough for a beer party (for myself)! If all the stuff arrives here as ordered with no damage this store moves to the top of my list of preferred "Astro" stores.

[Juno16]

Nice!
Just to let you know. It’s been years since I installed an ZWO EAF on my Explore Scientific ED102, but I had to do something a bit different for installation. I really don’t exactly remember, but it was something simple like I had to purchase longer mounting screws than came in the kit. Just a heads up in case you run into that issue.
Man, enjoy your new stuff!!!
Your weather is definitely going to suffer!!!

[JayTee]

Thanks Jim,

ZWO on their website now has pictures on how to install it on the ES102ED. They even have a parts list you're going to need from Home Depot with SKU numbers. Doesn't get much easier than that. Unless of course it's included in the kit itself, which it isn't.

[CharLakeAstro]

Looks good Henk
Own (3) ZWO EAFs. 2 of them are 5V powered by USB, and 1 is the older 12V.
I very much appreciate the ability to focus from indoors while imaging. I have scripted re-focus between filter changes also... instead of doing filter offsets.

The one piece of advice I can offer EAF owners - never try to force the motor shaft eg don't try to manual focus with the EAF attached.
I have read that somewhere... and have been uber-careful not to with mine

[JeffBevan]

I am reading through this thread as I have launched into a setup using ZWO products for the first time, AM5, ASI2600 MC Duo and am considering the ZWO Eaf. I have a Stellarvue that I am setting up. I have been using a Starlight Instruments EFS for a couple years on my CAT and like it. Rather significant difference in price but after reading through this I will likely stay with Starlight Instruments.

[Jockinireland]

I am reading through this thread as I have launched into a setup using ZWO products for the first time, AM5, ASI2600 MC Duo and am considering the ZWO Eaf. I have a Stellarvue that I am setting up. I have been using a Starlight Instruments EFS for a couple years on my CAT and like it. Rather significant difference in price but after reading through this I will likely stay with Starlight Instruments.

What in this thread puts you off the ZWO EAF? I ask because I use them on three different set ups and find them excellent.

[JeffBevan]

More than anything the fiddlyness of the connection to the focuser. I don't really want to use an allen wrench to overide for visual. I appreciate, greatly the "Made in USA" of the Starlight Instruments products and after using them one on another OTA.

[AstroBee]

I too am having a difficult time understanding the problem folks are having with focusing with the EAF or any other electronic focuser that doesn't have a clutch.
Now it is one thing if you are a visual observer and imager. You want a focuser that has a clutch for when you are there looking through the eyepiece, but if you are only an imager (like me 98% of the time), using the EAF or Pegasus Astro focuser without a clutch is not a problem.
I can't speak to the ASIair folks because I use NINA and NINA has a very easy looping exposure routine that will allow you to manually (electronically) tune focus. What I mean by that is you open up NINA, set the exposure to 2sec or whatever time you need to see something depending on your filter use, then make sure the button is clicked to not save the image to your hard drive, then click the loop button and start. You will almost instantly see an image that shows your current focus. It will now update every 2 seconds. Go to the focuser tab and it will show your current focuser position. Let's say it's at 9800 as an example. I usually start with big adjustments, like 200. Press the IN or OUT button and your focuser will move out to 10000 or in to 9600. On the next 2sec update you will see focus get better or worse. make the appropriate changes until focus appears to your eye to be good. Then start an AutoFocus routine to dial it in perfect.
No problem doing the same thing when I change filters manually. It has actually taken me longer to write this post than to do a re-focus.

Now, as for using Filter Offsets, it is a game changer and huge time saver. PatriotAstro on YouTube has an awesome video that explains how you set them up but I'll try and explain it here as best I can without visuals.
1. First thing you want to do is for each of your filters, do at least 3 or 4 auto focus routines. Example - RED - 9805, 9800, 9810. The number is never going to be exactly the same because of focuser backlash. Now you want to find the average of those 3 numbers. Add them together then divide by 3 or how ever many routines you did. 9805+9800+9810= 29415/3=9805. (FYI - I ran 5 autofocus runs to get my offsets just to be sure.)
2. After you have done all of your filters you should have a list like this. (This is just an example)
Lum=9800
Red= 9805
Green= 9810
Blue=8997
Ha=9823
OIII=9802
SII=8995
3. Now you need to order these filters in order from furthest out to nearest. In this example that would be Ha,Green,Red,OIII,Lum,Blue,SII. The reason for doing this is to eliminate backlash by having your focuser always traveling in one direction.
4. So your filter offsets would be:
Ha=0
Green= -13 (Ha-Grn)
Red= -5 (Grn-Red)
OIII= -3 (Red-OIII)
Lum= -2 (OIII-Lum)
Blue= -3 (Lum-Blue)
SII= -2 (Blue-SII)
5. And now here is where the huge time-savings come into play. You do an autofocus routine ONCE for your first filter Ha and then start shooting. If I'm doing all six or seven filters I usually shoot 3 per filter 3xHa, 3xGreen, 3xRed, etc, etc. When the filter changes, the offset is auto adjusted without having to wait for another auto-focus routine that can take a couple of minutes to complete.
When I cycle back to Ha I do another auto-focus routine.

Of course the alternative is to shoot all of your Lum, focus, shoot all your Red, etc, etc.. But in doing this you run the possibility of weather interfering with your night, batteries going dead, any number of reasons your session might be interrupted. And now you only have partial data that cannot be processed until another evening when you can capture the other filters. Also, you will be shooting all of one filter when the subject may be at 30° above the horizon and your next filter at 40°+, next at 55°+
It's better to rotate filters more often.

This was an extreme example shooting all 7 filters in one night which I rarely ever do. I will usually shoot all of my RGB in one evening and then spend individual evenings on each narrowband. But that's because I'm usually targeting over 30 hours of data which I realize many people do not go that deep. If I'm doing my RGB in one night I'll use offsets and shoot 5-10x each filter, autofocus and repeat.