SW EvoStar 72ED + EAF with DSLR?

[AstroViking]

Hi all,

Now that I have my setup under control and working the way I want it to, the next upgrade is looming on the horizon. My eyes are not as good as they could be, and I am having trouble getting perfect focus. So I'm looking at getting an EAF to do all the hard work for me.

My biggest concern is compatibility - the scope is an 'old model' EvoStar 72 with the long tube. I am using the SW 0.85 reducer with it, and when I have focus, there is about 5mm of focus tube showing.

I've had a search through various AP blogs and forums and found someone with an EvoStar 72 using an EAF with no problems at all, but no indication which model of 'scope he has.

Is 5mm of tube showing going to allow enough travel such that an EAF will function?

Given I'm still using a DSLR for imaging, (which is controlled by Ekos, too), I presume using the EAF with the DSLR could be a slow process? It already takes 6 seconds to write the image to the SD card and then download it to Ekos after the shutter closes...

Am I better off saving my pennies for a dedicated OSC astro cam and then getting the focuser?

Many thanks,
V

[The_bluester]

I can't answer how much focus travel will be needed with Ekos, but I think that is about the travel I had with my original Evostar 72 and Sequence Generator Pro focused OK with it.

The only thing I had to do with mine was linish down the outside of the flexible coupler I used as from memory it fouled on the inside of the focuser housing and needed a mm or so reduction in diameter to avoid it fouling.

[AstroViking]

Thanks for the reply, Paul. Now I just have to keep my eyes open for an EAF.

Cheers,
V

[AstroBogan]

Couldn't recommend the EAF enough. I just added one to my ZS81 and it is honestly a game changer. Setting it to AF every 30 mins-1 hour is a game changer for me, which meant I didn't have to struggle in the cold if I needed to refocus :rofl:

If you can get it to work, do it. It is worth every cent in the long run.

[AstroViking]

Hi Jacob,

Thanks for the "push" to get an EAF. :)

Can anyone recommend a suitable brand / model? Preferably something that is reasonably priced, modular and doesn't require a 12v supply (ie, USB powered).

From my looking around, this seems to narrow the field down to the ZWO unit. Are there any others that match my criteria?

Thanks,
V

BTW - not afraid to assemble a kit / DIY unit, either.

[oska]

I think the EAF is the only 5V so far. All the DIY ones I've looked at were all 12V. My old eyes love the EAF. You have to get one. Tell the Boss I said so, it's for you eyes and I know a doctor ;) It was recommended to me with high enthusiasm and they were under stating it.

[The_bluester]

I can't comment on anything but the ZWO unit (Which is the one actually branded "EAF") but I have had one for about four years (the older 12V version) which has been on three different scopes and is still performing perfectly.

The only issue I would see with it is that the internal temperature sensor reads higher than the other sensors around it, it is probably warmed slightly by being inside the unit with the electronics. As a focus trigger for automated focus that does not matter as you are looking for a change in temperature, not an absolute temperature.