42 replies to this topic

[dhalgren]

Sorry, I wasn't clear. I was talking about how you attached the EAF to the focuser.

[dhalgren]

Everyone, especially Dr. Frankenkeim, I have been posting mini versions of my 70mm images on this thread. Is that OK? Or do you want it to be more HW-centric?

[Dr. Frankenkeim]

Everyone, especially Dr. Frankenkeim, I have been posting mini versions of my 70mm images on this thread. Is that OK? Or do you want it to be more HW-centric?

Of course - that's great!!!

[decep]

Sorry, I wasn't clear. I was talking about how you attached the EAF to the focuser.

Ah.  The ZWO EAF attaches with the included screws.  In fact, all of the example pictures in the EAF manual are the Meade 6000 70mm Quad APO.

[Dr. Frankenkeim]

Ah.  The ZWO EAF attaches with the included screws.  In fact, all of the example pictures in the EAF manual are the Meade 6000 70mm Quad APO.

That's neat- I just checked it out. 

[Dr. Frankenkeim]

Speaking of focus: I am curious about your experience with focus change in relation to temperature change with this scope. I use the HFD tool in APP to manually focus, and it seems as if a temperature change of 1 1/2 to 2 degrees F requires focus readjustment. However, in APP this seems to translate to relative minor HFD change of around ~0.15.

[georgian82]

Speaking of focus: I am curious about your experience with focus change in relation to temperature change with this scope. I use the HFD tool in APP to manually focus, and it seems as if a temperature change of 1 1/2 to 2 degrees F requires focus readjustment. However, in APP this seems to translate to relative minor HFD change of around ~0.15.

My experience has been 2-3 degrees and I see a significant change. I installed an auto focuser (Rigel NSTEP) and now I don’t worry about it anymore...I just set it to auto focus every 60 min abs nails it every time. This has been one of the best investments, especially during the winter months when I can start imaging relatively early because it’s dark but where I see a huge temperature drop.

For reference, after the auto focuser kicks in, I usually see a final HFR reading of 1.2 - 1.4 depending on the filter I am using.

[dhalgren]

Ah.  The ZWO EAF attaches with the included screws.  In fact, all of the example pictures in the EAF manual are the Meade 6000 70mm Quad APO.

The body of telescope in the manual looks like the Meade astrograph, but that is not the focuser on mine. Perhaps mine is older or newer. I really like the focuser on mine and didn't want to mess with it trying out different things. But as is being discussed, the image quality is very sensitive to focus so I definitely want to be able to autofocus.

ZWO manual:

Mine:

[Dr. Frankenkeim]

The body of telescope in the manual looks like the Meade astrograph, but that is not the focuser on mine. Perhaps mine is older or newer. I really like the focuser on mine and didn't want to mess with it trying out different things. But as is being discussed, the image quality is very sensitive to focus so I definitely want to be able to autofocus.

ZWO manual:

 

True - maybe they changed the focuser since the pictures were taken (mine looks like the one you have). I do like it as well, and I think the fine focuser is pretty good. However, our temperatures in SoCal changes a lot within a few hours and something automated would for sure be nice. How do you check your manual focus right now? I use HFD in APP and compare the images taken over a period of time (I backed into the ambient temperature change that way).

[dhalgren]

Right now I am using a Bahtinov mask manually, zoomed in on a nearby bright star (mag 2 or brighter if possible). I try to refocus at least every 5 degrees F. and after a meridian flip. I would like to automate and do it more frequently. Usually the weather here has most of the drop in temperature in the first few hours after sunset and it stabilizes after midnight. So I'll do 60 minute or less sequences early and 90-120 after a meridian flip. I generally choose objects that transit around 00:00-01:00. The other night I focused 3 times between 21:00 and 00:30 and twice between 00:40 and 05:00. Total temperature change was 39F at 21:00 to 24F when I started doing flats at 05:00. I have a weather sensor about 20' from the scope, I don't trust the forecasters we tend to run colder (and windier) than they claim.

[Dr. Frankenkeim]

Right now I am using a Bahtinov mask manually, zoomed in on a nearby bright star (mag 2 or brighter if possible). I try to refocus at least every 5 degrees F. and after a meridian flip. I would like to automate and do it more frequently. Usually the weather here has most of the drop in temperature in the first few hours after sunset and it stabilizes after midnight. So I'll do 60 minute or less sequences early and 90-120 after a meridian flip. I generally choose objects that transit around 00:00-01:00. The other night I focused 3 times between 21:00 and 00:30 and twice between 00:40 and 05:00. Total temperature change was 39F at 21:00 to 24F when I started doing flats at 05:00. I have a weather sensor about 20' from the scope, I don't trust the forecasters we tend to run colder (and windier) than they claim.

Completely agree - it seems as when you look at three different weather sites you get four different opinions. Even Google and Alexa can't seem to agree and they are off by 8+ degrees very frequently. I like the weather sensor idea and thought about it before. Are you generally happy with it?

 

I have a similar experience too. With our temperature change earlier in the night it seems as if refocusing every 60-90 mins (max) is what I need to do. It would just be nice to have a better measurement besides me looking at the latest exposures in APP and tracking the HFD of a pre-selected star over time.

[Dr. Frankenkeim]

Hello - are any of you using the Subframe Selector Tool in PixInsight? My FWHM statistics continue to be substantially larger compared to others you see on CN or YT.

 

Is this a function of the larger FOV and "larger stars" included in the image, which could increase the average?

 

If I use the Leo Triplet as an example you can see that I am pretty centered on the Trio:

 

 

If I then run the Selector Tool in PI I am getting, what at least seems like, higher FWHM readings. Do you see those as well when you image, for example the Leo Triplet?

 

 

 

 

[Dr. Frankenkeim]

Here is the Subframe Screenshot. You can also see the refocusing.

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[AdamLW1982]

Hello, please could I ask for some advice. I have a Meade Series 6000 70mm Astrograph and recently bought a ZWO EAF, which I believe is compatible. As you can see from the attached image, there is a focus tensioner screw and then a number of small grub screws. All grub screws are present so I’m trying to work out which ones I should remove in order to securely fix the EAF bracket? I cannot find any information relating to the purpose of each grub screw so am a little reluctant to start removing any of them. I do not believe fixing in place of the focus tensioner screw only is sufficient despite some people taking this approach. I feel there would be too much twisting action with only a single fixing point. Any advice much appreciated. Thank you in advance.

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[Dr. Frankenkeim]

Hello, please could I ask for some advice. I have a Meade Series 6000 70mm Astrograph and recently bought a ZWO EAF, which I believe is compatible. As you can see from the attached image, there is a focus tensioner screw and then a number of small grub screws. All grub screws are present so I’m trying to work out which ones I should remove in order to securely fix the EAF bracket? I cannot find any information relating to the purpose of each grub screw so am a little reluctant to start removing any of them. I do not believe fixing in place of the focus tensioner screw only is sufficient despite some people taking this approach. I feel there would be too much twisting action with only a single fixing point. Any advice much appreciated. Thank you in advance.

Hi Adam,

 

I just installed my new EAF to the MEADE this week. I did remove the focus lock screw (you would not need it since the EAF needs to move freely) and one more screw closer to the EAF to fix the plate.

 

The picture should show it more clearly. I am not sure if this is the "official" set up but it works fine.

 

Hope that helps.

Frank

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Edited by Dr. Frankenkeim, 03 September 2021 - 06:24 PM.

[AdamLW1982]

Hi Frank. Thank you for the guidance and photo also, this is very helpful. There doesn’t seem to be any official guidance that I can find but based on your experience, I’ll do the same thing if it’s working for you. Would be nice to know the purpose of each grub screw and I did try to contact Meade but no luck.

Thanks again.

Adam

[Dr. Frankenkeim]

Hi Guys,

 

Would you have any recommendations for a good IR / UV cut filter that you use with a OSC camera and this scope?

 

Thank you!

Frank

[Aerions]

Hi Guys,

 

Would you have any recommendations for a good IR / UV cut filter that you use with a OSC camera and this scope?

 

Thank you!

Frank

I found that the $20 amazon svbony uv-ir cut worked just fine for me! I didn't buy it specifically to image with the meade and my old 533mc pro. A dark sky trip came up and I didn't want to use an L pro for broadband so I just hoped for the best. Not a hint of violet fringing with a zwo autofocuser!