43 replies to this topic

[Procurion]

Just cruising the forums and saw your post. If you are truly interested in Astroimaging also, your first concern should be a motorized mount. The example of your telescope in photo shows a simple mount with no way to track a nebula/star/planet. Your next best move is to get a decent goto/motorized mount and a guide scope(which can be uber cheap). Though small and unassuming, you little telescope can image some fantastic pics with the right equipment. Do as you wish and hope to hear what you decided to do! Have a good one!

[Euripides]

Went out for a few minutes the other night to look at the moon. Clear skies but cold! Forgot to put the dew shield on. Immediately realized my mistake the second I brought it back into the house.



Doh!

If you had the shield on, would be this possible ? I haven't faced that yet, we have good temperature here at the moment (about 20deg in or out)

[Euripides]

Just cruising the forums and saw your post. If you are truly interested in Astroimaging also, your first concern should be a motorized mount. The example of your telescope in photo shows a simple mount with no way to track a nebula/star/planet. Your next best move is to get a decent goto/motorized mount and a guide scope(which can be uber cheap). Though small and unassuming, you little telescope can image some fantastic pics with the right equipment. Do as you wish and hope to hear what you decided to do! Have a good one!

I suppose that you are not referring to me, correct? Cause I haven't uploaded my gear in a photo :-)

 

Just for the record, I do have the AZ GTI mount and probably I'm gonna proceed with the SW 127mm that anyone here love :-) I suppose it would be the best value for money move at the moment with my current gear.

 

One step at a time. It would be great if we all had money, space, a non yelling wife  so we can afford probably a SW 180.

[gfstallin]

If you had the shield on, would be this possible ? I haven't faced that yet, we have good temperature here at the moment (about 20deg in or out)

It will happen every time it is cold outside, regardless of whether or not you used a dew shield. Water vapor in the warm air in your house will condense on the cold corrector and anything else that had been placed outside. This is like the water that condenses on a cold glass of water on a hot, humid day. Condensation on the telescope is a fact of life for those of us in colder climates. As I'm sure you noticed, it dissipates quickly as the telescope warms. 

 

George

[Bowlerhat]

Based on the long thread, some has mounted a C6 and even overloading it, yet still get good tracking result. However there are also cases where it just can't take much loads without gear slipping.

 

I would get a lighter 5" mak instead.

[cupton]

It will happen every time it is cold outside, regardless of whether or not you used a dew shield. Water vapor in the warm air in your house will condense on the cold corrector and anything else that had been placed outside. This is like the water that condenses on a cold glass of water on a hot, humid day. Condensation on the telescope is a fact of life for those of us in colder climates. As I'm sure you noticed, it dissipates quickly as the telescope warms. 

 

George

Yea, there was no sign of dew actually when I was observing. It was cold out but it was dry. I had a couple of EP's sitting out as well and all was good till I brought it all in the house. It literally took seconds for it to fog up like that. I just let it sit out all night uncovered and capped everything the following morning. I don't think a dew shield would of done a darn thing even if it was on. Might of cut down the glare of the moon a bit but that's about it. It was cold, but it was probably some of the best views I have seen of the moon with the scope.

Edited by cupton, 14 November 2019 - 09:09 AM.

[mic1970]

I'm a fan of the Celestron 4" mak.  My buddy has one, and I "borrow" it whenever I can.

[Auburn80]

Yea, there was no sign of dew actually when I was observing. It was cold out but it was dry. I had a couple of EP's sitting out as well and all was good till I brought it all in the house. It literally took seconds for it to fog up like that. I just let it sit out all night uncovered and capped everything the following morning. I don't think a dew shield would of done a darn thing even if it was on. Might of cut down the glare of the moon a bit but that's about it. It was cold, but it was probably some of the best views I have seen of the moon with the scope.

Yep. And that's something I have to deal with in the summer here in the deep south. My optics are usually at 75°F and if I dont wait for a warm up, I'll get condensation if I expose the scope to typical 90° with 75% humidity around dusk.

[fcathell]

The Synta 127 Mak and the C-6 OTAs weigh pretty much the same. The C-6 is hard to beat from an aperture/weight factor.

 

FC

[charlesgeiger]

When you bring your scope in from a humid atmosphere you should cap the scope before bringing it inside.  Then in an hour or so you can uncap and look at it; it should be free of dew.  Of course one can have a dew heater on the lens (miniscus or corrector) which should eliminate during use...but always cap before bringing in.  Also, if your tube has a lot of dew on it, take a soft towel and dry off after capping and before bringing it in the house too.

As has been mentioned, if you do planetary photography you should have a mount which is up to the task.  Trying to take an exposure when the optic is not completely still will always give reduced results.  And it is a good idea to have the scope polar alligned and tracking for best results even if your exposures are very short.

Charlie

PS You would want at a very minimum a 5" aperture cat for enough resolution.

[mic1970]

Charles.... why does one do that? 

When you bring your scope in from a humid atmosphere you should cap the scope before bringing it inside.  Then in an hour or so you can uncap and look at it; it should be free of dew.  Of course one can have a dew heater on the lens (miniscus or corrector) which should eliminate during use...but always cap before bringing in.  Also, if your tube has a lot of dew on it, take a soft towel and dry off after capping and before bringing it in the house too.

As has been mentioned, if you do planetary photography you should have a mount which is up to the task.  Trying to take an exposure when the optic is not completely still will always give reduced results.  And it is a good idea to have the scope polar alligned and tracking for best results even if your exposures are very short.

Charlie

PS You would want at a very minimum a 5" aperture cat for enough resolution.

[gfstallin]

Charles.... why does one do that? 

Placing the cap on a cold telescope before bringing it inside can prevent dew from forming on the corrector or lens when you bring it inside. The caps aren't air tight, so dew can still form with this method, but if your cap is tight enough, it might work. It really hasn't worked with my Celestron SCTs, but a different cap design (like on the SW Maks) might produce better results. 

 

George

[Shorty Barlow]

In my experience with SW Mak's or even refractors with thread on lens caps dew still forms as soon as the OTA is moved from a cold environment to a warm one.

[gfstallin]

When you bring your scope in from a humid atmosphere you should cap the scope before bringing it inside.  Then in an hour or so you can uncap and look at it; it should be free of dew.  Of course one can have a dew heater on the lens (miniscus or corrector) which should eliminate during use...but always cap before bringing in.  Also, if your tube has a lot of dew on it, take a soft towel and dry off after capping and before bringing it in the house too.

As has been mentioned, if you do planetary photography you should have a mount which is up to the task.  Trying to take an exposure when the optic is not completely still will always give reduced results.  And it is a good idea to have the scope polar alligned and tracking for best results even if your exposures are very short.

Charlie

PS You would want at a very minimum a 5" aperture cat for enough resolution.

Admittedly, I always polar align, but folks have achieved excellent results with alt-az mounts and I've seen some amazing images from a couple planetary imagers who manual tracked the object. I would never suggest anyone try manual tracking, but alt-az tracking with no polar alignment is fine. When you get to sufficiently long focal lengths (I image with a C11 and 5 meters of focal length or more), the best polar alignment will not always keep the image in the FOV for more than a few minutes. You can also track the object within FireCapture, alt-az like the AZ-GTi or equatorial, so that the object stays within a set range in the FOV. 

 

George

[gfstallin]

In my experience with SW Mak's or even refractors with thread on lens caps dew still forms as soon as the OTA is moved from a cold environment to a warm one.

Yeah, that method has never worked for me either. I've tried it to no avail. I just make sure to place the OTA in the warmest area of the house so that the dew evaporates quickly. My wife knows I've been out imaging when she comes downstairs and sees an OTA, eyepiece case, and imaging accessories laid out in the middle of the living room floor to dry. The first thing in the morning I hear from my wife after a night of imaging is "So can we clean this up? I didn't want to touch anything." She doesn't touch anything like corrector plates or eyepiece glass, so I always count it as a minor victory. Sometimes she'll even ask how imaging went.  

 

George 

[gfstallin]

 I have the Orion Mak 150 and the az-gti head on a sturdy mount can handle  it. It's not 100% rock solid, but for visual observations it's manageable. 

I am attaching some cats & casses

Wojtek, 

 

This reminded me. One person found this setup to be more stable with a 5 kg payload: 

https://www.cloudyni...-counterweight/

 

I'm not sure the added weight makes the additional stability worth it, but since you already added that fine-looking tripod, I'm assuming you were not too concerned about an extra kilo here or there. 

 

Out of holiday-season gift request curiosity, which tripod are you using there?

 

George 

[Woj2007]

George,

 

Thank you for finding this thread, I might actually mount the counterweight to make the setup more balanced and stable.

 

The tripod / pier I am using comes from my first Newtonian telescope (6" f/6) from 1993, made in Poland. All metal, 24 lbs. 

 

Wojtek, 

 

This reminded me. One person found this setup to be more stable with a 5 kg payload: 

https://www.cloudyni...-counterweight/

 

I'm not sure the added weight makes the additional stability worth it, but since you already added that fine-looking tripod, I'm assuming you were not too concerned about an extra kilo here or there. 

 

Out of holiday-season gift request curiosity, which tripod are you using there?

 

George 

W 

[Euripides]

Finally is here :-)

 

Oh G, the 90 seems like toy now :-P

 

 

 

Probably it had a rough ride cause needs certainly collimation. Also I can see some debris but I hope this will not be an issue.

 

 

 

 

 

 

 

Edited by Euripides, 02 December 2019 - 04:33 AM.

[cupton]

Woot woot! Congrats! Looking forward to hearing your thoughts on it.