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Old 18-07-2018, 01:41 PM
Adam101 (Adam)
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Help with focusing

Hello, I have posted on here before that I couldnít get objects like mars or Jupiter to focus. I have waited for a perfect atmospheric conditions night like tonight to make sure it was not that. It isnít. So here is my question. What am I doing wrong I just canít get anything other than the moon to focus. I donít know if there are smaller focusing knobs that I canít find or something but this is my telescope. Please give any and all suggestions thanks.

Link to telescope: https://www.amazon.com/Computer-Cont...ector+telesope

This is all the same except for the usb camera.
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  #2  
Old 18-07-2018, 03:24 PM
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Atmos (Colin)
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One of the good things about astrophotography is that everything in the Sky has the same focus point.
If you achieve good focus on the moon then you are in focus for all planets and stars in the sky.

The times that the above statement is not correct is:
1) As the ambient temperature drops you do need to refocus but you are still in focus for anything in the sky.
2) There is some mechanical slippage (usually the focuser) when moving away from the moon.

Looking at your setup, I would suggest that your problem is magnification. If you achieve good focus on the moon and then point it at a planet, the planet is in focus but it is very small and not showing detail.
What you may need to invest in is a Barlow to increase your magnification for the planets.
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Old 18-07-2018, 04:55 PM
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mental4astro (Alexander)
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If you got to scope to focus on the Moon, the scope will also focus on everything else. It isn't selective on what it will and will not focus on.

Try focusing on the Moon again. Then, WITHOUT touching the focuser, move the scope on to the planets. If you haven't touched the focuser then everything else will be focused too.

I do remember your first thread asking for help.

Come to think of it, are you actually getting your scope to focus on the Moon? You said you did. Is the image razor sharp with the craters nice and detailed? There isn't any way possible for the Moon to fucus and not the planets.

Of course I do not know your experience with scopes, so I need to ask what your expectations are with planets? They will appear really small in your scope, and nothing of the scale and detail you can see with the Moon. If you knew this, then my apology.

Many people think that they will see the planets in the same way seen in photos from space probes or in those posted in this forum. You won't. These photos are all highly processed and using very sophisticated gear. Visually the planets are always small and the amount of detail we can see is dictated by the prevailing atmospheric conditions.

GGive the Moon another go, and then move onto say Jupiter next. DON'T TOUCH THE FOCUSER. The image cannot be in focus with the Moon and then not with the planets or stars.

Last edited by mental4astro; 20-07-2018 at 08:32 AM. Reason: Typo
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Old 18-07-2018, 06:18 PM
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doppler (Rick)
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Another thing to consider is that the planets are a lot fainter than the moon so you need to increase the gain or iso or lower the frame rate or you wont see much at all.
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Old 18-07-2018, 11:08 PM
astro744
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Are you using visual or via a camera. You say that your telescope is the same as the link you show except for the use camera. All the current advice is astrophotography related.

The advice on not touching the focuser once focused on the Moon when switching targets to another object is good except that if you were using a high power eyepiece you will have trouble aquiring a planet without first switching to a low power eyepiece which will more than likely require a focus change.

If visual What eyepiece have you used to focus on the Moon, I.e. What magnification were you using? Did you try the same eyepiece on planets? Have you tried other eyepieces?
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Old 19-07-2018, 11:20 AM
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mental4astro (Alexander)
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My writing was all visual related!

But it stands for both visual and photo.
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Old 23-07-2018, 02:01 AM
Adam101 (Adam)
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Thanks guys, I will definitely try not touching the focuser when switching. But I was using about 17mm eyepiece on the moon and is a 6 inch scope. But what Iím worried about is if I use the same eyepiece for planets it will be too small to see anything but a blob so how do you guys go from a smaller magnification to larger and do you have to focus it.
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Old 23-07-2018, 09:21 AM
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Allan_L (Allan)
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YES. a 17mm eyepiece in a 6" DOB will allow you to find the planet and centre it. You should get a clear (albeit small) image.
Then you increase magnification, either by adding a barlow (say 2x) or a lower number eyepiece.
I was looking at Jupiter, Saturn and Mars last night.
I am at a reasonably dark location, but not totally ideal.
I have a 10" DOB (Focal Length 1200)

The images were all fuzzy.
I was using a 12mm (TV Radian) with a 2x Barlow(Orion shorty-plus).
Yes you need to re-focus (generally) when changing eyepieces or adding a barlow.
Best advice is to focus on a near by star, until the image is as small as possible. (ie turning the focus nob further results in de-focusing the star and the image bets bigger and blurrier). [For Jupiter focus on a close moon].
At that point the scope is focused and you can then concentrate on the planet.
For me, that gave a magnification of 200 (Being1200/12 )*2
The image was wishy washy and not at all sharp. hard to make out detail.

Next I tried a 9mm (TV Nagler). - NO Barlow.
This gave me 133 magnification. (Being 1200/9)
The images were pretty small, and still not really sharp.
You could just make out the bands of Jupiter, but a novice I was with could not, nor could she determine the Cassini division in the rings of Saturn.

What I am getting at is that maybe you are expecting too much from your scope, especially where the atmospherics are far from ideal.

A week ago, at our Dark Site, the images using the same equipment were razor sharp and detail at 200x was rather good. (But not for Mars which is experiencing a planet wide dust storm which makes it look like a blurry featureless ball.

Sorry for rambling, but I hope relating these experiences helps you to understand the limits of planetary viewing.

I think your scopes Focal length is the same (1200)
So your magnifications would be similar for similar strength eyepieces as I mention.
I suspect your best planetary viewing would be at around 150 times (ie an 8mm Eyepiece or 16 with x2barlow),Plus or Minus!

Regards
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Old 23-07-2018, 02:06 PM
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mental4astro (Alexander)
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Adam, you may find it very helpful if you look for an astronomy club near to where you live. There you will be able to take your scope along and the good folk will be only too happy to show you how to use it and get it humming. Sometimes having someone actually show you what to do is better than all the ranting we can write down - it can get overwhelming and confusing.

From your last post I see that you need to familiarize yourself with the most basic of telescope functions, such as how eyepieces relate to the scope, what all the different eyepieces do, and how to use them. I fear that you might be feeling overwhelmed and what we are posting here might be too technical for where you are at in your astro experience - we can sometimes forget that we also started out not knowing anything too, and came only armed with enthusiasm and curiosity. Sometimes having someone patiently show us and talk to us is the best key to get us sorted out And the very last thing I want to do is throw a whole heap of tech talk that will only bamboozle you even more. This scope thing is not difficult at all, and it just sometime needs a little tweak for it to all click. If you are not used to the metric system of measurements it can get even more confusing. At the same time, I can also see that you are most keen and excited on using your scope, and your enthusiasm is half the battle won!

The planets are all so very far away that no matter how much magnification we throw at them, their image in the scope will never be very big. However, for despite the small image size, if your scope is set up well your eyes can pick up a fabulous amount of detail in those small images in the eyepiece.

Don't feel discouraged. We all want you to have a great experience with your much prized scope. It is a fine unit and it will do a great job. You may just need a bit of a hand to show you how to get it humming at its very best for you! And an astro club close to you is the best place to find some hands-on help
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Old 23-07-2018, 09:31 PM
m11 (Mel)
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I second everything that Alexander has mentioned. Great advice.

It can be frustrating at the start and indeed getting someone else to assist would help starting off. I have done a few sessions with people getting started and I think it helps to show the basics on how to use the scope and find objects. People also can ask questions and I can demonstrate to help out.

I think most would not want people to be frustrated and give up when this hobby is so rewarding.

All the best Adam

Quote:
Originally Posted by mental4astro View Post
Adam, you may find it very helpful if you look for an astronomy club near to where you live. There you will be able to take your scope along and the good folk will be only too happy to show you how to use it and get it humming. Sometimes having someone actually show you what to do is better than all the ranting we can write down - it can get overwhelming and confusing.

From your last post I see that you need to familiarize yourself with the most basic of telescope functions, such as how eyepieces relate to the scope, what all the different eyepieces do, and how to use them. I fear that you might be feeling overwhelmed and what we are posting here might be too technical for where you are at in your astro experience - we can sometimes forget that we also started out not knowing anything too, and came only armed with enthusiasm and curiosity. Sometimes having someone patiently show us and talk to us is the best key to get us sorted out And the very last thing I want to do is throw a whole heap of tech talk that will only bamboozle you even more. This scope thing is not difficult at all, and it just sometime needs a little tweak for it to all click. If you are not used to the metric system of measurements it can get even more confusing. At the same time, I can also see that you are most keen and excited on using your scope, and your enthusiasm is half the battle won!

The planets are all so very far away that no matter how much magnification we throw at them, their image in the scope will never be very big. However, for despite the small image size, if your scope is set up well your eyes can pick up a fabulous amount of detail in those small images in the eyepiece.

Don't feel discouraged. We all want you to have a great experience with your much prized scope. It is a fine unit and it will do a great job. You may just need a bit of a hand to show you how to get it humming at its very best for you! And an astro club close to you is the best place to find some hands-on help
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Old 24-07-2018, 08:41 AM
TwistedRider (Drew)
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+1 For Mel's advice.

Really appreciated him taking the time to come show me the basics.

I found what I thought was in focus, Mel got even sharper.

I guess that will come with some practice.

Seek some assistance and a chance to ask questions
Will certainly help things along for you.
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Old 24-07-2018, 10:07 AM
m11 (Mel)
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Hey Drew,

Great to catch up with you.

I think you have a good scope btw.

M11


Quote:
Originally Posted by TwistedRider View Post
+1 For Mel's advice.

Really appreciated him taking the time to come show me the basics.

I found what I thought was in focus, Mel got even sharper.

I guess that will come with some practice.

Seek some assistance and a chance to ask questions
Will certainly help things along for you.
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Old 24-07-2018, 08:54 PM
TwistedRider (Drew)
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Thanks Mel,

I was certainly happy with it.

Looking forward to some more viewing.
Going to see the eclipse this weekend... Weather permitting.

Quote:
Originally Posted by m11 View Post
Hey Drew,

Great to catch up with you.

I think you have a good scope btw.

M11
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Old 24-07-2018, 09:04 PM
m11 (Mel)
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Lets hope the weather holds out for all of us
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