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Newbie Alert! - Help with eyepieces and what I should be able to see


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Hi knowledgeable folks,

I'm new to astronomy, although I've had an interest for a long while, I was given a Skywatcher 200P with EQ5 mount for Christmas (well, part of it anyways!)

My issue now is that I've got two eye pieces and a barlow:

10mm

25 Super Wide Angle Relief

2x Barlow

I've been having a look in the night sky and last night it was clear for quite a while before the clouds rolled in and I managed to get the Orion Nebula into view, but it was blurred and I was not able to focus on it very well. I also viewed Jupiter but have not been able to see much more detail than a glowing orb with for bright dots.

My questions on this note are;

- what should I be able to see and how well?

- can I use a x5 barlow lens to increase the magnification?

- will a 4-6mm eye piece help the magnification or will I suffer from focus issues again?

I read through the sticky regarding eye pieces but was a little uncertain at the recommended eye pieces for an F/5 telescope, given the high power was only 2mm away from my current high power eye piece of 10mm.

My next issue is astro-photography. I have a Nikon D80 D-SLR, which I got for the job of taking astro images, however, the magnification is very low when mounting the camera directly to the telescope. I've seen various pieces of equipment that can be purchased which, as far as I can make out, are effectively barlow lenses for cameras. My questions on this are;

- what adapter is recommended for my scope and camera?

- can I use something like a x5 barlow (again) for the purpose of increasing magnification with my camera?

- am I missing any equipment that is essential for getting good high magnification heavenly images?

I think this is about all that I need help with right now, my only sideline concern is the focusing capabilities of the scopes focuser, will this be irrelevant with higher powers of magnification with different eye pieces and barlows?

Many Thanks in advanced for your help!

:)

Edited by AlexB
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By your description it seams you ware unlucky with the seeing conditions. What you sow is consistent with what I see on bad seeing nights or when dew forms on the mirrors/EPs.

Give it a few more tries when the weather allows. The 4 mags you can get out of your current gear are adequate to it. You may want to upgrade the quality of the gear. As to the 5x barlow it will only make things worst visually cause it will make the bad seeing conditions more noticeable and make objects look fainter. With the 10mm EP it will give you 500x which is well over the resolving power of a 200mm scope (400x max).

I have no experience with astro photography so I'll leave those for someone else.

EDIT: If you haven't done it yet, you may also want to check if the scope is collimated and allow enough time for it to cool before using high mags. If the difference in temp is too much, and you observe as soon as you take it out, everything seams out of focus.

Edited by pvaz
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Lots of questions there.

- what should I be able to see and how well?

Firstly don't expect to see the colourful deep sky objects as seen in the photographs. At best you will be able the pick out subtle blues and greens.

- can I use a x5 barlow lens to increase the magnification?

How much magnification do you need ? The Skywatcher 200P has a practical maximum magnification of 400x, so with a 5x barlow and the 10mm eyepiece you will have 500x magnification.

- will a 4-6mm eye piece help the magnification or will I suffer from focus issues again?

Focussing becomes more critical with shorter focal length eyepieces, but atmospheric conditions can dictate the maximum magnification. It is normally given that a telescope's practical magnification is 50x the aperture in inches (50 x 8 = 400). But this could only be achieved in perfect conditions (these rarely happen in the UK). 30x per inch is probably a better figure.

- what adapter is recommended for my scope and camera?

To attach the camera body to the focuser you will require a T-ring. The focuser on the 200P has a T thread located behind the eyepiece holder. Unscrew the holder and fit the T-ring. The camera body can now be attached to the telescope.

- can I use something like a x5 barlow (again) for the purpose of increasing magnification with my camera?

It depends on what you want to photograph

To find out the capabilities of your camera / telescope combination take a look at this website 12dstring astronomy

Peter

Edited by Cornelius Varley
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Welcome to SGL - that was a nice Xmas present !.

I can try and answer a few of your questions:

- what should I be able to see and how well?

Well much better than your experiences so far !. Your scope does need to cool down a bit if it's been at room temp - in the current conditions it will need 30-60 minutes to cool to a point where your will get steady images. Also moonlight drowns out most of evenr the brightest deep sky objects - M42 included. With a cool scope both your eyepieces should focus sharply - unless the scope is well out (and I meand really well out) of collimation, that is the mirrors are not aligned properly. Another possibility is that either your eyepiece or one of the mirrors became misted up which is a common occurance.

- can I use a x5 barlow lens to increase the magnification?

Yes, but with your eyepieces it will provide more magnfication that you can use - on most nights 250x is the maximum and often lower powers give better views. I've found 170x very nice on Jupiter and Mars with my 10" and 5" scopes.

- will a 4-6mm eye piece help the magnification or will I suffer from focus issues again?

I think you / we need to get to the bottom of your focus issues before getting more eyepieces - the ones you get with the scope, although not the best quality, should provide nice sharp views.

I'm not an imager but I'd suggest you need more practice using the mount and scope before venturing there - but there is potential in due course.

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Hello.

I've recently aquired the same scope and mount, it's fantastic isn't it :)

Same as you I'm still looking about trying to work out what everything is about, but, I don't know if you visited this site yet, if not, you should as the lady who runs it has the same scope and mount and has already done all the ground work you are struggling with ...

Astro-Baby Astronomy Website

I was intending buying a Celestron eyeopener eyepiece kit but after talking with the nice ladies and gents on SGL i had a look at the Revelation Photo-Visual Eyepiece and filter kit, when I sat down and looked at the range of eyepieces in this kit it seems to cover nearly the whole usable range of magnifications available with the 200P

If you want to see the advice I was given, have a look at the thread "at last ..." in the new comers section at the top it's all good and makes sense.

I have also as mentioned above 'treated' myself to Cheshire Collimating eyepiece as from what I've picked "with a reflector" they are an essential item.

Anyway, I just thought I should pass it on, hopefully this may be of some help to you.

Cheers

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I think that this link will answer a lot of your questions about eyepieces much better than I could ever manage.

http://stargazerslounge.com/primers-tutorials/63184-primer-understanding-choosing-eyepieces.html

If you have a good trawl around SGL you'll find loads of good stuff has already been answered for you, especially in the primers-tutorials and beginners help sections, at least that's what I'm doing, I just wish I'd come here a long time ago, I did most of my research out on the www and it was a bit of a slog

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The scope you have is a beauty. The 8" 200P is perfectly powerful enough to get some good views of most astronomical objects and you'd have to go quite a bit bigger to see much improvment.

Under a good dark sky and with your eyeballs dark adapted the 200 will show a very beautful M42. M13 in Hercules is also quite spectacular as is the double cluster in Casseiopia. The scope should, under good conditions, resolve cloud belts on Jupiter and Saturns Rings including the Cassini Division.

To get the best from the scope it needs to be collimated well, cooled down to ambient temp which can take 40 mins.

Dont go getting high mag eyepieces because you'll find you dont use them too much. I have a 5mm, 13mm, 26mm and 38mm. The eyepiece I use the most is the 38mm for clusters followed by the 13mm.

The 5mm is hardly ever used as sky conditions have never yet permitted x200 magnification.

The scopes theoretical max is 400 (2x each mm of aperture). UK skies rarely permit much above 200 and I mostly use about x135.

Get some eyetime in before buying eyepieces but you need a cheshire collimator to tune the scope and you may need a dewshield as well when the weather is damp.

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ps imaging is a technical challenge you probably dont need right now. I would advise you to get au-fait with the basics. There are rafts of potential issues with imaging.

Probably one of the best books on it is 'Making Every Photon Count' by SGLs Steppenwolf. Probably well worth a read.

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Hi there,

Thanks very much for the very quick replies! The focusing thing is probably due to the bio-interface, however, I did leave the scope out for some time before getting any views. I guess there was probably too much moisture in the air before the clouds were even visible so maybe that is to blame. I have viewed terrestrial objects with ok clarity (through a window.)

I guess I was kind of hoping to see a bit more resolution Jupiter than I am currently getting.

With regard to the answer about the T-Ring attachment, I've already used this on the telescope, however, the magnification is an issue for me there. Jupiter was a mere spec of pixels when blown up and as the telescope has up to 400x capability, I'm wondering what equipment I can use to boost the magnification for the camera, hence why I mentioned the x5 barlow. Do you have an opinion on that?

Using the following adapter... T Adaptor 1.25" ... I can then utilise a barlow with my camera. I 'think' my camera is a 50mm if that is relevant to figuring out which barlows I can realistically utilise.

Thanks so much for the help you're all giving me, it's much appreciated.

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Genearally speaking, if you want to photograph the planets, a webcam is a better option. It has the ability to take hundreds of exposures in a short time which can then be processed in a program such a Registax. This program can combine the images and extract the best detail. If you check the website I mentioned earllier you will see the relative image scales of the webcam and a DSLR. Remember 400x is only a theoretical maximum, atmospheric condtions will limit that to a lot less.

Peter

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Thanks, I will look into that, I was looking to get a camera kit too, is the Skywatcher variant acceptable, or do I need to spend some significant money to get the right bit of kit?

Also, thanks for the pointers to the book, I will probably be getting that one soon! :)

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For planetary imaging most people use a modified webcam. Their small ccds magnify the image more then a DSLR. The idea is to make a movie, split it into frames, choose the focused ones then use a program (registrax I believe) to stack those frames into a final (hopefully) more defined image.

DSLRs are more suited for DSOs as they allow long exposures and you can then stack them too. Most of the DSOs images you see here have a combined exposure of several hours and lots of time invested on processing technics.

A good book is vital, I read 2 ("Digital astrophotography" and "Lunar and Planetary Webcam") and came to the conclusion at this time of my life it's too much trouble... though eventually I want to try it out.

Ops! Posted at the same time as Peter. :)

Edited by pvaz
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Just so you can see, this is the image I got of Jupiter the other night, and admittedly, this was taken through a window so I wasn't expecting much, but this is without any barlow at all.

When I viewed the skywatcher site and looked at the gallery of images for this telescope, I was impressed with the images and written underneath them was that they had been taken with a Canon EOS 350d, so I naturally assumed a D80 would do a good job also.

Was this done only with a long shutter speed or is it done with composite images? I don't have a goto system or tracker so shutter speed seems out of the question??

:)

post-18273-133877418684_thumb.jpg

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Planets are too bright for long exposures. They will be burned and no detail will come out. You need shorter exposures and then stack the images to bring out the detail.

I only tried the moon in practice, with a camera lens, and I had to use between 1/200 and 1/320 to get some detail without burning the image.

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Just so you can see, this is the image I got of Jupiter the other night, and admittedly, this was taken through a window so I wasn't expecting much, but this is without any barlow at all.

When I viewed the skywatcher site and looked at the gallery of images for this telescope, I was impressed with the images and written underneath them was that they had been taken with a Canon EOS 350d, so I naturally assumed a D80 would do a good job also.

Was this done only with a long shutter speed or is it done with composite images? I don't have a goto system or tracker so shutter speed seems out of the question??

:)

It depends on what pictures you saw on the Skywatcher website. DSO's cover a greater area than a planet so are easier to photograph with a DSLR, planets are small in comparision.

DSO photography tends to start with several hours of photography, taking a number of images at different exposures rangeing from a few tens of seconds to several minutes duration and processing the images to obtain the most detail out of the exposures and then combining the images in Photoshop.

If you want to try planetary imaging, use a 3x barlow instead of a 5x, the 5x may be too much magnification for the telescope to handle. Take a number of shots and process them in Registax. By taking more images you will be able to extract more detail and improve the signal to noise ratio. If your camera has a video mode you could take a short video clip instead. Personally I don't believe a DSLR is the ideal camera for planetary photography but is suitable for lunar photography as the image scale is better and without the aid of a motor driven RA axis you will find most photography difficult.

Peter

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