First scope. A couple of questions.

[ubertank]

Hi everyone,

My 200P arrived today and I got my first use of it. Overall really happy. The moon was incredible through both the 10 and 25 eyepieces that came with it and I got my first glimpse of the bands around Jupiter. This was all through a thin veil of cloud, so I was really happy.

Sky is forecast pretty clear tomorrow so I'm planning to go out for my first real night and wanted a quick piece of advice if I may. I saw Jupiter like I said and whilst I could make out the bands, it was still pretty small. I wanted to pop out tomorrow to get something to increase my magnification in time for the evening and it's this I wanted some advice on.

Should I get a barlow and if so what magnification would you suggest, or should I go for a lens of around 6mm? Although the Barlow will give me more magnification options, I'm worried of the quality being sub-par compared to a 6mm.

Any advice regarding getting a better view of Jupiter tomorrow night would be much appreciated.

One final question. The images I got through my scope today I felt were pretty clear, but this is obviously coming from a layman's perspective. Will any scope you get out of the box require collimation or are they arriving these days at a standard it's not really necessary? I have a Cheshire collimator, but haven't attempted it yet.

Thanks for the advice in advance everyone. Feeling very enthused about the new hobby at the minute.

[jimmyjamjoejoe]

Pop the cheshire in, can't hurt to check.

As for the barlow, i'd grab another eyepiece to be honest. I think the best advice at the moment would be to grab a cheap 8-24mm zoom. Quality isn't too important to your laymans eyes, and it'l give you an idea of what focal lengths you'l use and don't use... Once you know that, you can look at buying decent eyepieces in those specific lengths. Personally, i find 7-8mm is maximum for most nights, though lately conditions have allowed more. If you want something you KNOW will be useful every session, get a decent 8mm. If you want to experiment, buy a zoom.

One final thought though - jupiter will always be small, as will all planets. Going from 20mm to 10mm doubles the magnification, but i bet it doesnt seem twice as big.... The same is true when going from 10mm to 5mm. And even if it does seem twice as big, twice the size of very small is still pretty small...

[Marki]

Sometimes pushing the magnification doesn't help if the atmospheric conditions aren't right. You'll just get a bigger fuzzier blob on Jupiter (for example) but lose the contrast and detail. I can sometimes make out more detail using a 20mm in my 100mm f13 refractor than I can with a 10mm (mind you last night was really good even with a 7mm in... ). One thing I find is that you need time at the ep...even at higher magnifications you get the odd second of absolute clarity when it all comes together, if you wait long enough. I'd really recommend an orthoscopic type ep for planetary viewing (not sure if they are best with reflectors at f6 - sure someone can advise).

As for barlows, well each to their own. Using a barlow to up the magnification seems to help in more light polluted skies (at least for me) as it seems to make the background darker. Having said that, I used to prefer to go with a higher mag ep rather than barlow as I thought having less glass in the way would be better. Then I got a televue 2.5x powermate and I'm not so sure any more... . I found this a really quality piece of kit which seems to add magnification and take nothing away in terms of light or focus or field of view. Makes me wonder just how good the general televue eps are (if I could ever afford one...).

Enough of me gibbering...clear skies and hope you got some good time out tonight

[ubertank]

I felt like the quality of Jupiter was really good actually, especially as it was behind thin cloud. I was pretty blown away to see it like that for the first time.

It seemed to have really good clarity actually which made me consider higher magnification to be possible without image quality being sacrificed too heavily, hence my query. Although it is small (and I appreciate it is going to be at 400 million miles away), every extra bit of detail I could see in it would be amazing.

I don't want to put across the idea I expect an enormous, perfect image you would see online because I really don't. It's just so impressive to see with the naked eye I'm craving any extra detail and size I can effectively muster.

[perrin6]

get a better eyepiece of about 6mm - 8mm focal length (6mm = 200x, 7mm =171X, 8mm = 150X) as the 10mm eyepiece that comes with the scope isn't great quality.

[RikM]

Which 200P did you get, the F5 Explorer or F6 Skyliner? They have different focal ratios and that may affect your choice of EP focal length.

What kind of detail could you make out on Jupiter with the supplied 10mm? This will help us to get a feel for your expectations and how much improvement you could expect from better kit. A view a planet's disc with a couple of cloud belts visible is great when you see it for the first time, but with good collimation, steady air, a well cooled mirror, and a nice eyepiece you could expect to see not only the cloud belts but lighter and darker areas within the belts. The great red spot in its lighter coloured hollow. It seems to float in the South equatorial belt. there is a sort of streamer like series of large eddies in the cloud belt trailing the great red spot at the moment, sort of spot echoes almost. The North equatorial belt seems to be a richer red colour at the moment, almost matching the colour of the great red spot, whereas the south equatorial belt is more a slightly darker brown colour. There are some interesting darker stripes at the south edge of the north equatorial belt though, which stand out quite well...in the fleeting moments when the air stills these details sort of pop out, if you spend the time looking.

One thing to note is that short focal length eyepieces tend to have short eyerelief. That means you have to get your eye very close to the lens to be able see through it properly. This simply isn't a problem for some people, and some eyepiece designs have extra lens elements built in which reduce this effect, but it can be a pain if you need the eye relief and don't have it. If you can, try and get along to a local astro society and have a look through a few different eyepieces before splashing out too much cash.

[ubertank]

It's a dobsonian 200P - http://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html

As for what detail I could make out - I could make out the two bands around the middle which appeared a green/brownish colour. I couldn't see any detail within the bands really as the image was quite small. There was no blurriness to the image particularly; it seemed very sharp actually.

I'm sure there is a wealth of detail yet to be had under the right conditions. The telescope was bring aimed out of the front door of the house, across a street through some light pollution, through some light clouds and then onto Jupiter! I was amazed to get this degree of detail.

Given the focal ratio of the scope, what would you suggest as the best way to achieve a larger image with good detail.

[RikM]

I find that generally the highest magnification I can use is (mm = F ratio), so 5mm with my f5 Explorer and 6mm with my astro society's f6 Dob. More often a little less magnification, very occasionally a little more.

Unfortunately, you can't just go on increasing the magnification forever. What tends to happen is that as you increase the magnification, you make the image bigger but you don't really get any extra detail (though the detail that is there may be easier to see...complicated huh?) Above a certain point, which varies from night to night depending on the steadiness of the atmosphere (the seeing), you actually just magnify the blurriness, so you get less detail. With time, you can often see more detail in a small sharp image than a big blurry one.

I think you are probably right, 6mm would be a fair choice for a 'highest magnification'. It would be very easy just say "get this one: http://www.teleskop-...----60--WA.html " but what suits one person, may not suit another, which is why it is important to have a go at an observing evening if you can.

It also depends on your budget. The new Celestron eyepieces http://www.firstligh...x-eyepiece.html are getting very good reviews and a 7mm would be usable most nights (my most often used high power EP is a 7mm) It should give much a better quality of view but it won't give a dramatic increase in magnification over your current 10mm. In fact with its larger 60° field compared to the 50° field of your 10mm, the planet may well appear the same size relative to the field of view. If you accept that it won't be usable every night or you just want a bigger view rather than more detail then a 5mm Excel LX wouldn't be a bad choice.

These new eyepieces http://www.firstligh...o-eyepiece.html are the ones everyone is waiting to see but they are not out yet. If I didn't need the long eyerelief, a 6mm one of those would be my choice. Or even better if they actually have any left, one of these http://www.365astron...a805b15c857391b.

[Catweazel]

I use a TMB Planetary EP http://compare.ebay.co.uk/like/160858485287?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla&crdt=0 in my f5 200P, I have a 7mm and a 5mm, and would say that the 7mm gets the most use; I also use it a lot in my other scopes, so it's a nice all-rounder and good value for the price. A lot of folks also like the BST EP for planetary viewing, but I personally get on better with the TMBs, having tried both. I think that the advice about trying some EPs out at an astro society is very wise, if you have one nearby.

[ubertank]

I actually bought a Celestron X-CEL LX 7mm in the end. I thought I would spend the extra and get something That will last for a while.

I also got a 2 x Barlow for future use aswell.

Will be going out tonight for the first time. Beautiful clear skies here luckily so am very excited.

[Catweazel]

Nice one ubertank, you can't really go wrong with the X-CEL's they are a quality EP. Hope you have a good night! Still cloudy here