Telescope Questions & Reviews

[nevers]

BBrock -<br /><br />Your welcome for the responses. crazyeddie has better answers then I do: I just know what I have and what to do with it, not the "whys" of it all. About M101; I hear you about SNP and it's stated magnitude. Try looking at it again without so much power. Try that 25mm at 48x that you have. I think you may notice more detail in the galaxy especially if you use averted vision. M33 [The Southern Pinwheel] is the same way and they are both huge galaxies. M33 has NGC's within it that you can see. M31 [Andromeda] has something within it called the "Association" that is located in one of the arms. If I remember right, it's a brighter area towards the left-bottom side (Reflector View). A Galaxy called Barnards Galaxy is so faint it is best seen in dark skies with a good finderscope. M82 [The Cigar] & M104 [Sombrero] on the other hand are two galaxies that I've found CAN take a little magnification without washing the whole thing out into nothingness.<br /><br />And "Yes", I do have a suggestion for fixing humid, muggy sky pollution. Move to the desert...! <img src="/images/icons/smile.gif" /> (But not to Las Vegas...!) <img src="/images/icons/wink.gif" />

 

[nevers]

Hi Pete - <br /><br />I've never heard of it but will certainly give it a look-over. Do you have a link for us?

 

[bbrock]

Brad<br /><br />I've been to the desert a few times ( Phoenix, Scottsdale, Flagstaff ) but that was some time ago. The low humidity would be great for deep space viewing. I appreciate your input on lower magnitude. If storms don't roll through tonight I will try the 25mm on M101. I didn't notice any NGC's within it, but I will target M33 to check what your are talking about. I'll have to waite until Cassiopia rolls further to the East before I try Andoromeda. I've looked at M31 several times with binoculars, but not with the 10" Dob. <br /><br />Thanks Much<br />Bill

 

[petepan]

Thanks crazyeddie, <br />I knew someone here would know !!<br /><br />For NEVERS, here is a link to the site..<br />http://www.gs-telescope.com/<br /><br />Basically, i found an ad in a 'Sky and Space' magazine, and it looked impressive, but the F4 part is a bit of a worry. I want to get a newer 'scope and this looked ideal. Thats probably why it seemed so reasonably priced ($799 Australian) Oh well, i will look for a 8" F6 instead. <br /><br />Like they say, it pays to do some homework first. Thanks again eddie!<br /><br />Cheers<br />Peter

 

[raven2490]

Barlows ...<br /><br />how much better is the 4 x compared to the 2x .. what is the difference ?

 

[nevers]

Hi TaaP -<br /><br />No, just be aware of the need. From my experiences I've never had to collimate my Orion Refractor. (Although I might have to after it took it's last dive!) From the get-go both Refractors have seemed to be in collimation.<br /><br />My 5" EQ Newtonian has never needed collimation. The XT10 did need collimation a couple of times and the 16" Dobsonian needs to be collimated every time I use it but that's only because I take the primary mirror out of the tube each time.<br /><br />I've never found good written "instructions" on how to collimate. I learned how to do it from hanging around people with more experience in the matter. It can be done without a laser (what's to say the laser itself is not out of collimation?) and is fairly easy. The basic concept it to make sure all the "circles" are concentric and evenly spaced within each other.<br /><br />'Scopes are supposed to come from the dealer/factory already collimated. If you buy from a local dealer they may be able to check it before you take it home. Once the 'scope is collimated, as long as the mirror is not removed it should remain that way for a while unless the 'scope is handled roughly or the vanes get loose. But "no", I do not find it a problem to collimate a Reflecting type telescope.

 

[nevers]

Hi Raven -<br /><br />Others opinions may differ - anything over 2x seems to be overkill. By the time you find your object and switch let's say a 20mm EP into the 4x Barlow you will probably have "lost" the object. In a way with a Barlow, you're narrowing the field of view. Maybe one of those "Zoom" EP's would be better?<br /><br />imho, there are few DSO's that will take high magnification. The planets are great under high power of over 400x but only in prime viewing conditions and with an APO Refractor or a with a large mirror. I do have EP's that will give my 'scope high power but I rarely use them.<br /><br />What better is high power if the object your looking at cannot handle it? I donno...4x seems like something I wouldn't be interested in...I'm sure some people are or they wouldn't make 'em. Anybody else...?

 

[bbrock]

I agree. Going beyond 2x Barlow is probably overkill. From the advice of crazyeddie and NEVERS and others, I have tried different combinations on deep sky objects and -- unless you have pristine skies -- stick with the lower powers. You have much more light to work with and more time to work with it.

 

[bbrock]

I have a question on EP's. I have been using 1.25" EP's. Is there an advantage to using 2" EP's. I assume a wider field of view for the same power or perhaps more light ?????? Is there a good compelling reason to use the more expensive 2" EP's. ?

 

[nevers]

Hi BBrock -<br /><br />I only have one 2" EP: it's a 30mm with a supposed 80 degree FOV as compared to the 52 degree of a Sirius Plossl. You can see the ad in the back of S&T and Astronomy mags. It's from AstroBuffet/1rpd and costs like $100 bucks. In my 16" f/4.5 there is a lot of coma near the edge. I've compared it with a 35mm Tele Vue Panoptic and it made mine look like junk. In my little 100mm f/6 Refractor it works great.<br /><br />I got it to look at large objects like the Veil, The Rosette Nebula and things like that. It does quite well. The Double Cluster is nice but I get that "fishbowl" effect going on with the larger 'scopes.<br /><br />The advantage...big honkin' peice of glass to look through! They're fun to have but anything else is nearly out of my price (well, what I'm willing to pay) range.

 

[nevers]

Hi TaaP -<br /><br />Ok, this is just me talking, I'm sure others may have different opinions.<br /><br />If you can't get an OIII filter, you're best bet although they are still rather expensive for the few number of objects you can use them on would be to get a Narrow Band filter. Something like Orion's Ultra Block. I've found it better then the SkyGlow filter. Plus, it doesn't really work as advertised: to improve the viewing of Nebulae in LP skies. It works great in dark skies.<br /><br />Colored Filters: I have the "basic" set of 4 colors. I've only found that I enjoy the medium blue and on Venus only. It cuts out some of the glare. On the other hand, there is another filter that does a better job plus you can use it on other planets and the Moon. It's a variable polarizing filter. If I had money for one filter and one filter only I'd get that one.<br /><br />An 8" 'scope will be able to see all of the Messier List at the very least and some of the brighter NGC's. You won't be disappointed in the choice of an 8" 'scope as far as what you can see as long as your not expecting Hubble quality or even magazine quality shots. Those pix are computer enhanced out the wazoo. Especially the ones in ads for 'scopes. If you look at my website I have pictures taken through some of my various 'scopes. I made them look as realistic as if they where that actual view through the said 'scope. Especially the pix in "Urban DSO's".<br /><br />Yep, you're getting ripped off if you can barely see Sag! <img src="/images/icons/frown.gif" /> Don't worry 'bout askin' too many questions. That's what we're all here for. I just hope I'm making sense and not wasting YOUR time! <img src="/images/icons/wink.gif" />

 

[nevers]

Hi TaaP -<br /><br />I'm not sure if you've asked or maybe I mentioned it already: these are the things I would get first (unless you already have them) before investing in OIII filters and such.<br /><br />- An 8 or 9 x 50 finderscope<br />- A Telrad or Red Dot finder<br />- A good star chart from Wil Tirion (DeepMap 600)<br />- An APO (just in case you get an "Achy" 'fractor someday) 2x Barlow<br />- A waterproof tarp (Don't leave home without them!) Plus, they make handy "Photon Shields"!<br />- An office chair (so you don't break your back looking through the EP)<br /><br />...and DON'T throw away the boxes when you get your new 'scope! <img src="/images/icons/smile.gif" />

 

[nevers]

Hi Alex -<br /><br />A tarp, you know: one of those like big pieces of plastic that you can use to cover stuff up with so it doesn't get dirty or wet. Just in case your out observing and it starts to do the "R" word before you can get your 'scope put away. I have 7 of them and I never go observing without them even if there's not a cloud in the sky. Keep us posted...

 

[nevers]

"Stacking" Software - <br /><br />- RegiStax 2 <br /><br />- AstroStack <br /><br />Both programs are "freeware" as long as you are using them for personal use. I like RegiStax better.<br /><br />TaaP -<br /><br />Glad you liked the website! Sierra is a good dog too. <img src="/images/icons/smile.gif" /> About Death Valley: I don't go there in the summer, it's just too hot. It can get up to 130 degrees. I've found the heat and cold affect the operator more then the 'scopes unless I go somewhere (rarely happens out here) where there is dew. Yuck...!

 

[nevers]

Hi Alex -<br /><br />The photos I've posted in "Urban Astronomy" were taken with a digital camera through a Meade 5" Refractor on an LXD mount. It is a "GoTo" mount and tracks both Declination and Right Ascension. My camera shutter stays open for a maximum of 15 seconds. They are not long exposures at all but if I take at least 10 single frames and stack them together with RegiStax: well, you've seen the results.<br /><br />When taking pix of the moon you won't need a flash: the moon is plenty bright enough. <img src="/images/icons/smile.gif" /> If you don't have a way to shut the flash off, tape something over it. I've taken "hand-held" photos of the moon before, not the greatest but it works. The moon requires a very short exposure time: depending on the phase it's somewhere in the realm of 1/500 @ f/4.

 

[nevers]

Sorry, I just woke up...yeah...like crazyeddie said. You don't need a "GoTo" but you have to have an EQ mount for any length of exposure with a one axis clock motor. I have taken some pretty decent shots of the moon and planets (and amazingly the Orion Nebula) through a Dobsonian. Something like that. I should wake up first. <img src="/images/icons/wink.gif" />

 

[bbrock]

I was going to ask this some day, now is a good time. All I have to work with is the XT10 Dob. I don't have any way to track, but can a digital camera - such as a Sony Movica be attached and take short time exposure pictures with low power EP's ( 25mm to 40 mm ). <br /><br />Second Question. This is for my edification. Regarding Focal Ratio. I realize f/n = focal length/apature, but what is the significance of the number. A low f/n is fast and a high f/n is slow ?? What if you are just after viewing deep sky. My XT10 is f/4.7 how does this compare to a telescope that is -- say -- f/10. ??? There is nothing I can do to change it, but it would be nice to have a better understanding of it. <br /><br />Bill

 

[nevers]

Hi Bill -<br /><br />There's different kinds of adapters and ways to take pix with a 'scope. The method I've chosen is the cheapest: through-the-eyepiece. And "yes", I have taken pix with my Dobs. The pix are of bright objects only: planets, moon and even M42. Back when I was taking them with the Dobs, I didn't have a stacking program, when they come back around believe me, I'll be clicking away. Orion makes a device called "SteadyPix", it's about $35. It attaches to the eyepiece and then the camera mounts to it. It's very easy to use with a little practice. However, there is this thing called "Vignette" (or some spelling like that, maybe crazy can explain it better) but it is very frustrating, you just have to learn to compensate for it. It seems the higher the power, the worse it is. Plus, because the 'scope is not tracking, you have to be quick when you've found the object and then attaching the SteadyPix and the Camera. But like I said, with a little practice, trial and error, it can be done. A rule seems to be: With an untracked 'scope, if you can see the object in the cameras monitor, you can take a picture of it.<br /><br />As far as your second question: I'm not a numbers person and don't really care to know at this point the why's: I just know the what's. Low f ratio, good for faint objects in reflectors. Low f ratio in refractors, good for wide field views. High f ratio in both, good for planets and moon. That's what I've found but I guess you already know that. Hopefully somebody else can explain the why's to ya...I'll check back for an answer with aspirin in hand. <img src="/images/icons/wink.gif" />

 

[nevers]

Hi crazy -<br /><br />Thanks, well said! (and I didn't even need to take the aspirin <img src="/images/icons/wink.gif" />).

 

[nevers]

Hi Alex -<br /><br />When you get your pix I hope we get to see them. That's the only way I really like to see the Sun: in a picture! <img src="/images/icons/smile.gif" /> Just kidding, but I am a night person afterall...<br /><br />Good luck on the 'scope...I hope eventually comes soon!

 

[tfwthom]

Some of the best sky charts I've seen in awhile are Sky-Spot. http://www.sky-spot.com/ I have the Double Stars, Messier Objects, and the Overlooked books. <div class="Discussion_UserSignature"> <font size="1" color="#3366ff">www.siriuslookers.org</font> </div>

 

[nevers]

Hi c_lou - <br /><br />Yes, I have 2 of them: I love it! It was one of the first things I got. I use one as a reference and the other to check off the things I've seen. I think the objects chosen are a good representation of what can be clearly seen in a 5" 'scope some of them take a 10" 'scope to pull detail out but it is a great map. I've only found two mistakes on it. The paper it's printed on is sort of laminated but if you get it wet, let it dry out before you fold it back up.

 

[nevers]

Hi TaaP -<br /><br />Well, I don't get much frost or dew here in Vegas. <img src="/images/icons/smile.gif" /> Humidity levels usually hover around 7%. Dust on the other hand is easy to come by: I hate it! For the frost or dew, you can get a Dew Shield: I call them Photon Phyters in my case for my battle against my neighbors porch lights and steet lights. I made some out of thick, black poster board. They're kind of flimsy but are easy to replace.

 

[nevers]

Hi c_lou -<br /><br />I think Thom is on vacation. Did you need a list of Double Stars? If so, I can send you some worksheets or direct you to them.<br /><br />Yep, the Deep 600 map is much sturdier then an ordinary road map. I don't have a table either, I use my boxes I pack my 'scopes in for that. They're just sittin' there anyway...might as well put them to use!

 

[nevers]

Hi c_lou -<br /><br />I have some other lists but for now, try this:<br /><br /> Saquaro Astronomy Club