Help! Motivate me, I am a discouraged amateur

[umadog]

It appears, according to the general gist of this thread, that the 10" 'sees' Mars as a clear, sharp red blob, and so does a 4". The 10" sees some of those Messiers as gray fuzzies, and so does a 4". The 10" has problems picking out stuff in light polluted areas, and so does a 4". The 10" can probably pick out some nice detail on Jupiter, Saturn and, of course, the Moon, and so does a 4". The 10", to be performing in ideal conditions, requires a good level of darkness and away from light pollution, and so does a 4", and so on.

I think that's broadly true, but you will see more detail with a 10". Objects such as globular cluster will be vastly more impressive at 10" compared to 4". The first 8" of aperture make a lot of difference and increasing aperture by an inch or two within that range will always help a lot.

Basically, if the sky background approaches the brightness of the object then you're going to have a hard time seeing the object. Aperture won't ever be able to help because the contrast isn't there. Contrast is king. However, if the contrast is there then a larger scope will help on most occasions. Exceptions include very large objects (e.g. the rosette) which don't fit into the FOV of the bigger scope.

1) 10" or 4", living in a light polluted city or town etc is basically limiting you to the brighter messiers and large solar system objects?

Don't forget double stars. There are plenty of bright NGC objects which will punch through light pollution. Exactly what you can see will depend on how much light pollution you actually have. Read up on the Bortle scale on the wikipedia to get a feeling for it. Even from the city, you will still see more with a 10". For starters, the 10" will take light pollution filters better than the 4". You will be able to magnify small planetary nebulae more with the 10", and these objects fair better than other DSOs from light polluted locations. Aperture will always help. The difference is that the 10" will be performing further from its true limits than the 4". The big problem with light pollution is that plenty of objects will be detectable but they will be featureless and uninteresting. You'll see more planetary detail with the 10".

2) if that is the case, if you do observe in an LP area, within a few millimeters at most (I imagine), you are both pretty much 'seeing' the same kind of thing in your eyepiece?

???

3) if you get out into areas of pitch darkness, then, of course, the 10" is going to clearly out perform the 4", but to what extent? What can a 10" do that a 4" in pitch black areas couldn't do?

It's simple, really. The 10" allows you to magnify more before the image gets too dim, so you can see details in objects more readily. Larger scope means more details. e.g. lots of filamentary detail in the Veil.

4) as a final question, aperture is rightly recommended; the bigger it gets, the more light it gathers etc etc, but ultimately, wouldn't it be location that is going to sway your observing potential, not only your aperture?

Yes, I think that's very true. Take a 10" somewhere truly dark and you'll see much more than a 20" from somewhere light polluted. The views are just so much prettier from a dark site. Even without optical aid, the view is majestic. Aperture is really over-rated in this regard.

5) Without that perfect location and sky, 10" or 4" are pretty much on equal ground? If location isn't seriously taken into account, one may end up seriously disappointed?

No, I wouldn't say they are on equal ground. You'll see more with 10". However, that's not to say the 4" is "worse." You'll get wider fields of view with the 4" and those are great for lots of objects. The views aren't dimmer, they're just lower power. It's more portable. Lots of positive points. The two scope complement each other. Neither is "better". It all depends what you're observing and how you're doing it.

[umadog]

To the OP: if you're discouraged then the best thing to do is to hook up with your local club. They will show you the way! Even better, get yourself to Chiefland: http://www.chiefland.com/chieflandastronomyvillage.php It's under 3 hours from you. Go!

[Qualia]

Wow! Thank you, Umadog. A most detailed and informative read. I think you've raised some essential points about this art and hobby and have certainly laid my questions to rest.

At the moment I'm trying to see what I can get up to with my little 4" in a city and the reason I asked these questions was that it seemed the 10" was having the same 'trouble' which surprised me. Evidently, that isn't necessarily the case and I'm glad you cleared that up for me.

It can be a tad frustrating trying to hunt out DSOs and not being able to see a thing, but it surprised me this wasn't possible with a 10". I've been trying to see if I could find M51 & M94 this week and alas no such luck, but I figured such was the case in a heavily LP city. No problems with M80 or M3, for example, basic star spliting and planet work which makes night gazing worth while and a joy.

Even though there are deserts and mountains near where I live (all within an hour's drive) I don't know when I will ever be able to get to a truly dark site. Buses don't run to them and I don't drive, but I figured this summer, I might head out and camp for a night, push the Tal and see what it really can do.

Again, thanks for your thoughtful and kind reply.

[petermarknimmo]

Do you know what you are looking for? In the case of messier objects, a galaxy will look like a small star with a fuzzy greyish halo around it. A nebula will show a little more detail, but will still look like a fuzzy grey patch (unless you are using a nebula filter). If you cannot see any of these, go for a star cluster as these are mostly easily distinguishable and will make an interesting target.

[fmandani]

Thanks everyone for their support and advice. I will definitely be joining a local astronomy club and continue my journey.

I am more excited than ever and look forward to exploring and discovering the night skies

As for viewfinders, I currently use the one that came with my dob and it works relatively well.. It has a crosshair on it and sometimes its hard to see the crosshair since its black against the black sky. Is the telrad way better in locating dso's?

[ismangil]

Telrad in a light polluted sky with no stars can only help initial placement. Fine tuning required at least 50mm finder to see more stars.

On mobile (excuse the strange predictive words...)