New lens

kramenyak77 (Kayne) · #1 22-07-2017, 07:13 PM

I'm testing out my new 12mm lens. Focusing on jupiter - is that Io or another moon in front of it, or is there a black dot in my field of view (LOL). Noob. 😊

Atmos (Colin) · #2 22-07-2017, 08:11 PM

That most likely means that you're out of focus and Jupiter has become a donut haha

kramenyak77 (Kayne) · #3 22-07-2017, 09:46 PM

You're right. So I learning that I have to adjust the focus every time I change lenses. On another note, I bought a TELRAD today. Now I have been able to properly align my scope and was able to see Saturn :-)

Atmos (Colin) · #4 23-07-2017, 12:39 AM

Yeah, every lens has a slightly different focus point. There are lens that are advertised as being parfocal but even they are slightly different, just a lot closer than they might be otherwise.

You can see Jupiters moons transit across it however so one of its moons may have been in front.
Silly me was actually thinking that you may have been focusing on Jupiter with a 12mm DSLR lens and seeing a moon

doppler (Rick) · #5 23-07-2017, 12:53 PM

Hi Mark, what you are using is a 12mm eyepiece you will confuse everyone by calling it a lens.
Re your Jupiter views check this website out it has info about the movement of Jupiter's moons.
http://www.users.on.net/~reynella/skywatch/ssky.htm

kramenyak77 (Kayne) · #6 23-07-2017, 01:00 PM

Sorry like I said I'm new so it's easy for me to make errors with terminology. I assumed (incorrectly I guess) that a lens is something which would focus light into my eye (like a contact lens). I'll use eyepiece from now on. Thanks for the correction. Thanks also for the link re:Jupiter.

glend (Glen) · #7 23-07-2017, 02:04 PM

Quote:

Originally Posted by kramenyak77

Sorry like I said I'm new so it's easy for me to make errors with terminology. I assumed (incorrectly I guess) that a lens is something which would focus light into my eye (like a contact lens). I'll use eyepiece from now on. Thanks for the correction. Thanks also for the link re:Jupiter.

To further confuse you Mark, there are some eye pieces which can attach to cameras like lenses, Hyperion eye pieces come to mine. They are modular and can be used to look through with your eye, or to screw onto a camera adaptor.

http://www.baader-planetarium.com/en...nsteiger).html

Scroll down to the description, it shows the adaptor.

doppler (Rick) · #8 23-07-2017, 03:06 PM

No need to be sorry, I still have to google for the meanings of a lot of astro terminology. Ask as many questions here as you like, you won't get bagged in this forum, very easy going lot here.

kramenyak77 (Kayne) · #9 23-07-2017, 04:09 PM

Thanks Rick. I think a question that I have that I'd be otherwise too embarrassed to ask is: I have a lot of trouble looking through eyepieces- I keep seeing my eyelashes or shadow of my eye. How do I correct this? It's really bugging me and I feel stupid. Looking through an eyepiece should not be so hard!

doppler (Rick) · #10 23-07-2017, 05:07 PM

Quote:

Originally Posted by kramenyak77

Thanks Rick. I think a question that I have that I'd be otherwise too embarrassed to ask is: I have a lot of trouble looking through eyepieces- I keep seeing my eyelashes or shadow of my eye. How do I correct this? It's really bugging me and I feel stupid. Looking through an eyepiece should not be so hard!

Some eyepieces are harder to look through than others usually wide field ie 40mm, in your case it sounds like you are getting reflections due to a source of light behind you, it doesn't take much. I have heard of some people putting a cloth over their head to darken the view from stray light.

ps you have a nice piece of kit there for a newbee, you must have some big plans ahead.

astro744 · #11 25-07-2017, 08:55 PM

An eyepiece is also known as an ocular.

kramenyak77 (Kayne) · #12 25-07-2017, 10:12 PM

Thanks Rick - yes I have big plans. I asked around at StarStuff and made sure that if I was going to spend some money, that I wanted the best I could afford. I made a Duncan Mask the other day and collimated my scope, it was significantly out of whack.

Thanks Astro. An ocular. Makes sense!

Nebulous (Chris) · #13 25-07-2017, 11:38 PM

Quote:

Originally Posted by kramenyak77

Thanks Rick. I think a question that I have that I'd be otherwise too embarrassed to ask is: I have a lot of trouble looking through eyepieces- I keep seeing my eyelashes or shadow of my eye. How do I correct this? It's really bugging me and I feel stupid. Looking through an eyepiece should not be so hard!

Hi Mark,

I'd say that was a pretty common problem. I certainly had to practice a bit before it became second nature. The eyepieces that i have all feature a rubber cone that lies flat against the side when packed away but can be popped out when in use, and that certainly helps gauge the right distance to hold the eyeball away from the surface.

Theres also a thing called "Eye relief" which refers to the relative distance. Explained in the link below :

http://oneminuteastronomer.com/5820/...ief-eyepieces/

Don't worry about it, I'm sure we've all been there when we started out. Practice is all it needs.

Cheers,

Chris