EP's to attention!

[Knighty2112]

OK, a little bored today, so I thought I'd line up all my EP's to attention. Half of them are stock EP's which came with various scopes (1st photo) , and the other lot in the 2nd photo are all EP's I've bought seperately. A quick run through of the guys are as follows (from left to right);

2nd photo; TMB Planetary II 4.5mm - Celestron Omni plossl 6mm & also 12mm - Vixen LV 15mm - Skywatcher plossl 17mm - Explore Scienticfic (2" EP) 25mm - Celestron Omni plossl 32mm

1st  photo; Skywatcher stock 4mm and 2x 10mm - Celestron Stock 10mm, 20mm, 20mm erecting EP - Skywatxher stock 2x Super 25mm

Plus I have two other stock EP's from a scope in the loft which are also stock Celestron's to at 10mm & 20mm EP's. To be honest I surprised myself how many I was awash with EP's! Hehe! I'm sure other members can outdo this shady mob of EP's too!

OK fellas! Stand down now!  

Oh! With three pairs of the same stock EP's, I'll be in good shape when I buy a binoviewer at some point later on this year too!

Edit: sorry the order of the pictures uploaded came up wrong, so edited to reflect that.

[pipnina]

I sure hope you get some clear skies soon! It looks like the withdrawal symptoms are setting in!

[Knighty2112]

5 minutes ago, pipnina said:

I sure hope you get some clear skies soon! It looks like the withdrawal symptoms are setting in!

Sure does! Yikes!  

[pipnina]

Just now, Knighty2112 said:

Sure does! Yikes!  

I am fortunate to have at least 2 hobbies going at once to alleviate boredom, even if my bank account isn't as happy.

 

[Yamez]

Nice eye pieces I've been interested in the celestron 6mm EP but have noticed it has a small viewing hole thing (don't know what to call it :D) would this effect the image if I were to photograph using this EP?

[Knighty2112]

6 hours ago, Yamez said:

Nice eye pieces I've been interested in the celestron 6mm EP but have noticed it has a small viewing hole thing (don't know what to call it :D) would this effect the image if I were to photograph using this EP?

The Celestron Omni 6mm is a plossl EP, and the lens that you look into on the EP is indeed quite small, which means you have to have your eye very close to view the image correctly, and also you have to move your eye around too to see the different parts of the view easier. The 4.5mm TMB Planetary II EP to the left of the 6mm plossl is a much better EP to view through as the exit lens is much larger, and you don't have to have your eye pressed quite as close to it as a plossl.

if you are going to do afocal photography, which basically means you hold the camera up to the EP eyepiece to take the shot, will be much harder to do with the 6mm plossl EP than the 4.5mm Planetary EP. You will only be able to photograph the moon and some of the planets this way. The moon will be quite easy to do, but it will be harder to get any great detail on Jupiter, but you should be able to capture the moons around it. 

[Yamez]

2 hours ago, Knighty2112 said:

The Celestron Omni 6mm is a plossl EP, and the lens that you look into on the EP is indeed quite small, which means you have to have your eye very close to view the image correctly, and also you have to move your eye around too to see the different parts of the view easier. The 4.5mm TMB Planetary II EP to the left of the 6mm plossl is a much better EP to view through as the exit lens is much larger, and you don't have to have your eye pressed quite as close to it as a plossl.

if you are going to do afocal photography, which basically means you hold the camera up to the EP eyepiece to take the shot, will be much harder to do with the 6mm plossl EP than the 4.5mm Planetary EP. You will only be able to photograph the moon and some of the planets this way. The moon will be quite easy to do, but it will be harder to get any great detail on Jupiter, but you should be able to capture the moons around it. 

I use a T-Ring with an extension tube to fit EP's inside of as i use a dslr camera and big planetary EP's don't fit inside the tube this is why i was interested in the 6mm Celestron EP. Would the small viewing hole still be a problem for a dslr?

[Knighty2112]

1 hour ago, Yamez said:

I use a T-Ring with an extension tube to fit EP's inside of as i use a dslr camera and big planetary EP's don't fit inside the tube this is why i was interested in the 6mm Celestron EP. Would the small viewing hole still be a problem for a dslr?

I'm not an imager, so can't answer that at all. Might be best to ask that as a question on a new topic. 

[Louis D]

12 hours ago, Yamez said:

Nice eye pieces I've been interested in the celestron 6mm EP but have noticed it has a small viewing hole thing (don't know what to call it :D) would this effect the image if I were to photograph using this EP?

It's called the eye lens (as opposed to the field lens at the other end).  And no, it's nearly impossible to do afocal photography with short eye relief eyepieces because the eyepiece exit pupil falls short of the entrance pupil of most camera lenses.  Perhaps if you used a miniature spy camera with a tiny lens it might work.  It might also work for eyepiece projection photography, though it would be very dim.

The general rule of thumb I've found to be true for afocal photography is that the eye lens on the eyepiece needs to be at least as large as the objective lens on the taking lens of the camera.  For instance, I can use a Pentax XW to project into my Olympus C4000 just fine due its small lens, but the Pentax XW doesn't work trying to project into my Canon 18-135mm lens.  The latter combination vignettes like crazy.  It doesn't even work with the much smaller 18-55mm kit lens.

If you use a small camera lens like those found on cell phones, you can get away with using eyepieces with much smaller eye lenses and much shorter eye relief than the Pentax XW series.