SingAstro

I am looking for a zoom eyepiece since I find it hard to do nature scoping with a fixed eyepiece. :roll:

Anybody selling or have advice. I will have to try before I buy, as I have no experience. :oops:

Thanks,
Aryanto

Harlequin Astronomics used to sell one and I have it but they have since closed shop. You can try Mc Gill whom I think is doing Scoptronics also or maybe check with Astrobargains if they can bring one in for you.
beware that the cheaper zoom eyepieces (<$200) have some colour and vignetting at 24mm. If you want it to be colour free, then it will have to be the televue one...($$$)

Hi Aryanto,

Perhaps you'd like to visit our product page as below?
http://www.mcgill.com.sg/shop/product_i ... a490531f34

There's also an interesting article at the end of the page. Might be useful to you!

We've run out of stock for this one but are ready to import more if the response here is good.

Cheers,
Jim, McGill

If you want it to be colour free, then it will have to be the televue one...($$$)

:?:

What do you mean by "Colour Free"?
Do you meant to say "Chromatic Abberation Free"?

Whoa, Televue zoom eyepiece so expensive hor...

There's also an interesting article at the end of the page. Might be useful to you!

Any useful article for nature/birdviewing?
The article mentions all astro stuff, a bit too out of space for me. :k-?:

Hi,

What do you mean by "Colour Free"?
Do you meant to say "Chromatic Abberation Free"?

Both mean the same thing. Chromatic Aberration is commonly refer as "false coour"... it is caused by the dispersion of the lens when different wavelengths of light will be focused on different positions. As a result, you'll see some colour fringes around the object... which is not part of the object... Basically, you'll see it at the edge of the object under bright lights if your setup contain Chromatic Aberration. See the attachment image... I use photoshop to enhance the contrast of the Chromatic Aberration to let you see what I mean... Normally, it won't be this serious... ha ha ha =P =P

Anyway, you may consider the Vixen LV 8-24mm zoom eyepiece, but it is not cheap... around S$300.

Have a nice day.

Aryanto wrote:I am looking for a zoom eyepiece since I find it hard to do nature scoping with a fixed eyepiece. :roll:

Anybody selling or have advice. I will have to try before I buy, as I have no experience. :oops:

Thanks,
Aryanto

Hi Aryanto,

Astrobargains has the Televue 8-24mm Click Stop Zoom eyepiece in stock. You can certainly try before you buy !

Best regards,

Hi Astrobargain,
I went to the website http://www.astrobargains.com/#EYEPIECES and found the description, but the link is wrong. Anyway, I went to Televue webpage and see that there is 2 types of zoom eyepiece: Nagler Zoom and Click Stop Zoom.
I hope you have patience for un-experienced buyer...
Questions:
1. What is the difference between TeleVue Nagler Zoom and Click Stop Zoom?
2. What is "click stop". It is mentioned in both TeleVue Nagler & Click Stop Zoom.
3. TeleVue Nagler zoom looks like a telescopic zoom (meaning the thing extend and retract for different "click stop". True or not?
4. Click TeleVue Stop Zoom does not. True or not?
5. They do not seem to have that continuous zoom like in camera. Is there such thing?

I don't own the nagler zoom cos it is so expensive and not that useful for my scope since it will have too high magnification and small FOV. Anyway, from the website it most probably means that the eyepiece can have different 'discrete' focal lengths. For the nagler zoom 2 to 4mm, it has fixed focal lengths at 2, 2.5, 3, 3.5 and 4mm; so a step increase in magnification. By rotating the lens section, it clicks to the focal lengths as stated. It is also parfocal for all the focal lengths meaning you don't have to refocus for the different magnification used. On the other hand a SLR camera zoom lens has 'analog' zoom meaning the zoom can be changed without having a step focal length increase. However, if I am not wrong, every time the camera lens is zoomed, it has to be refocused since the effective focal length is increased and the focal point is changed.

Hi,

1. What is the difference between TeleVue Nagler Zoom and Click Stop Zoom?

Other than the optical design (had to be different due to different zoom range) and the name =P, the main difference is the zoom range... the two TeleVue Nagler Zoom focal length range is 2mm to 4mm and 3mm to 6mm and the Click Stop Zoom focal length range is 8mm to 24mm.

2. What is "click stop". It is mentioned in both TeleVue Nagler & Click Stop Zoom.

It mean that it will "click" and stop in every selectable focal length in the zoom range.

3. TeleVue Nagler zoom looks like a telescopic zoom (meaning the thing extend and retract for different "click stop". True or not?

True. The top of the eyepiece will extend and retract as you select the different focal length in the zoom range.

4. Click TeleVue Stop Zoom does not. True or not?

Not quite sure on this, but I think the TeleVue Click Stop Zoom eyepiece does not extend or retract for different focal length in the zoom range.

5. They do not seem to have that continuous zoom like in camera. Is there such thing?

They do continuous change focal length, but will click stop at the selectable focal length. Anyway, some Zoom eyepiece do not have the click stop feature.

Have a nice day.