Color fringes on Leica APO 82 (1 Viewer)

Hi,
Recently, I tried a Leica 82 scope. We can really saw yellow/blue franges (on top and bottom of image) looking to a dark part in the garden at 25m distance (at 50x). The colour franges appears at approx 10-15mm from sides.
In the same birding group, I had a friend whic also have a Leica APO 65mm. I decided to look through with searching colour franges.... and I found them :eek!:.
Is there anybody who noticed it too? I am surprised of my finding as the former 77 & 62 scopes were perfect (no colour franges).
Does it means that glass quality fluorite of 82/62 is lower than 77/62?.
Any thoughts?
Yves

yves0071 said:

Hi,
Recently, I tried a Leica 82 scope. We can really saw yellow/blue franges (on top and bottom of image) looking to a dark part in the garden at 25m distance (at 50x). The colour franges appears at approx 10-15mm from sides.
In the same birding group, I had a friend whic also have a Leica APO 65mm. I decided to look through with searching colour franges.... and I found them :eek!:.
Is there anybody who noticed it too? I am surprised of my finding as the former 77 & 62 scopes were perfect (no colour franges).
Does it means that glass quality fluorite of 82/62 is lower than 77/62?.
Any thoughts?
Yves

Click to expand...

The 77/62 televids were actually manufactured by MeOpta although sold with a Leica badge. The new 82/65 televids are made by Leica. Leica made optics including the Untravids seem to suffer terribly from colour fringing (chromatic aberration).

What eyepiece did you have on the 62/77?

Thanks PennineBirder for this info.
It is a pity for such price and brand!

@Richard: I tried the 77 with the 20-60zoom
Maybe other user may confirm it (or not?!)
Yves

yves0071 said:

Recently, I tried a Leica 82 scope. We can really saw yellow/blue franges (on top and bottom of image) looking to a dark part in the garden at 25m distance (at 50x).

Click to expand...

I wouldn't be too quick to blame the objective lens for this. Fringes consisting of two different colors, like yellow and blue, appearing on opposite sides of an object is the form of chromatic aberration called lateral color. The most likely source for that form of chromatic aberration is the eyepiece. In fact all eyepieces have some off-axis lateral color, but some are much worse than others.

One way to test this is to place the eyepiece from your scope on another telescope which does not show the same type of yellow/blue fringes with other eyepieces and/or place an eyepiece which has low lateral color on other scopes on your scope. Does the yellow/blue lateral color stay with the eyepiece or the scope body?

Thanks Henry for your comment.
When I tested the 2 scopes (with their respective zooms), it was the same
colour fringe.
I do not know who is faulty (tube or eyepiece) and honestly, it does not really matter as final feeling of the brand/model is bad

I tried 2 Leica (65 & 82) from same generation and both of them were faulty.
Is it bad luck??? or should I consider that 100% of Leica latest generation of scopes are not managing chroma & color fringe well.

It is a pity for the most expensive zoom on market: nearly 800€!!! uffff
(I do not compare with Swaro ATX ones as technology is different).
My old Kowa 823 with old 20-60 zoom (and even with my 821 too) provides better results with no fringes.

Any additionnal comments from other users?
Regards
Yves

yves0071 said:

Thanks PennineBirder for this info.
It is a pity for such price and brand!

@Richard: I tried the 77 with the 20-60zoom
Maybe other user may confirm it (or not?!)
Yves

Click to expand...

I've got the Leica APO 62 with 26x fixed eyepiece and don't see any fringing. Just over a year ago when I looked to upgrade to a more recent Leica or Swarovski with a wide angle zoom eyepiece they both showed colour fringing. As far as I could tell, only the Kowa 883 25-60 was free of colour fringing, so I bought it.

Hi,

I have also tried a Leica 82 in a store against an admittedly difficult target of branches against a grey winter sky and was not impressed (neither was the owner, as he told me). Lateral color was quite visible.

I have looked through another example in the field and found nothing really terrible in the view but of course under different conditions and it would have been a bit rude to re-point the scope to some difficult target when there's people lining up behind me for a look...

A friend from the astro club has told me that he used to own a Leica 82 but didn't like the optics and has sold it before I could try it...

I agree with Henry that lateral color is usually an eyepiece problem - on the other hand the Leica zoom is quite well regarded in the astro world as is often used with a 2" adapter in various telescopes.
Astronomers tend to be quite discerning with their optics - on the other hand this tends to be used as a planetary zoom in medium sized and larger scopes, so the circumstances might hide lateral color as this tends to be seen off axis and planets will usually be kept dead center by the motorized mount.

Joachim

@Richard, Yes, I agree with you. I also have a 883 with a 25-60 zoom. => no color fringes (but only very slight image disformations on the sides). I also have a Leica 77 & 62 both with fixed EP and zoom and no colour fringes!

@Joachim: Thanks for your feed back. I look also planets but it is not my first objective.

Yves