someone knows this objective?

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soldevilla
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someone knows this objective?

Post by soldevilla »

The first lens I bought is a Leitz 170 / - L20 0.32 with integrated iris, some years ago. I have not used it too much because I prefer the Nikon, but this Leitz has the advantage that the cylinder measures just 10mm and allows me to illuminate my samples much better. but it always shows a chromatic aberration that I do not like. Does anyone have experience with this objective? Do you need any additional lens?

Ichthyophthirius
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Post by Ichthyophthirius »

Hi,

They don't need additional lenses but they do need compensating (Periplan) eyepieces. They are meant for inverted microscopes. The NA is very low so they can be used for a variety of slide/coverslip thicknesses.

The optical performance is never that great, even with Periplan eyepieces.

Regards,

Ichty

soldevilla
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Location: Barcelona, more or less

Post by soldevilla »

Thanks. I not have a Periplan eyepiece, but I own a lor of eyepieces for telescope. I will try some of them.

Lou Jost
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Post by Lou Jost »

No Soldevilla, his point is that Leica objectives do not correct all the CA, and need specific Leica (or similar) eyepieces to correct this specific amount and type of CA. This strategy was common among microscope manufactures manufacturers until Nikon started making CF objectives which correct all the CA (edit: that is, they correct all the CA BEFORE the image reaches the eyepiece, instead of relying on the eyepiece to do the correction, as Leica does).
Last edited by Lou Jost on Mon Dec 03, 2018 10:44 am, edited 1 time in total.

ChrisR
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Post by ChrisR »

I have one of those. It was the first objective I bought, about 10 years ago. It had an iris so I though it night be good for extra depth of field :roll: .

I used it to look at an EPROM chip and found, as you have, quite a lot of CA!
I was told it needed a projection eyepiece so I fond one - only to discover that it was for projecting, via a mirror, onto a screen :roll: :roll:
Chris R

soldevilla
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Location: Barcelona, more or less

Post by soldevilla »

I´ve found my projection eyepiece. I have unmounted it for cleaning and i have found that it is a very simple Huygens eyepiece :smt089 . I go to test an Ortho. Is the same design but both lens are a achromatic group.

PD. I have tested a 12,5mm eyepiece. Too much! only 0,2mm of field. I think I have a 40mm eyepiece, but it will not enough, I feel.

soldevilla
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Joined: Thu Dec 16, 2010 2:49 pm
Location: Barcelona, more or less

Post by soldevilla »

Nothing, I have tried everything I have and I do not get any major improvement. I have discovered fun things, as using a photographic duplicator between the lens and the camera. I expected that I would not get any image but yes, there is image and it is not especially bad; or place it in front of a photographic lens as if it were infinite (which has given me good results with other microscope objectives) with a result of a lot, too much increase. A 200mm telephoto lens produces a FOV of only 0.2mm.. But it does not surpass what I get with my finite lenses, so this objective will be filled with dust in the drawer.

ChrisR
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Post by ChrisR »

I expect youhave this - see P57:
http://www.science-info.net/docs/leitz/ ... ystems.pdf

"DO" means "with or without cover glass". (So it's not the same as mine)
this objective will be filled with dust in the drawer.
Be careful, they breed. I put two lenses like that in a drawer, and now it's full...
:-k
Chris R

Lou Jost
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Post by Lou Jost »

As I mentioned above, nothing will fix it except tmatched CA-correcting eyepieces/ projecting lenses. Stick with Nikon and modern Olympus objectives to avoid this problem. They correct all the CA. Other brands usually leave the CA partially uncorrected, and make matching eyepieces and projective lenses that do the work of correcting the CA.

soldevilla
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Joined: Thu Dec 16, 2010 2:49 pm
Location: Barcelona, more or less

Post by soldevilla »

ChrisR wrote:I expect youhave this - see P57:
http://www.science-info.net/docs/leitz/ ... ystems.pdf

"DO" means "with or without cover glass". (So it's not the same as mine)
this objective will be filled with dust in the drawer.
Be careful, they breed. I put two lenses like that in a drawer, and now it's full...
:-k
No, I did not know him. Thank you very much for that information, ChrisR.

I already have a few lenses in the drawer. Some I've been giving to friends who start with the microphotography. But I do not spend too much money on objectives. My hobbies pretend to eat my salary, and I must be very careful with my VISA. :roll:

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