Amber inclusion photography

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: Pau, rjlittlefield, ChrisR, Chris S.

Hon-shimeji
Posts: 30
Joined: Mon Mar 18, 2013 6:57 am
Location: Uppsala, Sweden

Amber inclusion photography

Post by Hon-shimeji »

Hi all,

I would like some tips about what objective to use together with my Olympus BH2 equipped with the UMA-illuminator (that I've bought but not received yet) for taking photos of amber inclusions?
I have a Olympus ulwd cd plan 40X objective with correction collar, but is this objective suitable for epi-illumination with the UMA? Since the objects I want to capture is 1-2 mm below the amber surface I thought the correction collar would be able to compensate for this. The amber has a refractive index of about 1.54 which is pretty much the same as glass.
Maybe a metallurgical objective with long working distance is better? But then I won't be able to compensate for the amber thickness...
Then I saw somewhere in the forum that it is necessary to use a polarisator to get a good image with bright field settings and epi-illumination, is this so?

Thanks in advance!

/Henrik

Pau
Site Admin
Posts: 5305
Joined: Wed Jan 20, 2010 8:57 am
Location: Valencia, Spain

Post by Pau »

In principle, if the working distance is enough to foucus the inclusion your approach seems to be the best one to avoid spherical aberration, and 40X objectives are very prone to this issue. At lower magnification the issue is less relevant and external incident illumination more doable

A good tric seems to put a coverglass oiled to the amber to have a flat clean surface: http://www.photomacrography1.net/forum/ ... 0509#20509
Then I saw somewhere in the forum that it is necessary to use a polarisator to get a good image with bright field settings and epi-illumination, is this so?
If not 100% necessary, it would be convenient in most cases to avoid glare due to reflections both from the optical surfaces of the objective lenses and subjet, even more if the objective is not specifically designed for this application
Pau

Hon-shimeji
Posts: 30
Joined: Mon Mar 18, 2013 6:57 am
Location: Uppsala, Sweden

Post by Hon-shimeji »

Thanks Pau!

JH
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Joined: Sat Mar 09, 2013 9:46 am
Location: Vallentuna, Stockholm, Sweden
Contact:

Post by JH »

Hi Henrik
I am very interested in finding out what results you will get with your setup. I have tried with a Nikon CF N 60 0.70 LWD with a correction ring for glass thickness, it works but it is difficult to get usefull pictures of amber inclusion with such high NA objectives. I do recomend the use of a coverslip and some glycerol or microscope oil. My best pictures have been with low NA objectives for example
www.photomacrography.net/forum/viewtopic.php?t=26079

Regards Jörgen

Hon-shimeji
Posts: 30
Joined: Mon Mar 18, 2013 6:57 am
Location: Uppsala, Sweden

Post by Hon-shimeji »

Hi Jörgen,

I'll let you know the results when i get the illuminator. The problem is I won't get the pictures I want with low power objectives since the things I want to capture (tiny fungi) is around 50-70 micrometers in length.

Regards,
Henrik

Beatsy
Posts: 1652
Joined: Fri Jul 05, 2013 3:10 am
Location: Malvern, UK

Post by Beatsy »

I successfully photographed a fly in amber with trans illumination by thinning down the amber until the fly was almost at the surface. Very fine wet&dry paper stuck to a piece of plate glass for the initial grinding then finished to a high gloss using 20k grit paper (as used for polishing the end of fibre optic cables), but brass polish give a pretty good finish too.

Assuming you can do this to your sample I imagine it would work very well for higher powers. I think you'd get a lot of glare with epi - though crossed polars could help reduce it.

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