First go at Dodt

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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LouiseScot
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Joined: Tue Jul 07, 2020 1:51 pm
Location: Scotland

First go at Dodt

#1 Post by LouiseScot » Sun Apr 04, 2021 7:38 pm

I was reading about Dodt illumination and was quite intrigued by it. It's just a particular form of oblique illumination and supposed to involve a gradient. As this is my first go I think I probably need to do some fine tuning... :)

Here's a diatom strew with some crops using the Nikon 40/0.85 and 3W violet-blue LED. Images taken with a mono camera. I've been testing out the violet-blue LED though I find it strange that it looks violet-blue to the naked eye but turns into a deep blue when viewed through an ocular. Maybe this is something to do with the short wavelength interacting with the glass/lenses? Tomorrow I'll take some shots with the dslr and see what colour it comes out as :)

Anyway, here is whole field (diatom strew) and some crops:

Dodt_Med_Nikon_40x_a_415nm_38pc_001.jpg
Dodt_Med_Nikon_40x_a_415nm_38pc_001.jpg (104.22 KiB) Viewed 1367 times

Dodt_Med_Nikon_40x_a_415nm_Crop100pc80pc_001.jpg
Dodt_Med_Nikon_40x_a_415nm_Crop100pc80pc_001.jpg (56.7 KiB) Viewed 1367 times

Dodt_Med_Nikon_40x_a_415nm_Crop100pcb_001.jpg
Dodt_Med_Nikon_40x_a_415nm_Crop100pcb_001.jpg (45.73 KiB) Viewed 1367 times


Dodt_Med_Nikon40x415nmCrop100pc50pc_002.jpg
Dodt_Med_Nikon40x415nmCrop100pc50pc_002.jpg (36.59 KiB) Viewed 1367 times


Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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75RR
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Location: Estepona, Spain

Re: First go at Dodt

#2 Post by 75RR » Sun Apr 04, 2021 7:58 pm

Here's a diatom strew with some crops using the Nikon 40/0.85 and 3W violet-blue LED.
I've been testing out the violet-blue LED though I find it strange that it looks violet-blue to the naked eye but turns into a deep blue when viewed through an ocular.
For my peace of mind - What precautions are you taking to protect your eyes?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

LouiseScot
Posts: 1167
Joined: Tue Jul 07, 2020 1:51 pm
Location: Scotland

Re: First go at Dodt

#3 Post by LouiseScot » Sun Apr 04, 2021 8:40 pm

75RR wrote:
Sun Apr 04, 2021 7:58 pm
Here's a diatom strew with some crops using the Nikon 40/0.85 and 3W violet-blue LED.
I've been testing out the violet-blue LED though I find it strange that it looks violet-blue to the naked eye but turns into a deep blue when viewed through an ocular.
For my peace of mind - What precautions are you taking to protect your eyes?
Hiya

It's not UV, it's visible light. As I mentioned above it looks a deep dark blue through the oculars and is really difficult to see much detail. So I'm basically just using the camera monitor anyway.

Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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