First post
Hello!
I had a little weekend project. I wanted to identify the ants on my backyard – north of Stockholm, Sweden – and to take some photos of them. The species is probably Formica polyctena – a close relative to Formica rufa but with less hair. I had a lot of problems with reflections; finally I made a double plastic ring diffuser from two bottles and used two LED-lights. Not perfect but acceptable.
Jörgen
Nikon E plan 4/0.1
Nikon N plan ph 10x 0.30
Last edited by JH on Sun Apr 07, 2013 3:37 pm, edited 1 time in total.
These look pretty good. You could make them quite a bit bigger. The forum allows up to 1024 pixels wide. You can easily adjust the JPEG "quality" setting if needed to fit within the 300 KB limit.
I suspect there is a lot more detail that we can see in these small versions.
The larger images help a lot. Yes, excellent detail, to be expected from a 10X NA 0.30 objective.
Looking again at your lighting, it appears to me that the subject is still getting quite a lot of light direct from one of the LEDs, with the diffusers providing fill light mostly from the other side. Those blown-out highlights on the left-facing surfaces indicate a concentrated light source in that direction.
If you want more even lighting, I suggest a single layer of that diffusion material, but extended upward to form a cylinder or even better a dome that surrounds the subject as nearly as possible.
On the other hand, if you were looking to get more "dramatic" lighting, then this setup has worked very well.
An intermediate style of lighting could be to retain what you currently have, but suspend a small piece of tissue paper or other thin lightly diffusing material between the light and the subject. The idea is for the subject to be illuminated from a wide angle by light coming from the entire area of the diffuser, as opposed to a narrow angle with light coming from just the lamp.
Jacek, thanks for the nice words.
Rik, thanks again for the advice. I tried some dome-shaped diffusers. The best result - with the ant and the leds I have - was with a half ping-pong ball. But there were still some areas with unwanted reflections. For the picture bellow I had to use two dome-shaped diffusers, the ping-pong ball and a plastic coffee cup.
In this case I used sub stacks or slabs. Most areas of the picture were easy to stack. Here is an example of an area that was troublesome. The first of the two first pictures is a Dmap made from all of the pictures, the second is a Dmap made from the slabs. In this case I made the slabs with 20 pictures and a 10 picture overlap (1-20, 10-30 etc). There are some differences between the two pictures, but not much. In this case I decided to use the Dmap from the slabs as starting picture for the retouching.
I have found the slabs very useful in the retouching process. The first of the two pictures bellow shows a single frame from the stack, the next picture shows one of the slabs. Due to the little DOF in the single pictures it was much easier for me to use the slabs than the single pictures for most of the retouching work. I have some dead pixels and some dust on the sensor, to retouch this I use the single Pictures, sometimes in combination with a Dmap stack made with a very high contrast threshold.
