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Will The Real Dicyrtomina saundersi Please Stand Up
e6filmuser
Registered Users Posts: 3,378 Major grins
The session was intended to see if the insertion of a Kiron x 1.5 (OM) TC, with its curved rear surface, would solve a flare problem with the Schneider HM 40mm reversed.
The aim was to find subjects, such as woodlice millipedes and Tomocerus, shots of which (flash), with this lens, had frequently been spoiled by slightly off-centre fogging. The lens was mounted on the TC and the TC onto the OM to 4/3 and then 4/3 to m4/3.
When during the session, a yellow Dicyrtomina saundersi was found, some more magnification was needed urgently. A 21mm extension tube was all that was available at short notice and this was placed between the TC and the OM to 4/3 adapter. This gave a FOV of ca 6.5mm.
I was aware that the position of a TC in a long extension can significantly affect the magnification. However, a check found the difference here to be too small to see.
The lighting was flash, the main gun being diffused. This meant that not enough intensity was provided, a snoot being needed. So, instead of f16, or even f11, I had to use f8 to avoid the need for high ISO (ISO 400 used). This gave a DOF approximately the same as the lateral dimensions of the subject, making in-focus tracking of the springtail in motion challenging.
This individual frequently (every 10 seconds or so) stopped and reared up on its hind legs.*
This yellow form, with little dark pigment other than on the posterior of the abdomen, is the original form published by Lubbock in his monograph. I last saw one of this colour variety in the 1ate 1960s or early 1970s.
*According to Hans Jenssens, in a reply to a Flickr post:
" This behaviour is typical for Dicyrtomina. They walk about and stop suddenly to 'wave' with their first legs upwards in the air. Then continue to walk. It could be a defense behaviour. But maybe they simply try to climb up to something they 'see' but isn't there..."
There dark pattern on the rear of the abdomen is said to be a mimic of the pattern on the dorsal side of the head, deflecting a predator's aim. This does not seem to be quite in this yellow form but anyway:
http://www.collembola.org/publicat/mimicry.htm
Not a bad result for a setup test! (I think I may also have cured the flare problem but I need more shots of suitable subjects to confirm that). The TC seems to have done a good job.
EM-1, 70mm extension, Schneider FM 40mm at f8, TTL, RC Twin flash, one free-standing, hand-held.
The images have been cropped, typically by ca 50%.
I believe this may be a first, in this forum for the yellow form and for the behaviour.
Harold
The aim was to find subjects, such as woodlice millipedes and Tomocerus, shots of which (flash), with this lens, had frequently been spoiled by slightly off-centre fogging. The lens was mounted on the TC and the TC onto the OM to 4/3 and then 4/3 to m4/3.
When during the session, a yellow Dicyrtomina saundersi was found, some more magnification was needed urgently. A 21mm extension tube was all that was available at short notice and this was placed between the TC and the OM to 4/3 adapter. This gave a FOV of ca 6.5mm.
I was aware that the position of a TC in a long extension can significantly affect the magnification. However, a check found the difference here to be too small to see.
The lighting was flash, the main gun being diffused. This meant that not enough intensity was provided, a snoot being needed. So, instead of f16, or even f11, I had to use f8 to avoid the need for high ISO (ISO 400 used). This gave a DOF approximately the same as the lateral dimensions of the subject, making in-focus tracking of the springtail in motion challenging.
This individual frequently (every 10 seconds or so) stopped and reared up on its hind legs.*
This yellow form, with little dark pigment other than on the posterior of the abdomen, is the original form published by Lubbock in his monograph. I last saw one of this colour variety in the 1ate 1960s or early 1970s.
*According to Hans Jenssens, in a reply to a Flickr post:
" This behaviour is typical for Dicyrtomina. They walk about and stop suddenly to 'wave' with their first legs upwards in the air. Then continue to walk. It could be a defense behaviour. But maybe they simply try to climb up to something they 'see' but isn't there..."
There dark pattern on the rear of the abdomen is said to be a mimic of the pattern on the dorsal side of the head, deflecting a predator's aim. This does not seem to be quite in this yellow form but anyway:
http://www.collembola.org/publicat/mimicry.htm
Not a bad result for a setup test! (I think I may also have cured the flare problem but I need more shots of suitable subjects to confirm that). The TC seems to have done a good job.
EM-1, 70mm extension, Schneider FM 40mm at f8, TTL, RC Twin flash, one free-standing, hand-held.
The images have been cropped, typically by ca 50%.
I believe this may be a first, in this forum for the yellow form and for the behaviour.
Harold
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Comments
Harold
Mod Edit: I corrected the title for you.
Thanks.
I agree about the background. As it is close to horizontal, together with the foreground, it is OOF anyway and any processing exaggerates that. The next session should have the springtail taking up much more of the frame. Hopefully I can get it against the sky or distant background.
Harold
Pick it up and put it on some art paper in your dining table with some window light!
Thanks for the tip. I will also brush any debris off the springtail!
It spent most of the time on the bare wood of the garden table onto which I had placed the thin log for (relatively) comfortable photographic access. Essentially, it was, by some degree of choice (it jumped), on a bare plank of wood with prominent grain, moderated by some decay and moss cover. in view of the rarity of the subject, I persisted where I might otherwise have moved on to something else on natural wood or bark.
Harold
Brian V.
http://www.flickr.com/photos/lordv/
http://www.lordv.smugmug.com/
Thanks, Brian.
Yes, a reshoot is required. I have placed some suitable pieces of wood on the ground for them to live under, such that I won't have to use the table surface as background. It is just matter of time before I get the shots I really want.
Harold
Harold
Believe it or not, today I picked up the wood I had placed on the ground and there was a yellow one. Unfortunately, it hopped off before I could get to the camera with it.