a coopertive subject
Hold that pose
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- jaharris1001
- Posts: 319
- Joined: Fri Jun 29, 2007 6:26 pm
- Location: Deltona Florida
Hold that pose
Jim
"I'm growing older,, but not up " Jimmy Buffett
"I'm growing older,, but not up " Jimmy Buffett
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- Location: Sourthern California
- jaharris1001
- Posts: 319
- Joined: Fri Jun 29, 2007 6:26 pm
- Location: Deltona Florida
Thanks Roy,, this was shot using a Sigma 105mm macro lens with a f11 aperture. Thanks for looking and commenting,, good luck with your new lensRoy Patience wrote:Jim,
.
What focal length and aperture? I'm trying to decide between and new 150 mm and 180 mm.
Thanks for sharing.
Roy
Jim
"I'm growing older,, but not up " Jimmy Buffett
"I'm growing older,, but not up " Jimmy Buffett
- Erland R.N.
- Posts: 335
- Joined: Mon Aug 07, 2006 5:20 pm
- Location: Kolding, Denmark
- Contact:
A nice photo of the female Blue Dasher, showing the heat-reducing obelisk posture.
I would have preferred a bit more blurred background, which could have been achieved by a slightly larger aperture, or a bit less distance to the dragonfly (or a longer lens like the 150 mm). But to be honest I think the dragonfly still stand out clear from the background.
Erland
I would have preferred a bit more blurred background, which could have been achieved by a slightly larger aperture, or a bit less distance to the dragonfly (or a longer lens like the 150 mm). But to be honest I think the dragonfly still stand out clear from the background.
Erland
- jaharris1001
- Posts: 319
- Joined: Fri Jun 29, 2007 6:26 pm
- Location: Deltona Florida
Thanks Erland,, how do you tell the males from the females ? I feel as you do on the backround,, like you said if I used a larger aperture I think it would have been better,, and that big stick on the bottom left is disstracting too,, I do like the dragon and her pose though,, thanks for commenting,,
Jim
Jim
Jim
"I'm growing older,, but not up " Jimmy Buffett
"I'm growing older,, but not up " Jimmy Buffett
- Erland R.N.
- Posts: 335
- Joined: Mon Aug 07, 2006 5:20 pm
- Location: Kolding, Denmark
- Contact:
Jim, in many of the dragonflies (like this species) the appendages at the end of the abdomen, differs in appearence between males and females.jaharris1001 wrote:Thanks Erland,, how do you tell the males from the females ?
Jim
The males got two long upper appendages, and they are rather long and close to each other.
The females appendages are often placed with some more distance between them (seen clearly in this picture), and they are in many species somewhat shorter.
Males always got a third appendage: the inferior one (lower), below the two supperior (two upper) appendages. The male use those three appendahes to grab the females head, so the mating wheel can be formed.
The females two appendages serves no function.
Also males got the secondary genitalia at the other end of the abdomen, under the 2nd segment.
Many females have what is called a vulvar scale (like the species here), where eggs will exit when laid, while other species have a functional ovipositor, the is like a needle that is stuck into plants etc. when eggs are laid. Both vulvar scale and ovipositor is placed under the 8/9th segment, that is quite close to the tip of the abdomen.
In many species females have a thicker abdomen.
In many species colours can tell which sex it is, as the males mature to a different colour.
In your previous picture of a male, I could see it was a male, because blue colour was forming on the upperside of the abdomen.
I got a page comparing two very similar dragonfly species, and here you can see females and males, and some of the differences I mentioned above:
http://home1.stofanet.dk/erland_refling ... tum_uk.htm
Hope this makes sence
Erland