Flight machine

Erland · Post by **Erland** » Mon Sep 26, 2005 11:45 am

Dragonflies from the Aeshna genus are represented by six species in Denmark. These are surely the most difficult dragonflies to photograph, because of mainly two factors.
They are very aware when perched and seldom tolerate in incoming photographer.
They are on the wings for hours at a time, especially in good weather.

For me it's always a delight to follow these insects in flight, even though I do not get to photograph them.

Back in September 2003 I wanted to try out catching them in flight, what a difficult task. One species, Aeshna mixta is a bit foregiving though, as it tends to hover still for a second or two at different spots at its territorie (the males).

I did get a lot of photos back then, but am really having a hard time doing this again the lasty two years. I nearly loose my breath when trying to shoot them in flight, and remember how I had to rest a couple of times.

6th September 2003, Svanemosen Kolding.
10D, sigma 180, iso 800, cropped away 200 pixels left side.

Erland

MikeBinOKlahoma · Post by **MikeBinOKlahoma** » Mon Sep 26, 2005 5:05 pm

Chasing down a dragonfly is rough--I've tried it not even aiming for flight shots and it was bad! This is a good job.

Did you use natural light for this? If so, the shot was even harder to get. Good job.

rjlittlefield · Post by **rjlittlefield** » Mon Sep 26, 2005 6:51 pm

A very nice picture -- even caught the front & back wings in different parts of their cycles!

Erland, you might appreciate the series of three articles on Dragonfly Flight by Wakeling and Ellington, posted at
http://jeb.biologists.org/cgi/reprint/200/3/543.pdf
http://jeb.biologists.org/cgi/reprint/200/3/557.pdf
http://jeb.biologists.org/cgi/reprint/200/3/583.pdf

They have way more information than I care to digest!

--Rik

Erland · Post by **Erland** » Tue Sep 27, 2005 2:44 am

Thank you for comments.

Mike, yes this is natural light, but I've used iso 800. I just started using flash this year,and havin't figured out how to actually use fast syncronisation yet.

And thanks Rik for those links, I've always struggled to find articles and stuff on the internet. Alle three printed out now, ready to be read.

I did a new conversion of the image yesterday with RawShooter Ess, where I reduced the iso800 noise in the conversion, but I think I might have given the picture a bit to much contrast.

Erland

Ken Ramos · Post by **Ken Ramos** » Tue Sep 27, 2005 3:44 am

Well, I have no comments on the tech side of shooting dragonflies but if I had shot this, I would be tickled! Nice work Erland!

rjlittlefield · Post by **rjlittlefield** » Wed Sep 28, 2005 6:31 pm

Erland wrote:I just started using flash this year,and havin't figured out how to actually use fast syncronisation yet.

Erland, I assume this is a Canon 10D.

The way I read the specifications, the fastest flash synchronization is 1/200 sec. That will be the fastest shutter speed at which the entire focal plane is open at one time to be exposed by the short pulse of light from electronic flash.

To use flash in natural light, you need to be close enough to the subject and have your aperture and ISO set small enough that your flash will give much more light in its pulse than the natural light will give in 1/200 second. It takes a powerful flash to do this in full sun at much distance. Of course aperture and ISO must also be set so that the flash will give you a good exposure. Depending on distance and power of your flash, there may be only a narrow range of aperture and ISO that will work well.

Mike, I think you use flash a lot -- perhaps you can give us good tips? (Or correct me, if I have explained this wrong.)

--Rik

Erland · Post by **Erland** » Thu Sep 29, 2005 12:01 pm

Yes, I'm not sure if my flash (the new sigma 140 macroflash) will be powerfull enough at distance. But maybe it would be possible at 1-1,5 meter (3-5 feet) distance, which is kind of the distance one can hope to shoot large dragonflies in flight. I guess the problem is that the distance varies all the time as it can also be an ok shot at 2,5 (8-9 feet) meter distance. So it would probably produce way different lightening of the subject at the varies distances.

Anyway, yes my camera is 10D, but my flash can run fast synchronisation mode, which should allow flash-photos at shutter openings shorter than 1/200 sec. I can't see how I could produce good flight shots at 1/200. Well I just checked this photos settings, and it's done at 1/320 sec, f10, iso800 , but normally I would like a faster shutter speed.

But I'm not sure how fast synchronisation works, maybe I should try it out at home where I have the time. and a large rare dragonfly is not waiting for me to finish off, so it can move on

That is not the time for experiments.

Erland

Erland · Post by **Erland** » Thu Sep 29, 2005 12:11 pm

rjlittlefield wrote:A very nice picture -- even caught the front & back wings in different parts of their cycles!

--Rik

Well the 180 degree phase difference between front and rear wings, shows that the dragonfly is hovering, standing still.

In foreward flight the rear wings leads the front wings by a 90 degree phase.

On my picture the front wings appear to be in it's downstroke, where it produces the lift, while the rearwings has just started it's upward movement with rotated wings (leading edge upwards)

Searching the "jeb.biologists.org" site I ended up printing out about 10 articles on dragonflies, now I have something to do in the dark winter months

Thanks

Erland

Erland

rjlittlefield · Post by **rjlittlefield** » Thu Sep 29, 2005 5:14 pm

Erland wrote:But I'm not sure how fast synchronisation works...

This had me puzzled for quite a while, but I think I tracked down the explanation.

Take a look at http://www.mir.com.my/rb/photography/ha ... h/f280.htm and http://www.geocities.com/maitani_fan/stage_3_2.html, describing the Olympus F280 flash that apparently introduced this technology.

The trick is that in FP mode, the unit does not put out one big flash, but rather a string of very short low power flashes. The string lasts long enough for the shutter curtains to complete their movement, and the pulses come close enough together to produce smooth illumination even when the curtain slit is very narrow to produce a short exposure time at each pixel. For the F280, the quoted values are 20,000 pulses per second, for 1/25 second. I could not find details for the Sigma flash.

Obviously I have not kept up to date on flash technology. This electronic FP flash trick had escaped my attention, but the F280 appears to have been around for at least 5 years, possibly 10 or more.

Extending the flash duration causes some of the light to be wasted, so the guide number will be lower than usual. For the F280, the loss would be large, since most of that 1/25 second would occur when both curtains were closed. Presumably the technology has gotten better, but I have no clue how much.

I will be interested to hear what it works out to be in your tests.

--Rik

S. Alden · Post by **S. Alden** » Sat Oct 01, 2005 3:59 pm

That is great

. One in flight is very hard. Congrats on the capture.