Butterflies

[doenoe]

Hello,

last week i did a little experiment in the butterfly garden of amsterdam zoo. Alot of the times i shoot butterflies there, i end up with a dark or black background. It can look really good, but now i wanted to try and get some white backgrounds. So i took a piece of white paper with me and held it behind the butterfly. So i kept my camera in one hand and the piece of paper in the other. The thing is that i have a 105mm macro lens and rather short arms, so to get the whole butterfly in frame i was stretching the live out of my arms.
These are shot with a Canon 50D, Sigma 105 2.8 macro and a Speedlite 430EX with a Lumiquest softbox on it. Settings were: 1/200, ISO100, F14







Thanks for looking
Greetz Daan

[Planapo]

Beautiful, Daan! I love the composition!

I would have thought you had set it all up in a studio, but reading your explanation how these were shot, I am even more in awe! Definitely worth muscle ache of your arm the next day.
Thanks for posting the details, and the lovely pictures of course!

--Betty

[ChrisR]

INteresting technique Daan, some striking compositions.

As the background is "irrelevant" here:-

If you moved back so your field width was say 60mm instead of 30mm, you'd get about three times the depth of field. It would go from about 2mm to 6mm. You would have to crop the middle out of the picture, of course, but it would be sharper overall.
And you'd have to get longer arms, or another pair, on legs.

A shorter lens from the same position would increase your field width with the same result.

SO, girlfriend or new lens? I know which is cheaper...

(and I hope someone checks my sums)

[Charles Krebs]

Really beautiful images.

All great... but that second one....!!!

[rjlittlefield]

Wonderful images! Clearly a case where I would never guess from looking at the photograph, what the photographer was doing.

I'm afraid there are some hidden assumptions buried in ChrisR's sums. Let's see if I can puzzle through this.

It's true that you get more DOF when you back off to shoot and then crop to the same final size, assuming that you use the same aperture setting in both cases. The increase in DOF is easily explained by looking at the cone angle: same aperture but more distance gives a narrower cone; narrower cone causes more DOF. Doubling the distance doubles the DOF.

But that's not the whole story.

When you back off, you also make the flash less intense at the subject location. Doubling the distance cuts the flash intensity by 4X. So you end up either increasing the flash power/duration by 4X, or you end up making the aperture bigger. If you choose the second route (making the aperture bigger), then what's needed is a 2X larger aperture, and your DOF is right back where you started. Or if you choose the first route, increasing the flash power/duration, then you could equally well have used that same higher power/duration at the original distance, with a 2X smaller aperture, and again gotten the same DOF at both distances. This works as long as the smaller aperture can actually be set, which it can in this case since that Sigma lens stops down to f/45 on Canon.

So I think it's a wash for DOF. Use whatever distance is convenient, and stop down for whatever DOF you want. At some point you'll be limited by diffraction, but that turns out to be a wash too -- the tradeoffs are not affected by distance as long as you can set corresponding apertures.

The backing-off trick is useful in some circumstances, notably when you can't stop down as far as you'd like by adjusting the aperture. That happened more often back in the days of film, when fixed ISO required a certain minimum exposure to get a usable image. With digital you have more freedom to make tradeoffs, so backing off for DOF doesn't help as often. The big exception is when working with compact digitals, which often bottom out at say f/8 even though the photographer might be willing to trade off some more sharpness in exchange for more DOF.

Hope this helps -- nice images!

--Rik

[LordV]

Worked well - can see you taking a selection of different coloured BGs next time

Brian v.

[ChrisR]

I checked the numbers. If you keep the same F number (14) on the lens, and back off to make the field width 60mm instead of 30, on a 23.6mm sensor, DOF does go from (approx) 2mm to 6mm. Hence my 3x.
But when you crop, you have to enlarge more, so the DOF sums should use a smaller Circle of Confusion. When you do that, you get back to 4mm, which is 2x.

So as had been said before, it would be good to decide up front what size print you want, and work out from that what aperture you can get away with.
I'd like a row of these and the next few you're going to take( ) on a wall each about a foot high.

This is sort-of begging a question - do you need more DOF?? Well I thought these would benefit from a bit more, as we're seeing them on screen. Just trying to be helpful!
These look as though they might have been still enough to take a few pics to stack. Is that so??

[doenoe]

First of all, thanks for the kind words
Also, this has been a pretty interesting thing to read. I havent done alot of stacking, maybe i should try that sometime. Wont have the white background then, cause ill probably need both hands to keep the camera steady. Ill try and see if i can get a higher F-number next time, i think the flash can still handle it. Just have to try it i guess.

[Harold Gough]

If you moved back so your field width was say 60mm instead of 30mm, you'd get about three times the depth of field.

I use this principle quite a lot for hand-held macro.

SO, girlfriend or new lens? I know which is cheaper...

If you don't like the lens you can send it back and get a refund.

Harold

[Harold Gough]

So i took a piece of white paper with me and held it behind the butterfly. So i kept my camera in one hand and the piece of paper in the other.

Great results, Dan.

I have found that this technique is usually awkward, mainly with the paper curling slightly, sometimes giving uneven lighting. A piece of card is better. I carry a Grey Card with me for metering purposes and its back is white. (Any such white surface has an alternative use, as a reflector).

Harold

[doenoe]

thank you
And i had several A4 pieces of paper on a stack and foulded them twice. So it didnt curling that much. I wasnt planning on using that as a background, but i wanted to use it as a reflector. But after 2 shots i found out it was easier too use it as a background (easier, not easy )

[Harold Gough]

thank you
And i had several A4 pieces of paper on a stack and foulded them twice. So it didnt curling that much. I wasnt planning on using that as a background, but i wanted to use it as a reflector. But after 2 shots i found out it was easier too use it as a background (easier, not easy )

Dan, be careful using the word "paper" around butterflies. "Papered" butterflies are dead ones in a folded, envelope-like, sheet of paper for storage or for posting. They are sensitive creatures!

Harold

[AndrewC]

Lovely pictures Dan.

Tips to make life easier, perhaps:

1)Buy a "plamp", makes life a lot easier for holding backgrounds in place

http://cgi.ebay.co.uk/The-Plamp-by-Wimb ... 2ea8fc901e

2) Try a monopod for the camera - not as cumbersome as a tripod but takes the strain off your arms. I saw a guy using a monopod with a Novoflex Magic Ball head on top several months ago - at first glance it looked a bit clumsy but he let me have a play and it was really, really easy to use.

EDIT: it was a BOGEN 3265 pistol grip ballhead

Andrew

[Harold Gough]

Tips to make life easier, perhaps:

1)Buy a "plamp", makes life a lot easier for holding backgrounds in place

http://cgi.ebay.co.uk/The-Plamp-by-Wimb ... 2ea8fc901e

How refreshing to find affordable Wimberley hardware!

Harold

[AndrewC]

Tips to make life easier, perhaps:

1)Buy a "plamp", makes life a lot easier for holding backgrounds in place

http://cgi.ebay.co.uk/The-Plamp-by-Wimb ... 2ea8fc901e

How refreshing to find affordable Wimberley hardware!

Harold