Tuesday, July 29, 2008

Left Hand Brace


Critter Mix for July series 1-4
Originally uploaded by Dalantech.
I’ve put off writing this tutorial for a while because the technique I’m going to describe falls into a category that I call a “cheap trick” but it’s so useful and results in such razor sharp images that I felt it was time to commit it to words.

Since I do all of my macro hand held (the critters I go after are normally too active for a tripod to be practical) I’m always looking for a way to brace the camera. First because I don’t crop and composition is important and keeping the camera steady helps me to place the critter where I want it in the frame, but also because the flash can’t freeze all the motion in the scene. No matter how short the flash duration is it will never be short enough to give you sharp details if there is a lot of movement. I’m convinced that a lot of the image softness that people blame on diffraction is really nothing more than a form of “macro motion blur”.

One trick that I’ve been using to keep everything steady I’m going to call the “Left Hand Brace” method, and here’s how it works: I’ll slowly take hold of the flower that the subject is on by pinching the stem between my left index finger and thumb. I’ll then brace the lens on that same hand and focus the scene by sliding the lens. Since the flower and the lens are all on the same support (my left hand) when one of them moves they both move so it’s easy to keep everything perfectly “still” and I have a lot of control ever where I put the area of sharp focus. Another benefit of holding onto the flower’s stem is that I can slowly rotate the flower and change the angle to get different compositions.

It doesn’t always work, and it helps if the critter is hungrier than it is scared of me, but when I am successful at holding onto the flower I can get some very unique images that are razor sharp even when shooting at high magnification and Fstops. The image included with this tutorial is a recent example of what I can do with the Left Hand Brace method.

9 comments:

pwnell said...

I know a lot has been said about flash and freezing movement, but how can you say that no matter how short the flash duration you will always get (visible/detectable) blur when there is motion in the scene?

Surely there is a limit where the flash's duration is short enough, and assuming ambient light is enough stops down that it is irrelevant, where it illuminates a subject so briefly that the distance on the CCD plane travelled during that illumination is less than one pixel - making it for all practical differences imperceivable?

Dalantech said...

@ pwnell: For a standard camera flash, or even a dedicated macro flash (like the MT-24EX that I use) the flash duration will never be short enough to freeze all of the motion at life size and higher magnification. The problem is in the level of detail that each pixel represents. The amount of detail contained in one pixel for a landscape shot is nothing compared to the amount of detail contained in that same pixel when shooting at life size, so movement during the exposure is a much greater problem when shooting at high magnification. IMHO the 1/focal length rule for setting the shutter speed doesn't apply once you hit 1/4 life size...

Also consider diffraction -it's defined as light bending as it passes though a small opening. That bending causes the light to spread out so that light rays that should only strike one photo receptor on the camera's sensor starts hitting adjacent photo receptors. So what's the difference between diffraction and a one pixel movement during the exposure? I'd argue that their effects would look almost identicle...

Once I realized that macro photography was nothing more than a form of high speed photography and I started doing what I could to eliminate camera and subject movement and to get my flash duration as short as possible then the quality of my work increased by an order of magnitude. Keep in mind as you go through my images that I always shoot at F11 (and sometimes as high as F14) even at 5x...

mack1time said...

Wow
First let me say thank you!
I just found the "no-cropping zone" and am thoroughly impressed. You have inspired me and I will slowly be reading my way through your site. Thanks for sharing your techniques for perfection!!!!
I love the fact all your images are original size and un-cropped. Also your lighting is impeccable.

Dalantech said...

Thanks mack1time! :)

Bugsfish said...

Hi John as allways fantastic and really helpfull, thanks for sharing.
Regards
Javier

SteB said...

As you know I have been using this technique I learned from seeing this blog and I can vouch for how effective it is. I will be for ever grateful for this tip, because in the windy weather we have had of late in the UK it has been a real saver. I also agree entirely that a lot of apparent softness attributed to diffraction is actually motion blur. Although of course motion blur, diffraction and lens aberrations close-up all effect image sharpness and in practice its probably difficult to separate them all.

I mentioned before using a glove, and I have found some stretch camoflauge ones (with leaf patterns on them) that might be ideal. They are the type sold for wildlife photography or shooting. I am thinking of using a finger or 2 behind the subject to prevent a black background. I haven't ordered them yet as there's a few other things I need to get at the same time. I'll let you know how it works.

Sorry for not leaving any posts before on your blog but I'm fairly new to the whole internet thing.

Dalantech said...

Thanks Javier and Steb :)

I'll have to look into the camouflage gloves -that sounds like an excellent idea!

Lukacs Zoli said...

Thank you ! I have been using your technique with a mobile phone with homemade macro lenses, with good results!

John Kimbler said...

@ Lukacs: Happy to help :)