Macro Exercises #2 Focusing.
Lord Vetinari
Registered Users Posts: 15,901 Major grins
As demonstrated in exercise #1 macrophotography suffers from one big problem- lack of DOF. This means accurate focusing is critical in most macrophotography. Unless you are using a tripod with a remote and have a flat subject which is well lit, it also means manual focusing has to be used.
Why manual focus ?
1. Macro lenses tend to have slow AF which will not keep up with any movement.
2. You are often in a low light situation due to the magnification where the AF will not lock anyway.
3. The camera does not know what part of the subject you are trying to focus on and by the time you have changed focus point or locked focus point, often the subject will have moved.
By developing and practicing your own MF technique you can considerably increase the number of keepers you get.
Exercises.
Fraid we need the 1/2" flat headed screw again for this. Set the camera in M mode ISO200, 1/200th, Fll with external flash in ETTL mode or the onboard flash popped up. Set the lens to manual focus and minimum focus distance. Stand the screw on a table near the edge on it's base so it's pointing at the ceiling. Try taking 3 shots of the tip of the screw at an angle of about 45' to the table under the following conditions.
1. Without touching the table of anything else, try to hold focus on the screw tip and take 3 pics.
2. Again without touching the table try moving gently back and forth with your body and take 3 pics as you pass through the focus point.
3. With your elbows resting on the table take 3 pics.
4. Find a pole eg a broom handle, grip the pole in your left hand whilst also holding the camera and without leaning the pole on the table, slide the camera to the focus point and take 3 pictures.
One hint on doing this- the eye/ brain often fool you in doing this by interpreting "most in focus" as being in focus. This means that you will often back focus something like a screw tip or an insects eye becuse you tend to regard seeing more in focus (ie actually back focused) as being in focus- hope that makes sense
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Check the pictures for focus accuracy and precision. (accuracy means did I get the focus where I wanted it, and precision means did I get the focus point in a similar place in each of the 3 pics even if it was not in the correct place.
You should find you get better accuracy and precision with 3 & 4 than 1 & 2.
With some practice you should find you get better accuracy and precision with 2 over method 1. If you try and hold focus whilst taking a shot you are much more likely to get muscle tremors than if you are moving.
In nearly all my macrophotography I set the magnification I want before approaching the subject, by preference I would then try to lean on something- the ground, a wall or even myself (ie elbows on knees) or if the subject is on a solid surface I rest the lens on the same surface. Failing that I use a bean pole to stabilise the camera, move in slowly to near the focus point and then use the sway technique to accurately focus and take the pic.
I suspect I slow my breathing down when doing this but certainly do not hold my breath.
One point about the swaying method is that once you get used to it you can use it even when the subject is also moving - often the case in macro.
As an output from this exercise I would just like to know which method you had the most sucess with in terms of accuracy and precision - just put the methods in order best to worse.
Brian V.
Why manual focus ?
1. Macro lenses tend to have slow AF which will not keep up with any movement.
2. You are often in a low light situation due to the magnification where the AF will not lock anyway.
3. The camera does not know what part of the subject you are trying to focus on and by the time you have changed focus point or locked focus point, often the subject will have moved.
By developing and practicing your own MF technique you can considerably increase the number of keepers you get.
Exercises.
Fraid we need the 1/2" flat headed screw again for this. Set the camera in M mode ISO200, 1/200th, Fll with external flash in ETTL mode or the onboard flash popped up. Set the lens to manual focus and minimum focus distance. Stand the screw on a table near the edge on it's base so it's pointing at the ceiling. Try taking 3 shots of the tip of the screw at an angle of about 45' to the table under the following conditions.
1. Without touching the table of anything else, try to hold focus on the screw tip and take 3 pics.
2. Again without touching the table try moving gently back and forth with your body and take 3 pics as you pass through the focus point.
3. With your elbows resting on the table take 3 pics.
4. Find a pole eg a broom handle, grip the pole in your left hand whilst also holding the camera and without leaning the pole on the table, slide the camera to the focus point and take 3 pictures.
One hint on doing this- the eye/ brain often fool you in doing this by interpreting "most in focus" as being in focus. This means that you will often back focus something like a screw tip or an insects eye becuse you tend to regard seeing more in focus (ie actually back focused) as being in focus- hope that makes sense
.Check the pictures for focus accuracy and precision. (accuracy means did I get the focus where I wanted it, and precision means did I get the focus point in a similar place in each of the 3 pics even if it was not in the correct place.
You should find you get better accuracy and precision with 3 & 4 than 1 & 2.
With some practice you should find you get better accuracy and precision with 2 over method 1. If you try and hold focus whilst taking a shot you are much more likely to get muscle tremors than if you are moving.
In nearly all my macrophotography I set the magnification I want before approaching the subject, by preference I would then try to lean on something- the ground, a wall or even myself (ie elbows on knees) or if the subject is on a solid surface I rest the lens on the same surface. Failing that I use a bean pole to stabilise the camera, move in slowly to near the focus point and then use the sway technique to accurately focus and take the pic.
I suspect I slow my breathing down when doing this but certainly do not hold my breath.
One point about the swaying method is that once you get used to it you can use it even when the subject is also moving - often the case in macro.
As an output from this exercise I would just like to know which method you had the most sucess with in terms of accuracy and precision - just put the methods in order best to worse.
Brian V.
0
Comments
One thing I should mention if you are trying manual focus is to make sure your viewfinder dioptre adjustment is correct.
Just look through the viewfinder at a fairly bright subject and without focusing on it move the dioptre adjustment wheel until the focus points in the viewfinder appear sharp. Then check the adjustment by using the lens in manual and the camera on a table withy a printed box as a subject (well lit) move the camera towards the subject and see if you get focus confirmation by half pressing the shutter when you think it's in focus in the viewfinder. take a few pics just to make sure.
Brian V.
http://www.flickr.com/photos/lordv/
http://www.lordv.smugmug.com/
Now listen up folks, Brian doesn't mean go out and get drunk when he talks about swaying okay
... Skippy
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Skippy (Australia) - Moderator of "HOLY MACRO" and "OTHER COOL SHOTS"
ALBUM http://ozzieskip.smugmug.com/
:skippy Everyone has the right to be stupid, but some people just abuse the privilege :dgrin
I was out shooting crab spiders today in less than ideal conditions and when I stepped back to take a break I noticed that I was breathing hard. I wasn't holding my breath, but I had slowed it down for too long.
If I'm shooting below life size I use the focus ring after composing the image, then move my body slightly to fine tune. If I'm shooting above life size then I rock back and forth like a mental patient!
Put a monopod on order today...
Looking for tips on macro photography? Check out my Blog: No Cropping Zone.
Today I found a LadyBug, she was in the Apple Tree too high for my reach, so I simply moved her to where I could get better access.
I use the Sway method, cause be danged if I can hold still
I hold the shutter half way down and I sway ever so slightly back and forth.
Really there is not point trying to refocus especially if your hand holding because at some stage your going to be back out of focus
I find holding my breath I forget to breath and end up gasping as I try to hold my breath and sway at the same time.
Yup today I was very happy with my result but I think that can be improved when I no longer have to hand hold my flash
Thanks for the lesson Brian ....... Skippy
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Skippy (Australia) - Moderator of "HOLY MACRO" and "OTHER COOL SHOTS"
ALBUM http://ozzieskip.smugmug.com/
:skippy Everyone has the right to be stupid, but some people just abuse the privilege :dgrin
Thanks for the lessons. I have been trying to use your swaying technique. I have some more practicing to do.....
T
www.studioTphotos.com
"Each day comes bearing its own gifts. Untie the ribbons."
----Ruth Ann Schubacker
My favourite methods were swaying through the focal point,
elbows resting on table (if available)
with pole.
All these methods gave good results imho. a combination of the pole with swaying i think is the best.
Something to rest your elbows on would be great but i dont think there would be situations that would permit it.. but wedging up against a tree or fence or anything as well as wedging my elbows into my stomach would be a good idea.
Here is my pic of what i shot after i did the exercise .
f/11, 1/200, onboard flash fev -1.0, outside light..
Its a flower bud on a tree, dont know which one.
Thanks for a great tutorial.
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Most macro shooters will try to rest on something if it's available - I often end up resting the camera on bits of me.
Focus looks good in the pic- rhink it's a bottlebrush or similar (callistemon)
Brian V.
http://www.flickr.com/photos/lordv/
http://www.lordv.smugmug.com/
My eyesight isn't perfect, so I wouldn't mind having a way to check the focus when shooting macros - aside from checking the image afterwards in the lcd window or looking at them later on the computer screen. Any thoughts on this?
Thanks,
Gretchen
My SmugMug Galleries
I've seen other threads that recommend using live view to check focus before tripping the shutter. There may also be a magnify button available to check focus in live view even more closely (there is on my D90)
GeorgeM
Gretchen - for checking for dust I think a high power magnifiying lens would be better and easier to use if you also want to remove the dust with a small brush or something. If you have a photo editing programme, it's not normally too hard to clone out the offending dust from a photo unless there is a lot of it when it becomes a bit tedius.
Re focus aid for taking the shots. This is more difficult, I have tried a slightly magnifying viewfinder magnifiier but of course this also makes the viewfinder slightly dimmer as well and I gave up using it after a while. Depending on you camera you can use liveview on the lcd panel with magnification to check focus. Last suggestion would be to just focus bracket your shot by moving focus slightly + or - from where you think the focus point is and take 3 shots altogether.
Brian V.
http://www.flickr.com/photos/lordv/
http://www.lordv.smugmug.com/
Gretchen
My SmugMug Galleries
This thread has definitely given me a lesson in camera advancement and I am glad you came first to serve as an example of view finding with bad eyesight, haha. I have been having some preview issues as well and was just about to pull the trigger on this software that promised me all of the things I feel are impossible. I have followed the guidance given to you and am quite pleased as I am trying to get better reviews online for my photography business. Do you guys ever check out Angie's List to see what the competition is up to?