Macro Help

rjackjames · Feb 15, 2009

I ordered a Sigma 150 mm macro lens, the Extension tubes 12, 20, 36 mm and a macro flash but for some reason, it keeps hunting for a focus lock.

I tried using the extension tubes and the lens and the macro flash outdoors and its still searching for a focus lock?

Please help or any advice.

Battou · Feb 15, 2009

Manual Focus.

With any real serious Macro work, especially with the use of extention tubes you are considerably reducing the amount of light that reaches the film plain/censor, this is in turn causing the AF issues you are having.

this high key macro taken with the use of a bellows left my viewfinder so dark to the point my split screen would not work and if a manual focus split screen is having difficulty forget auto focus points.

JerryPH · Feb 15, 2009

You are not making sense... why extension tubes on a lens that can already do 1:1 macro? Not a good idea, if I understand you in the first place.

- Is your lens on a camera that is rock solid tripod mounted? (the 105mm is about the biggest you can go hand-held)

- are you shooting in enough light so that the camera can focus? (Even if you are using flashes, the camera focuses BEFORE the flashes even work)

- 99% of macro shots should be focused manually anyways, especially with the lens you have.

I have the Sigma 105mm F/2.8 macro and never had issues with autofocusing, as long as there was adequate light for the camera to be able to focus. If not, I use a little flash-light to assist it's focusing, let it focus, turn off the light and depress the shutter button the rest of the way.

Battou · Feb 15, 2009

JerryPH said:
You are not making sense... why extension tubes on a lens that can already do 1:1 macro? Not a good idea, if I understand you in the first place.

- Is your lens on a camera that is rock solid tripod mounted? (the 105mm is about the biggest you can go hand-held)

- are you shooting in enough light so that the camera can focus? (Even if you are using flashes, the camera focuses BEFORE the flashes even work)

- 99% of macro shots should be focused manually anyways, especially with the lens you have.

Using extention tubes on a macro lens that is capable of 1:1 is not an unorthodox practice, merely entering into the range of super macro by exceeding 1:1, I do it with some frequency.

rjackjames · Feb 15, 2009

JerryPH said:
- are you shooting in enough light so that the camera can focus? (Even if you are using flashes, the camera focuses BEFORE the flashes even work)

- 99% of macro shots should be focused manually anyways, especially with the lens you have.

Its a bit cloudy outside and I am shooting like in the f8-16 ranges, I am using the sigma 150mm macro and the MR14EX flash, so i can seem to find the problem hmmmm..........i should have did my homework a little more?

Battou · Feb 15, 2009

f8-16 ranges, yup that'll do it.

Don't feel bad, half of the homework is hands on field work anyway

rjackjames · Feb 15, 2009

Battou said:
f8-16 ranges, yup that'll do it.

Don't feel bad, half of the homework is hands on field work anyway

Yea practice some more when the weather gives me a chance.

rjackjames · Feb 18, 2009

I need some Help? My Sigma 150mm lens seems to be autofocusing very slow? is that common with all macro lens? Please advice if i have a defective lens.

Overread · Feb 18, 2009

Right first off yes macro lenses are slower then normal lenses for auto focus - even with the HSM motor in the sigma its still a slower lens. Auto focus is just not a prime requirement of macro photography and you will notice that you have to turn the focus wheel a lot to move the focus, because its so precies that means there is even more range for it to move through before it can get to the right focus point.
Now the lens does have a limiter switch which you can use to limit which region of the lens will use AF for - that can help if you using it for normal work and don't want it to go through all the macro focusing points.

Do practice to get manucal focusing right- the way I do it is to set the focus wheel all the way over to the closest it can focus (max magnification factor point as well) and then move yourself and the camera close to the subject to aquire focus. If you have AF turned off you can half press the shutter button whilst doing this. That will do two things - firstly it will give you a red af lock on in the viewfinder when you get your foucus right (at the focal points you have active) not essential but can be handy in dimmer light - secondly it means when you hit the shutter you have less distance to press the button and thus make less shake on the camera.

Also try rocking gently back and forth when you get near the point of focus so that you can get it right where you want it in a shot

edit - this might also be of interest to you:
http://www.thephotoforum.com/forum/...rters-extension-tubes-macro-test-results.html
results with the 150mm macro when combined with teleconverters and extension tubes

rjackjames · Feb 18, 2009

Thanx, I tried it in even bright conditions and I dont even get a lock or a beep. So i am wondering if I have a defective lens. I am on vacation right now, so I have to worry about this lens wen I get back i was hopeing to do some macro work while on vacation, i guess not.

Overread · Feb 18, 2009

for macro work you don't need the AF though - turn it into manual mode and then make sure your diopter is set right and then shoot away. If there is an error with the AF it won't impact your shooting that way at all.

The camera should be able to get a lock onto normal subjects (as I say Af at macro distances is not always going to work - ok on butterflies (there is a lot of target

) but smaller things its just not a help to macro work)

rjackjames · Feb 18, 2009

I am using it for flowers since there its alot around where I am at.

table1349 · Feb 18, 2009

rjackjames said:
I need some Help? My Sigma 150mm lens seems to be autofocusing very slow? is that common with all macro lens? Please advice if i have a defective lens.

First question: Yes
Second question: No

The defect in this equation is you using auto focus for macro. Switch AF off and focus by hand and body movement. First, find a small still object similar to your intended subject and focus on it at the working range you want to use. (If you are shooting static subjects, coins, small parts etc then just use the subject) Usually you are going to want to be very close to the minimum focusing distance.

Now focus on your intended subject by moving you and the camera body back and forth until the subject is in focus. Need a wider shot move back a touch and re-focus by hand. After you have set your initial focus you will be in range to easily adjust.

Keep in mind that most macro lenses are marvelous for other uses. My Canon 100mm f2.8 is an outstanding portrait lens, crisp, sharp and vibrant. For those times I use AF. For macro it is always manual.

rjackjames · Feb 18, 2009

gryphonslair99 said:
First question: Yes
Second question: No

Keep in mind that most macro lenses are marvelous for other uses. My Canon 100mm f2.8 is an outstanding portrait lens, crisp, sharp and vibrant. For those times I use AF. For macro it is always manual.

I tried using the lens at portrait of my sister and it doesnt even focus I have to use all manual. I might just return the lens after my trip and see if I do have a defective lens.

Overread · Feb 18, 2009

for flowers stick to manual - AF sort of works side onto a butterfly since its mostly a flatish surface, a flower is very 3D and complex - you want the focus where you want it - not where the machine thinks it should be.