Macro - How to use Focus Limiter on lens

[Green Mountain Girl]

Recently purchased an older (pre-owned) model Sigma 150mm macro lens, no VR/OS. This is my first macro lens, and I am a bit confused about what is the right way to use the focus limiter.

I have been leaving it on full and using manual. My assumption is that it is for use in AF mode. How close do you need to be for the smaller range setting? How far should you be to use the mid-range to infinity setting? The few times I have tried using the limiter, it tends to hunt a lot. Should I be using center-weighted metering instead of evaluative/matrix?

Help with this would be appreciated!

Susan

[Ken MT]

Metering should have no effect on the focus, but the focus points may have depending if the focus point used is the one that you want.

I see in Digital review of this lens produced in 1996 as follows
"An optically great lens will not show its strength if it delivers an out of focus image. Unfortunately, I had a lot of mis-autofocused results from this lens - far more than could have been my fault. Sigma's internal HSM (Hypersonic Motor) autofocusing is very nice - quiet with FTM (Full Time Manual) focusing. But it is only moderately fast and it showed inconsistent accuracy in both one-shot and AI Servo AF modes. The Sigma 150 focuses even more slowly in low light. A 3-position focus limiter switch (seen above) helps with the speed issue - it prevents long distance hunting."

I recommend that for macro use (eg close up) then manual focus will give you many more keepers. For longer distance then AF may be considered, but manual focus will have the image focused on the item that you want, not what the camera thinks should be in focus.

[xpatUSA]

Recently purchased an older (pre-owned) model Sigma 150mm macro lens, no VR/OS. This is my first macro lens, and I am a bit confused about what is the right way to use the focus limiter.

I have been leaving it on full and using manual. My assumption is that it is for use in AF mode. How close do you need to be for the smaller range setting? How far should you be to use the mid-range to infinity setting? The few times I have tried using the limiter, it tends to hunt a lot. Should I be using center-weighted metering instead of evaluative/matrix?

Susan

I have the 70mm version. I never use AF for any close-up shots. But SLRgear has this to say about AF on your lens:

AF Operation
Thanks to its hypersonic motor (HSM), AF operation is fast and precise, with a minimum of hunting. a 3-position switch on the lens barrel lets you limit the focus range, with settings of Full (no limit), 0.52m - infinity (for distant subjects), or to 0.38-0.52m, for close subjects. It's pretty common on macro lenses to have a limit switch that keeps them from going all the way to closest focus, reducing AF hunting with distant subjects, but I think this is the first time I've seen a lens that had a similar function to support close-up work as well. I did find that the cameras hunted more at very close shooting distances, but it wasn't clear whether this was the fault of the camera or the lens. They did always find a valid focus point eventually, and the worst hunting was perhaps a second or so at closest focus.

And, speaking of closest focus, it gets very close indeed. A minimum focal distance of 38cm may not sound like a lot, but keep in mind that this distance is measured to the film/sensor plane of the camera, not to the front element. Measuring from the front of the lens, closest focus is only about 10cm, or four inches. At that distance, the frame width was about 22mm on our EOS-20D test body.

You can read more here: http://slrgear.com/reviews/showprodu...uct/180/cat/30

I always use center-area metering on my older Sigma cameras and spot metering on the Panasonic, i.e. I do my own "evaluation" not always that well but it's mine. There's something not quite right about letting the camera's design engineers do everything for you , eh?

[William W]

I am a bit confused about what is the right way to use the focus limiter. My assumption is that it is for use in AF mode.

Yes. The Focus Limiter is for use when using the Lens, in Auto Focus Mode.

How close do you need to be for the smaller range setting?
How far should you be to use the mid-range to infinity setting?

The Focus Limiter will have distance settings on it.

From memory that lens has three – and the way you asked the question confirms my memory.

So you need to read what is the distance range stated on each of the settings and that will represent a distance measurement from the Plane of Sharp Focus on the Subject to the Camera’s Film Plane. (or Sensor Plane)

The Greek letter ‘phi’ ɸ which is marked on the camera’s body is where the Film Plane is located – so you can measure the range to the Subject thus:
:

The few times I have tried using the limiter, it tends to hunt a lot.

That was maybe because you were generally using AF for macro and / or the scene was hard for the lens to nail focus, anyway.

The idea of the limiter is to allow you to select a really close shooting range eliminating all the distance shooting range; or on the other hand to choose a distant shooting range and eliminate all the very close range.

For example, if you wanted to use the lens for Portraiture you would choose the Distant Shooting range – and for Macro you would choose the Close Shooting range.

In either case, Macro lenses by design have a very long focus turret movement from Closest to Infinity – so the AUTO focussing will always be slow compared to a traditional Prime lens of the same Focal Length.

Should I be using center-weighted metering instead of evaluative/matrix?

The metering mode of the camera will have no affect or effect on the AF performance.

For accuracy and suitability of the Metering Mode Choice for Macro Work: I would expect that Nikon’s ‘Matrix’ Mode would be a better choice in most cases for most Macro Work. For a Canon DSLR, I would generally choose “Evaluative” for Macro work.

Typically a macro scene is suited for Matrix or Evaluative metering, because, for example, I would not want an intense light or shade area in the centre of the frame (e.g. a small section of a stamin) to bias the average meter reading of the total, but very small area, of 30mm of the middle of the flower, which is in shot.

However, each shot is different and I suggest you learn HOW each of you metering modes works on your camera(s) - this is probably the WORST learnt area of Photography, today.

WW

[Green Mountain Girl]

I always use center-area metering on my older Sigma cameras...
There's something not quite right about letting the camera's design engineers do everything for you , eh?

Ted, Thanks for showing me the review. I have not seen this site before. Because of the very small subject matter, I have been wondering if center-weighted would be better than matrix/evaluative. Will have to try both and compare.

You are right about not letting the camera's design engineers do everything! Otherwise, what is my brain for?!

Susan

[Green Mountain Girl]

So you need to read what is the distance range stated on each of the settings and that will represent a distance measurement from the Plane of Sharp Focus on the Subject to the Camera’s Film Plane. (or Sensor Plane)

The idea of the limiter is to allow you to select a really close shooting range eliminating all the distance shooting range; or on the other hand to choose a distant shooting range and eliminate all the very close range.

For example, if you wanted to use the lens for Portraiture you would choose the Distant Shooting range – and for Macro you would choose the Close Shooting range.

In either case, Macro lenses by design have a very long focus turret movement from Closest to Infinity – so the AUTO focusing will always be slow compared to a traditional Prime lens of the same Focal Length.

For accuracy and suitability of the Metering Mode Choice for Macro Work: I would expect that Nikon’s ‘Matrix’ Mode would be a better choice in most cases for most Macro Work.

Typically a macro scene is suited for Matrix or Evaluative metering, because, for example, I would not want an intense light or shade area in the centre of the frame (e.g. a small section of a stamin) to bias the average meter reading of the total, but very small area, of 30mm of the middle of the flower, which is in shot.

However, each shot is different and I suggest you learn HOW each of your metering modes works on your camera(s) - this is probably the WORST learned area of Photography, today.

Thanks Bill for your detailed explanation of how the limiter works. This is exactly what I was hoping for, and it has helped tremendously.

About the metering modes - a lot of people seem to know what they are for, but I have not experimented much with them, leaving my camera set to Matrix all the time. This is my first DSLR, and I chose the Nikon D7000 - this meant a steep learning curve. Now I am reaching a point where I want to explore more of the functions on the camera, so perhaps metering modes should be at the top of the list!

Appreciate your help.

Susan

[William W]

You are welcome.

I am reaching a point where I want to explore more of the functions on the camera, so perhaps metering modes should be at the top of the list!

There is no "perhaps" about it - just do it.

People learn their best, in all different ways: but for mostly all people, it is good to have a few basic facts expressed in simple terms as a beginning.

First the TTL Meter meters everything as a light grey tone. So, shooting a black sheep in a coal mine - the meter will overexpose it and believe it is "correctly exposed" as if it were a grey Sheep. And shooting a White Sheep in a Snow Storm the meter will underexpose it and also believe it has done a "correct exposure" for a grey sheep in a grey background.

Secondly if you read your user manual you will get an idea of what each Metering Mode is attempting to do - and basically what each metering mode does, is bias or average particular areas of the frame into an algorithm and then spits out what the camera thinks is the "correct" exposure.

Also you camera's user guide will (might) give you vague examples of when to use each metering mode.

Armed with these wonky facts - I suggest you make a set of the same photos a few of different scenes using all the different metering modes your camera has available for each scene - and just walk yourself through the differences . . .and seek the answer as to "why"?

WW

[Green Mountain Girl]

There is no "perhaps" about it - just do it.

People learn their best, in all different ways: but for mostly all people, it is good to have a few basic facts expressed in simple terms as a beginning.

First the TTL Meter meters everything as a light grey tone. So, shooting a black sheep in a coal mine - the meter will overexpose it and believe it is "correctly exposed" as if it were a grey Sheep. And shooting a White Sheep in a Snow Storm the meter will underexpose it and also believe it has done a "correct exposure" for a grey sheep in a grey background.

Secondly if you read your user manual you will get an idea of what each Metering Mode is attempting to do - and basically what each metering mode does, is bias or average particular areas of the frame into an algorithm and then spits out what the camera thinks is the "correct" exposure.

Armed with these wonky facts - I suggest you make a set of the same photos a few of different scenes using all the different metering modes your camera has available for each scene - and just walk yourself through the differences . . .and seek the answer as to "why"?

WW

Bill: That is a great idea. It is simple, and effective.

Kind of like when I was interested in the differences between photo papers. I printed a "test photo" side-by-side with one of my own images on a selection of papers and saw how each one presented the pictures. That way I was able to decide which ones I like the best.

I have done similar things with exposures and ISO, although not in a very organized manner.

Luckily this weekend will be excellent weather, and I am sure to find time to go out in my "back yard" with my camera. Of course, tomorrow afternoon will be busy - we always watch the Kentucky Derby on TV... But the early morning is when I like best to go out.

Thank you for helping with this. IMO, you are a good teacher - I promise to complete my "assignment" and let you know the results!!!

Have a great day.

Susan

[William W]

I promise to complete my "assignment" and let you know the results!!!

Have a great day.

Susan

Good.

Return this thread.

Enjoy the Derby.


WW

[Green Mountain Girl]

Good.

Return this thread.

Enjoy the Derby.


WW

Hi Bill!

The Derby was exciting, enjoyed it very much. Also the other races. Love horses, used to train thoroughbreds at the track. So I know a lot about what it takes to get a young horse ready for a big race.

Went out yesterday morning and took some photos with each of the meter modes, using aperture-priority. Left all other parameters the same. The only thing that changed was the shutter speed. Most of the photos looked pretty similar overall, but differences in exposure (as can be expected).

The matrix images were better for the scenes that had a wide variety of levels of light. The center-focused varied depending on what I put in the middle, spot-metering varied by where I put the focus point. On a lighter area --> more shadows, on a darker area --> brighter light areas.

I begin to understand when I should use them, although still not entirely sure. Some say that with macro, matrix is better. But I have a macro image of some moss, where the primary subject might have come out brighter if I had set it on spot-meter. Of course, the rest would have been darker, so only experimenting will tell if the effect would be what I want or not.

Let me know if I have it right! Thanks for the suggestion to try this.

Susan

[Green Mountain Girl]

Good.

Return this thread.

Enjoy the Derby.


WW

Hi Bill!

The Derby was exciting, enjoyed it very much. Also the other races. Love horses, used to train thoroughbreds at the track. So I know a lot about what it takes to get a young horse ready for a big race.

Went out yesterday morning and took some photos with each of the meter modes, using aperture-priority. Left all other parameters the same. The only thing that changed was the shutter speed. Most of the photos looked pretty similar overall, but differences in exposure (as can be expected).

The matrix images were better for the scenes that had a wide variety of levels of light. The center-focused varied depending on what I put in the middle, spot-metering varied by where I put the focus point. On a lighter area --> more shadows, on a darker area --> brighter light areas.

I begin to understand when I should use them, although still not entirely sure. Some say that with macro, matrix is better. But I have a macro image of some moss, where the primary subject might have come out brighter if I had set it on spot-meter. Of course, the rest would have been darker, so only experimenting will tell if the effect would be what I want or not.

Let me know if I have it right! Thanks for the suggestion to try this.

Susan

[Glenn NK]

I recommend that for macro use (eg close up) then manual focus will give you many more keepers. For longer distance then AF may be considered, but manual focus will have the image focused on the item that you want, not what the camera thinks should be in focus.

In approximately 20,000 macro/closeup shots I don't recall ever using AF. When the DOF is paper thin, the camera is incredibly dumb at focusing on the right part of the object.

Glenn

[xpatUSA]

The matrix images were better for the scenes that had a wide variety of levels of light. The center-focused varied depending on what I put in the middle, spot-metering varied by where I put the focus point. On a lighter area --> more shadows, on a darker area --> brighter light areas.

I begin to understand when I should use them, although still not entirely sure.

If I understand correctly, re: spot and center-focus, you've seen the effects of metering different parts of a scene. The next step, IMHO, is to be able to evaluate a scene, decide which part of the scene has a middling brightness, meter it by pushing the button half-way, re-framing the scene and then pushing the button the rest of the way.

If you get it right and assuming there's not a huge range of brightness in the scene the pic should be OK, exposure-wise. If not, then re-think your evaluation. The point of this post is to get you from cut-and-try to instead pre-judging a scene, metering where you have judged is best and taking the shot. It becomes almost automatic after a while, trust me.

Then you'll learn what everyone means about black cats on a dark gray blanket, white wedding dresses, etc, etc, which will lead you to probably meter a brighter point in an overall bright scene and vice-versa. And the result will be yours, not some engineers.

In the world of watches, the Japanese concept of 'wabi' is often quoted. It refers to the amount of successful human effort that went into making a watch. Seiko watches, untouched by humans through the entire production process, have no wabi at all and, from an artistic POV, are worthless.

I believe that all-manual exposures that need little post-processing have more wabi than pics taken in e.g. my Panasonic's "intelligent Auto Mode".

[Inkanyezi]

AF for macro does not work very well when you approach the closest tistance that the lens can focus. It is also very easy to get a bit too close, which makes focusing impossible. Those are the reasons why macro work is seldom done with AF.

With many DSLR cameras focusing is exceetingly difficult in the viewfinder and a lot easier in live view when available, particularly when you can enlarge a small area for precise focusing. At very close distances, focusing is accomplished by moving the whole setup back and forth, either the subject or the camera. We "rock in" focus by slowly swaying back and forth with the camera. With some cameras without live view, there is a focus confirmation light in the viewfinder, which can be used to find focus.

[William W]

Went out yesterday morning and took some photos with each of the meter modes, using aperture-priority. Left all other parameters the same. The only thing that changed was the shutter speed. Most of the photos looked pretty similar overall, but differences in exposure (as can be expected).

The matrix images were better for the scenes that had a wide variety of levels of light. The center-focused varied depending on what I put in the middle, spot-metering varied by where I put the focus point. On a lighter area --> more shadows, on a darker area --> brighter light areas.

I begin to understand when I should use them, although still not entirely sure. Some say that with macro, matrix is better. But I have a macro image of some moss, where the primary subject might have come out brighter if I had set it on spot-meter. Of course, the rest would have been darker, so only experimenting will tell if the effect would be what I want or not.

You are “right” in so far as you have a good description of what they do. Now you need to start thinking and applying. There is no right or wrong method, but many methods which will work for you.

What Ted Cousins wrote here, I suggest you follow up – as one of the MANY follow-ups you do- :
“If I understand correctly, re: spot and center-focus, you've seen the effects of metering different parts of a scene. The next step, IMHO, is to be able to evaluate a scene, decide which part of the scene has a middling brightness, meter it by pushing the button half-way, re-framing the scene and then pushing the button the rest of the way”

What Ted suggests, is one way you can use Spot Metering effectively.
That is how I use Spot Metering, quite often.

But you need to also need to have a reasonable idea of the tones (colours) which resemble photographic grey as well as judging which parts of the scene has middle brightness.

For example: a white dress in middle brightness will meter differently to a black dog in middle brightness.

***

Some practical examples:



You might NOT want to meter the middle brightness of a scene and have that as your middle exposure: but you might want to meter the main feature of the scene and have that as you middle exposure – allowing parts of the scene to blow out or go to black-black.

Some areas blown out:


Candid Portrait - Available (sun) Light 5D & 135/2 (Spot Metering on Shadow Side of face and opened up one stop)

In this shot the “Middle Brightness” of the scene, was NOT the shadow side of the face, but that is what was metered as the “correct exposure” with no regard to what parts of the scene would blow out. (it is indeed, ‘zinc cream’ on her face). This is an example of how Spot metering can be useful for back lit Subjects.


Some areas black-black:


“Athlete in Green Room” – Candid Portrait - 5D + EF100F/2.8Macro F/2.8 @ 1/8s @ ISO1600 HH,Spot Meter on face opened up about 1½ Stops, Manual, Available (room) Light, AWB.

In this shot the “Middle Brightness” of the scene, was NOT the highlight skin on the face, but that is what was metered as the “correct exposure” with no regard to what parts of the scene would go to black-black.


Several exposure readings:

You might also want to use Spot Metering to make a few exposure readings in a complex scene and then calculate the final exposure manually to ensure the maximum detail and exposure range throughout the final image. The top is the JPEG SOOC, the bottom is the final:


“End of Day”


Evaluative (Matrix) & 'general scenes':

On the other hand – Evaluative Metering (‘Matrix’ on Nikon) is very handy and quick for most general scenes. Again the top is the JPEG SOOC and the bottom is the final:



Maybe not to use Evaluative?:

But some scenes appear as ‘most general scenes’ but might not be - this is especially so if there are dark areas which you might want to keep in detail, for example the background buildings and trees here. Again the top is the JPEG SOOC and the bottom is the final image:



If this particular scene were shot according to the Evaluative Meter suggestion, then, although the sky would have been “very nice”, there would not have been enough exposure to pull out the background as cleanly. And even though the (overcast) sky appears to be close to blown-out in the original, there is enough data there for recovery.

This is a good example of "Expose To The Right" (ETTR) - as if one were using Evaluative (or Matrix) metering and the histogram were pushed to as far to the right as possible the same (or close to it) result would be attained.

But I don't use histograms all that much: because to use an histogram one has to make the photograph in the first place and then check the exposure for it ? ? ? . . . and that is back to front thinking for me.

That's why I like to know how the meter in each of my cameras work; so I can use the light meter and make any exposure adjustments: BEFORE I make the shot.

***

I mentioned that you need to know what resembles ‘photographic grey’ – well good green grass does. The palm of my hand requires 1½ stops open. The White of a Wedding Gown requires two stops open, in open shade I would push it open 2⅓ Stops . . . etc. You can learn these in regard to what Subjects you generally shoot.

For example you like horses: IF you make photos of a lot of horses, then find one or two common horse colours as some of your references. For example I know a lot of common dress material colours and can use them as reference (as well as white dress) simple because I need to shoot Wedding Portraiture effectively, accurately and quickly.

*

You can also meter from a Photographic Grey card, too.


If you use a reference material (for example a grey card, or grass or your hand), for your exposure reading then you must ensure that the reference material is in the SAME LIGHT and facing the SAME DIRECTION as the Subject that you wish to photograph.

For example, in the image above, the Photographer is making a light meter reading and the Subject will be standing in the shade, where the Grey card is located. Thus if there is any sunlit background in his shot, it will be blown out as per the sample image posted.

WW

[Green Mountain Girl]

If I understand correctly, re: spot and center-focus, you've seen the effects of metering different parts of a scene.

What I actually did was to meter the same part of the same scene using matrix, center, and spot. This was an effort to see what effects would result.

The next step, IMHO, is to be able to evaluate a scene, decide which part of the scene has a middling brightness, meter it by pushing the button half-way, re-framing the scene and then pushing the button the rest of the way.

Which metering mode are you suggesting for this? Also, I have to wonder if metering the part with middling brightness is a solution for all photographic objectives. What if I want to isolate one element and expose it properly, allowing the majority of the rest of the image to fall into shadows (for instance)?

...The point of this post is to get you from cut-and-try to instead pre-judging a scene, metering where you have judged is best and taking the shot. It becomes almost automatic after a while, trust me.

This is why I engaged in the experiment - to understand how the different metering modes will affect exposure of the image.

Then you'll learn what everyone means about black cats on a dark gray blanket, white wedding dresses, etc, etc, which will lead you to probably meter a brighter point in an overall bright scene and vice-versa. And the result will be yours, not some engineers.

Yes, I understand - you don't want to use matrix for either of these examples since it will want to average the colors and they will all be "off". Black cat - center or spot on the cat; white wedding dress - center or spot on the brightest white. Question for you: how do you decide which of these to use - center vs spot?

I believe that all-manual exposures that need little post-processing have more wabi than pics taken in e.g. my Panasonic's "intelligent Auto Mode".

To me, the whole point of learning about the different metering modes is to be able to take the best possible picture in-camera. Since I out-grew my point-and-shoot, I have never used full Auto - it's a waste of time because I don't learn to be a better photographer that way.

In a sense, I LOVE my mistakes because they TEACH me!

I also learn from those who take the time and make the effort to explain things. Thank you.

Susan

[Green Mountain Girl]

In approximately 20,000 macro/closeup shots I don't recall ever using AF. When the DOF is paper thin, the camera is incredibly dumb at focusing on the right part of the object.

Glenn, you are right about that! All the more reason why I have been confused about the focus limiter...

Not only did I have no idea how to use it, I also didn't know what it is for. Now I have a general idea of how to use it. Still not sure why I should use it. Of course, if there is plenty of time to play with focus, it seems like it could be used to get an approximation, then switch to manual to fine-tune. Nice thing about the lens is that I can do that.

Susan

[Cantab]

Bill, many thanks for doing your informative and illustrated post.

[Green Mountain Girl]

AF for macro does not work very well when you approach the closest distance that the lens can focus. It is also very easy to get a bit too close, which makes focusing impossible. Those are the reasons why macro work is seldom done with AF.

With many DSLR cameras focusing is exceedingly difficult in the viewfinder and a lot easier in live view when available, particularly when you can enlarge a small area for precise focusing. At very close distances, focusing is accomplished by moving the whole setup back and forth, either the subject or the camera. We "rock in" focus by slowly swaying back and forth with the camera. With some cameras without live view, there is a focus confirmation light in the viewfinder, which can be used to find focus.

The viewfinder is definitely not good for seeing what the camera sees when doing macro! I have been using LV and magnification. I also have a focus confirmation light in the viewfinder, but as OP have mentioned, it might not be what I want to have in focus!

As for getting too close - I experienced that the first time I tried the lens. Had to back off a bit, remembering the 15" focusing distance of the lens. That, of course, was using the AF. From the advice I have received, I now understand that the best way to focus is manually for macro. I'll save the AF for when I use the lens for other kinds of photographs.

Thanks for your input!

Susan

[William W]

All the more reason why I have been confused about the focus limiter... Not only did I have no idea how to use it, I also didn't know what it is for. Now I have a general idea of how to use it. Still not sure why I should use it.

The image “Athlete in Green Room” is an example which should work on a multiplicity of levels.

As well as an example of how Spot Metering was used to attain an exposure for the shot, it is also an example of how the Focus Limiter was used on the EF 100 F/2.8 USM Macro Lens – the limiter was set to the “further” distance, hence the AF did not run back and forth across the full range of the lens’s focussing capacity. It was still slow AF, but not as slow as it could have been.

Also the image is an example of good hand holding and shutter release techniques (1/8 second) and an example of how a Macro Lens can be used for Portraiture (often discussed) .

The image is also an example of unacceptable unpreparedness:

If the Photographer were properly prepared then he would not have had that lens on the camera at all. He would have returned his cameras and lenses to their correct resting positions (i.e. not having a Macro Lens attached) and he would have had either the 50/1.4 or 85/1.8 on that camera BEFORE he arrived at the Athletic Field.

Both of those two other lenses have faster AF. Both would have been better physically balanced to make that shot. Both have the capacity to open wider, should the Photographer had chosen to use a faster Shutter Speed.

In all these respects the 100/2.8 was the incorrect lens to have on the camera when walking into that shooting scenario where one came across a candid portrait opportunity: but to take the few seconds to change lenses, the moment would have be disturbed and the opportunity of the shot, lost.

I was very annoyed at those aspects of that particular shot and I have not made that same mistake since

***

On the other handed, I do sometimes use AF with a macro lens in which case I use the full range of the AF:

“Flower at Sunrise” 5D & EF 100 F/2.8 Macro (HH)

WW