My Nikkor 55-200 mm lens has a minimum focusing distance of 36 inches, which seems to work nicely on floral shots. It was suggested that I look into the Sigma 75-300 macro lens, which I found has a minimal focus distance of 40 inches, and works in the macro setting at only 200-300 mm. What is the advantage of a macro lens over my Nikkor, which provides a full field image for subjects of about 2 inches?
First, the zoom lens you mention has a macro setting, which will allow the camera to focus closer than it ordinarily would. This can be useful for larger subjects, or smaller subject placed in context. Your example of floral shots is a good example of what this type of lens will do well.
The second part, I believe, is asking about macro lenses in general. I am going to start at the beginning, assuming a minimal amount of knowledge. Also, I am going to assume that you are working with a full frame digital camera, or film body. With the cropped sensors, you'll get even more magnification, so don't let that confuse the issue.
A true macro lens will allow close focussing to a relatively high magnification ratio, such as 1:2 (half life size, so a 2" object in real life will be recorded as a 1" object on the sensor, at the minimum focusing distance - that qualification applies to everything that follows), 1:1 (1" in real life is 1" on the sensor), or even beyond that such as Canon's 65 mm 1x-5x (where 5x means an object 1/5" in real life will be 1" on the sensor - yes, you read that correctly).
Most normal lenses will let you get down to at best 1:5 (5" in real life will be 1" on the sensor). A zoom lens with a macro feature can often do better, sometimes even down to 1:2.
With accessories such as extension tubes or diopters, you can sometimes get those zooms/zoom macros pretty close to 1:1.
Here are some of the positives/negatives:
Pros
- Less expensive.
- One less lens to carry
- Great if you don't do a lot of work near 1:2, or beyond (little macro work)
- With a zoom lens, you have more compositional flexibility. This can be handy for poor location conditions or just a different shot.
Cons
- The lenses were not optimized for closeup work, so you'll lose a bit of sharpness
- Slower to work with, as adding an extension take time - not good for a fast moving bug
- Getting down to 1:1, or life size, is tougher or impossible, depending on your gear.
- Teleconvertors are usually a bad idea on zoom lenses.
Which brings us to true macro lenses. A longer macro lens, suchs as most in the 90-200 mm range, will get you down to 1:1 without any additional accessories. Just stick it on your camera and you can shoot everything from bugs to cityscapes, with the same lens.
Additional accessories will easily let you go beyond 1:1. Put a 2x converter on it and at minimum focussing distance you are already at twice life size. These lenses are usually so sharp that a 1.4x convertor will have little, if any, noticeable effect on sharpness and a 2x can readily be used without serious sharpness issues. Extension tubes and dioptor are also handy for getting even closer.
Pros:
- Lens design is optimized for near focus
- It is a prime lens (which is almost always sharper than a zoom)
- You start with 1:1 for a maximum magnification, rather than trying to get there.
- Macros, except the Canon 65mm 1x-5x, can be used for normal photography without penalty.
- Accessories such as diopters, teleconvertors and extension tubes will let you go nuts with magnification.
- There are no bad macro lenses on the market today from a major manufacturer
Cons
- It is another lens to buy
- Slow to focus
- It is a dedicated investment. Are you going to work near 1:3 to 1:1 enough to justify its purchase?
- Near 1:1, and beyond, depth of field becomes razor thin. Near 5:1, for all practical field purposes it ceases to exist.
- With current lens designs, diffraction becomes an issue at lower f-stops (the effective f-stop is a lot smaller than the physical one you are shooting at)
- Near 1:1 and beyond, it becomes a lot tougher to work. Your failure rate, especially if you are shooting in the field, will tend to skyrocket due to things like the macro hurricane (a small breeze becomes a gale in the viewfinder). Patience really is a virtue here.
Unclear if it is a pro or con
- It can be pretty addictive
Hopefully that answers some of your questions.
Posted by Randall Quon on April 3, 2009 at 10:24 PM
Great summary Dan. One correction though, everything you write about magnification applies to crop bodies the same as full frame bodies. For example, a 1:1 ratio, 1" in real life = 1" on full frame sensor = 1" on crop sensor.
Greg, what Dan explained above implicitly includes this: If you want to get into close-up and macro, get a prime macro lens. You've already got a zoom, the prime macro lenses are incredibly sharp, and almost all the zoom macro lenses aren't. And if you want to get closer with your Nikkor, a high-quality diopter is a much more flexible and less expensive alternative (which you can use on the prime macro you get once you're addicted).
Discussion
6 repliesFirst, the zoom lens you mention has a macro setting, which will allow the camera to focus closer than it ordinarily would. This can be useful for larger subjects, or smaller subject placed in context. Your example of floral shots is a good example of what this type of lens will do well.
The second part, I believe, is asking about macro lenses in general. I am going to start at the beginning, assuming a minimal amount of knowledge. Also, I am going to assume that you are working with a full frame digital camera, or film body. With the cropped sensors, you'll get even more magnification, so don't let that confuse the issue.
A true macro lens will allow close focussing to a relatively high magnification ratio, such as 1:2 (half life size, so a 2" object in real life will be recorded as a 1" object on the sensor, at the minimum focusing distance - that qualification applies to everything that follows), 1:1 (1" in real life is 1" on the sensor), or even beyond that such as Canon's 65 mm 1x-5x (where 5x means an object 1/5" in real life will be 1" on the sensor - yes, you read that correctly).
Most normal lenses will let you get down to at best 1:5 (5" in real life will be 1" on the sensor). A zoom lens with a macro feature can often do better, sometimes even down to 1:2.
With accessories such as extension tubes or diopters, you can sometimes get those zooms/zoom macros pretty close to 1:1.
Here are some of the positives/negatives:
Pros
- Less expensive.
- One less lens to carry
- Great if you don't do a lot of work near 1:2, or beyond (little macro work)
- With a zoom lens, you have more compositional flexibility. This can be handy for poor location conditions or just a different shot.
Cons
- The lenses were not optimized for closeup work, so you'll lose a bit of sharpness
- Slower to work with, as adding an extension take time - not good for a fast moving bug
- Getting down to 1:1, or life size, is tougher or impossible, depending on your gear.
- Teleconvertors are usually a bad idea on zoom lenses.
Which brings us to true macro lenses. A longer macro lens, suchs as most in the 90-200 mm range, will get you down to 1:1 without any additional accessories. Just stick it on your camera and you can shoot everything from bugs to cityscapes, with the same lens.
Additional accessories will easily let you go beyond 1:1. Put a 2x converter on it and at minimum focussing distance you are already at twice life size. These lenses are usually so sharp that a 1.4x convertor will have little, if any, noticeable effect on sharpness and a 2x can readily be used without serious sharpness issues. Extension tubes and dioptor are also handy for getting even closer.
Pros:
- Lens design is optimized for near focus
- It is a prime lens (which is almost always sharper than a zoom)
- You start with 1:1 for a maximum magnification, rather than trying to get there.
- Macros, except the Canon 65mm 1x-5x, can be used for normal photography without penalty.
- Accessories such as diopters, teleconvertors and extension tubes will let you go nuts with magnification.
- There are no bad macro lenses on the market today from a major manufacturer
Cons
- It is another lens to buy
- Slow to focus
- It is a dedicated investment. Are you going to work near 1:3 to 1:1 enough to justify its purchase?
- Near 1:1, and beyond, depth of field becomes razor thin. Near 5:1, for all practical field purposes it ceases to exist.
- With current lens designs, diffraction becomes an issue at lower f-stops (the effective f-stop is a lot smaller than the physical one you are shooting at)
- Near 1:1 and beyond, it becomes a lot tougher to work. Your failure rate, especially if you are shooting in the field, will tend to skyrocket due to things like the macro hurricane (a small breeze becomes a gale in the viewfinder). Patience really is a virtue here.
Unclear if it is a pro or con
- It can be pretty addictive
Hopefully that answers some of your questions.
http://www.amazon.com/Shaws-Closeups-Nature-Practical-Photography/dp/0817440526/ref=sr_1_1?ie=UTF8&s=books&qid=1239211924&sr=8-1