What exactly is a macro lens?

[Rash Oval Knave]

I was recently told that the Nikon's 50mm f/1.8D AF lens isn't a macro lens. Before this revelation, I thought that a macro lens was one with a large aperture, where the large aperture would provide a shallow depth of field, thereby singling out your subject.

So if that's not the case, what constitutes a macro lens? How do I get those ridiculously awesome singled out flower shots that everyone seems to love? And finally, what's a good macro lens for a new-to-DSLR, Nikon D90 owner to start with to begin to understand the fundamentals of this type of photography, but will allow them to pursue more difficult feats once they grasp the basics?

Thanks,
Shravan

[LoveDSLR]

Originally Posted by Rash Oval Knave

So if that's not the case, what constitutes a macro lens?

Life-size 1:1 (image in the camera is the same size as the subject)
Flat field (a must to shoot flat objects such as stamps)
optimized for close-ups

Originally Posted by Rash Oval Knave

And finally, what's a good macro lens for a new-to-DSLR, Nikon D90 owner...

Longer focal length generally allows you to shoot from a greater working distance.

[firebox40dash5]

^ Pretty well sums it up. A macro lens is optimized for close focusing, generally 1:1 reproduction at minimum focusing distance. 3rd parties like Sigma tend to fudge that a little, designating lenses "Macro" when they only have 1:2 or less reproduction ratios.

If you want to stay with Nikon lenses, the 85mm and 105mm Macro are both great choices. The longer your focal length, the farther your working distances, the easier it is to get a shot without needing flashes. Keep in mind the minimum focusing distance in the specs is from the film/sensor plane, not the front of the lens, so you can wind up REALLY close with shorter focal lengths. The 60mm AF-S for example, has a MFD of 185mm, and is 89mm long, minus ~25mm more from the rear of the mount to the sensor... you wind up ~3" from your subject at 1:1!

[J. r. Weems]

I went with the 105 as above, to give my subjects a bit more room and in order to not get my own light. JMHO

[Shokinen]

Originally Posted by Rash Oval Knave

And finally, what's a good macro lens for a new-to-DSLR, Nikon D90 owner to start with to begin to understand the fundamentals of this type of photography, but will allow them to pursue more difficult feats once they grasp the basics?

Check the Nikon 85mm DX f3.5. It was specifically designed to provided a macro solution for the crop sensors such as the D90. It's fairly new (was released in december) so there is not much reviews but I read good thing about this lens. It's also cheaper then the 105mm Micro.

Hope this help

[tinwhistle]

So, the longer the focal length the further away the sensor is to acheive the 1:1 ratio? For instance, if I take macro pictures of insects I'd want a 70mm macro 1:1 as opposed to a 28mm 1:1 macro. That should translate into getting the insect to take up the whole image with the 70mm from further away? Chris

[Rash Oval Knave]

Originally Posted by tinwhistle

So, the longer the focal length the further away the sensor is to acheive the 1:1 ratio? For instance, if I take macro pictures of insects I'd want a 70mm macro 1:1 as opposed to a 28mm 1:1 macro. That should translate into getting the insect to take up the whole image with the 70mm from further away? Chris

That sounds like the case to me (and it makes sense, because the lens is longer).


If that's what macro lenses are all about, then what's the point of the Nikon 50mm f/1.8 lens? Although it's fast, doesn't the fact that it's a fixed focal length lens provide too many restrictions/limit its uses greatly?

~ Shravan

[firebox40dash5]

Originally Posted by Rash Oval Knave

If that's what macro lenses are all about, then what's the point of the Nikon 50mm f/1.8 lens? Although it's fast, doesn't the fact that it's a fixed focal length lens provide too many restrictions/limit its uses greatly?

~ Shravan

1. Shooting in dim light without cranking up ISO or using a flash
2. Getting a shallower DOF

Zoom with your feet. Additionally, the image quality of most fast 50mm lenses and newer cameras means you can effectively crop more to get the FOV you want... provided you're too far, not too close.

[Shokinen]

Hey firebox40dash5,

Correct me if I'm wroing but I beleive you purchase the Nikon 85mm f3.5 ?

How do you like it ?

[vandergus]

So, the longer the focal length the further away the sensor is to acheive the 1:1 ratio? For instance, if I take macro pictures of insects I'd want a 70mm macro 1:1 as opposed to a 28mm 1:1 macro. That should translate into getting the insect to take up the whole image with the 70mm from further away? Chris

That's correct but you should also pay attention to the actual minimum working distance specified by the manufacturer. This will tell you exactly how much room you have between the front of the lens and the subject. The reason you can't really strictly on focal lengths is that the focal length may change at close focusing distances. For example, the Nikon 60mm AF-S micro has a minimum working distance of about 2" while the Tamron 60mm macro has a working distance of 4". Same focal length, but different working distances. The 60mm length that is specified by the manufacturer is only the focal length when focused at infinity. At closer focusing distances, they can fudge with that number a little bit. Some fudge more than others.