Here are a couple of queries on macro lenses that I have received on the blog:
"I am after a macro lens, not particularly for insects, but for close up baby shots and the odd product shot....I have a Nikon D5100 (i.e not a full frame camera) and I was looking at the Nikon 40mm 2.8 Micro lens. The only thing I am worried about is that I already have the 50mm 1.8...will these two lenses be very similar? I want to get a macro but don't want to invest in something thats too similar to what I have got"
"I have currently Canon 50mm F1.8 and the Canon T3i. I want to take Macro lens Canon 100mm F2.8, but I heard this lens can also be used for portraits, is it true? If that's the case, is there any reason to carry my 50mm F1.8 except for focal length and f value "1" difference?"
First off, there is absolutely no reason why you can't use a macro lens for normal, everday photography such as portraits etc. The beauty of using a macro lens is that you are almost getting two lenses in one - you can use it as an everyday lens but also have the ability to take close up shots - great for newborns or for nature shots. These lenses are designed to be extremely sharp so will give beautiful results when used for portraits - some say too sharp (as they will show up your wrinkles in sharply defined glory) but personally I would rather have a sharp image and soften out the areas I want in editing rather than not have it there to begin with. There is also no reason why you can't also use these for landscape or street photography too - it's the focal length which will play the most important part in what your lens will be best suited for beyond the obvious macro work.
Leaving aside the issue of focal length for a moment, there are a couple of differences between a macro and a "standard" lens. The first is the aperture they can stop down to. Most macros will stop down to about F2.8 - this is more than enough for macro work but for using the lens as a portrait lens, you may wish to have the extra stops that an F1.8 lens can give you. You may find this an issue if you like to take portraits with extremely shallow depth of field, or if you need the extra amount of light that opening up your aperture wider can give you.
Secondly, some macro lenses can be slower to focus than their standard lens counterparts so might not be the best option for action photography. That said, not all macro lenses are created equal, and how good your camera body AF system is can also have an impact on this. If you are planning to use the lens for portraiture where the subject is still, this won't be an issue, however, if you also want the lens to double up for photographing your kids at soccer practice, check the reviews for the focus speed of the macro you are interested in.
Neither of these are deal breakers as far as I am concerned, but you should be aware of this if you are planning on investing on a macro to have a dual purpose.
The main factor is using a macro lens for non-macro work will be your focal length. If you want it to double as a portrait lens, then getting one in the range of 70 - 135 is best if you have a full frame camera. So, if I wanted my macro lens to double as a classic portrait lens on a full frame I would go for the 100mm (or around) and on a crop frame a 60mm or even 90MM (Remember that you need adjust the focal length if you have a crop frame to take in your camera's field of view) 100mm on a crop frame might be a little long for working with children (they would have to be a little way away from you) but if you prefer working from a distance then you won't find this a problem. That's definitely down to personal choice but remember a 100mm on crop frame equates to around 160mm. If you already have a 50mm lens, you can use this as your reference point - when using this are you struggling to fit all you want in the frame or would you prefer to be able to stand farther back?
To answer the specific questions above, yes, the 40mm will be similar in the field of view it gives you (although it is slightly closer). When deciding on your lens choices, remember it's about creating a collection that suits what you are shooting, where you plan to do it, and your personal shooting style. If you are sticking with primes instead of zooms (again, personal preference) then try to get a good range of focal lengths so you can shoot in a variety of situations. For example, a 35mm f/2 and 60mm macro might suit you better than having a 40mm macro and the Canon 50mm f/1.8 , as this gives you a bit more space between the focal ranges and also the F stops. (the 35mm would be great for indoors, and the 60 for portraits and macro) Or keep your 50mm and go for a longer length macro like an 85 or 90mm - again, it's spacing out the focal lengths. The 85mm on a crop would make a great outdoor lens. (equivalent to around 135mm on a full frame)
However, the difference between the Canon EF 50mm f/1.8 and 100mm is relatively substantial. A 100mm is too long for indoor shots on a crop frame, possibly a little long outdoors for shooting children but great for times when you are able to have your children a little way away from you. In my humble opinion, a 100mm macro isn't a substitute for the 50mm F1.8, but would complement by giving you an indoor and outdoor lens.
There are alternative options for macro - you can buy macro filters which will turn your humble little 50mm F1.8 into a macro lens cheaply , or extension tubes which are a little more expensive. I have never used either, but I would bear in mind that in most cases you get what you pay for. If you are unsure about whether macro is for you, it can be a cheap introduction to it. There are several options out there - make sure they fit your mount and off you go! If you still want the quality but only require macro for a short period - say with the birth of a new baby - then there is also the option of hiring these for a couple of weeks or so until you get what you need.
I hope this answered your questions on this - as with all lens choices, it's about creating a collection of lenses that works for you - where you want to shoot, what you want to shoot, how close or far back you like to be, whether you want a zoom or primes, and how much you are willing to spend. I can try to guide you, but I ultimately only you know the answers to all these questions to make the decision!
I hope you have found this helpful!
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