I'm sure this has been posted before and I have searched through discussions and googled till my eyes are starting to fall out of my head.
Can someone please explain to me (in simple terms :-) the mm number on a lens - ie 50mm, 90mm.
Background: I want a new lens - I have been trying to choose between a 50mm prime for portraiture and a macro THEN someone mentioned that I could use a 90mm macro for portraiture as well - there was mention that this could be difficult in low light? So I thought hooray - that solves all my problems but the low light thing has me worried as I don't have lighting expertise or equipment and I don't want to end up with a lens that I can't use or drives me nuts because I can't get enough light in.
To add to my confusion there is also a 60mm macro and a 50mm macro - my goodness it seems they make lens in every conceivable number and now my head hurts. Can someone please help???
When got my first DSLR, I did not realize that most are not Full Frame, as a 35mm film camera. I thought that a 75-105mm lens would be great for portraiture. Wrong.
Would those focal lengths work? Yes. In a crammed setting, no way. A focal length of 75-105mm would be great for a 35mm film camera. For a non-full frame digital (your D7000 is not full frame), you can take those numbers and multiply them by 1.5. So, a 50mm lens is equivalent to a 75mm for full frame, which is ideal for portraiture. Stick with the 50mm. Nikon makes a killer 50mm 1.8 prime. Macro scmacro. You want t portraits? Get the faster lens.
For the record, in 35mm speak, 50mm is considered "normal" (what the human eye would see). So, a 35mm focal length in non full frame digital is "normal".
Still, a 50mm or 60mm prime lens IS a portrait lens for what you need.
Also when you can afford a Prime, over a zoom, you will have a better lens. Unless you use a zoom for effect. Or, if you are tryign to get more for less.
In short. The mm is the zoom factor. The bigger the number the more zoom you get. All lens can take macro shoot but only true macro lens will take one to one shots. I.e if your sensor in your camera is 10mm across then if you take a photo of a ruler the closest spot where it is in focus should read 10mm on the ruler.
The f stop is how fast the light can come in your camera so it is this that determines how much ambient light is needed to correctly expose your image. The lower the number the faster the light comes into your camera the less ambient light you need.
I do a lot of portraits and it is very rare that I would use anything less than 80mm and in fact I normally use 105 and around 200mm, but sometimes out to 400mm. I do this for a few reasons but that's probably a different and longer story. :)
@saranna when you say portraiture do you mean mostly natural light or studio portraiture?
A couple of issues spring to mind that could be expanded on a bit more. One is depth-of-field; for portraits you almost always want a shallow DOF to isolate your subject from the background (not necessarily such a big deal in the studio). The 'faster' the lens (smaller the f-number), the more you can reduce DOF (at a given focal length and distance from the subject). So a 50mm f/1.4 prime will give you noticeably less DOF than a 50mm f/2.8 macro for instance (as well as being better in low light).
The other issue is visual extension or compression (properly called perspective distortion). In simple terms a wide-angle lens makes whatever is closest to the lens (e.g. a person's nose) seem abnormally large compared to things that are more distant (e.g. their ears). Longer focal length lenses tend to make relatively near and distant objects appear more similar in size (i.e. compressed). In short, at wide focal lengths portraits tend to be unflattering. The ideal for portraiture is generally considered something 'a bit longer than normal' e.g. 50-60mm for an APS sized sensor, which equates to around 75-90mm on a full frame camera. Unlike depth-of-field, perspective distortion is not a function of the focal length printed on the lens, but rather the angle of view. What counts when you think about perspective distortion is the 'effective focal length' (or full frame equivalent).
Sorry if that is confusing! I'll try again. With a longer focal length lens:
1. you have to stand further from your subject to fit them in the frame (a problem in cramped conditions as mentioned above, but a good thing for macro as you don't have to get as close)
2. you get more visual compression (due to the fact you are standing further away). Up to a point this is a good thing for portraits, or so I'm told (I don't shoot people as a rule!) ;)
3. you get shallower depth-of-field at a given aperture it is easier to isolate your subject against a smooth background. For an explanation of why, see here.
Wow, and based on the spam above, you can also save big money on fashion shoes! I wonder if you're required to buy a good lens first to take advantage of their incredible offer?
@dieter Thanks for typing all this out - I was reading through and wondering when someone was going to explain aperture, which relates to light much more than focal length does.
@saranna I would agree with almost everything said EXCEPT: "Also when you can afford a Prime, over a zoom, you will have a better lens. Unless you use a zoom for effect. Or, if you are tryign to get more for less."
"Prime" just means fixed focal length - no zooming. Entry level zooms do not have large apertures, but there are expensive zooms/telephotos that are just as nice for portraiture.
As @agima suggested, if you are going to be shooting outside and have plenty of room, long focal lengths are perfectly fine. Here is an example of someone using long focal lengths: http://youtu.be/U90BQUpISBs
I have a D7000, and I prefer to use my 70-200 f/2.8 when I have the room. The great thing about having a little zoom is that it saves you from moving around as much so you can be sure to fill the frame. But I also use my 35mm f/1.8 prime especially when I'm shooting portraits of kids and am chasing them around, shooting from closer distance. If you're just starting, both the 35mm or 50mm f/1.8 are great, cheap lens to start off with for portraits and experimenting with apertures. There are many photographers who take much better pictures than me with these two lenses!
Using my D7000, here is a portrait I recently took with my 35mm...
@johnkratofil cheers, although I sailed a bit close to the wind with my explanation of depth-of-field and focal length. Have updated my comment above so it now reads correctly.
You've give perfect examples of the style of portraits you can take at with wide and tele lenses. Those two pics say it all, really!
Here's an example of the extremely shallow DOF you get at f/1.4 (50mm lens)
@cluvlj Thanks - I think I caught some of that :-) and have been slowly starting to understand this notion of the numbers changing with the crop sensor- sort of. I do like portraits but... I like macro too - you see my dilemma and the attraction of a macro that works for portraits too :-) So basically the 90mm would be hard to use in a small room? and the 60mm would be better on a crop sensor? @agima Thanks Brendan - when you say those numbers though - you are you talking primes right? I'm guessing a 50mm macro would be different to a 50mm prime? is it the ratio?
@dieter Thanks Dieter - yes natural light only. That was really helpful thank you! particularly the info about how close/far away you need to be! and thanks for the picture - your daughter is gorgeous and that picture is stunning!
@johnkratofil - thanks. Yes I do love both the kit lens we got with the D7000 but would really like to get those really close marcos. I have been told that a prime lens for portraiture is something you really have to try so would like to get there one day. If I won the lotto I would love to get a 100mm macro and a 50mm f1.8 prime but.... seen as I don't play lotto I need to compromise lol
The are great. The lens show up in protective cases with a return bag. If you only use the lens every now now then, this is the way to go. Or you can use these guys to test out lens that you may want to purchase.
Tweets ahoy!
Join the Group
Pin With Me
Would those focal lengths work? Yes. In a crammed setting, no way. A focal length of 75-105mm would be great for a 35mm film camera. For a non-full frame digital (your D7000 is not full frame), you can take those numbers and multiply them by 1.5. So, a 50mm lens is equivalent to a 75mm for full frame, which is ideal for portraiture. Stick with the 50mm. Nikon makes a killer 50mm 1.8 prime. Macro scmacro. You want t portraits? Get the faster lens.
For the record, in 35mm speak, 50mm is considered "normal" (what the human eye would see). So, a 35mm focal length in non full frame digital is "normal".
Still, a 50mm or 60mm prime lens IS a portrait lens for what you need.
Best of luck on your endeavor.
10-24mm = Superwide angle
24-35-Wide angle
35-60-Normal
60+=tele
Also when you can afford a Prime, over a zoom, you will have a better lens. Unless you use a zoom for effect. Or, if you are tryign to get more for less.
(my opinion)
If you want an explanation in engineering speak:
http://www.kenrockwell.com/tech/lens-specifications.htm
The f stop is how fast the light can come in your camera so it is this that determines how much ambient light is needed to correctly expose your image. The lower the number the faster the light comes into your camera the less ambient light you need.
I do a lot of portraits and it is very rare that I would use anything less than 80mm and in fact I normally use 105 and around 200mm, but sometimes out to 400mm. I do this for a few reasons but that's probably a different and longer story. :)
A couple of issues spring to mind that could be expanded on a bit more. One is depth-of-field; for portraits you almost always want a shallow DOF to isolate your subject from the background (not necessarily such a big deal in the studio). The 'faster' the lens (smaller the f-number), the more you can reduce DOF (at a given focal length and distance from the subject). So a 50mm f/1.4 prime will give you noticeably less DOF than a 50mm f/2.8 macro for instance (as well as being better in low light).
The other issue is visual extension or compression (properly called perspective distortion). In simple terms a wide-angle lens makes whatever is closest to the lens (e.g. a person's nose) seem abnormally large compared to things that are more distant (e.g. their ears). Longer focal length lenses tend to make relatively near and distant objects appear more similar in size (i.e. compressed). In short, at wide focal lengths portraits tend to be unflattering. The ideal for portraiture is generally considered something 'a bit longer than normal' e.g. 50-60mm for an APS sized sensor, which equates to around 75-90mm on a full frame camera. Unlike depth-of-field, perspective distortion is not a function of the focal length printed on the lens, but rather the angle of view. What counts when you think about perspective distortion is the 'effective focal length' (or full frame equivalent).
Sorry if that is confusing! I'll try again. With a longer focal length lens:
1. you have to stand further from your subject to fit them in the frame (a problem in cramped conditions as mentioned above, but a good thing for macro as you don't have to get as close)
2. you get more visual compression (due to the fact you are standing further away). Up to a point this is a good thing for portraits, or so I'm told (I don't shoot people as a rule!) ;)
3.
you get shallower depth-of-field at a given apertureit is easier to isolate your subject against a smooth background. For an explanation of why, see here.Hope some of this is helpful :)
@saranna I would agree with almost everything said EXCEPT: "Also when you can afford a Prime, over a zoom, you will have a better lens. Unless you use a zoom for effect. Or, if you are tryign to get more for less."
"Prime" just means fixed focal length - no zooming. Entry level zooms do not have large apertures, but there are expensive zooms/telephotos that are just as nice for portraiture.
As @agima suggested, if you are going to be shooting outside and have plenty of room, long focal lengths are perfectly fine. Here is an example of someone using long focal lengths: http://youtu.be/U90BQUpISBs
I have a D7000, and I prefer to use my 70-200 f/2.8 when I have the room. The great thing about having a little zoom is that it saves you from moving around as much so you can be sure to fill the frame. But I also use my 35mm f/1.8 prime especially when I'm shooting portraits of kids and am chasing them around, shooting from closer distance. If you're just starting, both the 35mm or 50mm f/1.8 are great, cheap lens to start off with for portraits and experimenting with apertures. There are many photographers who take much better pictures than me with these two lenses!
Using my D7000, here is a portrait I recently took with my 35mm...
And here is one taken with the 70-200:
You've give perfect examples of the style of portraits you can take at with wide and tele lenses. Those two pics say it all, really!
Here's an example of the extremely shallow DOF you get at f/1.4 (50mm lens)
@agima Thanks Brendan - when you say those numbers though - you are you talking primes right? I'm guessing a 50mm macro would be different to a 50mm prime? is it the ratio?
@dieter Thanks Dieter - yes natural light only. That was really helpful thank you! particularly the info about how close/far away you need to be! and thanks for the picture - your daughter is gorgeous and that picture is stunning!
@johnkratofil - thanks. Yes I do love both the kit lens we got with the D7000 but would really like to get those really close marcos. I have been told that a prime lens for portraiture is something you really have to try so would like to get there one day. If I won the lotto I would love to get a 100mm macro and a 50mm f1.8 prime but.... seen as I don't play lotto I need to compromise lol
Since you are an Aussie girl you should rent the lends and give them a try
I have used these guys:
http://rentalens.com.au/
The are great. The lens show up in protective cases with a return bag. If you only use the lens every now now then, this is the way to go. Or you can use these guys to test out lens that you may want to purchase.