why is a 50mm a must have?

[andrewvid]

i've been reading around and there are many places where people say that a 50mm lens is a must have. why is this?
i know they are fairly cheap but i don't quite get why a fixed focal is a must have?
any thoughts?

cheers

Andrew

[Kerrie]

I think because they come in very fast apertures, which serves nicely in low light, at a good price?

:confused013

I got one.....but prefer my 35mm f2....which is closer on my cropped sensor to 50mm than my 50 is lol


Good thread....I'm curious too

[andylo]

why is a 50mm a must have?

??? Who have said that :confused013

[OzzieTraveller]

G'day Andrew

Back in film camera days when the 50mm lens was 'standard' ie- it gave an image about life-size, portrait 'togs found that the 85mm lens gave a 1-1/2 sized image which provided them with a 'nice looking' image from a distance that a) gave separation from the sybject, and b) was not too far away needing shouted instructions

With dSLR's and their cropped sensors where you get 'about life-size at about 38mm [within your 18-55 lens] it means that a 50mm lens now creates an image much the same as the old 85mm lens did years ago. Thus many 'togs into portraiture are discovering that a rebranded 50mm lens [now branded a "nifty-50"] has become an interesting addition to their armoury

Whether you need one is totally up to you ... many 'togs I know of just use the 18-55 locked into 55mm
Regards, Phil

[ameerat42]

i've been reading around and there are many places where people say that a 50mm lens is a must have. why is this?
... but i don't quite get why a fixed focal is a must have?
any thoughts?

1. Never heard of it myself, unless it's a good focal length to put "nifty" in front of. That has catchphrase value at least.
2. Wouldn't have a clue why THEY'd say that, but it would be a reasonable portrait focal length on a crop body.
3. A "fixed focal" would have the potential to have fairly well optimised optics compared to a zoom.
4. ???
Am.

[andrewvid]

??? Who have said that :confused013

i have seen quite a few articles that explain the usefulness and convenience a 50mm has to offer and that it is a 'must have' arcording to them.

[KeeFy]

I reckon why it's a "must have" is because of the cheapness of it and the ability to explore fast apertures and shallower DOF than the kit lenses. Well canon is cheap, nikon is almost double the price.. but double the build quality as well.

[junqbox]

Not neccessarily sure 'it's a must have' but, as said above-

-is generally regarded (on 35mm format) as similar to what the eye see's. A 35mm would be the equivalent on a crop sensor body.
-using a single focal length lens (non-zoom) can help you work more creatively, by having to re-adjust your position or the subject to acheive the result you want.
-fixed focal length lenses often have higher aperture openings (smaller number, eg- 1.2, 1.8, etc) so you can work in environments with less ambient light.

[Cyza]

I too have seen the word "need" and "50mm" coupled pretty often online, places such as digitalrev (http://www.youtube.com/watch?v=PwmCrGVS3ZQ)

I think it's the fact that they're so affordable due to being produced in such mass quantities, for most it's the first lens after kit lenses.
Such a high aperture, makes them very usable in low light, and achieving incredibly narrow depth's of fields naturally is another one of their big draw cards.

as to why their is such a bigger market for budget 50mm's as opposed to to 35mm's is beyond me. Most people using a 50mm on a full frame will use a 1.4 or 1.2, whilst most people on a tighter budget with an APS-C camera will have the budget 1.8. Would seem logical to have the 35mm mass produced and sold at <150 dollars since most people buying such a cheap lens will have an APS-C camera and 35mm is much more usable on a crop body.

according to DWI:
Canon EF 35mm F2.0
Price: $344.00 AUD

Canon EF 50mm F1.8I (http://www.dwidigitalcameras.com.au/store/product.asp?idProduct=63)
Price: $123.00 AUD

[jjphoto]

i've been reading around and there are many places where people say that a 50mm lens is a must have. why is this?
i know they are fairly cheap but i don't quite get why a fixed focal is a must have?
any thoughts?

cheers

Andrew

I have no idea what you've been reading but chances are that most of it refers to FF (35mm) bodies, film or digital. This is where the 50mm lens is the 'standard' lens. A 50mm lens is NOT a must have on any format other than 35mm, that is if you even consider it a must have in the first place.

50mm, on a 35mm camera, gives you an image which is about equivalent to that which you see with the naked eye. So, if you have your right eye in the viewfinder and the left eye open (and looking at the same subject) then the 2 images will appear approximately the same size. Of course this is NOT the case when the 50mm is on a crop camera (where it becomes a short tele lens) or for that matter medium format (where it becomes a wide angle lens).

As 50mm lenses are extremely cheap, yet extremely good, there's little if any reason NOT to have one. That's probably the best reason to consider one a 'must have'.

Re the fixed focal length part of your question. You can buy fast lenses, such as F1, 1.2, 1.4, 1.8 or F2 in fixed focal lengths (or primes) which are simply not available in zooms. For example you won't even find an F2.0 zoom for the 35mm format where an F2.8 zoom is considered fast. You can buy an F1.4 50mm lens for less than $150 quite effortlessly (if you have a camera that allows the use of Alternative or Legacy lenses (http://photocornucopia.com/1027.html)) because there are plenty of lenses from the film era which can be used on modern digital bodies.

Manual focus Industar 50-2 fitted to Canon 5D2 (http://photocornucopia.com/1041.html)
http://photocornucopia.com/images/Lenses/Industar_502/ind_011_400.jpg

Fixed focal length lenses also allow a high standard of image quality at a relatively low manufacturing cost. For example, I have an Industar 50-2 (a 50mm F3.5 lens) which is sharper than the 24-70/2.8 zoom (at 50mm) which cost about a 100 times more (although it's not a fair comparison, the zoom is far better in many respects)!

A 50-60mm macro lens is a nice alternative to a normal 50mm lens. They are normally much slower, from F2 to about F4, but the added close range ability can make them very handy indeed.

JJ

[Xenedis]

i've been reading around and there are many places where people say that a 50mm lens is a must have. why is this?
i know they are fairly cheap but i don't quite get why a fixed focal is a must have?

My personal opinion is that 50mm is definitely not a 'must-have'.

I find it the most boring and utterly useless focal length in the known universe.

<teenager leet-speek mode>
It is teh suckz0r!
</teenager leet-speek mode>

50mm is neither wide nor long, and it shows me the same sort of framing I see naturally with my own eyes; in other words, within the confines of a 3:2 frame, it doesn't give me a sweeping vista, nor narrow in on the details of distant subject matter.

I don't have the focal length in either prime or zoom format. I don't want it and would never use it. :-)

My advice is not to worry about what other people consider to be a 'must-have', and concentrate on what you consider to be a 'must-have' for your photography.

[Kym]

Historically 50mm on a 35mm film body was a standard less because it was supposed to give a view similar to the human eye.
50mm lenses we supplied as the kit or standard lens of the day.
My first SLR was a Pentax MX with a 50/17 lens ~1976
I still have both and use the 50/1.7 sometimes.
Sometimes I put some macro extension tubes and use it for the odd bit of macro work

[arthurking83]

I like 50mm ... the only problem tho is that it's one of those focal lengths I hardly ever use! :p

I'm either at 45mm or less, or 55mm and beyond :scrtch:

Why I ever bothered to get two 50mm's is beyond me ... they make for pretty ok macro lenses tho(if you have the right lens type).

seriously, as already said .. cheap .. and good IQ.

I hardly ever use primes, but they are a very good way to discipline yourself to see before you shoot, rather than zoom(in or out) and shoot.
Harder in many ways to make the photo interesting, so it teaches you to see better.

[sunny6teen]

it used to be the lens of choice for student photographers. partly because primes have have better optics and are fast.
mostly because they were cheap and students have no money :D
I'll bet few use the 50mm range outside of study/street photography.

if you're on a tight budget but still want good glass....then I guess it is a 'must have'. it'll run rings around any kit lens.
...also make for a great paperweight.

[Seabee]

I got it because it was cheap and I actually love it! It was the cheapest lens I could get when I got my 7d body and I just wanted a lens on there to practice with until I purchased the 100mm macro!! I use it for food photography and such and will continue to do so I believe as my lens buying continues lol!!
I did hear once that it was a 'must have' for beginners because it taught them to compose with their feet rather than rely on zooms!

[junqbox]

btw, further to my post above.
About the only thing I use mine for is product photography in a fixed environment to help maintain scaling etc.

[Seabee]

Ha ha ..... See I was on the right track and didn't even know it lol!

[Xebadir]

I think that there are a few aspects...why I have a 50:
1. I wanted to shoot in ridiculously low light but didn't have the ISO capabilities or expensive glass. (Fading light trying to identify a tornado is a pain in the backside)
2. I think they are fantastic at forcing me to compose my images in a more attractive way - I tend to shoot my zooms like primes in the majority anyway now probably because of this, but I really think zooms are the worst thing you can give to a photography beginner. - I would say 50mm equivalent is probably the better terminology.
3. Panoramic stitch: Short telephoto on crop = fantastic low distorting lens for panoramic compisitions.
4. The light hiking lens - if I had to take one lens it would probably be my 50 mm - I can achieve most things I need to with it if I have to using either composition or a few old tricks. If someone made a light ultrawide I might go there instead but its just not there atm.

[Feg]

50mm on a smaller chip camera is a pretty useful lens as a medium length portrait lens.On a full frame,I would have to agree it's a pretty boring length and my 50mm gets used very rarely.

[Tommo1965]

theres not many 1.8 lenses that you can buy for $300....plus its light...qood IQ and sharpness { I only know Nikon}...Id love a Nikon 50mmF1.2 manual focus Lens...its a gem..

[Brian500au]

My two most used lens this year are the 85mm and when I need a little wider, the 50mm. I do a lot of portrait / glam style of photography and rarely use a zoom. I use my feet as a zoom for both lens. I use a 1.3x canon body and find both these lens are perfect for the work I do.

[andrewvid]

hmm.. interesting so far! now that people mention it i realise that i do zoom a lot instead of taking those few extra steps to get closer!

[roastman]

I think that there are a few aspects...why I have a 50:
3. Panoramic stitch: Short telephoto on crop = fantastic low distorting lens for panoramic compisitions.

This is a really good point. Does anyone use this on a full frame for panoramics? It would seem like a fantastic option for poor light and super crisp shots. If the focal length a tad too small, especially if you do portrait orientation stitching?

[roastman]

Also, I believe (may be wrong) but the 50 mm was extremely popular as a photo journalist lens. This was predominately because it did supply a life size view, plus was an extremely fast piece of glass. Lots of photo journalism relies on very fast grab shots and if you had to choose a focal length that was likely to get you a shot, the 50 mm was your best bet. As a journalistic or street photography lens, a 50 mm is a good compromise between the focal lengths available, although this is not as relevant to small sensor bodies.

At they don't require as much complexity in construction, they can be produced quite cheaply. Funny, but reading this discussion has prompted me to look at buying one!

[ameerat42]

Summary to date:

NO - Lots more stuff here - YES.

And actually, I thought that the historical reason for a f=50mm on 35mm frame, or any other considered "standard" focal length, was that it approximated the length of the diagonal of the frame.
Originally I had some rangefinder cameras with f=45mm lenses. This is approx the 43mm of the diagonal.

[Kym]

AP has the week 50 '50mm' competition tradition.
You have to shoot an image at 50mm regardless of the camera sensor you use.

We even have a banner for that...
http://www.ausphotography.net.au/forum/images/APlogo_d_50mm2.jpg

:cool:

[Xenedis]

My view on the 'nifty fifty' lens (a 50/1.8 of whatever make) is that it a great learning tool for the following reasons:


it teaches people to compose by appropriate physical proximity; and
it allows people to experiment with shallow DOF and low-light situations very inexpensively.


I'd recommend one to people purely for those reasons, and actually did so the other day.

Personally, I still dislike the focal length and have no use for it. If you happen to like the focal length or otherwise find it useful, than all the better. If I cared for 50mm I'd buy a Canon EF 50mm f/1.2L, but as nice a lens as that is, the focal length is (for me) its weakness.

[William]

Was'nt it that it approximated the field of view of the human eyes as well ?

[Xenedis]

Was'nt it that it approximated the field of view of the human eyes as well ?

The 'standard' focal length on a given camera system is that which is similar to the length of the diagonal dimension of the focal plane.

On a 135-format camera, the diagonal dimension of the focal plane is 43.3mm. A 50mm lens is close to that.

On some medium-format cameras, the 'standard' focal length is 80mm.

On a 135-format camera, a 50mm lens provides basically the same framing/subject size you can see with your eyes. if you have a Canon 1Ds/5D or Nikon D3/D700/D800, mount a 50mm lens and look through the viewfinder. Then lower the camera and look at the same subject.

The size of the subject should be just about identical when viewed either way.

Whether or not this view is a benefit or a weakness is a matter of individual preference. Personally I don't like a lens which shows me what I can see without that lens; I like lenses to be wide or long, as they give me views and visual effects my eyes cannot see, and as such are far more interesting to me.

50mm bores me and nothing I shoot calls for that focal length.

[WhoDo]

[snip]... partly because primes have have better optics and are fast.[snip]...mostly because they were cheap and students have no money :D [snip] ... if you're on a tight budget but still want good glass....then I guess it is a 'must have'. it'll run rings around any kit lens.
This is precisely why my 50mm f/1.8D was the first lens I bought for my new D7000 (after the kit lenses that came in the bundle of course). Bang-for-buck in terms of image quality and usability in lower light IMHO. I use it most often for natural light portraiture on the DX format sensor; can't afford strobes either ... yet. Even if money were no object I'd still have one of these in my kit, although it would probably be the f/1.4G version.

[mikec]

The 'standard' focal length on a given camera system is that which is similar to the length of the diagonal dimension of the focal plane.

On a 135-format camera, the diagonal dimension of the focal plane is 43.3mm. A 50mm lens is close to that.

On some medium-format cameras, the 'standard' focal length is 80mm.


Yep totally right on that and I think that's half the reason 50mm is so popular, it's a left over of the days when 50mm was the standard with all 35mm film cameras. If you look at any 2nd hand medium format body most of them will come with an 80 / 75mm lens depending on the body.

[dbax]

saw the nifty fifty 50mm 1.8 II in a JB's cattledog this morning for $96, why not have it ?

[Xenedis]

saw the nifty fifty 50mm 1.8 II in a JB's cattledog this morning for $96, why not have it ?

I think it's worthwhile to point out what's good about this Canon lens, as well as what's bad.

What's good?


It's light.
It's small.
It's fast (as in wide aperture).
It's sharp.
It's inexpensive.
On an APS-C camera, it provides classic portrait framing.


What's bad?


Its barrel and mount is plastic.
It has no distance gauge.
It has no ultrasonic focus motor.
It's slow to focus, and noisy, too.
The focus ring is awkwardly positioned and small.
It has a five-bladed diaphragm, producing unappealing pentagonal bokeh.

[William]

All true John, But IMO it's good value for money, Great for pano's as well , I once did a pano using the 50mm 1.8 II , 21 shots, Three rows of 7 Portrait , The definition was amazing , The image quality is great , Must admit , I'm like you and hardly use it in daily shots , I plan soon to do a day or two , Just using the nifty fifty

[Xenedis]

All true John, But IMO it's good value for money

It's unquestionably good value for money.

That's on economical terms. Just because it's cheap and delivers very decent results doesn't mean it's the right tool, though. :-)



Great for pano's as well

Yes -- for panoramic stitch composites it's better to use a longer lens to avoid weird transitions and distortion. Plus, the remote subject matter won't be as small in the frame.

[Mary Anne]

I gave my nifty fifty along with my 20D to one of my granddaughters as she needed it for her TAFE course.
I missed it on the 40D so I upgraded to the 50mm f1.4 to use in low light. I dont use it a lot though its there when I need it.

[farmer_rob]

I have a 35/1.8 and a 50/1.8 - both are a really cheap way of getting a nice shallow depth of field.

[Brian500au]

With the 50mm lens it is horses for courses - if you need it why not use it.

For my line of work if I am shooting in portrait orientation I use a 85mm f1.2, but if I am shooting in landscape orientation and I don't want to move too far away from the person I am working with then the 50mm f1.2 is perfect for the job on a 1D (1.3x). It still gives me that separation from the back ground, no distortion, and if i am doing studio work and close it down a bit, it is tack sharp.

I only ever go wider when I have run out of room to move back - and it that case I worry about distortion of the image (person).

[Delfi]

Normal lens (those that cover the same angle of view that the angle diagonal from the nodal point to the film or the sensor) are the most easy to design from cheap alternatives to ultra high end standards (add one lens to the triplet design and you can go along, put some double-gauss design to work and you have a masterpiece and go beyond and you are in heaven)

This results on a lot options to chose and before the use of zoom lenses as standard, the normal lens was produced for every body constructed. In the 60's the photographic use shifted to the wide-angle and the need to solve more difficult problems arose. And the Zooms bypassed the problem without solving it.

If you want some examples of good lenses (optically and constructively) you can find many 50 mm for 135 format, many 80 for medium format cameras and many 35 mm for APS cameras

I have now many 50 mm lenses, constructed from 1953 to now and I love them, but I understand the need for wides or teles.

[Erin]

I'm addicted to my primes. I love my 35mm as it's an equiv to the 50mm on a full-frame sensor (I've got APSC, naturally). But I've also got a 50mm and an 85mm, all are 1.8. Tack-sharp and generally "fast" lenses. I think they'll always have the slight edge over telephotos in that respect. They also force me to move so that I HAVE to evaluate a whole scene rather than just stand in one spot more often than not - my zoom is my feet, so getting in closer allows me to see more detail than I would otherwise notice.

Speaking of the 50mm 1.2... is there a point in having a lens that goes that wide? The DOF is so shallow as to be nigh impossible to use - I have a hard enough time at 1.8. :angry0:

[jjphoto]

...

Speaking of the 50mm 1.2... is there a point in having a lens that goes that wide? The DOF is so shallow as to be nigh impossible to use - I have a hard enough time at 1.8. :angry0:

The difference between F1.4 and F1.2 is some where between a 1/3 to a 1/2 stop. It's a significant and worthwhile difference but an F1.2 doesn't become much more difficult to focus or use than an F1.4 lens (not withstanding some possible further softeneing of the image when wide open which makes manual focusing a little harder still). I'm a big fan of fast lenses and will always choose a fast lens over a slow one, for many reasons, and you can always stop down a fast lens if you need to.

JJ

[Kym]

It should be that everyone should have at least one 50mm prime fast lens ! :cool:

[ameerat42]

The difference between F1.4 and F1.2 is some where between a 1/3 to a 1/2 stop. It's a significant and worthwhile difference but an F1.2 doesn't become much more difficult to focus or use than an F1.4 lens (not withstanding some possible further softeneing of the image when wide open which makes manual focusing a little harder still). I'm a big fan of fast lenses and will always choose a fast lens over a slow one, for many reasons, and you can always stop down a fast lens if you need to.

JJ

That's about right. f/1 to f/1.4 is one stop.
Am.

[Xenedis]

It should be that everyone should have at least one 50mm prime fast lens ! :cool:

I have four fast prime lenses: 35/1.4, 85/1.2, 135/2 and 300/2.8.

Note the lack of 50mm. :-D

[Xenedis]

The difference between F1.4 and F1.2 is some where between a 1/3 to a 1/2 stop.

f/1.2 is a half-stop interval.

[arthurking83]

f/1.2 is a half-stop interval.

Not exactly.

JJ is correct, in that it's somewhere between 1/3rd and 1/2 stop.

The value f/1.2 is used as both a 1/3 and also 1/2 stop value difference.

It's due to the rounding factor, it's rounded both up and down depending of use.

1/3rd stops aperture stops from f/1.0 are:

f/1.0, f/1.1 and then f/1.2(actual number being f/1.259) to go on to the full stop at f/1.4 ...

But .... if you then use half stop intervals from f/1.0 you also get:

f/1.0, f/1.2(actual number being f/1.189) and then f/1.4.

The formula is based on a square root of 2 value.

mathematically speaking it is closer to 1/2 stop in terms of a more accurate exposure, as the rounding factor is smaller at the 1/2 stop interval compared to the 1/3rd interval.


but!! ..... knowing how much more power the marketing departments wield over the engineering folks have at any manufacturer, you can also bet that this actual physical size of the aperture is going to be closer to the 1/3 stop rounded value than it is to the 1/2 stop rounded value.

[Steve Axford]

Ah - but is the actual fstop f1.259? And it is just the displayed fstop that is f1.2? It may be much easier to engineer the fstops to 1/2 or 1/3 rather than the displayed or marketing values.

[jdreamer]

I used to have both 35mm and 50mm which I found 35mm to be more suitable to what I normally shot. However, 50mm is certainly a lens that comes in handy!

[Kym]

While on f/stops... The library has the gory details for the new members...

http://www.ausphotography.net.au/forum/showlibrary.php?title=New_To_Photography:f_stop_chart
and
http://www.ausphotography.net.au/forum/showlibrary.php?title=New_To_Photography:The_Exposure_Triangle_-_Shutter_Speed_Aperture_ISO_Sensitivity

[patrickv]

I'm a bit surprised ... No love for the 50mm !! All zooms !!
The 50mm (or the 30 to 35 equivalent for small sensors) is my favourite all time lens.
What I photograph with it just looks right. If I had to have only one lens, I'd definitely go with this one.

Sure, I'm old school, I was processing my Tri-X in the 80s ...

The 50mm looks right, as a viewer it feels "just as if I was there". This is very compelling for a photo that brings emotion to the viewer, not some "special visual effect" shot ...

For me, changing focal length to compose is a terrible lazy habit. Whenever possible, the perspective should be a deliberate thing. Sure, there are a few cases that don't give you much choice, such as interiors (need wide or you won't see anything) and sports/wildlife (you can't approach) but as a general thing it feels much better to use a "normal lens".

But just imagine a photo of some wide animal with a 50mm perspective, or even slightly wild angle. You're not a long distance observer any more, you're right there and it feels like you're just there. It would make a spectacular image.

I like the "wide animal" and "wild angle" mixup. I'll leave it in.

[Kym]

@patrick - Perspective!! Yes!!

Even if you use a zoom lens, changing the perspective with your feet is absolutely needed!

[KeeFy]

Speaking of the 50mm 1.2... is there a point in having a lens that goes that wide? The DOF is so shallow as to be nigh impossible to use - I have a hard enough time at 1.8. :angry0:

If you are taking photo of a scene/subject up close, then natrually you'll have issues. Once you move further away like 2+ 3m. It's really easy and the DOF is shallow enough for the subject to be in focus (like a person) and blur out the back scene.

I do however agree it's hard to use the 50 f1.2 on a crop sensor and i had some issues using it with the 7D.

http://farm8.staticflickr.com/7032/6822325203_66908d9454_b.jpg

http://farm8.staticflickr.com/7024/6822337285_98e9b02bea_b.jpg

Both shot at f1.2 with a 5D classic.

Keith

[LJG]

This thread is interesting reading. I have had 3 50mm lenses over the years. The Canon f1.8, then the Canon f1.4, now I have the Sigma f1.4. Whenever I shoot people I either use my Sigma 50mm or my Sigma 85mm f1.4. I like the suject seperation a narrow depth of field has. I also think having a fixed focal length can be more fun to use and makes you think that bit more about composing your shot, rather than just standing stationary and zooming in or out. They can be a lot of fun to use, but are they a must have? That comes down to personal preference.

[Terri]

Interesting thread. It caught my attention. I too have a 50mm "because everyone said you should" ha! I too have found very little use for it - and have had very little success the few times I have used it. I'm sure it's me, not the lens. I use my 35mm heaps more.

[mikec]

@ patrick and kym

Completely agree, I find I usually use my zoom's like a prime. I'll get the approximate focal length I want and just walk back and forth to frame. Only time I really take advantage of zooms is when I can't move eg. hanging on a rope doing climbing shots.

I like being able to quickly shoot an 85mm head and shoulder shot then get in at like 135mm for a closer detail shot with a consistent and considered perspective. This is particularly import for a typology series I'm doing at uni at the moment.

[ving]

read kyms post.

basically you dont need it, no one needs on but they are good to have.

[Lazyshooter]

I have a 50mm prime and I actually use it quite regularly. I like the focal length on the crop sensor and has the advantages over standard zooms in that it is 1) smaller and 2) faster. My tip would be to get your zoom and set it to 35mm or 50mm and go and take some photos at that focal length, see what works for you.

[patrickv]

Interesting thread. It caught my attention. I too have a 50mm "because everyone said you should" ha! I too have found very little use for it - and have had very little success the few times I have used it. I'm sure it's me, not the lens. I use my 35mm heaps more.

The "you should use a 50mm" saying originates from when everyone mostly used 35mm film (ie. full frame cameras), which is actually not so long ago, approximately ten years.
As technology advanced, camera makers started to make digital cameras. At first it was so challenging that they couldn't make a single decent 35mm size sensor at all without messing up thousands of them. What they did manage was to make smaller sensors, 1.5x times smaller (Nikon) and 1.6x times smaller (Canon). Technology improved and at last in the five last years ago they were able to make bigger sensors (D3, 2007), but it's still extremely costly because of the reject numbers. Anyway, this means that most consumer cameras have a smaller sensor than the regular 35mm film equivalent.

The actual 50mm number means nothing by itself. It only has signification when combined with a sensor/film size. When people started to say (rightfully) that we should use a 50mm, practically everyone used the same size sensor: the regular 35mm. The saying has remained, but now most people have a camera with a smaller sensor.

The real meaning of this saying is actually "you should use a lens that gives you a 39.6 x 27 angle of view" because it's similar to eyesight. On film or on FX, it translates to 50mm. On DX it translates to 50 divided by the smaller surface, which is 33.3. Therefore your 35mm is actually providing a "50mm equivalent perspective" and you are doing exactly what is recommended.

For Canon it's 1.6x and not 1.5x so the closest approximation is more 30mm. Canon don't make a 30mm prime lens, they only make a 35 f/2 and a 35 f/1.4L so to have a "normal perspective" on Canon crop, I would rather recommend the Sigma 50mm F1.4 EX DC HSM lens. It's a beautiful lens, crisp, very fast, nice bokeh, not too expensive. They sometimes have autofocus issues (calibration) but you just have to bring them to warranty and it will be OK within a few days.

For a DX/Crop sensor (most of us), a 50mm becomes a portrait lens. It's still good to have but it's definitely not an all-rounder.

Cheers.

[Lance B]

As people have suggested, the 50mm lens being a "must have" is from the 35mm SLR film days when it was sold as the standard lens with every camera, now the standard lens is the kit zoom. The DSLR kit zoom is usually a focal length range from 17 or 18mm - 50 or 70mm or thereabouts on cropped sensor camera (APS C or DX) and 24mm - 70mm or thereabouts on a FF camera. These zooms incorporate the standard focal length for their respective formats in that zoom range.

The beauty of the 50mm lens nowadays is that it serves two purposes and hence why it is probably still reasonably popular and that is that on FF it is the "standard" lens but on a cropped sensor camera (APS C or DX) it becomes a very wide aperture portrait lens.

As for a "must have", it depends on what you shoot. As I shoot with a FF camera, I rarely use focal lengths around the 50mm mark except maybe a few times when taking holiday snaps with my 24-70 zoom. In fact, mostly I am shooting either at the extreme wide end or at the long end of the 24-70.

[zollo]

most already know, but 50mm is not similar to eyesight as most would experience everyday. 50mm is equivalent to only one eye open. As in close one eye, and thats equal to 50mm. The actual width of lens that is closely equivalent to what we can make out with both eyes open is 24mm, before it becomes blurred peripheral vision.

Which is why I much prefer either a 35mm or 28mm prime lens, for walk around/holiday style shots, and for environmental portraits too. 28mm is probably my favourite, as it gives a natural feel, whereas the 50mm feels slightly telephoto to me. Of course there will be more distortion at 28 than 50, but shoot it correct and on a prime you should still be able to get away with it.

[arthurking83]

......

The actual 50mm number means nothing by itself. It only has signification when combined with a sensor/film size. When people started to say (rightfully) that we should use a 50mm, practically everyone used the same size sensor: the regular 35mm. The saying has remained, but now most people have a camera with a smaller sensor.

this is not actually correct!

The focal length of the lens has a meaning and it's exact in it's meaning. It's a measure of it's magnification onto the sensor plane(whether that sensor is film or digital or paper or whatever else can be used).
Basically it's ability to record an image of a particular size onto the sensing material.

it's way too complicated to describe examples of how this actually works and the technical benefits of choosing differing focal lengths over others, but you are partly correct in that the size format of the sensing material plays a factor in the lenses ability to record it's image as well.
But a 50mm lens is a 50mm lens, irrespective of the format used, if you want a lens to magnify a subject to a particular size.




.... For Canon it's 1.6x and not 1.5x so the closest approximation is more 30mm. Canon don't make a 30mm prime lens, they only make a 35 f/2 and a 35 f/1.4L so to have a "normal perspective" on Canon crop, I would rather recommend the Sigma 50mm F1.4 EX DC HSM lens. ....

I'm sure you meant to say the 30mm Sigma lens and not the 50mm version .. 50mm version is also a nice lens to have.

But lets not get bogged down in semantic discussions of technical reasoning as to why a 50mm lens is handy or vital to have. The OP's question didn't seem to bother about technical discussions as to why a 50mm lens was a must have.. and in reality there are none for it.

I don't use either of my 50mm lenses for the 'natural human eye perspective' they give me.
In fact I find it quite boring to be honest.
I like the individual lenses ability to render the scene in a particular manner .. whether that with subtle contrast and or colour nuances, or bokeh or just for the fast aperture they allow(at a reasonable price!).

I acquire my lenses due to what I believe will give me a particular look that it has proven to achieve, either via samples I've stumbled across from others, or for myself via testing.

My first 50mm was the Nikon 50/1.2 and I got it simply for the ability to render images in a particular way for a given price.

had price been no object, I can unequivocally state that I'd have got the 58mm f/1.2 instead.. but that would have cost me about 6x the price of the 50mm.(58 mm is by far the superior lens, in many respects).

Later on, I liked the image samples I saw from the Sigma 50mm, and walked into a shop and wanted to try one out for myself.
The shop also had the Nikon 50/1.4 AF-S as well in stock and a slightly cheaper price(back then) .. as the Sigma was more rare!!?? :confused:
I tried them both and immediately I thought the Sigma lens produced nicer bokeh on the images I captured in the shop with both lenses. So I got the Sigma and not the Nikon version.
I wanted another 50mm fast lens that had an AF-S autofocusing ability as well.
I could have chosen the AF-D(screw driven version) as well, but that lens never entered into the equation at all due to it's older focusing system design.

Why did I get another 50mm lens? .. especially as I don't particularly favour the perspective it gives me!! ... simply because those lenses gave nice looking images that I now have the ability to capture.
( I suppose the onus is on me to capture those 'nice looking images' ... and hopefully one day I will! :p)

I suppose the terminology used may also be partly to blame for the confusing messages it implies:

'A must have' taken literally could be interpreted as expressing an idea or notion that can't be lived without for some reason.

If the term is taken with a different context, say as a colloquialism .. the way you can transfer this expression to another gizmo, gadget or idea .. eg: an iPhone(or more accurately a smart phone).

I resisted for ages getting a smart phone .. all I wanted a phone for was to make PHONE calls!! (kind'a makes sense really as that's the purpose of 'em).

But my PDA eventually died(or is playing up to a point where it's unusable) and they're no longer being made(for good reason).
So I ummed and ahhed and got myself an Android phone.

Now I can do my PDA tasks, log keeping, spreadsheet editing, and other personal files keeping on my phone with critical data backed up to the PC and so forth.
After years of resisting, it's now become a 'must have' for me as it's replaced the PDA that I used to store stuff on.

So, just like a smart phone is a 'must have' ... so is a 50mm lens in photography terms.
That is; it's not a vital instrument for every day survival ... but it's so well priced, that you'd be mad not to have one.
Even if it's only for occasional use, as mine get used.

[N*A*M]

i used to hate the 50mm FOV. but for some reason i have three 50mm lenses at the moment. the AF-S 50 f/1.8 is pretty sweet, but the Sony SEL50 with stabilisation is excellent as well.

[Jorge Arguello]

I have read the same on magazines and articles.

This is what I think:

Sales man says: A 50mm (or 35mm) is a must...
End user says: A 50mm (or 35mm) is a must if you need it.

[bugshutter]

All of the above

[andrewvid]

All of the above

Great answer! ;)

..thanks everyone, this has certainly given me a big insight to the 'nifty fifty'