50mm f/1.4 USM, 40mm f/2.8 STM or something different?

[mhinshaw]

Greetings,

I am about a year into my DLSR experience with the Rebel T3i w/ EF-S 18-135mm f/3.5-5.6 IS lens kit.  Definitely an improvement over my Canon PowerShot point and shoot, but I am looking to get a bit more serious with my photos.  I have found this forum and the reviews at the-digital-picture.com's website very helpful. 

Situation: I have a first child on the way in 3.5 weeks, so I am not looking to spend more than $400 or so for my next step up lens.  In conjunction with the child will be a need for quicker shots, low-lighting capabilities and a lens that can do solid portraits.  I'm leaning towards the 50mm f/1.4 USM, but I have some questions/comments that I would appreciate some input on.

1. The 50mm f/1.4 will likely hold up far longer than the 50mm f/1.8 counterpart that also seems so popular?  It should have a much better bokeh as well from the reviews I've seen.
2. I've looked at the 50mm focal length in my 18-135mm (to keep the crop factor in mind) and it seems workable in most situations for full-body portraits, although indoors could pose some challenges.  Maybe the 40mm pancake is better in this respect, but will sacrificing about two stops (f/2.8) make for some tougher indoor/kids/motion photos?  The cheaper price is nice though.
3. While probably out of my budget, any thoughts on cheaper, non-Canon alternatives with bigger max aperture such as the Tamron 17-50mm f/2.8 XR Di II Lens or Sigma 18-35mm f/1.8 DC HSM Art Lens?  Both could satisfy my desire for larger aperture and provide more versatility than a prime lens.
4. I want a lens that won't require much flash work in low-lighting situations as I am really a newbie on flash photography for now.

I know a lot of people are so satisfied with the 50mm f/1.4 that they just leave it on their camera as their general purpose lens.  Does this seem about my most reasonable next step up for my budget and my goals?  Surprisingly, my wedding photographer used L series lens everywhere else but then used the 50mm f/1.4 USM for many of the closer portrait type shots.  I figured he would have the 1.2 L series for those, but maybe he forgot it that day or something.  Viewing those photos is a great way to see what I may be able to get, even though he was using a full-frame 5D mark II and likely photoshopped many of the photos.

Thanks in advance for the help and the support I've found throughout the forum.

[ebiggs1]

Absolutely buy the Sigma 18-35mm f/1.8 DC HSM Art Lens?  It is fantastic but it is way more than $400 bucks.

Nix the idea of the Tamron 17-50mm f/2.8 XR Di II Lens.  Although it would be a nice enough lens for most people but not for me.  I believe they are also a little more than $400 bucks.

And a big no to the 40mm "Pancake" and EF 50mm f1.8.  Don't go there.

Now the EF 50mm f1.4 is a very fine lens and is your choice with the conditions you have set. 

Just because somebody is a "professional" photographer dose not automatically mean they have to be using "L" series lenses.  You use whatever gets the job done.  Red ring or not.  A 50mm has been a main stay lens since the beginning.

[TCampbell]

I noticed you're thinking of the low focal length as a way to capture more light.  But keep in mind it does more than capture more light... it also decreases the depth of field.

Each full stop of difference (the kit lens at 50mm is f/5.6) doubles the light collection -- that much is true.  So a 50mm f/1.4 lens is four full stops faster ... working out to 16 times more light.  That's the good news.

But you can't forget that it also creates a shallow depth of field.

Suppose you're framing up a close shot at about 5' away.  At 5' with a 50mm f/5.6 your depth of field is .64 feet.  That's somewhat shallow but it is enough to get a nicely focused face of a person.  

Now suppose you switch to an f/1.4 focal ratio at the same distance in order to capture more light.  At the same 5' focusing distance but using 50mm f/1.4 the depth of field drops and is .16' (just shy of 2").  That's not very much wiggle room for focus.

(I have an application on my phone that calculates this data, but you can use the online website DOFmaster.com to look up this same info.  Enter the camera body type, lens focal length, focal ratio, and focus distance and it will tell you the depth of field (range at which subjects will appear to be in acceptable focus) as well as the near and far limits.)

You've really got to be careful when using very low focal ratios because of the extremely shallow depth of field.  It's possible to get a nose in good focus and have the eyes out of focus.   Most people prefer to stay away from the extreme lower limits of what the lens can do.  Nearly all of my lenses offer at least f/2.8 or faster and yet I tend to do most shooting at f/4 or higher and dip down to f/2.8 only when I know it's appropriate.

The EF 50mm f/1.4 USM is a much much better lens than the f/1.8 non-USM lens.  The major appeal of the f/1.8 is it's affordability -- and that's great, but you do sacrifice quite a bit for that affordability.  The 50mm f/1.4 has significantly better build quality, faster and quieter focusing motors, more aperture blades for a better aperture shape, a better quality to the background blur... I sometimes have to manually focus a lens and I appreciate that it has distance index marks on the lens barrel (the f/1.8 does not)..

For versatility, the Sigma 18-35mm f/1.8 is _very_ attractive.  That's going to provide you with a wide-angle to normal zoom range but no telephoto zoom.  To shoot portraits with such a lens you'd probably prefer to keep it at the 35mm end because wide-angle lenses tend to create perspective distortions which aren't very flattering to the face.  A 50mm focal length works very nicely for portraiture on an APS-C crop frame body like your T3i.

[mhinshaw]

Thanks for your response.  Looking through my wedding photos, I definitely understand what you're describing.  With the 50mm f/1.4, they shot many photos at 1.4 or 1.6 to get very specific things in focus (on the bride usually of course).  Even some of their 3/4 body portraits with the both of us were shot at 1.4 though, which makes it look more "artsy" I suppose with the very narrow DOF.  I like the bokeh it created.  Example of f/1.4 from the EF 50mm f/1.4 USM (credit: Matt Frye, One Tree Photography):

From looking at other photos from the same lens, looks like if I shoot the 50mm f/1.4 at f/2 or f/2.8 or higher, I should have an ability to get the DOF I am looking for for portraits.  The f/1.4 should come in handy when doing some very close detail baby photos.

The Sigmas I looked at are out of my price range for now, but I figured I should at least investigate some other options other than Canon .  On down the road I may look to them for my next lens to upgrade my 18-135mm kit lens.

I think the 50mm f/1.4 is what I will run with for now.  Thanks.

[mhinshaw]

Also - any recommendations on lens hoods and filters for the 50mm f/1.4 USM?  I haven't even used a lens hood for my 18-135mm kit lens... shame on me?

[ebiggs1]

The EF 50mm f1.4 is for you.  You will learn to use the DOF to your advantage with time.  It is not quite as dire as Mr. Campbell makes it sound.  DOF is not a line and once it is crossed it is OOF.  It graduates slightly with each setting.

DSLR's do not require any filter like film cameras did.  But a protective filter is a good idea.  I use them most of the time.

But remember it comes off just like it went on.  So if need be, take it off if the situation warrants it.

I encourage prople to use their lens' hood 95% of the time.  It makes a huge difference in some pictures and at least some differenc in many.

However the biggest investment you can make to improve your photos is a post processing program.  The best for the amatuers is Photoshop Elements.

[cale_kat]

@mhindshaw, ebiggs1 mentions that the 50 has been a staple in photography for a long time but that was only true in the context of 35mm or FF photography. With an effective "capture area" of ~85mm, the fifty is an excellent portrait lens but gives on some of its versatility, IMHO. A 35mm would be closer to the 50 us film-shooters remember.

A 17-50 f/2.8 is a very versatile zoom range for the crop sensor group.

[mhinshaw]

cale_kat, I agree I would prefer the 35mm for my crop sensor, but I think those lenses are running a bit beyond my budget at the moment. 

The 17-50 f/2.8 you reference, do you mean the EF-S 17-55 f/2.8 IS USM? 

[ebiggs1]

Agreed the 35mm focal length is closer to "normal" on a crop body, does not deny the fact that even when there were no FF DSLR's the 50mm still reigns as king of lenses.

More lens makers past and present make at least one 50mm.  Most make several variations.

No matter it is a inexpensive most versitle lens.  Remember your feet are not fixed to the ground when you put a lens on your camera.

[cale_kat]

To the OP, I'm not going to aggressively promote 3rd party lenses on Canon's site. They are very kind hosts and it would not be polite to test their generousity.

I was given a Nikkormat with an 50mm f/2 lens for high school graduation. The 50mm was the normal lens and served me well. It came with "pedal" zoom. Ha ha.

But feet can't control composition beyond the obvious distinction that the forground subject will get larger or smaller. If you want to control for the background in your composition, scale it to a natural size while keeping the enlarged foreground subject, you're going to need some increase in focal length. Feet can't give you that. This is where the 17-50mm zoom holds an advantage.

It isn't always a question of zoom vs prime as they both have their strengths and weaknesses. Try one and then the other, composing a picture as you would for your next shooting assignment. It's a very personal thing that will help you define your style

Edited to add, the Canon 35mm f/2 IS USM looks like a steal of a lens at a street price of ~$550. (A note concerning my role in spending other people's money... IT'S FUN! But YMMV.)