I am a beginning photographer and want to upgrade my gear. I have a crop sensor Canon camera and usually use a 50mm 1.8 lens for my portraits. Recently I have been looking at the Sigma 35mm 1.4 lens but not sure if buying it would be worth it.
First of all, don't upgrade your gear unless you know why you are doing it. 'Because I like playing with new gadgets' is a perfectly good (well, maybe not so good), and very common reason, but instead I'll concentrate on possible reasons which have some photographic aspect.
There are, really two of these:
- because the lens you have is not good enough quality;
- because the lens you have won't do something you need it to do apart from in the limited sense of raw quality.
I will disregard (1) because I am quite sure that the 50/1.8 Canon lens is perfectly fine. People obsess both about absolute lens quality and about the magic qualities of certain lenses and like to think that these qualities will somehow make a huge difference to their photographs. Almost always they won't. And before you dismiss me as not understanding lenses: I have a rather substantial collection of lenses some of which are claimed to have near-mystical qualities (and in some cases actually mystical qualities), and at least one of which I had specially fabricated by gnomes from sand imported from the Moon. I love them, especially the lunar ones, but they just don't make me a great photographer.
So that leaves (2): will the new lens do something photographically interesting the old one won't? Well, yes, it will:
- it is about half a stop faster;
- it is wider – its field of view is different;
- ... and there may be some other features associated with this specific lens which I don't know about.
For (1): half a stop isn't much: you won't get shallower DoF really as the lens is also wider, and it's just not that much of a gain. Don't buy it for this.
For (3) I don't know. Perhaps there are some considerations specific to this particular lens and/or camera combination.
But (2) is the big question, and where it comes to knowing why you want it.
The 50mm lens you have is a mildly long lens on a crop-sensor camera. It is probably a lovely lens for portraits, but it's rather long for the way people tend to use lenses for, say, street or environmental photography.
The 35mm lens is going to be much closer to the traditional 'standard' field of view. It is still quite a lot longer than a lot of people use (Canon's APS-C crop factor is 1.6X, not 1.5X like most everyone else), but a lot of cameras used to come with lenses of 55mm which (remember this was for 35mm film) has about the same field of view as this lens when used on a crop body.
So, well, what do you want to be able to do? If what you want to do is make portraits of people then the 50mm you have is probably close to ideal. If what you want to be able to do is more like street photography, then the 35mm may be better, but you might also consider something wider: With Canon's 1.6X crop factor a 24mm lens would be about equivalent to 35-40mm on full frame in terms of field of view, and this is a lovely length.
So, as I said, it depends on what you want to do, and only you can answer that question. In particular the 35mm lens is not just a better version of the lens you have: even if it is better, it's not the same field of view, and would want to be used in a different way.
Well, I don't know in your special case, but generally speaking it is definitely worth it. On APS-C it works as a normal lens (that is ~50 mm) of a tremendous quality.
On full frame is a little wide but the quality is outstanding from edge to edge starting from F/1.8. Here is an example. I use it extensively on my Full Frame Canon. Of course, YMMV.
I don't have the 35 mm. But I have the 50 and the 20 mm.
I bought the Canon 50 mm 1.8 just as you then wanted something better.
Bought the Sigma 50 mm 1.4 Art and almost got religious.
I recently bought the 20 mm after a long search after which was the best.
Here is a good review of the 35 mm Christopher has in my opinion very good reviews https://youtu.be/qzxiAZ90S5o .
And since you are on APS-C then 35 mm is not very wide.
I believe you should go wider.
The 20 mm I have has its drawbacks too, I can't use filters* and it's really really heavy.
The 24 mm does not have the bulging front lens so that could means filters are possible.
Then there is the 18-35 mm 1.8 for APS-C.
It's the same aperture as you have but a zoom that will get you covered for the most part.
Me personally are not interested in zooms and I feel the 1.8 is too high. But it's all personal preference.
I can also completely dismiss the "Sigma lenses can't focus on Canon cameras".
That is just plain wrong. They focus fine.
With my limited experience of 10-ish lenses, they focus the fastest.
* I can use filters but that means I need to use square filters and that is not great when I mostly have the camera hanging on my shoulder.
If I was a landscape fotographer or something more stationary with a tripod then I would invest in it but as it is now. No thanks...
Only you can say, but I would suggest it's not worth it. For what purpose would you use it? Also, Sigma lenses on DSLR Canons can focus poorly, especially when shooting through the viewfinder (phase detect autofocus being used), because everything is reverse engineered in the lens - camera communications.
50/1.8 gets you more background blur than 35/1.4, because 50/1.8 = 27.778 whereas 35/1.4 = 25 exactly. If that's what you are after, shoot with 50/1.8.
If slightly wider field of view with nearly the same (slightly less) amount of background blur is what you're after, i.e. if you want a different shooting distance for portraits (shoot closer), then perhaps 35/1.4 would be the right lens of you. It may be a bit long as a walkaround lens, though.
For crop sensor Canon, 35mm real focal length is equivalent to 56mm (35mm equivalent). It's not a standard lens, it's a very very slight tele (although it's on the boundary between standard and slight tele). The difference between 35mm and 50mm is not THAT large. I suggest you shouldn't own both 35mm and 50mm at the same time unless you collect lenses.
Standard lens for crop Canons would be anything between 22mm - 30mm or so.
There is a 24mm f/2.8 lens, but unfortunately, for crop cameras, the f/2.8 does not allow you to get massive depth of field effects.
There is too a 28mm f/1.8 but it's significantly more expensive than 24mm f/2.8. Also, you don't get as much background blur with 28/1.8 as you would get with 50/1.8. But, as a standard lens, perhaps background blur is not what you're after?
If you're looking for a standard prime lens, consider choosing between 28mm f/1.8 and 24mm f/2.8. The 24mm f/2.8 is so cheap anyway that it is worth getting. For 24mm f/2.8, you are getting a good amount of sharpness at a very reasonable cost, although it does have vignetting when wide open.
A consideration may be if you plan to update to full frame someday. 28mm f/1.8 works on full frame, 24mm f/2.8 doesn't (but the latter is very cheap anyway, and you can sell it if you decide to do the update).
I decided to pick 24mm f/2.8 to complement my 50mm f/1.8. I was happy with the choice, but I ended up updating to full frame.
Don't forget longer focal lengths. The 85mm f/1.8 lens is very good value for money, and if you ever update to full frame, takes the place of the 50mm f/1.8. It's useful on crop too as a longer tele too, to obtain even more background blur than 50mm f/1.8.