40mm f/2.8 or 50mm f/1.4

[nicku]

Hi,

I want to buy a new fixed focal lens and i can,t decide between 40mm f/2.8 or 50mm f1.4. i mention that i will use the lens on a APS-C body ( Canon 7D) only for people and portraits.

Wat is your experience with those two lenses? there is a significant difference in IQ at 2.8 , difference in AF speed etc. I use L zooms and the only fixed focal lens i currently use is 100mm f/2.8 USM.

I am not interested in weight or dimensions of the lens ... only in IQ. The price difference between 40mm and 50mm is worth it???

Thanks,
Nik

[Random Orbits]

You mentioned havng L-zooms, so I'm assuming that you already have a good lens than spans 40-50mm.  If so, I see no reason to consider the 40mm especially after you mentioned that IQ is more important than weight or dimensions.  If you don't have any fast primes, a f/1.4 prime might be worth looking into for low-light photography and shallower DOF. 

[neuroanatomist]

If you don't have any fast primes, a f/1.4 prime might be worth looking into for low-light photography and shallower DOF.

Agreed - especially if your L-zoom(s) are f/2.8, a fast prime would be the better choice.  For portraits on APS-C, you might also consider the 85/1.8 (better build and IQ than the 50/1.4, if you have the room to use it).

[nicku]

My L lenses are 17-40 f/4 and 70-200 f/4 and i need a fast prime for shallow DOF other than 100mm f/2.8.

85mm on a APS-C sensor is a little bit long (not a big difference from my 100mm)

[EOBeav]

At some point, you're going to want a wider aperture than f/2.8. That's the only drawback against the new 40mm that I can see. However, the price to performance ratio seems to be out of this world on that lens.

[Random Orbits]

My L lenses are 17-40 f/4 and 70-200 f/4 and i need a fast prime for shallow DOF other than 100mm f/2.8.

85mm on a APS-C sensor is a little bit long (not a big difference from my 100mm)

I'd suggest looking at 30-35mm and 50mm primes.  I'd try to get as much separation in aperture from your zooms as you can afford.  It will give you significantly shallower DOF and a larger separation will give you more opportunities/reasons to use a prime.  The 35L is a great lens, but the 35 f/2 and Sigma f/1.4 (APS-C only) are options.  There isn't a clear winner at 50mm, so it's mostly a choice between the 50 f/1.4 and Sigma's 50 f/1.4.

[preppyak]

My L lenses are 17-40 f/4 and 70-200 f/4 and i need a fast prime for shallow DOF other than 100mm f/2.8.

85mm on a APS-C sensor is a little bit long (not a big difference from my 100mm)

You sound like the perfect candidate for something like the 35mm f/2, or the 28mm f/1.8. They each would give you 2 stops over your zoom in that range, but also a different perspective than the 100mm. I think you might find a 50mm and 100mm to leave you without a wide low-light option. When "people" is more than 1 person, both the 50mm and 100mm will be too close, in a way the 28 or 35 wouldn't.

The 28mm would hold up if you ever moved to full frame, though the 35mm would probably be a little lacking (40mm would be sharper and the light gathering negligible).

So, I'd say either the 28mm f/1.8 for group stuff....the Sigma 30mm if you know you'll stay APS-C...or the 50mm f/1.4 if you rarely shoot more than one person

[Ryan708]

Hell, if you want REAL price/performance the fantastic plastic, nifty fifty (50f/1.8 ) is excellent bargain, and quite a fast lens so you get good subject seperation. Build quality is about the only downfall for portraiture. I love mine. My father-in-law is borrowing it and I miss it. haha. My 28 f/2.8 is a little narrow and at 2.8 doesnt offer alot of background blur. It is nice and sharp however. The 50/1.8 is tack sharp above 2.8 as well. thats my $.02

[nicku]

My L lenses are 17-40 f/4 and 70-200 f/4 and i need a fast prime for shallow DOF other than 100mm f/2.8.

85mm on a APS-C sensor is a little bit long (not a big difference from my 100mm)

You sound like the perfect candidate for something like the 35mm f/2, or the 28mm f/1.8. They each would give you 2 stops over your zoom in that range, but also a different perspective than the 100mm. I think you might find a 50mm and 100mm to leave you without a wide low-light option. When "people" is more than 1 person, both the 50mm and 100mm will be too close, in a way the 28 or 35 wouldn't.

The 28mm would hold up if you ever moved to full frame, though the 35mm would probably be a little lacking (40mm would be sharper and the light gathering negligible).

So, I'd say either the 28mm f/1.8 for group stuff....the Sigma 30mm if you know you'll stay APS-C...or the 50mm f/1.4 if you rarely shoot more than one person

I probably will move to FF with the next body. All my lenses are and will be compatible with FF.  for wide angle pics i use the 17-40mm i need the 40/50mm only for single max. two persons portraits. i will look into the 28mm and 35mm along with the 50mm 1.4

Thanks for the replies 
Br,
Nik

[FunPhotons]

I have both and like the 40mm better.

[Ew]

+1 on the 28 1.8 - love it on crop and FF.

The funny thing is, I find that I get pushed into a different mode of sorts with the 40.
I feel the need to get in closer, and push different angles.  This is the case with both a 5D2 and 7D.
Lots of fun.  Similar in this regards to the 28 1.8 on the 7D.

With the 50 1.4 its a bit of a more classical feel; and I don't get the urge to perform acrobatics while shooting.

Having both, I can't say that I would give up one over the other.  They each give a difference experience.  I will admit though, I still use the 50 more.  Since adding the 40, I would say its approx 4:1 shots taken (mostly low light).

[rhysb123]

I have both lenses.

I was considering selling the 50mm (to fund the 85mm L) but I've now decided to keep both the 40 + 50.

In my opinion the 40mm IQ is better than the 50mm. OK, you're missing out on some f-stops but the 40mm for me just 'works'. I use it on a 5D and a 7D - on both it's fantastic. I'm keeping the 50mm for those times when the light is really bad! (I shoot weddings - some venues are just so dark).

I had the 35mm f2 but that was just a 'toy', I wanted the 35mm L but just couldn't justify the cost, then the 'forty shorty' came along and I totally love it.

A quick few test shots with the 40 shorty here (they are not that exciting though!):

http://rhysbaker.com/blog/index.php?showimage=1234

Rhys

[briansquibb]

I have both and I like the 40 as a walkabout

I dont really understand the fixation on fast lens - especially when one considers the satisfaction from the 70-200 f/2.8

The 40 gives excellent IQ from f/2.8 onwards - it makes a nice landscape lens

[RLPhoto]

I'd get the 50 1.4 first. It's IQ is solid and similiar to the pancake @ 2.8 with the added speed if needed.