Canon EF 40 STM f/2.8 vs Canon EF 50 f/1.8

[Photog82]

I have a 7D and the EF 50 1.8 II lens. Then lens is OK, it's sort of soft for my liking at 1.8-2.8 which is where I want to buy this lens. Some shots come out good, some don't, I'm not sure why. It's also a little long for me while indoors.

I'm considering the EF 40 2.8 as it is a little wider on the 7D vs the 50. However, I'm wondering if 2.8 is wide enough. I'll have to look in Lightroom to see what I normally shoot with on the 50. I know I've used 1.8 for certain shots during Christmas for the bokeh.

Does anyone have any comparisons between the two lenses?

[DSLR_Newbie]

I have both these lenses and in term if image quality in my opinion they are very much identical.

the 50mm has an advantage in terms of aperture F1.8 and the 40mm has an advantage in terms of focal length(wider).

In terms of using them on a crop sensor body the effective focal lengths are 50X1.6 = 80mm and 40X1.6=64mm which can be a bit longer for indoors.

I have a 60D which is also crop sensor.

Recently i have added a new lens to my setup and its the Sigma 30mm F1.4

On a crop sensor body the 30mm range is an actual 30 X 1.6 = 48mm which is near the standard 50mm on a full frame and it has F1.4 which is great for indoors.

the image quality in the 30mm is very similar if not slightly better than the 50mmF1.8 and 40mmF2.8.

[Photog82]

Thanks for the information, it was helpful. I wish they had something wider than 40 or 50. The sigma looks interesting, I've never used a non-canon lens before. I basically want a lens in the 30-50mm range @ at least 1.8 for indoor photos of kids. The 50 works in most situation as most of our rooms are large.

[Sean Setters]

I owned the Sigma 30mm f/1.4 when I had two crop bodies. However, once I upgraded one of them to a full-frame body, I found I didn't need the Sigma anymore as the Canon 50mm f/1.4 provided the same view on the full frame.

However, I can vouch for the Sigma. I really liked it on my 7D/50D.
http://www.flickr.com/search/?w=22336705@N08&q=sigma

[DSLR_Newbie]

Thanks for the information, it was helpful. I wish they had something wider than 40 or 50. The sigma looks interesting, I've never used a non-canon lens before. I basically want a lens in the 30-50mm range @ at least 1.8 for indoor photos of kids. The 50 works in most situation as most of our rooms are large.

that would be a great lens but alas no one makes one (not that i know of) until then its either primes or you go up to F2.8 which is still not bad for indoors.