50mm 1.4 usefulness questions

I have had the Canon 50 1.4 for about 4 months and am curious if this lens is good for anything else besides portraits? I have taken some excellent/sharp closeups and portraits using this lens, but then there are times when I just want to take something not so close up (i.e.: group shots, landscapes, etc.) and the pictures just aren't that great. Now, it could definately be user error on my part, but I was curious how everyone else is using this little gem?

I have attached a picture that was taken in a dark room during an elementary school Christmas program. I was having a blast getting all kinds of pictures using the large aperatures of my 50 and 70-200, but the pictures from the 50 just aren't as well focused as the ones from the L zoom. Now, before I get bashed for attempting to compare a non L prime to an L zoom, I have taken pictures using my 85 1.8 from a distance greater than 10 feet with great success. I know that if I would have used a flash that my results would have been better (possibly), but I like using available/ambient light when possible. Is it that the DOF at a large aperature is so thin that this kind of shot is not recommended, or am I in need of Canon's help? I hope to learn something from this so I can continue to improve my skills, so please feel free to give any advice or pointers.

And yes, the autofocus had a lock and I was holding at still as I could be considering the conditions. EXIF 1/160 f/1.8 ISO 800

the DOF is thin at 1.8... looks like the lighting was pretty bad too making it hard to stop down to get a good DOF. probably should have gone ahead & bumped the ISO to 1600 as well, noise can be handled in PP

I use my 50 for landscapes all the time & love the results i get from it

by the way, what was your focus point in this image?

I had these same issues with my 50 1.8 back in the day. That's why I sold it. I didn't use the 1.4 enough to find out if it was the same way in these same conditions, but my 70-200IS is fine in these scenarios. I can only surmise that it's the lack of ring USM. The 50 1.8 I believe has a micro motor (but not USM) and the 1.4 has micro-USM.

At f/1.8, I'd only expect two rows of kids in focus. I don't really shoot large groups normally, but this one is also at f/1.8:

The 50 is great but has limitations, open aperture shots need to be reasonably close, shooting at a long distance at f1.8 like the example you show will not be sharp as the lens will struggle to resolve that much detail, the closer you get to a subject the better the lens performs when shooting open aperture. Get to know it's traits and its a great performer. It's almost always on my camera and I have two L's. The only way you will get great results at that distance wide open is to get an L prime.

I figured I was too far from the stage (about 20+feet) and with the only light source coming from the stage area this wouldn't have been the best anyway. The grain at 1600 was almost too much. I tried it first, but found it discouraging from zooming in on the LCD. I went ahead with the larger aperature, but now looking back I should have tried a little smaller aperature instead. I had the center focus point on as I understood it to be the best when using larger aperatures. I haven't had too much luck lately with using the all/automatic focusing points, so I am still trying to learn from my mistakes. Thanks for all that have offered help. Like I said, I am still trying to learn from my mistakes...thank goodness for digital