Moving from 50mm f1.8 to 30/50mm f1.4?

[chphoto]

I currently have Canon's nifty fifty, which I do have something of a soft spot for. However, since getting the 7D I've not been as impressed as I was with it when mounted to the 400D. I'm assuming it's mainly because of the 18mp ruthlessly picking out flaws when AF isn't spot on, etc?

Focussing can often be a pain with it, I'm finding it lacks accuracy with the 7D, maybe the camera's AF system is simply too fast for the lens' non-USM motor to keep up. This means that some shots are out of focus, even when using a narrower aperture to get a wider DoF. Sometimes even on a static subject! I've looked into the micro-adjustments but other times it nails the focus spot on...

I love the 50mm length on the 1.6x crop body, so I was looking at a direct swap out to a 50mm f1.4, either the Canon or Sigma... Having read reviews of both on the-digital-picture, the Sigma experienced inaccurate focussing too often compared to the Canon, but is slightly better built and possibly gives better results.

Or do I scrap the idea of a new 50mm and get Sigma's 30mm f1.4... I've enjoyed portraits recently using my Tamron 17-50.. f2.8 around the middle of the zoom range!

Opinions please

 

[amtaylor]

I currently have Canon's nifty fifty, which I do have something of a soft spot for. However, since getting the 7D I've not been as impressed as I was with it when mounted to the 400D. I'm assuming it's mainly because of the 18mp ruthlessly picking out flaws when AF isn't spot on, etc?

Focussing can often be a pain with it, I'm finding it lacks accuracy with the 7D, maybe the camera's AF system is simply too fast for the lens' non-USM motor to keep up. This means that some shots are out of focus, even when using a narrower aperture to get a wider DoF. Sometimes even on a static subject! I've looked into the micro-adjustments but other times it nails the focus spot on...

I love the 50mm length on the 1.6x crop body, so I was looking at a direct swap out to a 50mm f1.4, either the Canon or Sigma... Having read reviews of both on the-digital-picture, the Sigma experienced inaccurate focussing too often compared to the Canon, but is slightly better built and possibly gives better results.

Or do I scrap the idea of a new 50mm and get Sigma's 30mm f1.4... I've enjoyed portraits recently using my Tamron 17-50.. f2.8 around the middle of the zoom range!

Opinions please

I'm not sure you will find the focusing on the 50mm 1.4 much better. It hunts when light is not briliant much the same as the 1.8 just without the noise. I never really got on with either the 1.8 or the 1.4 personally but thats just my opinion.

 

[romeo21]

I also have a 7D and have a 50 1.8 i think its an ok lens great in low light but i find it a little to long for me so i'm at my desk waiting for my sigma 30mm 1.4 to turn up

 

[Jelster]

You option could be to find a Mk1 Canon 50mm f1.8. I still have mine from my film days and to be honest it works well on the 7D; admittedly not the fastest lens to focus, but I don't have any issues with it. Maybe it's because it was designed to work with film, rather than the smaller sensors of a crop body ? :shrug:

Steve

 

[neil_g]

Having read reviews of both on the-digital-picture, the Sigma experienced inaccurate focussing too often compared to the Canon, but is slightly better built and possibly gives better results.

without knowing what the reviewer was shooting, in what conditions and at what settings id take that with a pinch of salt. shooting at 1.4 for example is quite hard hand held due to the extremely thin DOF. but otherwise the AF has always been bob-on (obviously in low light it will hunt like any lens).

 

[SixToes]

The Sigma 50mm is generally rated above the equivalent Canon for IQ. I don't know what it's AF is supposed to be like, although based on my Sigma 30mm I'd expect it to be good.

I had the Canon 50mm 1.8 and now have the 1.4. The 1.4 definitely focusses faster and quieter. I think it is a bit more accurate too, but TBH if you are at high ISO and wide open the problem could be your expectations rather than the lens. Have you tried using your most accurate AF point and pointing it at a high contrast point on the same focal plane as what you are actually trying to focus on?