Low light: 50mm F1.8 vs F1.4 or other?

[tim]

Myself and a few others have run into some problems with my 50mm F1.8 lens - see here (http://photography-on-the.net/forum/showthread.php?t=66959) and here (http://www.photography-on-the.net/forum/showthread.php?t=66835) for details. To summarise quickly, when using the 50mm F1.8 wide open at F1.8 the focus doesn't work quite right. Things look sharp in the viewfinder, but in the image on the PC is clearly not focussed correctly - mine consistently front focuses.

My lens has just been serviced by Canon, they say they didn't adjust it because it was already optimal, and made the comment that a USM lens would allow for more precise focusing. I'm not sure if that's the problem or not, but either way i've decided to replace the nifty fifty, after i've done some more tests. Of course tests aren't everything, but my real world photos are soft too, which is a big problem.

The obvious choice is the 50mm F1.4. It's priced reasonably for a USM lens that fast. The question is would that lens have the same problem as the 1.8 lens? If anyone has both lenses i'd love if they could test them both out, and i'm sure other people would find the information very useful.

I could also go with a different lens. I've heard good things about the 85mm F1.8, though that might be a bit longer than i'm after.

Does anyone have any thoughts, comments, or suggestions? The main use for the lens is theatre, maybe weddings (at least one wedding), and creative pics with very narrow DOF.

[Sean-Mcr]

I bought the 1.4 last week and i posted this problem i'm having with it yesterday http://photography-on-the.net/forum/showthread.php?t=70057

By no means am i saying this is the norm for the lens it's just an issue i'm having with it. I was wondering if anybody else was having the same

I also bought the 85 1.8 at the same time and it has been flawless

[tim]

Sean - hunting's most likely a different problem to this one, I thought hunting was mainly controled by the camera, not the lens. Strange that it's just with that one lens - maybe exchange it and see if the next one's any better?

[Sean-Mcr]

It's can't be the camera the 85 hits every time and the kit and 16-35. I never meant to presume it's the same problem sorry if that's how it came across. Just wanted to hilight a problem i was having with mine

I'm going to have to exchange it tim.

Sorry if i took it off topic there;)

[tim]

It's can't be the camera the 85 hits every time and the kit and 16-35. I never meant to presume it's the same problem sorry if that's how it came across. Just wanted to hilgiht a problem i was having with mine

I'm going to have to exchange it tim.

Sorry if i took it off topic there;)

No problem and not off topic at all, thanks for sharing and I appreciate you pointing out your problem, I hope you get your problem fixed :) It doesn't help me solve my problem though!

[Sean-Mcr]

There's one taken with the 85 wide open i'll search through my 50's for you

[tim]

Thanks Sean. I can take good images with my 1.8 as well some times, not all images are bad. The issue is that the keeper ratio is very low because of the focus issue. I don't think I need an image from the 1.4, though it won't hurt!

Anyone else have any thoughts on a good low light lens? My main uses are theatre, and maybe in the future weddings.

[Sean-Mcr]

This is the only one i can find right now, not the greatest of examples.

[tim]

Nice photos, and both are nice and sharp where it counts :)

[Sean-Mcr]

I don't think you could go wrong with the 85. I'm really happy with what the 50 can do when it does it!!!

Back to the store at the weekend

[roanjohn]

Theater?? Then you have no choice but to get the 85 f1.8......or even the 100 f2. A lot of times, the body and lens combo both contribute to accurate focus especially when tracking objects. In your case, since you have the 20D, its probably the lens. I would say that if 50 is a good focal length for you, then you are better off investing in the 1.4 version. It has USM and it focuses fast.........this lens would be good for weddings too.

Ro1

[tim]

85mm might be nice for theatre... I couldn't get a wide shot with it obviuosly, not without standing back a long way.

Does anyone have the 50mm F1.8 and the F1.4 to compare? If i'm going to consider the 1.4 i'd really like to know that it's better at focusing than the 1.8.

[Steve Parr]

I've had no real issues with either the 50mm f/1.8 or the 85mm f/1.8. This was shot with the 85mm f/1.8:


http://onstagephotography.com/images/earth2.jpg

Shot at ISO 200, 1/30, f/1.8.
Steve

[tim]

Any other input? If you guys could buy one low light lens for theatre and weddings, would you get the 85mm F1.8 or the 50mm F1.4? I'm wondering how useful the F1.4 will be, the DOF would be very very narrow and perhaps not usable very often.

[DeeplyDigital]

Any other input? If you guys could buy one low light lens for theatre and weddings, would you get the 85mm F1.8 or the 50mm F1.4? I'm wondering how useful the F1.4 will be, the DOF would be very very narrow and perhaps not usable very often.
50 1,4 - in combination with the 20D it is wonderful. I use it inside w. no flash, at night outside with a high ISO setting, nice bokeh. The 85 is too close with the 1.6 crop factor. The 50 gives you more room to play with.

J.

[tim]

I'm def getting the 1.4, thanks for the advice :)

[Sean-Mcr]

I dont agree about the 85 being too close for indoors, the photo of Diane my partner was taken maybe eight to ten feet away at most.

[karusel]

Can someone tell me what exactly is wrong in a lens when it front/backfocuses - by that I mean what the service has to do to repair it, is it just some microchip or something else? What about when camera is missing focus?

I'm really dying for a's to those q's.