135L hunting in low light. A mere fact of life?

Can anyone confirm this please? I am still playing around the house with the 135L and obviously need to go out on the field but mine certainly hunt a lot in dim light.

I have to say I have been really spoiled in the last month with the Sigma 35mm f1.4 that can focus in near total darkness. I tested the 85mm f1.8 and the Tamron 90mm f2.8 and the 135L is not really worst but certainly not better. Strangely, I expected more from the legendary L lens. Hype victim?

I might also fail to realize that a 135mm lens let less light inside than a 85mm and even more a 35mm. (how I fail to grasp it when I am presently writing it I cannot say)

Please just tell me how your 135L behave in dim light compared with your other lenses.

Thankee!

I though 6d was so much better than 5dmk3 in this regard?

I tested my 5dmk3 and 135L. I could focus at ISO25600, f2, 1/30. So sigma works better in something like this as my 35L had issues.

I think the 6D is better yes but the lens is going to have an impact on how much light reach the sensor.

Is the shutter speed a good measurement of this particular problem? I am not sure it's affecting the focus at all.

Do you mean it hunt a lot or that it is broken and you cannot test it? The Sigma is incredible in extreme low light. Just for fun I tested the S35 now and where the 135 hunt it can focus like if its daylight. No lag at all. Just for fun I closed the small lamp I was using, only letting the computer screen light the room and it still lock. Slower but reliable. Best lens of 2012 no doubt about it.

How close are you focusing? If you're trying to AF in low light and at close to minimum focus, the lens is probably going to hunt more than at longer distances...

Earwax69 wrote in post #15438812
I think the 6D is better yes but the lens is going to have an impact on how much light reach the sensor.

Is the shutter speed a good measurement of this particular problem? I am not sure it's affecting the focus at all.

Do you mean it hunt a lot or that it is broken and you cannot test it? The Sigma is incredible in extreme low light. Just for fun I tested the S35 now and where the 135 hunt it can focus like if its daylight. No lag at all. Just for fun I closed the small lamp I was using, only letting the computer screen light the room and it still lock. Slower but reliable. Best lens of 2012 no doubt about it.

What I meant my 35L was slower to AF while 135L could focus easily. You need to tell what light level by sharing ISO, aperture and ss. Every person low light is different IMHO. I assume you using center AF point on your camera.

Maybe it is 6d.

ISO 12800, f2, 1/200.

Maybe if you where in the room here with me, you would say I am crazy to try to focus on that stupid cable under the desk. I dont think there's a way to quantify the problem (if there's a problem).

The only objective things I can say is that this here 135L is similar to this here 85mm f1.8 lens in AF threshold and that the Sigma 35mm is a very different beast. Not very helpful but it give an idea.

@Rudi; Around 2m. That's encouraging!

What I will need to do is to take the lens out by evening and see how it behave. It will be better than the t3i for sure. For very dark settings, I will be wise to use the Sigma 35mm.

Anyway, with the ISO noise at these levels, it will be an exercise in futility. Now I'll take my leave as it is time to go to bed here in the other hemisphere. I'll check the forum in the morning.

Thanks for the replies and interest.