135mm f2 L prime

[shadowcatcher]

Dear All,

 

Just a quick question. Can someone tell me why exactly what the switch on the

barrel marked 0.9M and 1.6M does? Also any tips on when to switch it between

the two? I am 95% sure why but want to make make sure I get the best out of it.

 

I must add it is the sharpest lens I have ever seen, absolutely awesome.

 

Many thanks,

 

Kev (complete moron)

[hakon_soreide]

0.9m and 1.6m would be the focus limiter, setting the close focus limit to either 0.9 metres and 1.6 respectively - to avoid as much focus travel and focus hunting when in general use (ie. more than 1.6 metres).

[shadowcatcher]

Dear Hakon,

 

Many thanks for the reply. I use it for portraits, where I stand between 3-8 feet away from the sitter and if I have understood correctly, I should set the focus limit to 0.9M? However sharpness of the lens won't be affected regardless of setting?

 

Many thanks

Kev

[robin_sibson1]

Many Canon lenses have a switch that selects the AF range. The ONLY reason to set it to anything other then the full focus range is to improve AF performance, including, particularly on macro lenses used at normal distances, to prevent 'hunting' through the full focus range when focus cannot be acquired by a small adjustment. Once the lens is focused, the setting of the focus limiter switch has no impact on image quality.

 

It is conventional for owners of the 135/2L to declare that they could be parted from it only if it was pulled from their cold dead fingers. Hyperbole apart, you are now finding out why they say that. It is one of a small number of Canon lenses that really do seem to transcend the usual lens-design compromises. The recently introduced 70~200/4L IS may well come to be regarded in the same way.

 

You may not yet realise how versatile your 135/2L actually is. It is an excellent performer with the Extender 1.4x, to the point that you really don't need a 200/2.8 as well, although results with the Extender 2x are, in my experience at least, nothing to write home about. And it can be used for long-standoff close-up work - good for the larger butterflies and dragonflies - with the EF25 tube. It even accepts macro flashes (MR-14EX and MT-24EX) via the Macrolite Adapter 72C without vignetting.

[steve_parrott]

This is by far my favorite portrait lens. I use it on a 1Ds, (full frame sensor), so I suppose it

might be a little too much for a crop camera, or you just have to stand well back! I always

just leave the switch on the full range focus setting simply so it is one less thing I have to

remember. It is always ready to focus in all conditions. Here is a shot of my wife taken a

few weeks ago with this lens.

[colin carron]

The point of the focus limiter switch is mostly for when you are photographing something that needs fast focusing, say birds in flight or sport or whatever. With the 'distant' setting selected the lens focuses fatser as it does not need to hunt up and down the whole focus travel but just the 'distant' but. As you focus closer the amount of movement of the lens away from the sensor plane increases so closer objects need a disproportionally larger amuont of focus travel.

 

Triffic lens.

[shadowcatcher]

I have noticed that at F2 when doing portraits, it is very easy to get the focus on the eye wrong, one slip and the eyebrows are in focus and the eyeballs blurred (Steve, not only is that a technical masterpiece but it is a lovely portrait). I am still a bit confused which setting I should use in the portrait scenario?

 

Many thanks for you comments and help though,

 

Kev

[ken schwarz]

Kev-- At f/2, you have very shallow depth of field, so yes, it's hard to get one eye in focus, never mind both if you shoot wide-open. In my experience, it's best to focus on the eye that will be the natural point of attention in the portrait, which is almost always the more brightly lit of the two. It's good practice--although easier said than done--to take multiple versions of the shot using different eyes for focus points so that you can see how this works during editing. Don't let the subject distance change after you lock focus: just a smidgen off, and the eye won't be sharp. Also, you will need a pretty fast shutter speed to prevent motion blur, so don't be afraid to pump up ISO a bit in favor of some extra breathing room if you need it.

[shadowcatcher]

Cheers Ken, so is it 0.9M or 1.6M for head and shoulder portraits?

 

Cheers Chaps.

 

Kev

[mark u]

There is another reason for limiting the focus range other than trying to maximise focus speed - simply, you don't want something in the foreground in focus. This could apply e.g. to shooting through mesh fencing at a zoo, or a soccer goal net. With a fast lens such foreground obstructions can be made to disappear by using them wide open, even though you may not be able to get right up to them.

 

For portrait work, such considerations do not apply - you certainly wouldn't want to find that just because you decided on a tight composition that you needed to readjust the focus limiter, so set it to full range. AF speed isn't going to be a consideration either.

[alan_myers]

Or just stop down a little to f2.8 or f4 for a little more depth of field.

 

Just because a lens can achieve f2, doesn't mean it always should be used wide open.

[colin carron]

I usually set my lenses with a limiter to the 1.6m setting unless what I want to shoot might possibly be that close.

[ken schwarz]

Kev, leave the lens on the closer setting for portrait work. The reason for the focus limiter is to prevent a long focus hunt cycle when you have a hard time locking focus on far-away objects, not eyes in portraits like you describe.

[ken schwarz]

That said, 1.6m is pretty tight with a 135mm lens, especially with a crop body. If you set it it to 1.6 and you try to focus closer, the camera will refuse. In that case, just set it to 0.9 and you're all set. You don't have to worry about subtle misbehavior--if you get it wrong, you'll know.

[shadowcatcher]

Many, thanks for all the responses and help,you are all magnificent . I must say this lens is worth every penny, an absolute beauty and so sharp my colleague reckons he can see the cells in his epidermis! Best wishes, Kev