Lenses & Converters

[The_Moaner]

Hi All,
I now own the Sigma 150mm f2.8 Macro & a 70-200 f4 Canon lens. Used on a Canon 7D until I find a second hand 50D in good nick.
Which 1.4 teleconverter will work the best with both lenses.??
Thanks.
Dennis.

[nightshade]

I use the Kenko 1.4x and it works well with all functions with my Nikkor and Sigma lenses (and my Kenko tubes) All you need to watch out for is that no elements touch

[nigel_b]

1.4x - ask yourself if its worth it? Less picture quality, less light, smaller depth of focus.

1.7x - significant reach advantage, pay the penalties as above

2.0x - don't waste your time.

My view FWIW.

[Lancashire Lad]

Originally Posted by nigel_b

1.4x - ask yourself if its worth it? Less picture quality, less light, smaller depth of focus....

I can't vouch for the other magnifications, because I don't have them.

But with specific regard to macro use, I consistently use the Sigma 1.4x converter attached to my Sigma 180mm macro lens.

The quality is outstanding. The additional magnification is very much worth it. I'm not sure whether there is in fact any reduction in depth of field - I've certainly never noticed or found any problem with that.
Yes, you do lose a stop of light, but my subjects are static (fungi mainly) and I always use a tripod. - Exposure times are regularly in the multi second range.

I've had the converter attached to the lens for about 18months now, and have never taken it off. (All of the Nikon/Sigma shots in my WAB Gallery during the last 18months use that combination).

Regards,
Mike.

[MeadsMan]

Surely your not replacing a 7D with a 50D !!! ????

I dont think you will find a 1.7 converter to fit Canon lenses.I use the Kenko 1.4 converter,and I feel it does take the edge off my photos very slightly.I think You do lose some depth of field,as my photo backgrounds actually appear to me to be generally more blurred cleaner and better with a converter attached,and that`s with the smaller aperture caused by the converter.

[Foz]

Hi Dennis,
I dont think the Canon1.4x will fit the Sigma but it works well on the 70-200f4L.
One advantage of using an extender on a macro lens is that it will increase the f stops.
The canon180f3.5L goes from a max f32 to f45 with a 1.4x fitted, giving better DoF.
I think JT has a Kenko extender, why not ask to try his?

Clive

[squishy]

Originally Posted by Foz

Hi Dennis,
I dont think the Canon1.4x will fit the Sigma but it works well on the 70-200f4L.
One advantage of using an extender on a macro lens is that it will increase the f stops.
The canon180f3.5L goes from a max f32 to f45 with a 1.4x fitted, giving better DoF.
I think JT has a Kenko extender, why not ask to try his?

Clive

I wouldn't think it's much of an advantage have f/45 available. Surely you either have to have heavenly light or incredibly sluggish exposure times, and diffraction would seriously erode details. If you need the DoF of f/45, I would be looking at focus stacking at larger apertures instead.


The longer focal lengths of the extender will give more blurred backgrounds because of the perspective difference (it's blurring it the same amount, but the area of background in the frame is smaller), rather than being because DoF gets smaller.
If you take the same framing with the same aperture DoF will be the same regardless of focal length, it's the different perspective of longer lenses that makes the background more diffuse.

[Foz]

Hi Squishy,
you may be right about image stacking giving better results but if an image is used as natural history in some Welsh photo comps, editing, other than slight sharpening and levels is not allowed.
I know that the Moaner does enter these comps, so would need to get the image right in camera.
I shoot in Jpeg and have a custom menu in camera for high f stops, and it seems to work OK for me.
I find at f45 I need to use around ISO6400 to get a good shutter speed, unless I have time to set up my flash system (MT-24EX +2x EX580Mk2's as slaves) then I can easily shoot at ISO 100.
I dont use photoshop as I wouldnt know how to open it, but maybe one day....


Clive

[squishy]

I suppose if you can't focus stack then f/45 must be the only way to get a good DoF for macro sometimes.

I sometimes wonder why competitions don't allow focus stacking, but I suppose if they allow one kind of multiple frame image, it's hard to disallow other things like HDR.

You must have a very good lighting technique to be able to shoot at ISO 100, at 1:1 f/45 becomes in light transmission terms effectively f/180!

[nightshade]

How about making one of these? Create An Automated Macro Rail For Image Stacking | DIYPhotography.net