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View Full Version : Macro lens help please....


petrovich
2nd February 2009, 05:46 AM
I am considering two models at present, the Oly 50mm macro and the Sigma 105mm macro. Could anyone explain to me what distances I would need to be from my subject to get prime focus with either of the above, considering I have loads of flower shots to take and wish to take some bug ones as well.
Does the Sigma effectively become a 200 macro and the Oly a 100 macro.

Regards

mike_j
2nd February 2009, 08:22 AM
It depends on what you mean by macro (or flower). I have just done a rough check and to fill the frame with an image of an upright 35mm film cassette a 50mm lens front element was about 6 inches and a 90mm about 12 inches from the subject. The film cassette would be about the size of a small flower head I suppose.

Hope this helps.

90mm is certainly better for insects and on other subjects I generally prefer this longer reach.

DekHog
2nd February 2009, 09:22 AM
...also worth remembering that the Sigma will do true 1:1 macro, whereas the Oly won't... not on it's own anyway, so that means a fair bit of extra expense again if you want 1:1

yorky
2nd February 2009, 09:54 AM
I have the 35mm macro which does do 1 to 1 true macro but you are so very close to your subject, its fine for botanical subjects but frightens any living subject away. In that respect the 105 Sigme is a fine all round 210 focal length lens which is better for live subjects. It is also useful as a 210 lens in its own right and is extremly sharp

Archphoto
2nd February 2009, 10:33 AM
One thing you have to consider too: Depth of Field.
The longer the lens the less DOF and so on.

Peter

Who's_E
2nd February 2009, 11:22 AM
Make sure you have a go with both "in the field" before making your decision.

Yes, the Sigma 105mm is very sharp and will do 1:1 macro shots. However it does not handle nearly as well as the Olympus 50mm.

Nick

petrovich
2nd February 2009, 12:10 PM
Thanks everyone, I am going to give the Sigma a go during the week and the Oly at the weekend. The Sigma looks the winner at this moment though.

Regards

Ian
2nd February 2009, 12:28 PM
Thanks everyone, I am going to give the Sigma a go during the week and the Oly at the weekend. The Sigma looks the winner at this moment though.

Regards

We reviewed the Sigma 105 a while back on FTU:

http://fourthirds-user.com/2007/08/sigma_105mm_f28_ex_dg_macro_lens_review.php

Ian

smashingthewindow
2nd February 2009, 12:42 PM
If you have a look at slrgear.com the lens reviews are excellent. I was choosing between the 35mm f3.5 and the 50mm f2 for macro, the 35 does 1:1 whereas the 50 does not. Also there is little difference in the quality of lenses. I found that the extra cost of the 50 compared to that of the macro, although I would be getting f2 was not worth it.

I was actually just about to post a sell ad for a 35mm macro lens, amongst other items. The one I eventually bought after looking on slrgear and numeroujs reviews. If you are interested check it out.

I hope this helped, David

mike_j
2nd February 2009, 12:45 PM
One thing you have to consider too: Depth of Field.
The longer the lens the less DOF and so on.

Peter

This is an area which I don't fully understand at a technical level but I believe that the only thing that determines DoF is magnification. So an image at a given reproduction ratio on the film (sensor) has the same DoF regardless of the focal length of lens used.

The term macro is a difficult area. The definition is simple: the image on the film is the same size as the original. So on a large format a full head shot is macro, on a modern compact a grain of rice is macro? Wrotniak and others argue that it should be defined in other terms and I tend to take the view that a 35mm slide or equivalent subject, filling the frame of whatever camera I am using, is macro.

On this basis a 4/3 macro lens only needs to be 1:2 ratio to be as effective as a 1:1 on 35mm and this is confirmed by my Tamron adaptall 90mm which gives the same field of view on the Oly e510 without the extension tube as it does on my 35mm SLR with the extension tube.

photo_owl
2nd February 2009, 02:20 PM
yes re your observation on magnification and dof

Peter's comment is an often repeated one that ignores the effect of the reduced working distance.