Macro lens: I'm troubled - DPChallenge Forums

Canon EF 17-40mm f/4.0L USM

04/24/2005 10:37:29 AM · #1

Hi again! I'm troubled with some doubts regarding macro lenses.

I was peeking in Sigma homepage because I'm getting found of macro photography and I was woundering some options. But there are a few things that I don't understand.

Here's some examples:
Sigma macro 105mm f2.8 EX DG
minimum focus distance: 31.3 cm
maximum magnification: 1:1

Sigma apo macro 150mm f2.8 EX DG HSM
minimum focus distance: 38 cm
maximum magnification: 1:1

So I'm im doubt: is the only advantage of buying the 150mm over the 105mm is that I can take pictures from far away? (sinse the magnification ratio is the same 1:1)??? And how is this so if they start focusing in such an equal distance? Wouldn't it be logical that they start focus almoust in the same distance that the 150mm should give more magnification? I really don't undestand...

I know own a 70-300 D ED and it's minumum focus distance is about 1 meter, but at that distance I can zoom to 300mm and still focus. So I can get quite close, but not macro enough. Will I get more close with a macro lens? I gess so but much more?

And for example I'm also interested in the sigma 50-500mm F4-6.3 EX RF HSM

it has a minumum focus distance between 100 and 300 cm!!! (yes, very far!!!) But it says it has a magnification ratio of 1:5.2. So at the end isn't it going to produce a more close up picture, because of the higher magnification ratio?

Please someone can put some light in my troubled mind?

thanks

soup

Canon EOS-30D

04/24/2005 10:45:22 AM · #2

if you want very close up - true macro either of the sigma lenses you mention will work well - the 105mm will be a bit easier to handle as an all around lense - the 150mm i think will be a bit too heavy.

i have the sigma 105mm f:2.8 and use it constantly for both close up and normal shooting.

none of the telephoto zooms are going to get you as close as a dedicated macro lense.

i can't explain the technicals of how the magnification stuff works.

at 1:1 with the 105mm or 150mm macro - a US nickle would more than fill the frame, and be clipped at the edges.

Message edited by author 2005-04-24 10:45:53.

e301

04/24/2005 10:45:35 AM · #3

5.2:1 would be a higher magnification ratio, rather than the other way around.

All you actually get with the 150mm is a narrower field of view - and those distances seem about right for them both to get 1:1 magnification. At that magnification you can fill the frame with something 22mm wide - without going for one of the outrageous macro-only lenses that's the best you're ever going to get out of one lens with no adaptors etc.

So it seems to me your choice comes down to whether a 105 or a 150 is the lens you need for other stuff; proce; and the HSM.

E

Canon RF 24-70mm f/2.8 L IS

04/24/2005 10:51:17 AM · #4

I've been always in doubt with the magnification rate of the lens.

The 50-500 wasn't for the same purpose. It was just an example of magnification rate given by the manufacturer.

Has someone used similar macro Nikon lens?

And whou about the 105mm versus the 150mm? Is the real difference just how close are you from your subject?

e301

04/24/2005 10:53:51 AM · #5

In terms of macro size - size of image on sensor, yes. There will be some depth of field implications, but only minor ones, and some relative perspective things too - but agin, very minor.

kirbic

Canon EOS R5

04/24/2005 10:58:45 AM · #6

You're right that the specs are confusing... If one lens has 1.42 times the focal length as another (150/105 = 1.42), then we'd expect that the subject distance at 1:1 would be 1.42 times as great for the 150 as well, and it is not. The reason is, the focal length of the lens may change as you move towards maximum magnification.
I know this happens on the Canon 100 macro, and suspect it happens here as well.
So to sum up, yes, both lenses will give you pretty much the same minimum field of view (22mm approximately, as previously posted), but one will give you a slightly longer working distance. You also might consider how each of the lenses will work for you as a normal lens. I do as much "normal" work with my 100mm macro as I do actual macro work.

Gauti

Canon EOS-7D

Canon EF 17-40mm f/4.0L USM

04/24/2005 11:21:04 AM · #7

some examples of what different focal lengths do in a macro lens in this excellent review of the new Canon EF-S 60mm 2.8 macro at the digital review dot com
scroll down to background blur comparison

Prof_Fate

04/24/2005 11:50:50 AM · #8

A true macro lens gives you 1:1 magnification - which means the item you are photographing will be taht exact size on the film (or sensor). Canon makes a 5X macro lens too if you really want to get into it (in this case the item will appear 5 times life size on the sensor/film).

The big zooms that have macro modes are often listed as 1:3 or 1:5 - meaning the subject will appear 1/3 or 1/5 actual size on the film/sensor.

Another option is extension tubes. They can be used with any lens and offer varying magnification factors.

A close up lens/filter attaches onto the end of a lens like a filter and allows you to focus closer to a subject.

Examples:
with extention tubes on a 135mm lens (100% crop):

and a cluse up lens on a 50mm 1.8 lens - I was about 1" from the subject. This was resized.

Canon EF 24-105mm f/4.0L IS

04/24/2005 01:31:48 PM · #9

Ok. I was seeing the magnification ratio backwards. Thank's for the explanation.

Any opinions about what macro lenses you folks use and how much you like them?

Corwyn

04/24/2005 01:46:00 PM · #10

I use the 100mm 2.8 canon

and I love it

Beetle

Canon EOS-5D Mark II

04/24/2005 01:46:37 PM · #11

I took this one yesterday with my Sigma lens (details with photo)