Few questions about Macro (lens)

[Raj]

Hi,

I am inclined to get a macro lens. I have some question though.

1. Usually Macro lens specs says it gives 1:1 magnification. Now what does this means ? A 2cm object will appear at same scale i.e 2cm on photo at 100% magnification ?

2. I was looking at some wide angle lenses (sigma) & their min' focussing distance at ~18 cms, however magnification is upto scale of 1:5. Cant this be used to do macro work ? & what is more difficult to achieve in a lens - 1:1 or 1:mad: (higher than 1)

Rather than getting a ~50/100 mm prime (more on telephot side) wont it be better to get a ultra-wide (~15mm may be with some zoom) & do macro also with it or this impractical ?

Please let me know your thoughts & recommendations. From what I have read so far in this section EF 100 mm f2.8 is on top with Sigma 105 second on my list.

Thanks

[tim]

1) 1:1 means if you put an object 1cm wide at the lenses minimum focusing distance, the image it projects on the sensor will be 1cm across.

2) No. Well yes, but you won't get the same detail in small objects. I wouldn't call it a macro lens.

3) I don't think 100mm is long enough, i'm getting extension tubes when I get around to it. Primes are good because they're razor sharp.

The macro lenses from Canon, Sigma, and Tamron all have good reputations, but the Canon usually comes out as the preferred one. I have one and it's a great lens :)

[steven]

The problem with using wide angle lens for macro is they are wide angle.
This, I sure sounds dumb, but really.
With the large angle of view that these lenses have you cannot get close enough to fill the image are to achive true macro (1:1).

You can use wide angle to do close photography but it will be less than 1:1.

One of the issues with macro photography is working distance.
The smaller the focal length the smaller the working distance.
This is one reason that the 100mm is so popular for macro work. It gives you a reasonable amount of working distance for 1:1.

I have the 100mm and 180mm macro lens and I find the 100mm the best for most of my macro work.

[DocFrankenstein]

If you have a telephoto zoom, you can get kenko extension rings and it's gonna give you nice results.

This picture was taken with sigma 70-200 f/2.8 and 36+20+12 extension rings:
http://andrew4137.fotopic.net/p12721812.html
http://andrew4137.fotopic.net/p12459574.html 2 meg file!

At 70mm I get life size, but I have to be REALLY close. About 2-3 inches working distance.

At 200mm I get 1:2 (4.5 cm across the frame) but the working distance is close to 60-70 cm from the front element of the lens. :)

But u lose autofocus and about 2 stops of light with the extension tubes. True macro lens would be much more convenient to work with, but I'm just playing around.

[Raj]

Thanks for your replies guys.
I can understand the advantage of working distance with 100mm (actually with 1.6x , it will be 160 mm on my 20D). No problem.

But lets say if I have a 10mm wide angle (prime) & a 100mm prime marked as macro & if I can focus quite close to subject with 10mm, why would image have less details than 100mm ? Apart from working distance, is there any other factor ?

My only concern is that a 100mm will require frequent lens change.
This time of year is Cherry blossem season in Tokyo, so probably next two weekends I will be out shooting macro's + landscape, so I was wondering if a single lens will suffice ..

Doc, are you taking about extension tubes ? or diaptor rings ? Well I tried kenko +3 diaptor filter on my sigma 18-125, it brings down focus to ~20 cm, however I get terrible headache using it :-( As soon as I put the diaptor on & look into vf I start getting tears in my eyes & within 5 mins of shooting terrible headache which forces me straight to bed :-( FYI I wear spectacles with complex cylendrical/spherical combo... so may be this method dosent works for me.
Guess extension tubes may be different. All they do is bring down the min focussing distance, right ? I can get kenkjo extension set here for ~$100 but salesman said results wont be that good.

[Raj]

On a separate note, I was almost about to purchase sigma 15mm fish eye this morning but the salesman said i wont get the fish eye effect on a DSLR because of crop factor. Some reviews on net also say so. However I did saw some posts here from fisheye lens with noticable distortion.

How do this works, do any of you use fish eye ?

[tim]

With a 100mm lens the subject will fill more of the frame, cover more pixels, and will hence have more detail. You don't need a zoom because for macro the DOF is very narrow, you move forward and backwards slightly to get what you want in focus. It takes time and experience to get good at it - i'm not yet.

Extension tubes make the image larger because the increase the distance between the lens and the sensor. They're just hollow tubes, it makes no difference what brand you use. The lesson learned here is NEVER listen to salesmen.

Remember the DSLRs have a crop factor, not a magnification factor. You'll get the same effect but it won't be so wide.

[DocFrankenstein]

I was using extension tubes. Here they are 2x more expensive. :(

Wide angle just won't work. You'd have to place the subject way too close... maybe millimeters from the front elements.

You have to remember, that you'll probably want to take pictures of bugs too. Some of them bite, others won't let you get very close... So the longer the focal length of the macro lens the better.

Cheers

[Raj]

You have to remember, that you'll probably want to take pictures of bugs too. Some of them bite, others won't let you get very close... So the longer the focal length of the macro lens the better.

Cheers

This definately makes sense ! EF 100mm f2.8 looks most promising candidate then :-)

[Andy_T]

Look at posts from user Schmoelzl, he proves (with a picture of his lovely daughter, as usual :wink: ) that the 100/2.8 macro also is a great portrait lens.

Best regards,
Andy

[Fer]

I have been thinking of getting a macro lens as well (I have used my kenko extention rings but I hate that I have to be REALLY close to the subject, specially if it´s a bug) ... I have surfed around the net and I´ve read that the EF 100mm f2.8 is a good option. Now, here is a newbie question: How far away from the subject should I be if I want to photograph a bug with that lens?

[Raj]

Look at posts from user Schmoelzl, he proves (with a picture of his lovely daughter, as usual :wink: ) that the 100/2.8 macro also is a great portrait lens.

Best regards,
Andy
Yup ! I have seen that pic & frankly speaking its so good that it can be on canon catalog to promote 100/2.8 lens :-)

[MarkoPolo]

The canon 100mm macro is sharp as a tack! I used all the techniques mentioned above, extension tubes, diopters etc, but wasn't really pleased until I got the Macro. You'll love this lens.

[Pyromaniac]

I have the 50mm f/2.5 macro which has 1:2 magnifacation(never used the 100mm macro), and it is way better than using a wide agnle lens or a normal lens with extention tubes. It might be a good compramise for you, it doesn't have the 1:1 of the 100mm macro but it does have a reasonalbly good field of view(46 degrees) for landscape or portraits. The 50mm macro is also very sharp and pretty fast with an f/2.5