A rough guide to macro

[Gordon Laing]

Hi popo, sorry I didn't notice this earlier - great post, and consider it sticky!

[FNGTF84]

gr8

[dhale]

I noticed in the example photo you used that there is room in exposure time and ISO for you to have used a smaller aperture.

Up close with small stuff I always try to get as much of the bug in focus as possible. I specialize in micro photography, and it is very hard to get all the area of interest with lenses that have very shallow dof at close focus distances. It is easy to make a shot with part of the area of interest in focus. Even with the very best lenses it is tough. My Nikkor Micro 60mm and 105mm f2.8 lenses do a great job, but I always find myself closing down the f stop, and raising the ISO slightly to try to include more of the area of interest in sharp focus.

[popo]

I assume you mean the Damselfly at the start? I agree, now I would have used a smaller aperture. I think that was actually taken on my fist trip out with that lens, and I haven't had a DSLR long at the time. But it is all still a trade off and it got the result at the time.

[BDS]

thank you for this guide, popo

i've just purchased a raynox dcr-250 macro lens with a 8-Diopter magnification for my Canon SX10 and your thread was very helpfull.

Here's what I could squeeze out of my first attempts:

It's a field flower having about 2inch in diameter.Used f11 so the light isn't that good.Also used a gorillapod, ISO 80, 2 sec exposure.

[Thomas]

Everything you always wanted to know about magnification...
but were afraid to ask.
See this thread.

[jgmatthews]

Thanks for the guide - I am thinking about getting into some macro photography and was wondering if, as with focal lengths, the cropped sensor would have any effect on the image.

I am currently looking at the Sigma 105mm macro (second hand) which has a 1:1 magnification. With the APSC sensor would this still detect and image of 1:1 size however since the sensor is smaller it would then multiply the image by 1.6? Is this correct or am I making things too complicated for myself.

Also, does anyone have any experience with this lens? I would love the 150mm for the HSM and it would suit my style for non-macro use more however is double the price.

[popo]

If you're looking at the whole image, then yes, the crop factor will play a part in the perceived magnification. But as that applies to all lenses equally, it doesn't make a difference unless you're looking across bodies, where the pixel count will also have some impact. Overall it isn't something to be concerned about unless you know you will be needing rather high magnifications.

I'm not familiar with the Sigma 105mm, but I do have the 150mm. The HSM is a nice feature but largely not needed for macro itself where manual focus comes in. As a general lens, even with HSM, the AF is somewhat slower than average. As a generalisation, prime 1:1 macro lenses are high image quality so it shouldn't be a big concern there.

[AL]

Good post, really makes sense to me now.... Thanks Popo!

[Tikva]

Very informative thread. Thanks for posting, popo!

You said that macro lenses usually start at around 50 mm. Lets assume, there is a 50 mm, 85 mm and 100 mm macro dedicated prime lens. Their label says they all deliver 1:1 magnification. So, when it comes to macro photography what's the advantage or disadvantage in having a shorter or longer lens?

[popo]

For the same magnification, a longer focal length generally gets you more space between the front of the lens and the focus point. A longer distance is handy if getting really close to the subject might be difficult.

[jeremy1302]

To add to popo, it gets very difficult to light your subject focussed at 1:1 when your using a shorter focal length as its easy to get in the way of your own light.

[Tikva]

Thank you popo and jeremy for the explanation.

[Bmann]

Great guide, this is of great interest to me as I am just about to buy a macro lens. Looking at the Tamron 90mm (budget restraints). Any thoughts. Thanks

[JBomb]

awesome, just what i needed.
Thanks for the tips