Canon EF 100mm f/2.8 Macro USM vs Tamron SP Autofocus 90mm f/2.8 DI Macro Lens

[Denosha]

Yep. Just for reference my macro shots are usually taken at 1/250s, ISO400, F11-F16 and I have to use flash for these settings. How long an exposure time would really depend on the lighting conditions at the time. But the problem is most of the time you'll be shooting in the shade or under the canopy of trees (bugs don't seem to like the heat either) where light is scarce. By using a flash you don't really have to worry about all these problems.

 

[DeSwitch]

The Tamron is my choice. Reason is image quality is on par or some claim better than Canon and so much cheaper. The slow focusing does not bothers me as I use manual focusing when taking macros.

The $400 savings can buy a lot of other accessories like plamp, focus rail etc.

 

[hwchoy]

Longer exposure like how long? Looked up some macro shots and their EXIF... usually shutter is 1/200 and high f stops like f11 to f14. Does that mean that this setup is usually with flash taken?

you see, in most macro shots what you need is DOF, which drives your aperture down, and hence you need hugeass amount of light.

 

[yehosaphat]

you see, in most macro shots what you need is DOF, which drives your aperture down, and hence you need hugeass amount of light.

Ok! Sorry newbie qn... I understand in macro shots you just want your subject to be in sharp focus while blurring out the distracting background. So if you have deep DOF, you will have everything in focus as well? :think:

 

[hwchoy]

Yep. Just for reference my macro shots are usually taken at 1/250s, ISO400, F11-F16 and I have to use flash for these settings. How long an exposure time would really depend on the lighting conditions at the time. But the problem is most of the time you'll be shooting in the shade or under the canopy of trees (bugs don't seem to like the heat either) where light is scarce. By using a flash you don't really have to worry about all these problems.

since you flash anyway, why don't use a lower ISO?

 

[hwchoy]

Ok! Sorry newbie qn... I understand in macro shots you just want your subject to be in sharp focus while blurring out the distracting background. So if you have deep DOF, you will have everything in focus as well? :think:

no, at macro working distance, your DOF is literally paper thin. remember that DOF is also determined by lens to subject distance. count yourself lucky to get a whole bug in focus!

so here is another macro trick. when push comes to shove, pull back from the subject so as to increase DOF. then crop the image down to the required subject.

 

[hwchoy]

here is a very small orchid flower, about 5mm across (so the frame covers only about 1cm wide) you can see the DOF for yourself. EF 100mm Macro at ƒ/11 1/250s ISO200.

 

[Denosha]

since you flash anyway, why don't use a lower ISO?

1. To get some natural light in, if possible (although it ain't much unless it's under sunlight)
2. Save my flash batts so the refresh time is faster and thus the turn-around time to the next shot is also faster (i normally try to get in as many shots as possible before the bug runs off)
3. The 20D's ISO400 is already pretty clean and since I always try to nail the exposure in camera, I won't see any extra noise by having to adjust the exposure in PP.

 

[hwchoy]

3. The 20D's ISO400 is already pretty clean and since I always try to nail the exposure in camera, I won't see any extra noise by having to adjust the exposure in PP.

yeah that's the great thing about the 20D. :thumbsup: or basically Canon CMOS in general.

 

[yehosaphat]

no, at macro working distance, your DOF is literally paper thin. remember that DOF is also determined by lens to subject distance. count yourself lucky to get a whole bug in focus!

so here is another macro trick. when push comes to shove, pull back from the subject so as to increase DOF. then crop the image down to the required subject.

What is 'when push comes to shove'?

So can I say that the longer the distance of your lens to subject, the DOF will be larger? And the closer you are, the thinner the DOF?

 

[yehosaphat]

1. To get some natural light in, if possible (although it ain't much unless it's under sunlight)
2. Save my flash batts so the refresh time is faster and thus the turn-around time to the next shot is also faster (i normally try to get in as many shots as possible before the bug runs off)
3. The 20D's ISO400 is already pretty clean and since I always try to nail the exposure in camera, I won't see any extra noise by having to adjust the exposure in PP.

For 1) how does increasing ISO allow some natural light in? :dunno: I tot higher ISO allows you to use faster shutter speed with the same aperture? And using faster shutter speed effectively cuts out more light in right?:sweat:

 

[hwchoy]

What is 'when push comes to shove'?

haiyo!

this means "boh pian", "lan lan", "kena sai" :sweatsm: when you have NO OTHER WAY then NO CHOICE.

So can I say that the longer the distance of your lens to subject, the DOF will be larger? And the closer you are, the thinner the DOF?

yes. there is an excellent article on DOF, in order to understand it properly you need to first understand COC (circle of confusion).

smaller aperture = deeper DOF
larger subject distance = deeper DOF
smaller imaging sensor = deeper DOF
smaller print size = deeper DOF

 

[siewkhee]

IQ wise both lens head to head but Canon wins and pricey because:

-Internal focusing (lens does not extend)
-FTM
-USM (faster focusing speed)
-better built quality

For me, I'll rather pay the extra because I really hate the lens extending during focusing. One reason why I rather wait for the 24-70L replacement, hopefully an IS version.

The 100macro is sharpest in my lens lineup. I also have the 70-200IS, 85, 50 1.8 and 17-40L. You'll love it and I believe it deserve a red ring in terms of IQ.

 

[Denosha]

For 1) how does increasing ISO allow some natural light in? :dunno: I tot higher ISO allows you to use faster shutter speed with the same aperture? And using faster shutter speed effectively cuts out more light in right?:sweat:

Erm, because everything else is constant (the aperture and shutterspeed) so increasing the ISO allows more natural light in (ie. the flash can fire at a lower power to acheive the correct exposure, thus increasing the amount of contribution from natural light).

 

[yehosaphat]

hmm... thanks for the comments :think: wow it is a lot of stuff to learn in macro. Can you recommend any good books, courses or materials on how to improve in this area.... or perhaps can you all share how you all pick macro photography up and how you all learnt along the way?

Think it will be a good learning experience for all!

 

[Denosha]

This guy is an inspiration and good source of info: http://www.beautifulbugs.com/beautifulbugs/howto.htm

 

[hwchoy]

hmm... thanks for the comments :think: wow it is a lot of stuff to learn in macro. Can you recommend any good books, courses or materials on how to improve in this area.... or perhaps can you all share how you all pick macro photography up and how you all learnt along the way?

Think it will be a good learning experience for all!

just start shooting and learn and improve from there. get a close-up filter or a cheaper macro lens and go. later if you really like this subject area then decide on the macro workhorse lens (you still need to decide on brand and focal length).

 

[yehosaphat]

This guy is an inspiration and good source of info: http://www.beautifulbugs.com/beautifulbugs/howto.htm

Thanks Denosha for this very informative link... so mainly shoot in manual mode at f16-f22 and shutter speed arnd 1/125 and let the external E-TTL flash decide the power right?

I have canon 420EX. Any comments on this flash for macro? I know not the best but is this sufficient?

 

[hwchoy]

you can use the 420EX mounted on the hotshoe to trigger some cheap $20 slave flash. useful for static macro shots.

the choice of aperture is dependent on the DOF you want to achieve, so practice and you will start to get some feel for it. also try shooting the same subject at different aperture and compare the results. usually I prefer to use aperture priority mode.

 

[yehosaphat]

you can use the 420EX mounted on the hotshoe to trigger some cheap $20 slave flash. useful for static macro shots.

the choice of aperture is dependent on the DOF you want to achieve, so practice and you will start to get some feel for it. also try shooting the same subject at different aperture and compare the results. usually I prefer to use aperture priority mode.

Wah... got $20 flash one ah... any pictorial diagram how the setup will look like?

If you use Av mode and let the cam decide your shutter speed, what happens if the cam chooses a much slower shutter speed?