First shots from a new Macro

Hello. I'm new to the forum and don't have a ton of experience shooting digital slrs. I've been cruising through the threads seeing the great macro shots that everyone has been posting and decided to give it a try myself. I bought a Sigma 105 macro Wednesday and have been testing it out over the past couple of evenings.

I purchased locally and I have a few days to exchange it if I'm unhappy. So, my first tests have been to see if i can get a sharp image by setting up something that's not trying to run away from me. I figure I can chase the bugs around later.

After a few tests, I'm a little unsure if I have a good lens. The middle range aperature settings are pretty sharp, and I'm not sure if I should expect any better quality. Wide open seems a little soft, but from what I've read that seems normal for most lenses. My dissapointment in the lens begins around f25 and gets worse as the aperature gets smaller.

Looks good to me. My Sigma 105mm macro lens starts giving noticeable diffraction softening of the image around F16 or smaller. I tend to shoot around F11-F13. I forget where I saw it but apparently macro lenses when they are at minimum focus behave as if the aperture is a lot smaller than it really is, so diffraction softening kicks in earlier than with normal lenses.
Brian V.

Thanks for the input LordV. I've been admiring your photos for a while now. Your work has been an inspiration to me and one of the reasons I went with this lens.

I guess maybe it doens't really matter since I probably won't be shooting @f45, but you don't happen do have any idea what's up with the lint and specs in my last photo do you? It only shows up for me with this lens when the aperature is really tiny.

Looks fine to me spitstickler, what ISO are you using though? these look quite noisy. For macro try and keep your ISO on 100 as any noise tends to kill the finest of details. The f2.8 has such a shallow depth of field it can give the impression that it is soft, as Brian mentioned you probably want to work between f11-f16 to get a resonable DOF for macro work but you will get diffraction as you go to very small apertures - NB. this will happen with all lenses not just the Sigma. The "lint" you are seeing is just dust on your sensor, this will become more apparent at smaller apertures. Invest in a rocket blower and you'll be able to get rid of most of it. For further info do a search on sensor cleaning.

Have fun!

Thanks,
As Nitsch suggests the specks are sensor dust- only shows up on very even backgrounds normally at small aperture.
Brian V.

also, if you're shooting at f/45, smudges, lint, and tiny scratches on the front element, or any dust that has managed to get inside the lens, will be in focus. And no matter how stable a platform you use, an 8 second exposure at that magnification will almost certainly have a little motion blur.

Here's a new shot at 100 iso @ f14. It definitely has less noise in it than before and seems pretty sharp.

Thanks for the reply mg. I figured a little blurriness would probably come along with the long exposure since I've also shot some flower pics outside in the sunlight to test the lens. I haven't had any luck getting anything sharp yet. The slightest breeze has pretty much made that impossible for me since it will always wiggle things just a little bit. Although I did figure I'd be pretty safe inside with the tripod shooting an object that doesn't easily move, but I guess 8 seconds is a pretty long time.

I figure the only way for me to learn how to shoot good macros is to shoot lots and lots of macros until I figure it out. The very shallow depth of field has been a challenge for me, even with a tripod. But I'm starting to see a tiny bit of improvement.

I bought the big sigma flash with the idea of setting it up with the macro lens at I've seen others do in the forum. I've just begun to mess around with it, but haven't gotten very far yet. I've never used a flash that wasn't built into the camera, and I rarely used it just because the results typically looks bad. Would you say a flash is really the only way of capturing something really sharp with a small aperature then?

I for one, love using a flash when possible, And I always use a tripod, the slightest breeze, or any movement at all, can throw of the picture. Here's another tip, when you are practicing, make sure the subject you are focusing, if possible, is not angled away or toward you, just as perpendicular as you can. lots of practice will go a long way.

I wouldn't go so far as to say flash is the only way of capturing a good image but it makes life so much easier.

Just to get you started, the general sort of settings I use are ISO100, 1/200, Flash (normally with some positive FEC applied) and an aperture between f11 and f16. f13 is a bit of a favourite of mine. I normally shoot handheld, lens in manual focus mode, set the magnification level and then move slightly back or forward to bring the subject into focus.

Here's a couple of bugs shot using this technique:

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I nearly always use flash with my 105mm. I shoot handheld in the same manner as nitsch above. (manual focus, camera in manual 1/200th F11-F16 ETTL flash)
Here's a pic of how the rig is set up with the flash on a modded vidcam light bracket.