Sigma 50mm f/2.8 EX DG Macro vs. Tamron SP AF 90mm

[will_c]

maybe an other option you might want to consider: Canon macro EF-s 60mm 1:2,8. It's perfect for portaits (on 50D 96mm) It's producing very sharp images. Great for macro on flowers. For insects and other bugs you need to be too close.
I bought mine "used". Apart from lens scratches, there is little what can go wrong with this lens. it's very solid build, and as it does not extend nor rotate the front lens, it does not collect any dust or moisture inside.

I agree. Never, not even once, has the Canon 60mm macro let me down in any way. It's very reliable, IQ is superb, it's compact, and the focal length is useful for many purposes, including photos of people. I have no experience with the other options that you are considering, though.

[Geoff F]

Are your tiny subjects alive or dead? And how big do you want to print?

For dead, or constrained bugs, one of the smaller macro lenses would work fine. Also flowers and other inanimate objects.

But for live nervous insects you need something considerably bigger which will give you a working distance of at least 1 ft and the ability to photograph something around 10 mm long and print at 10 x 8 ins. A 150 mm lens is a popular size but isn't cheap. Sigma and Canon produce well liked lenses.

Most of my summertime photos are insects and I use the Sigma 180 mm which gives me that little big more 'breathing space'. But this is a large heavy tripod only lens, although a tripod is recommended for any macro work, and it comes at a specialist price; the excellent Canon version is even more specialist in price!

Some people do manage to photograph a few sleepy insects with a small handheld lens but if you want to become a serious insect photographer with consistent results I recommend using a 150 mm lens.

This type of lens, however, is for the enthusiast and isn't on the recommended list for portraits or other general use.

As an alternative, extension tubes will convert a reasonably close focusing lens into an acceptable macro lens. I have obtained satisfactory results using a 25 mm tube on my Canon 70-300 lens. Once again, it becomes tripod only though.

Tubes don't degrade the image although you do lose a bit of light which means a slightly higher ISO setting. Manual focus is recommended and you need to consider the shallow depth of field and focus accordingly. With a zoom lens I would suggest a 25 mm tube should work OK and will cost around £100 for the genuine Canon article.

[Andy]

.... if you want to become a serious insect photographer with consistent results I recommend using a 150 mm lens.

It depends on what magnification you want really. For less than 1:1 the longer the lens the easier it is to get close enough but they're not much use for higher magnifications.

If you like shooting at higher magnifications (as I do) I find shorter lenses are more useful.....I'd much rather put a set of Kenko tubes on a 100mm than a 2x teleconvertor on a 180mm to get 2:1 for example. On APS-C I find 100mm is long enough to maintain a reasonable working distance with larger insects but is still short enough so you can double the magnification easily with tubes. Still not much use for anything except macro though.

When you're used to working with the MP-E 65mm the working distance of a 100mm (on APS-C) feels like a luxury and has a narrow enough angle of view to isolate nice bits of background. The 180mm almost feels too easy! One of the challenges I enjoy about insect macro is getting close so the newest addition to my macro kit is a TS-E 90mm to shoot the kind of stuff I used with the 100mm on a tripod. Maybe I'm just a glutten for punishment though

[Banner1976]

Thank you for all advices. I still have a time to think about it, because it's gonna take me a few weeks to collect money. Thank you very much!