I thought I had it all sorted and, now that I have the money to buy it, doubts are cropping up, so help me out here.
I want a macro lens for small scale still life. Minimum size of subject is likely to be about 10mm. Being a cheapskate, it would also be nice to double this up as a portrait lens. However, this is not as important.
I have been using extension tubes with 50mm lenses (either my Canon nifty fifty or my Sigma 18-50mm f/2.8 EX DC, neither of which is ideal). I have become frustrated with how close I need to get, which makes light placement difficult. I would also like the additional DoF from taking a step or two back.
I have been looking at the Sigma 70mm f/2.8 EX DG, which has excellent IQ and would give me an effective 105mm on my cropped sensor, which seems plenty. However, that is only 20mm away from what I already have and I get momentary doubts whether this will be enough. Then I look at the Sigma 105mm EX DG OS HSM, which would give me an effective 170mm ish, which seems excessive, particularly if I am ever going to use it as a portrait lens.
And then there is the price. I have found the 70mm used for about £180, which is great. The 105mm used starts at £315, which is a huge hike in price. There appears to be an earlier model of 105mm, which is roughly the same price as the 70mm. However, this is without the IS and there appear to be autofocus problems with it, so no go on that one.
I am likely to upgrade my camera to a full frame at some point. However, I am buying for this camera and am prepared to sell any lenses that don't do the job if and when I do my camera swap.
So, as you can see, I am tying myself into a knot with all this over-thinking. Any further thoughts might make it all so much more difficult, or might very much help. You don't know until you try!
Thanks in advance.