More extensions, raynox or a TC for more magnification?

Currently I'm using a Sigma 105/2.8 + 56 mm extensions. I get approx. 1.85:1 with my 40D. What will the magnification and working distance be if I mount: Raynox DCR250, 1.4x TC OR 2x TC? Which of these would cause least image quality loss? What I want is more magnification. Should I buy more extensions, Raynox or a TC? If I should go for a TC - which models should I preffer and which should I avoid? I'm starting to think about a TC, but I'm not sure if it should be 1.4x or 2x.

Tcs will give you exctly the multiplication factor on them when mounted next to the camera body.
ie 1.4Xtc would give 1.4* 1.85 = 2.6:1
The DCR-250 would add another .84 to the mag ie 2.7:1
Your current working distances would be the same with a TC mounted and shorter with a diopter added. Generally I would expect more IQ loss with a TC vs a quality diopter.
You might want to consider a more powerful diopter such as a RAynox MSN-202 or perhaps a reversed 50mm lens on the 105mm. A reversed 50mm lens will giveabout +2 to your mags ie around 2:1 at max focus, 3:1 at min focus with no ext tubes used.
Brian V.

Thank you, LordV. Another think I wanted to ask - will there be any difference if I mount a TC after the body, then extensions or if the TC is between the body and the lens? I've tried reversing a 50/1.8 II in front of the Sigma but I'm not sure the results will be good enough. So the magnification with a 1.4 TC and a DCR 250 would be the same, but what will the working distance with the DCR be?

BorislavKostov wrote in post #13302244
Thank you, LordV. Another think I wanted to ask - will there be any difference if I mount a TC after the body, then extensions or if the TC is between the body and the lens? I've tried reversing a 50/1.8 II in front of the Sigma but I'm not sure the results will be good enough. So the magnification with a 1.4 TC and a DCR 250 would be the same, but what will the working distance with the DCR be?

I'd be suprised if the results of reversing a 50mm lens onto the 105 are not better than using a TC. I used to do exactly that.
For max mag a TC should always be mounted firat on the body - then ext tubes if present then the main lens then a diopter or reversed lens.

Fraid I don't know off hand what the working distance with the DCR-250 would be apart from guessing it as being around 2" in front of the lens. As commented the working distance with a TC will be the same as it would without it.

Brian V.

Last night I've tried reversing the 50/1.8 in front of the Sigma 105, but the result was approx. 2.4x magnification at about 1-2 cm from the lens, which for me is useless. So I'm thinking again which would be better - the less magnification of a 1.4x TC or the more of the 2x, but eventually with more quality loss.

I found that the 2x did not perform as well as the 1.4x when used in the conventional (non Macro) way.The image quality was really not good.

dick

is it relevant for you to spend the money instead (or save the money) to get the MPE?

I can't afford the MP-E, that's the problem. Do you think I don't dream about it? So I'm trying to find a cheaper and still useful solution for higher magnification macro. I'm currently waiting my Sigma APO 2x EX DG TC to arrive tomorow

gotcha. sorry.
well, i think you got some good advice so far...and good luck with the 2X DG TC.

I finally tested the new setup and I'm very satisfied of the results:

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