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02-07-2017, 04:17 AM   #16
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QuoteOriginally posted by LoneWolf Quote
However without knowing whether responder is making his / her comment based on full frame or APS-C (or eqivalent) some of the answers could be misleading. It would be appreciated if responders would state where they are coming from. It is a common omisssion when giving opinions and it is often (too often) a very frustrating one. 35mm, 50mm, 100mm in full frame gives 52.5 mm, 75 mm, 150 mm in APS-C: quite a difference.
But the working distance, magnification and DoF at the minimum focus distance (in macro range) does not change. It stays the same, on FF or APSC. The only thing that changes is FoV (which makes the photo look like it has higher magnification). DA 35mm macro is not made for FF, but the DFA 50mm and DFA 100mm are, so it really doesn't matter where you use them. I don't see how FF vs. APSC would complicate things in this case at all. Especially because we talk about 50mm and 100mm because these are the focal lengths available on the market. Nobody is making a 52.5mm macro lens for FF. Even 75mm or 150mm macro lenses are really rare these days.

02-07-2017, 04:53 AM   #17
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QuoteOriginally posted by LoneWolf Quote
An interesting question with interesting replies.

However without knowing whether responder is making his / her comment based on full frame or APS-C (or eqivalent) some of the answers could be misleading. It would be appreciated if responders would state where they are coming from. It is a common omisssion when giving opinions and it is often (too often) a very frustrating one. 35mm, 50mm, 100mm in full frame gives 52.5 mm, 75 mm, 150 mm in APS-C: quite a difference.
QuoteOriginally posted by Na Horuk Quote
But the working distance, magnification and DoF at the minimum focus distance (in macro range) does not change. It stays the same, on FF or APSC. The only thing that changes is FoV (which makes the photo look like it has higher magnification). DA 35mm macro is not made for FF, but the DFA 50mm and DFA 100mm are, so it really doesn't matter where you use them. I don't see how FF vs. APSC would complicate things in this case at all. Especially because we talk about 50mm and 100mm because these are the focal lengths available on the market. Nobody is making a 52.5mm macro lens for FF. Even 75mm or 150mm macro lenses are really rare these days.
I think that the OP is getting two types of response, the first type talks about the sensor size and crop factor, which is really irrelevant for macro, because true macro is all about the absolute magnification of the image on the sensor, and working distance, all of which depend wholly on focal length .

Once you start talking equivelent focal lengths, you are discussing non macro uses of the lens. Specifically using the macro lens for normal photography.

The second discussion comes into play when on a limited budget, I.e. What else can I use my lens for


One last point to throw into the discussion, is the focusing method of the lens, and how they achieve 1:1 macro.

Many of the current selection of AF macro lenses achieve 1:1 by internal focusing, which actually changes the focal length to achieve focus. Some people refer to this as focus breathing, it is a behaviour that is commonly discussed in wide ratio zoom lenses where people noted that the actual focal length was much shorter than the labelled lens focal length once you focused closer than infinity. The observation goes back however to the 1970's. The Pentax K28/2 had a fixed rear element design, which was the forerunner of internal focusing and it was reported then in lens tests that the focal length reduced the closer you focused.

The result of this last discussion is that a 100mm macro might not be 100mm at 1:1 , all you need to know is the minimum working distance.

There is an advantage to IF lenses and varying focal length, as you go for 1:1 however. The resulting light fall off as you increase magnification is not as bad as with a true macro that moves ALL the lenses in the group away from the sensor to focus.
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