Used E-M10 or E-M10 ii?


Mu-43 Hall of Famer
Jun 20, 2015
Massachusetts, USA
I don't find the Sigma 60mm macro on B&H. But I also don't see the Sigma 19mm (which I have but dislike) there either. Seems like they have discontinued some models.

The Sigma 60 was not a macro lens. It was one of their "Art" lenses and as you speculate, it has been discontinued along with the 30/2.8 Art lens.


Mu-43 Hall of Famer
Apr 24, 2018
SF Bay Area, California, USA
Well in the case of this discussion the OP was asking strictly about 4/3rds format and how it related back to his old 135 film days. So 2x. No need to get him all turned around with a bunch of extra steps to get to that same number.

Ya, I don't deal with anything but 4/3rds so life is easy for me. If you deal with a lot of formats, then I can see how this method might work for some. But I have to ask, what is the different between memorizing a crop factor vs. memorizing a "normal" focal length for each system and then doing a bunch of math? But to answer your question, the 1" Nikon is 2.7x, 6x6 is 0.55x, and 4x5 is x0.27 (I would just say "0.3" as close enough). :thumbup:

Yes if you only deal with one format, memorizing the single crop factor is easy.

What I wasn't sure about was that the OP's reference was, since he mentioned both OM1 (35mm film) and T3 (APS-C). So to me, initially it wasn't clear which camera was he talking about using the lenses on.
With the T3, you have to go from APS-C to FF, then FF to m4/3. You need to know two crop factors.​
In hindsight, it would be the OM1, cuz today, the 135 lens has essentially disappeared, so he is unlikely to have a 135 EF lens. Back in the film days, the 135 was a very common lens.

If you have multiple systems/formats, generally you will know what the normal lens is for each system.
OK, if you only shoot zooms, like in m4/3, APS-C and FF, you may not have a normal lens, nor know what it is for your format.
For film you just look at your lens, as you are likely to have a normal lens. In my case, I have the normal lens for all of my film formats.
If you wet print film, you will know what the normal lens is, cuz the standard printing lens for a film format, is generally the same as the normal lens. Even if you only used zooms for 35mm film, you will print with a 50mm lens.

If we say a studio portrait lens for a head and shoulder shot is 2x the normal lens.
Then I can pick any film/sensor format, then easily compute 2x the normal lens, to determine the lens to use.
For m4/3, 25mm x 2x = 50mm. For APS-C, 35mm x 2x = 70mm. For 35mm/FF, 50mm x 2x = 100mm. For 6x6, 80mm x 2x = 160mm. For 4x5, 150mm x 2x = 300mm

The alternative is, you have to know a reference lens. Like, the teacher uses a 70mm on his APS-C camera.
Yes, this is a forced example, as I don't know of a 70mm prime lens.​
Using crop factor conversion: First you have to convert from APS-C to FF (70mm x 1.5 = 105mm), then FF to your target format say m4/3 (105mm / 2 = 53mm) .
You have to know the crop factor for the various formats, to get the FF equivalent lens.​
If you are lucky the teacher will tell you the reference FF lens, eliminating the first difficult calculation.​
BTW, the 105 was a common head and shoulder portrait lens for 35mm film cameras, back in the film days.​

Real example. I saw a neat pic, taken with a 210mm lens on a 4x5 camera. How do I duplicate that shot?
I can see where it was taken from, but what lens to use?
First I would figure out the magnification of the original lens. 210mm / 150mm = 1.4x.
Then figure my target lens. For m4/3, 25mm x 1.4x = 35mm.

KISS. Because of the different formats, for ME, I find it simpler to simply stay within the format and avoid using the crop factor.

Long answer, but in the end, just use whatever is easiest for YOU.


Mu-43 Top Veteran
Jun 2, 2015
what is the equivalent 6x6 lens for my m4/3 45mm lens? I have no idea what the reverse crop factor from FF to 6x6 is.

There is no exact crop factor because 6x6 is a square format. You can't use diagonal FOV as a measure because of the format differences. If you print a 6x6 image to a 2:3 ratio like 24x36mm, then you could discuss FOV comparisons.

Even 24x36mm to m43 can't calculate an exact crop factor because one format is a 2:3 ratio, the other is a 3:4 ratio.

Life is too short to worry about this :dash2:


Mu-43 Regular
May 5, 2015
To jump on this thread and ask a quick question - I have an E-M10 (first gen), and I'm considering upgrading it.

My main issue with this E-M10 is shutter lag (or feel of shutter lag). Some of the other improvements like 5-axis are attractive too, and who would complain about better/more image quality?

But really my question is - do subsequent gens of the E-M10 improve on the shutter lag/feel? I've handled occasionally E-M5 mk II, and it's shutter feel was fine for me - in other words I don't feel the need to jump up to an E-M1 or need super-burst shooting speeds. (In fact I'd rather not gain any significant body size)


Mu-43 Hall of Famer
Apr 24, 2018
SF Bay Area, California, USA
I don't feel that my EM10-mk2 has shutter lag. I use the EM10 along with my EM1, and shutter lag is not an issue for me.
What I HATE for shutter lag are my Canon P&S. ARGH.

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