Olympus 25mm f1.8 or Sigma 30mm f2.8

Discussion in 'This or That? (MFT only)' started by Roswellien, Jan 22, 2015.

  1. Roswellien

    Roswellien Mu-43 Regular

    Sep 1, 2014
    New Mexico
    Looking for a prime to fill the gap between my 14mm Panasonic and 45mm Olympus. I know they differ quite a bit in FOV but they are both in the range I'm looking for. Is the jump from f2.8 to f1.8 worth over double the $$? How's the sharpness on the sigma compared to the Olympus?
  2. physicsdude

    physicsdude Mu-43 Regular

    Feb 11, 2014
    I cant say anything about those lenses, but maybe a used buy is the way to go and then a no brainer for you..
    105$ in our marketplace from another user for the Sigma 30mm
  3. ManofKent

    ManofKent Hopefully still learning

    Dec 26, 2014
    Faversham, Kent, UK
    I don't own the Olympus 25mm, but central sharpness on the Sigma 30mm is pretty much up there with the Oly 45mm and not far behind at the edges/corners - I suspect the Oly 25 has the edge over the Sigma, but I doubt in real shooting sharpness will ever be an issue with the Sigma.

    I love the way the Sigma renders images - transitions between in and out of focus areas are nice and rounded. That extra stop could be very useful though. I've also got the 20mm Panasonic so can swap to that if I need the extra speed. If I was to own one mid-prime I'd be looking at the pana-leica 25mm over the Oly because of the way it renders.
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  4. Jazz80

    Jazz80 Mu-43 Rookie

    Apr 27, 2014
    Hi from my experience of both lenses:

    Pros of Oly 25
    - both lenses are sharp wide open, but found the Oly with better edge to edge sharpness
    - slightly smaller in size compared to SIG (as it was developed for a large sensor)
    - 1.8 vs 2.8. Depends on your style of shooting to determine if u need the wider aperture / better low light performance

    Pros of Sig 30
    - cheaper
    - comes with a pouch

    Both come with lens hood.

    If u can afford the Oly, buy that and be done with it. You may find if u buy the sigma u may want to replace it down the track (may not happen to u but something to think about).

    Either way both are nice lenses.

    Good luck with your choice!
  5. Dayam

    Dayam Mu-43 Regular

    Jan 15, 2014
    I've used both lenses.

    While the Sigma 30mm is sharp, the Olympus 25mm is sharper. It also focuses faster and is f1.8 compared to the f2.8 of the Sigma. Also, the Sigma is quite big as it was originally designed for APS-C sensors.

    I'd say the 25mm is the way to go. :)
  6. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    The Sigma also has significantly more visible CA than the Olympus. The only thing going for the Sigma is its price.
  7. ManofKent

    ManofKent Hopefully still learning

    Dec 26, 2014
    Faversham, Kent, UK
    I've not found CA a problem on the Sigma 30mm, even viewed at 100% in areas of high contrast

    It's under half a pixel in the centre and under 3/4 pixel on the edges according to test reports...

    The Sigma has a tad less barrel distortion than the Oly, but like CA it's not a problem for either lens.

    There's not really a bad standard lens out there for m43. Don't rule out the 25mm Pana-Leica if you can afford it, or the Pana 20mm either (cheap and very sharp). Have a look through the sample threads - MTF, CA, fall-off charts etc. are useful, to a degree, but don't tell you everything. If I had the money I'd have one of each for different shots :smile:
  8. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
  9. ManofKent

    ManofKent Hopefully still learning

    Dec 26, 2014
    Faversham, Kent, UK
    Interesting ephotozine's tests show very limited CA - less than 0.25 pixel centre and less than 0.75 at the edge: http://www.ephotozine.com/articles/...0/images/highres-Sigma30mmDNCA_1334231945.jpg

    It's not significantly different to their readings on the Olympus 25mm: http://www.ephotozine.com/articles/...images/highres-Olympus25mm18CA_1397552009.jpg

    Whether there's sample variation I can't comment.
  10. Serhan

    Serhan Mu-43 Top Veteran

    May 7, 2011
    I have both and Olympus is my favorite lens, zero distortion and has even sharpness. 25mm is same size as 45mm. You can check eg wide open Oly has same as max corner sharpness of Sigma:

    You can answer if it is worth it for you or not, you will gain extra 1.3 stop of light. Each incremental increase costs more eg compare it to 1 stop going from 45m 1.8 to 42.5 1.2... Here is 25mm wide open shot w/ gm1:


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  11. gryphon1911

    gryphon1911 Mu-43 Hall of Famer

    Mar 13, 2014
    Central Ohio, USA
    Price is less of an issue if you look at used o refurbished. Oly refurb site has the 25/1.8 for $319.99.

    Well worth the price if you ask me. It was a real workhorse lens for me over the last weekend. Was shooting at night and the f/1.8 aperture was extremely helpful.
  12. davidzvi

    davidzvi Mu-43 Hall of Famer

    Aug 12, 2012
    Outside Boston MA
    I went with the Sigma 30. But my choice was based on 3 main factors.

    1. Only one m4/3 lens I currently own cost more than $200, that was a specific target.
    2. Fast is nice, but I'm typically at f/2.8 or more anyway. If I really need something faster I can always grab something from my other kit. (I know not everyone has a full FX pro setup, but the fact that I do played into this and reason one.)
    3. Focal length. I also have the 14. But at the other end I have the Sigma 60. Mainly because of price but also because I've had both the 75 and 45 and find I prefer 60. So the 30 fit better: 14 / 30 / 60 (double, double)
    In your case if the 25 v 30 really does not matter that much to you then the questions I see are:

    1. Do you find yourself using the faster speed of the 45? If so the 25 will give you a closer to 14mm faster option.
    2. Can you determine if you wish the 45 was a little wider or the 14 was a bit narrower more? That might lead to one or the other.
    3. The 30 is in the middle. But the 25 would be just under the double, double I have (times 1.8 instead of times 2 in each case). I seem to remember reading something some time back about double focal lengths being a good spacing measure. One of those things that sticks in your mind but you really can't remember from where.
    4. Does price matter? I got my 30 through GreenToe for $170 new in the box, the current version.