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2.8 vs 2.0 or So

Discussion in 'Native Lenses' started by gobeatty, Nov 14, 2014.

  1. gobeatty

    gobeatty Mu-43 Regular

    Sep 15, 2014
    All -

    I've seen countless posts where it is recommended to carry an f1.8 prime or f1.7 prime in addition to the 12-40 2.8. I'm wondering, given the very good high ISO performance of the recent cameras, what the feeling is of the added value of buying, carrying and having to switch lenses for an additional stop or maybe a stop and a third.


    - Greg
  2. WT21

    WT21 Super Moderator Subscribing Member

    Feb 19, 2010
    Depends on what you are doing. In normal light from morning till evening, 2.8 is pretty good. In situations with slow shutter speeds and/or good indoor light, 2.8 can be fine. In situations where a venue might be dark, but there are bright spot lights (e.g. a performance), then 2.8 can do it. 2.8 also works fine for flash.

    But a lot of folks get obsessed with shooting in the dark. You need faster than 2.8 for that.

    The other reason is for DOF (which sadly is often overused or mistaken for image quality).

    There is absolutely a place for a fast prime, and I think it complements a 2.8 zoom very nicely. You need to decide yourself what you shoot, and if you need one. Don't just get one because someone says you should.
    • Like Like x 1
  3. gryphon1911

    gryphon1911 Mu-43 Hall of Famer Subscribing Member

    Mar 13, 2014
    Central Ohio, USA
    it depends on the type of shooting you do and at what level you'll accept at the high ISO as not good enough image quality. You might benefit from a 1 stop faster shutter speed or one stop lower ISO with the prime lens.

    If none of that really interests you, then getting the prime in addition to the zoom probably makes little sense.

    If I were to do an overlap in zooms/primes - I tend to get the zooms as a slower aperture and use them for general shooting in good light. I keep the Oly 12-50 because it is weather sealed. I'm usually a prime shooter anyway.
  4. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    I've got the 12-40 and the Oly 12, 17, 25, 45 and 75 mm f/1.8 or f/2 primes as well as the f/1.4 PL 25mm.

    I can shoot hand held at night in lowish light at f/2.8 to f/4 and most of the shots in my post in this thread except for the first were shot at those apertures with either the 12mm or the f/1.8 25mm : https://www.mu-43.com/showthread.php?t=70574

    That means I could effectively have shot every image I included in that thread with the 12-40 so those images may give you some idea of what you could get at f/2.8 to f/4 with the 12-40.

    Shooting at those apertures, however, I ended up setting the camera to ISO 800/1600 and wherever possible I prefer to use ISO 200 in order to maximise dynamic range and also to minimise noise. I've shot in similar light levels using ISO 200 with the PL 25mm by shooting at f/1.4 and also got good results though you need to make sure your subject is in a lit area if you're going to use ISO 200 and I probably couldn't have managed it at that ISO level and avoided some camera shake without using IBIS. There are limits to what you can manage to hand hold before you need to start increasing your ISO setting. Even so, I did miss a couple of shots because of subject motion blur and I may have done better shooting at ISO 3200 that night.

    So, if you're asking if you can get by with just the 12-40 in low light/night shots then the answer is going to be "yes" provided you ensure that your subject has some light falling on it and you're prepared to shoot at higher ISO settings. Choice of camera may make a bit of difference as well as the E-M5 is a little bit better with longer exposures than the E-M1 but that wasn't an issue with my shots in the thread I linked to (some were with the E-M1/25mm, the others with the E-M5 12mm so I effectively "zoomed" between those focal lengths several times that night by swapping cameras) since all exposures were short enough for hand holding.

    I haven't tried my 12-40 under that kind of low light condition but one other difference between it and the primes is the size and weight of the 12-40. That may actually make it a bit more stable to hold than the primes, or a bit more tiring over time. I don't know. I do know that you will need to increase your ISO more at longer focal lengths on the 12-40 simply because you'll need to use shorter exposure times as you increase your focal length. That means that the 45mm prime will have a bit more advantage over the 12-40 in terms of what you can hand hold than the 12mm will have if you start shooting those primes wide open. If you're going to shoot the primes at f/2.8 then, given the sharpness of the 12-40 wide open, you're not going to get much advantage from the primes at all. On the other hand there is the big advantage of the 12-40 which is the ability to zoom rather than needing to swap lenses or cameras.

    Bottom line: the primes will let you shoot at wider apertures than the 12-40 and that can help keep your shutter speed faster and your ISO setting lower, but it also reduces your depth of field. The primes are also smaller and lighter which may be another advantage. If you don't need any of those advantages then you can get by quite happily with the 12-40 but if you need one or more of those advantages then you need a prime, at least until someone makes a faster zoom in that range. If you don't do much low light/night shooting then I think it's possible that the 12-40 may well be all of the lens you need.
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  5. dvc762

    dvc762 New to Mu-43

    Nov 27, 2012
    As people have already mentioned, it depends on what you are shooting and your expectations on image quality. As an example of the former, there is a difference between shooting static subjects vs people in motion in low light. If static subjects then very slow shutter speeds can allow for low ISO and therefore better quality. But if you are shooting people (like at a party), they may not be moving quickly but you might still want a decently fast shutter speed (I like 1/60 or better) to prevent blurring. Again YMMV and circumstances still matter -- like if there is dancing even faster shutter speeds may be called for.

    As for my own experience, I have found 2.8 in lower light acceptable for things like night shots of buildings or even food pictures in a restaurant. OTOH I've definitely been happy to switch to a 1.7 prime for shots of people in the same settings -- note that even then I might try 2.0 or so to get better DOF, etc.
  6. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium
    a couple of things

    1) prime lenses for micro 4/3 are pretty stellar wide open

    2) all the sub f2 primes are much smaller physically/less intimidating that the 12-40 zoom

    3) low flat light like in a restaurant will always be less than good... no many how many f stops you throw at the problem its still bad light

  7. Whtrbt7

    Whtrbt7 Mu-43 Veteran

    Jan 7, 2014
    Faster than f/2 lenses tend to do better in lower light. In comparison to f/2.8, that's the difference between ISO 1600 and ISO 3200 at least. Shooting outside at night, I would still use a diffused flash to create some extra light but really, it's easier to shoot in lower light with faster lenses. I wish I could have the same resolution and quality with a smaller sensor sometimes so I could get additional DOF at night.
  8. gobeatty

    gobeatty Mu-43 Regular

    Sep 15, 2014
    Thank you everyone for your very thoughtful and thorough replies. I have several primes for my FF Canon but end up using the zoom almost all of the time. Even with the EM10 I feel I can shoot at much higher iso than in the film days negating some of the benefit of faster lenses. If the light is just so the extra stop makes a difference. But darker than this and I'm out of luck; lighter than this and I'm fine with the slower lens. For narrower dof one stop makes a difference but not so much.

    For now I am using the kit zoom with the EM10 and am debating the 12-40 f2.8 or one or possibly two primes. The primes would make a considerable difference vs the zoom but are not as flexible. The 2.8 zoom is less than a stop faster at the wide end (vs 3.5), which is what I use most indoors. So I'm finding it difficult to justify the cost of the 2.8 zoo, and the primes, while offering a good increase in speed, do so at the cost of perhaps not working so well in my shooting scenarios.
  9. The idea of solving the problem of shooting in low light by using faster lenses hits a wall when the decreasing depth-of-field and increasing lens aberrations creates more image quality issues than higher ISO values or slower shutter speeds. This is the same reasoning behind the fallacy of cameras with larger sensors being superior in low light.

    For me the point of a prime lens is compactness and for the odd occasion where using a larger aperture and a shallower depth-of-field will give me a look that I want.
  10. tjdean01

    tjdean01 Mu-43 Top Veteran

    Feb 20, 2013
    12 gives you size and a stop
    14 gives you super tiny size
    17 gives you size and 1.4 stop
    20 gives you super tiny size, 1.5 stop, and sharper
    25 gives you 2 stops and sharper
    30 gives you focusing speed and sharper
    45 gives you length, size, 1.4 stop, and sharper
    60 gives you length, size, sharper
    75 gives you length, 1.4 stop, and sharper

    20 and 45 give you the most, I'd say, especially when you factor in the price.
  11. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Suppose you are at 2.8 at your maximum acceptable ISO and the shutter speed is 1/20. This is not enough to freeze most human actions. Add 1 extra stop and one third and you get something like 1/50 or 1/60. Or if you are shooting a static subject you could go from 1/10 to 1/30 where it's easier to get a few good shots. Shoot indoor on a cloudy day and the ISO will bump to 3200 quite often.
    I quite like pictures shot at ISO 6400, 12000 or more, with only the croma noise removed, so it depends on what you need/like.

    If you use a tripod there is often no need for the extra stop. So the situations where you can really benefit from the difference are not that common, but when it happens you'll wish any extra speed you can get. Have a look at your pictures data and you'll see if and how often you are pushing the limits of the sensor.

    I bought the 20/1.7 to have a prime (different way of shooting) and to have a small lens (first version, used, quite cheap) to use as an alternative to the 12-40, not to swap it on the fly.
  12. EarthQuake

    EarthQuake Mu-43 Top Veteran

    Sep 30, 2013
    Noise is discussed often when talking about high ISO but really this is only part of the picture. Noise can be OK at high ISO if you expose properly, but dynamic range is significantly reduced, so if you need to recover highlight or shadow detail, you're basically out of luck, plus nailing the exposure isn't something that is easy to do for every shot (IMO at least). So a faster lens either gets you a faster shutter speed at the same ISO or allows you to use a lower ISO and get more dynamic range, which means files that have a lot more room for manipulation in post.

    Personally, I really like the 12-40/2.8, but if I'm going to be shooting in low light, I will take the 25/1.4 (2 stops faster), the 42.5/1.2 (2.5 stops faster) or both. I also have the 12/2, but at only 1 stop faster I don't find myself using it that much. 2 stops is quite significant though, and the high ISO point applies independently of the lens used. If you're ok with image quality at 6400 that simply means that the faster lens can shoot in a wider array of lighting conditions. Two stops means 6400 vs 25600, or usable vs only for emergencies.

    If you shoot mostly in day light, the 12-40/2.8 works great.
  13. lightmonkey

    lightmonkey Mu-43 Veteran

    Dec 22, 2013
    as far as sharpness and image quality, im pretty sure the 12-40 is sharper than anything else olympus makes aperture for aperture, esp at overlapping FL

    where it matters is shutter-speed, determined by t-stop, and for example the prime 25/1.8 measures t2.0 and the zoom measures t3.2.... greater difference than assumed f1.8 vs f2.8

    in the day if you shoot at ISO 200 vs 400 or 640 its not much of a visual difference. at night, having to push it 1600 to 3200 or 4000 however is quite a huge gap in perceived iq.
  14. Ulfric M Douglas

    Ulfric M Douglas Mu-43 Hall of Famer

    Mar 6, 2010
    In this case I think you personally would do better with the zoom, as it is ingrained.
    My fast zoom stays in the box mostly but I use multiple bodies with primes.

    Go for the excellent 12-40 and leave prime buying until later?
  15. gobeatty

    gobeatty Mu-43 Regular

    Sep 15, 2014
    When I bought my full frame Canon, I was rather obsessed with ultimate image quality and wanted sharpness and absence of noise, even at high ISO, that would please a pixel peeper.

    Those days are behind me and I'm fine shooting up to 6400 with the Olympus. I keep noise reduction off and adjust to taste in post. The EM10 has on board flash as well and I've spent some time learning how to use it (I'm not a fan of the default behavior). The loss of dynamic range hasn't been an issue for me but I do see it and see where it could be an issue in certain situations with certain goals in mind.

    I guess for now I'm enjoying my minimalist setup. One camera one lens. Ok, I have the 40-150 as well, but very little overlap there so no question really of which lens to being or use. In considering the Pro zoom or primes I'm just not finding the need as compelling as I did in the film days where every stop made a practical difference given that ISOs were lower in general and I couldn't switch ISO on the fly unless I carried two bodies.

    I agree with everything everyone has graciously posted BTW. I have handled the 17 1.8 and think about it often. Gorgeous tiny lens with manual focus on the fly. Like someone else said, I doubt I would carry it and switch if I had the 2.8 zoom. Instead it would be a different choice to carry and shoot with. I might carry and switch compared to my kit zoom as the speed difference is about 2 stops.

    A longer fast prime would be nice for shallower depth of field. For my full frame I have the 85 1.8. I am surprised though how seldom I use it although my zooms on full frame are already capable of narrow depth of field at least in m43 terms. I wish there was a more robust used market. I see used lenses posted on Craigslist for weeks at fair prices without selling. So I'm concerned of being stuck with a lens I don't want and can't liquidate without taking a considerable loss.
  16. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    I think this is not completely true. The 75 is considered the sharpest lens by any tests/reviews I've read. The 12-40 is at its best at the wide end, so it could be really close to the 12mm, but I'm not so sure how it would compare with the 45 at the long end. It's not so easy to find a direct comparison of reviews as most reviews of those primes were done with 12MP sensors, but even with the old sensor the 45 looks slightly better:


    I would be happy say that the 12-40 is close or on par with most primes. Good enough for me.
  17. John M Flores

    John M Flores Super Moderator

    Jan 7, 2011
    Don't forget T-Stops

    Remember that F-stop is simply a ratio of a lens' focal length to entrance pupil and is conveniently used as a proxy for light gathering ability. But a F2.8 zoom is likely to have more elements than a F2.8 prime and each element and each coating costs light. That's where T-stops come into play as they are actual measurements of a lens' light transmission abilities.

    So while an F2.0 prime is just one F-stop away from an F2.8 zoom, I likely more than one T-stop away, and that challenging 25mm F2.8 1/10s shot quickly becomes an easier 25mm F2.8 1/25s or 1/30s or even 1/40s shot.
  18. gobeatty

    gobeatty Mu-43 Regular

    Sep 15, 2014
    I hear ya John. I guess with the ISO capabilities of these cameras, most of my former challenging shots are less so. I'm sitting in a Starbucks now and meter 30th, f3.5 at ISO 800. Not the darkest of caves by any means but I've got two more stops to go to get to 3200. F3.5 is equivalent to f7 on full frame so would seldom need more depth. There still are challenging shots but they are a good bit darker than they used to be. As another poster mentioned, as the light gets THAT dark the quality of the light can also degrade. Most common for me would be dim indoor lights that have no little to no blue to them. In these settings, controlling the light if at all possible is a better option than shooting wide open at f1.2 (depending what look you are after).

    The excellent points made in this thread though are not helping my GAS though ;-)
  19. SojiOkita

    SojiOkita Mu-43 All-Pro

    Feb 23, 2014
    I think that one important thing is the fun you have using your lenses.
    In many situations, I find that using a prime is more fun. There's also more DOF possibilities.

    I also think that f/2.8 is not very fast (Sigma makes a 18-35 f/1.8 for APS cameras. That's a fast zoom)
    When I used Canon gear, I had a 17-55 f/2.8 IS which was very good but when I wanted something fast (or a thinner DOF), it was not enough.
  20. Rasmus

    Rasmus Mu-43 Top Veteran Subscribing Member

    Nov 16, 2013
    Stockholm, Sweden.
    I own the Panasonic 12-35 and not the Oly 12-40, but I reckon they are about on par. The primes that I consider sharper than the the 12-35 are the CV25/0.95, the 75/1.8 and the Nocticron 42.5/1.2. The ZD 150/2 and the 300/2.8 are maybe also sharper then the 12-35, but I've never seen a review of the 300 and the 150/2 review I've seen is made on a 10 mp sensor.
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