What's with my 50mm looking so soft?

Discussion in 'Digital Photography' started by Drag'nGT, Feb 6, 2011.

  1. Drag'nGT macrumors 68000

    Drag'nGT

    Joined:
    Sep 20, 2008
    #1
    First, thanks for looking to try and help. :)

    Okay, I don't have L glass but I have heard the 50mm is really sharp and yet I don't see it or my lens is not right. Or I stare at so many L threads that I'm even more disappointed... :(

    I have some photos to share to help determine what's the issue. If you guys don't feel I took the right kind of photos (these are a little on the macro side) tell me and I'll do something more portrait style and post pics.

    Tripod, center dot focus point in Aperture Priority: Link=photobucket "full size" I really should find a way to host full size photos.

    Canon 28-135mm @ 50mm & f4.5 1/60
    100%
    [​IMG]

    Canon 50mm f1.8 MK1 @ f4.5 1/80
    100%
    [​IMG]


    At the crop I'm surprised to see the 50mm is actually sharper. But the point of the 50mm is the f1.8. Here's what it looks like:

    Canon 50mm f1.8 MK1 @ f1.8 1/60
    100%
    [​IMG]


    I thought the shutter might be open too long, so I shortened it. No appreciable difference.

    Canon 50mm f1.8 MK1 @ f1.8 1/200


    What's going on?
     
  2. davegoody macrumors 6502

    davegoody

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    #2
    You may want to check your ISO settings. There is discernable noise on your images, you don't state what body you are using, what mode you were using etc. (I know I could find this out by d/l the images and checking the EXIF data, but can't be bothered). On most bodies, using an ISO of 1600 or above creates a lot of digital noise, sometimes this happens at 800 too under some conditions. VERY dependent on body, I use a 7d and frequently use ISO 1600 and sometimes also ISO 3200 to good effect...... your mileage may vary depending on body in use. No doubt my results would be even better if I were using a 5D MkII as the full-frame sensor on this body is awesome at high ISO.
     
  3. FroColin macrumors regular

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    Jun 4, 2008
    #3
    Yeah, the noise is the ISO but the other thing is a lens is never going to be super sharp when it's open all the way, especially if it's a 100 dollar lens. That lens is going to be it's sharpest at like... 4.0 maybe even 8.0 or something. Depends on the lens. Read reviews on the lens, you will find where it's at it's sharpest. The other thing is that yes the 50 is fairly sharp because it's a prime but the really good pictures you see are stopped down. And also sharpened in post, the way that color is made from a camera is... Well that's another discussion but the point is this isn't unexpected when your at 1.8. The noise is the ISO. 100 or 200 is going to look the best. Once you get into the 800 and up it's going to be noisy
     
  4. fcortese macrumors demi-god

    fcortese

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    #4
    Agree on the f stop setting. Here's a picture taken at f/4.5 with my 50 F1.8:

    [​IMG]
     
  5. OreoCookie macrumors 68030

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    #5
    Actually, the results are by no means surprising, it was to be expected that the 50 mm at f/4+ easily outperforms a 4x zoom. Almost all lenses reach their optimal performance after stopping down the aperture by one or two stops (as a rule of thumb, just double the initial aperture value). Even wide open, the 50 mm shot looks ok to me.

    If you want to judge the sharpness of a lens, you should use very low ISO values and a tripod. And then you need to be very careful to set the focus properly. The depth of field of a 50 mm lens wide open is much smaller than when stopped down by two EVs. Hence, a slight movement of the camera can move the focal plane and make it appear as if your lens is less sharp.

    Lastly, I've noticed a somewhat misplaced trust in the red L that Canon likes to put on some lenses, but not others. Optical performance does not depend on whether or not Canon appends a red L to the name of the lens or not. There are plenty of non-L lenses whose optical performance is first-rate. And there are some disappointing L lenses* (e. g. the 50 mm L's optical performance is not that great, but if you need an ultra-large aperture lens, there simply is no competition).

    * Of course, expectations increase with price.
     
  6. TWLreal macrumors 6502

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    #6
    You are correct that the point of a 50mm f/1.8 is that it is f/1.8.

    It's point isn't to be tack sharp at f/1.8.

    With that in mind, there is nothing wrong with your lens.

    And for the record, using a holographic sticker is quite possibly one of the last things you would want to judge a lens' resolution on. I mean, really.
     
  7. TWLreal macrumors 6502

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    #7
    It's not misplaced trust that Canon happens to brand their highest performing lenses with the red L.

    While you are correct that there are some, I wouldn't say plenty, non-L lenses that are terrific. It is also correct that every L lens outperforms its non-L counterpart, if it even exists. This is where we place our so-called "misplaced" trust if you want to call it that.

    I don't think most people would call the only autofocus 50mm f/1.2 in existence disappointing. If others want to play Canon's game, they are more than welcome to show they can do it better. I'm sure their main competitor will do it and one-up Canon but that's a few years out and is to be expected.
     
  8. Edge100 macrumors 68000

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    #8
    Sorry, but I really don't see an issue here. The 50/1.8 is not what I'd call "sharp" at f/1.8; your results are just about exactly what I'd expect.

    If you want a Canon-mount 50mm lens that's sharp at f/1.8, you're going to need to invest in either the Canon 50 f/1.2L or the Sigma 50 f/1.4.
     
  9. TWLreal macrumors 6502

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    #9
    Also for the record, you might want to stop looking at 100% crops as no one really looks at photos 2 inches away.

    Unless you're actively looking for a lens that has amazing resolution for some specific applications, sharpness is far from the first thing you should worry about when capturing images.

    Enjoy your fast lens for being fast.

    [​IMG]

    http://www.flickr.com/photos/msmelva/3070597738/
     
  10. Drag'nGT thread starter macrumors 68000

    Drag'nGT

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    #10
    Sorry for not giving info on the body and ISO. My body is a Canon 50D.
    If you use Safari I recommend installing an extension called ExifExt. It lets you right click on any image and get the Exif data. :cool:

    I'm not bothered by the noise in these photos because the noise doesn't affect the edge sharpness I was trying to point out. In fact, the sharpest shot has the noise you guys are talking about (ISO 1000). The last crop at f1.8 has an ISO of 160. Yes, the noise is gone but the lens is also softer.

    OreoCookie, I guess I see it like owning a sports car. I want to shoot in the lower apertures because that's what I bought it for. It annoys me that the lens ends up less sharp at those apertures. Or should I say the DoF is harder to find? And I understand that shooting at those levels is also more difficult. But every stop reduces my creamy bokeh sandwich which is much to my dislike. :(
     
  11. Edge100 macrumors 68000

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    #11
    Yes; a $99 sports car.
     
  12. OreoCookie macrumors 68030

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    #12
    No, they don't brand their highest performing lenses with a red L, they brand their more expensive full frame lenses with a red L. Of course, more expensive lenses tend to perform better, but in my opinion, the reasoning is reversed: the more you spend for a lens, the better the optical quality tends to be.
    What quantifies `plenty' sure is a matter of debate. But for people with crop bodies (such as the OP) in particular, non-L (and also non-Canon) lenses are often better (e. g. Canon's 17-55 mm f/2.8 as a bread-and-butter zoom, Tokina's 11-16 mm f/2.8 as UW zoom come to mind).
    I don't think so, the 50 mm f/1.2 L lens, for instance, is optically not very good and is outperformed by the Sigma 50 mm, for instance. The optics of the 85 mm f/1.2 L also suffer from quite a few problems (e. g. a friend of mine who owns one says that his suffers from field curvature, i. e. the focal plane isn't really a plane) and Canon's non-L f/1.8 version is optically at least as good.*

    Of course, the reason you're buying an f/1.2 lens is usually not wanting the highest attainable optical quality, but the large aperture -- and you're willing to some optical quality for that. This is what these lenses were made for after all.

    * Other potential problems are mitigated by Canon's excellent service: in Europe, if you buy an L lens, you also get a focus adjustment by a service point for free. So if you're not happy with the focus of your rather expensive lens (especially those with a very large initial aperture), you can send in your body and lens and they'll calibrate the two.
    The trust is misplaced, because many noobs mistake the L for something that it is not. The L is not a good indicator of what to expect, the price of the lens compared to other competitors, on the other hand, is usually better. They don't expect that non-L lenses can outperform L lenses, even though they do: if you compare, say, an 85 mm f/1.8 at f/4 with the 24-105 mm f/4 L wide open, the prime will deliver better IQ. Hardly surprising, given that I'm comparing apples to oranges in my example.

    The real world is simply more complicated than having or not having a red (or golden) ring. In the real world, people buy lenses with a purpose and a budget in mind. While I'm not a Canon guy, I wouldn't have changed about half of my lenses even if I were shooting Canon or Sony or Pentax -- they're third-party lenses. Although I must say, my favorite lens is a pro-grade Nikkor.
    If you (as the buyer) expect better resolution than slower lenses, then I think you'll be disappointed. But the point then is that the expectations of the buyer are misplaced.
    I absolutely agree.
     
  13. chrono1081 macrumors 604

    chrono1081

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    #13
    I didn't read the whole thread but there is always the possibility you simply got a bad copy. It's happened to be before I just exchanged it.

    Also I'll send my lenses to Canon if I notice their performance drop. It can happen with a lot of travel and lenses getting banged around. Canon will recalibrate them for a fee.
     
  14. OreoCookie macrumors 68030

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    #14
    First of all, I think you misunderstand the term depth of field: when you take a photo, you focus on something at a certain distance. The layer where things appear sharpest is called `focal plane.' Depending on the aperture and the resolution of your camera, things appear sharp in front and to the back of the focal plane. I doubt you care to know about the mathematical definitions here, but you can find a good technical explanation here, so I'll skip it. The depth of field is the area where things (by definition) appear sharp and depends on focal length, aperture and subject distance (and also on the pixel size on your camera's sensor). The smaller the depth of field, the easier it is to spot whether or not the actual focal plane coincides with where you wanted it to be.

    With my big 80-200 mm zoom, the depth of field can be of the order of 1 cm, so I can see whether the focal plane coincides with the pupil or the corner of the eye. Movements of subject and photographer can likewise change whether or not `you've focussed correctly.'

    After this long prelude, here's my two-part answer:
    (1) Almost all but a few lenses reach optimal performance when stopped down by one or two EV. That's certainly the case for the 50 mm -- which is optically a rather good lens, especially considering the price.
    (2) The lower the depth of field, the harder it is to set the parameters correctly. That's why you don't see any focussing problems on those very cheap 18-55 mm kit lenses that are put on most consumer-grade dsls by default these days: the larger depth of field makes it irrelevant if the focus is placed 1 cm in front or in the back of where you wanted it to be, you simply won't be able to tell the results.

    I think your sports car analogy is apt: you need to learn how to control it. In this case, I suggest you should forget about looking at pictures at 100 %, especially if you haven't properly controlled the conditions (tripod, shooting at low ISO, being perpendicular to the books, etc.).
     
  15. TWLreal macrumors 6502

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    #15
    And every L lens is the highest performing lens in its respective lineup.

    It just happens that good lenses are branded L and are also expensive. No one really wants to try arguing what started what.
    I don't count third party lenses in my definition of some. They are not part of the Canon family and shouldn't be directly compared and they rarely directly compete in the first place.
    This statement should end right now and you can ask me again when Sigma, or anyone else, makes an autofocus 50mm f/1.2.
    Again, if someone else other than Canon wants to make an autofocus 85mm f/1.2, there is no comparison to be made.
    Since you obviously know all of that, why even question the existence of both EF f/1.2 lenses in the first place?

    As I have stated above, an f/1.2 lens' point isn't to be tack sharp at f/1.2. The point of a 50mm f/1.2 and 85mm f/1.2 is that they are f/1.2 and they are unmatched in this respect.
    I fail to see what your point is, specially if you know your comparison is completely flawed and irrelevant.
    Obviously you would expect people in the real world to "buy lenses with a purpose and a budget in mind" and the L branding is a simple way for Canon to let consumers know this is a professional level equipment that is distinctively superior to other lenses in their lineup.
    What?

    Are you creating a theoretical situation where someone is buying an EF 50mm f/1.2 L USM and expecting great resolution power out of it?

    If not, people buy a fast lens because it's fast. They, should, usually know going in that there are caveats to fast lenses. That is the burden of the buyer. You don't have to personally worry about that.
     
  16. TWLreal macrumors 6502

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    #16
    I am quoting this but this is replied to the OP.

    It's not about controlling a sports car.

    It's about knowing its limitations.

    You should not expect any lens to perform well wide open, minus extremely rare cases.

    Not to reiterate but no one should go in expecting great performance wide open when buying a fast lens. You buy it because it's fast. Or because it's inexpensive or because you like the focal length. But you don't buy a 50mm f/1.8 to get amazing resolution scores wide open.

    Again, the performance of your lens is on par and there is nothing to worry about. You are simply disappointed because you are looking at 100% crops. Don't do it.
     
  17. Drag'nGT thread starter macrumors 68000

    Drag'nGT

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    #17
    The reason I started this was because I wasn't seeing the performance I read about. Looking for my first prime the consensus was that the 'nifty fifty' is sharp as hell and shows great definition etc... Yet in real life I couldn't get those results. So I got a little concerned. This is a MK1 and obviously used, I thought that maybe something was off.

    I started looking at the crops because of the threads online showing the sharpness at 100%
    I didn't realize that I shouldn't see it really sharp wide open.


    And yet the $300 f1.4 is better on paper and in build quality but only slightly better in terms of the photos. There's a ton of 1.4 vs 1.8 comparisons. The photos are up to each individual what looks the best. And yes, the 1.4 is better overall.


    Oreo, thank you. I couldn't get the terms right for what I wanted to explain. And you're right, I'm learning to control a new lens. I'll leave it on the camera for a week or two and see how much I improve in using it.
     
  18. jabbott, Feb 6, 2011
    Last edited: Feb 6, 2011

    jabbott macrumors 6502

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    #18
    Most lenses are soft at their wide open aperture. This is due to a few reasons:
    • Light rays are entering from many off angles, resulting in aberrations. These off-axis rays also help create the bokeh you are looking for.
    • The lens itself may not have enough corrective optics to reduce or eliminate the aberrations mentioned above.
    • Softness may potentially be due to consistent front- or back-focusing of the lens, which can be corrected on a camera body that supports AF micro-adjustment (your 50D supports this, so I would try this and see if it helps).
    There are some notable exceptions to the softness at wide open rule... the following Canon lenses are very sharp when wide open:
    • 17-40mm f/4L USM (center only)
    • TS-E 24mm f/3.5L II
    • 70-200mm f/2.8L IS II USM
    • 100mm f/2.8L IS USM Macro and its non-L cousin
    • 135mm f/2L USM
    • 180mm f/3.5L USM Macro
    • Most 200mm and greater focal length L-series prime lenses
    Note that none of them have a maximum aperture below f/2. Unfortunately all of Canon's 50mm lenses (even the L) are softer than average when wide open. This is partly due to over-reliance on the same type of double gauss lens design that Canon has been using since 1968. Sigma makes a sharper 50mm f/1.4, but it sometimes has AF inconsistency issues. The Sigma 50mm f/2.8 Macro is really sharp in the center but it won't give you the bokeh that your f/1.8 does due to the smaller maximum aperture.

    You may also want to read "'This Lens is Soft' and Other Myths" as well as the follow-up article. Both have a lot of insights about the issue. Another good one that talks about issues with wide aperture lenses is How to Shoot with Wide Aperture Lenses. I agree with TWLreal that from the images you have showed, it looks on par for the 50mm f/1.8 when wide open.
     
  19. TWLreal macrumors 6502

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    #19
    Some people enjoy comparing test charts and you do so at 100%.

    In real life, you don't do that.
    It can be sharp wide open.

    You just have to look at the entire image instead of a 100% crop of a small section of your 15 megapixel image.

    I wouldn't sweat it.

    Also for the record, there are plenty more lenses that are remarkable wide open other than the ones in jabbott's list. In case someone reads it and thinks there are only a handful of lenses in that list.
     
  20. Policar, Feb 6, 2011
    Last edited: Feb 6, 2011

    Policar macrumors 6502a

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    #20
    That's sharper than my sample and pretty darned excellent. I don't know what camera you're using but a 7d produces 6 foot wide prints at 72dpi (low-to-average monitor resolution) so keep that in mind when comparing at 100%. Be glad you didn't spring for the L lens: at the same f-stops, the 50mm is as sharp or sharper than the vast majority of them.

    There aren't really any ultra-fast lenses that are super sharp wide open. Once you get past f2 things go soft. Even the best of the best are sharpest around f4. If you spend thousands and thousands you'll get better performance, but even the best lenses aren't that good wide open. The cheapest solution would be to buy a 5DII and 85mm f1.8. Shallow depth of field, similar field of view, and much sharper due to the larger sensor. Past that point, seriously diminishing returns.

    That said, what you've posted is an example of really good performance. At $100. In the days of film it took $3,000 6x7 kits to get comparable performance, which was then lost half the time with optical printing. If you're not going to print larger than mural-sized, it's fine. If you are, you've got to pony up some serious money or accept a little softness. One thing to consider is shooting at 100ISO or 200ISO and then using some smart sharpen in Photoshop. Or stopping down even to f2.8, where you'll get reasonably shallow focus and a sharper image.
     
  21. TheReef macrumors 68000

    TheReef

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    #21
    Your focus may be fine already, just throwing it in to what's been said already - I find zooming-in in live-view can assist greatly in nailing perfect focus which is crucial when shooting at wide apertures.
     
  22. OreoCookie, Feb 7, 2011
    Last edited: Feb 7, 2011

    OreoCookie macrumors 68030

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    #22
    Wow, you really are quite the fanboy, aren't you?
    You missed that the OP was making an analogous comparison (I substituted the 28-135 mm by the 24-105 mm and the 50 mm f/1.8 by the 85 mm f/1.8), so in the context of this thread, I think it's relevant.
    The L branding isn't very useful except for marketing, because if you want to make an informed decision, it won't really help that much to decide between lenses. Should I get a 70-200 mm f/4, f/4 IS, f/2.8 or f/2.8 IS (yes, I realize those are all L lenses, that's the point) -- or perhaps I should get a third-party 70-200 mm zoom instead? Should I get a slower lens with better IQ or a faster lens? What if I want an UW zoom for a crop body? Or a 28 mm prime?
    It's not a completely unreasonable expectation: other manufacturers offer f/1.8 and f/1.4 versions of their 50 mm and ~80 mm lenses and then, the f/1.4 usually has better optical characteristics. I reckon the reason that only Canon makes f/1.2 lenses that autofocus is that the other companies have come to the conclusion the compromises aren't worth it in their opinion. I'm not saying Canon made the wrong decision (I had the chance to play with the 85 mm f/1.2 for a bit and it is just an insane lens), I'm saying they made the conscious decision to spec the lens at f/1.2 rather than f/1.4.
     
  23. jeremy h macrumors 6502

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    #23
    I too have a 50d and in the past have had a lot of frustration with sharpness. I'm no pro photographer but as Graphic Designer I know enough photography to get by OK. Was getting very disappointed with my results. (I was using 'consumer' lenses - Sigma's and Canons (including the nifty fifty) but generally topping out at £250-300 ish.)

    I solved it by a couple of steps - nothing technical. Sounds obvious, but bought a much better lens. (currently using a 17-55mm f/2.8 - cost around £800). Massively better results. (The 2.8 with IS gives me better results than my Sigma 30mm 1.4) Also someone said that the 50d is very unforgiving with cheaper lenses - why that should be I have no idea, but my experience seems to bear it out. So have learnt a lesson - save up and buy one good lens - not several cheaper ones instead. Also I switched to the Canon Download utility which comes with the camera (as opposed to just using Lightroom 2.) Bit of a pain to use compared but seems to give better results with the 50d.
     
  24. TWLreal macrumors 6502

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    #24
    You can read into it however you want to.

    It doesn't change the fact that there are no comparison to be made at f/1.2 from anyone else for both Canon's autofocus f/1.2 lenses.

    Using the fanboy card when someone is stating a fact is a somewhat weak argument.
    It is useful within its own family of lenses.

    The one branded L will be of higher quality than the one without, if there is in fact a non-L counterpart.
    In this decision, the person should be smart enough to consider his budget and needs since all else is almost being equal. That is simple logic.

    If the person decides to consider third-party then the L brand has little to no effect as it doesn't exist outside the Canon family. Unless you consider each manufacturer's own professional grade branding, which just complicates the entire argument needlessly. With that said, within Canon's own lenses, L lenses are of the highest quality if there is an equivalent non-L counterpart.
    Personal decision.
    The person should be smart enough to realize there are no L branded EF-S lenses so therefore, he can simply choose between whichever EF-S compatible ultra wide zoom he wants.

    There is no L branded 28mm lens, so again, he may choose between whichever 28mm is available.

    Obviously, one should know that not having the L does not mean the lens is bad. But if it does have it, one should know it is of better quality than if it didn't have one. Simple.
    That's not really a question so I'm not going to say anything other than continuing on my previous line of thought.

    The two Canon autofocus f/1.2 lenses quite possibly exist out of pure "Just because we can" mentality. Or just to have some of the fastest autofocus lenses in existence, for whoever feels the need to use them.

    If a person feels that the EF 50mm f/1.2 L USM and EF 85mm f/1.2 L II USM compromise too much, they can take a step back and get the EF 50mm f/1.4 USM and EF 85mm f/1.8. The option is there. Everyone's happy.
     
  25. TWLreal macrumors 6502

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    #25
    You can quite possibly chalk this up to inexperience or user error.

    No offense to you particularly, but I am guessing there are higher chances of misuse than having a bad lens.

    Fast lenses in the hands of inexperienced users does not generally yield the best results. Inexpensive fast lenses are simply recommended to new users in order for them to explore the possibilities of depth-of-field.

    This is repeating myself too many times but you do not use fast lenses for their resolving power, generally. Expecting "sharpness" out of fast lenses is just going to make you disappointed, more so if you are just starting out.

    You use fast lenses because they are fast. Not because you read somewhere online they are sharp.
    This can somewhat be true in a completely different context but it might be ridiculous in this one.

    My $75 EF 50mm f/1.8 II resolves better than my $1,299 EF 24-105 f/4 L IS USM.

    You use one or the other in different situations. Every lens has its place, even $75 ones.
     

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