wide aperture and low light

Discussion in 'Wedding and Event' started by laurenm, Sep 24, 2006.

  1. I can't post my samples so you'll have to take my word for it that "they stunk". At wedding I assisted last week, I tried something I have tried before (also without luck which is why I have steered clear of it until now) - shooting with my 50mm 1.4 during reception without flash. Basically, very occassionally, I got a neat looking candid of people talking at the tables or whatever. But mostly, I had trouble with focusing. I'm not sure what my question is because I'm not sure what the problem is - the wide aperture making the in focus area small and sensitive, or the low light making it hard to auto focus? or both? and whichever the problem, what is the solution? Can it be a matter of just practicing to get the focus right? When I switched back to flash, I was able to focus and still use wide aperture. I practiced with my dog friday, though it wasn't in low light and he mostly wasn't moving so not sure how good it was for practice and things came out as I wanted. (just first group of shots is from friday- up to his wearing glasses) http://www.photo.net/photodb/folder?folder_id=524837 I have to stop avoiding this lens and be able to use it. What's the use of 1.4 if I can't use it-
     
  2. beautiful dog. My little ankle biter wont stay still long enough. A friend called desperatly with gear issues and I rushed to her aid. Loaned her my SB800's and broke out the Leica for fun since I wasn't on the clock. Here was an attempt yesterday from my Leica. Both lense and camera date to 1959, and I think it shows. Can't wait to get back my 90 cron shots with my other M3 body, because I know that one is in better shape. My focusing was pretty good, even with the recession (?) shots.
    00IB2b-32590384.jpg
     
  3. Lauren, When using these wide aperturs, you have to develop good focusing techniques. The best practice is learning how to use your selective focus points while you have the camera to your eye. Learning to use these focus points fluently, will minimize movement and will ensure focus position. The focus/recompose technique is worthless with an apeture of 1.4......simply too little DOF for the slightlest mis-focus position. Also, remember the rules of hand holding sufficient shutter speeds in natural light (shutter must be equal to the focal length) (unless using proper lighting ratios).
     
  4. Hi Lauren, if I remember correctly you are shooting with the D70. They are not the best at finding focus in low light. Practice manual focusing and using the focused indicator in the bottom left of the display in the viewfinder, then reframe and shoot. I hope that answers your question.
     
  5. Have you looked at this site yet? http://www.dofmaster.com/dofjs.html Wide open apertures are tricky and it's good to know exactly what will be in focus at a given aperture and distance. This calculator will show you that if you focus on something 20 feet away with your 50mm lens at f/1.4 on a D70, the area in focus will be 2.75 feet. So for photographing a few people, you'll want to be at least that far away, maybe further. Write down the focus distance at certain f/stops, get familiar with them, and you'll know that lens well.
     
  6. Can't you switch your flash to some AF assist only mode? - I've seen a few PJs having their flashes riged up at no flash allowed locations. Practicing AF spot selection is a good idea too.
     
  7. You just found out for yourself that myth of using fast lenses for low light is just that: a myth. Fast lenses give you a nice bright viewfinder, but that's about it. There are very few good images to be had at wide open, especially in social events where more often that not you end up trying to photograph a group of people up close; one person ends up in focus but the rest are blurred. Sure, you can take a nice portrait that way or snatch a nice candid of that cute flowergirl, but in most cases the DOF is way too shallow... (as demonstrated above, it also works well enough for a big overview shot where the focus is on or near infinity; you might just get enough DOF way out there) Practice will help, but at the end of the day, in my opinion, f/1.4 is not that useful.
     
  8. Try setting the camera to use the center AF area. I think that one is the most sensitive. Then you have to look for something contrasty to focus on. Then practice at home in similar dim light to what you had at the reception.
     
  9. First be sure your problems aren't due to handholding or motion blur. Rule that out--remember, flash freezes motion so the difference you saw between the no flash and flash shots could have been due to that fact. Once you rule out the two things I mention, decide whether to use the autofocus or use manual focus. As others have said, f1.4 has very little depth of field to use as a margin of error. If you use autofocus, use the center focus point and/or rig up your flash so that you can use the focus assist without the flash firing. I don't know how to do that with the Nikon/SB800. And practicing is good. If you decide to use manual focus, you might want to investigate getting a split prism screen.
     
  10. Jeff Ascough has used a Leica 50mm Noctilux f/1.0 at weddings with fairly "decent" results. I use my fast lenses wide open all the time. 85/1.2 @ 1.2 about 90% of the time, and that has a shallower DOF than a 50/1.4. My favorite lenses for hunting couples shots at a reception is a 135/2L which I can't remember ever setting beyond f/2.8. I just don't shoot them from 5 ft away. I don't know about your Camera Lauren, but with Canons, the faster aperture lenses DO focus quicker and more accurately because the more sensitive AF points are activated ... where they are not with lenses above f/2.8. So, no matter what aperture you have selected, all modern lenses stay wide open while focusing, so a faster aperture lens will focus faster, and in some cases more accurately than slower lenses. On some older AF cameras only the center focus indicator is the "sensitive" one. Of course IF you need more DOF (whether it's a fast aperture lenses or not), you have to stop down ... fast lenses aren't glued wide open, they do have other aperture settings to select when needed ... like when shooting a group. Conversly, a slow lens can never be set to f/1.4 when you want it. Lauren, there are a number of things that can effect the appearance of being in focus. Distance to subject plays a big part in depth of field even when the lens is set wide open. The further away you are the more DOF a lens gains. If you start moving closer than DOF becomes narrower and narrower. Another thing I've seen (and done myself) is get to ambitious with shutter speeds when using a fast aperture lens. IMO, subject movement spoils the appearence of focus just as often as shallow DOF. When shooting wide open you have to take all of the above into consideration, AND have good technique. A solid stance is necessary when shooting close up while wide open. Subject movement and your movement can combine to throw the focus area out just enough to soften the eyes for example. Practice is the cure, and learning more about how DOF works with all lenses.
     
  11. Love DOFmaster and have nearly memorized my fav focal lengths. What BAS says is correct. With a 50mm you have to almost think in terms of a wide angle. My 35mm is easier to use, but the effect is still the same. I used the 35mm a few weeks ago indoors for a reception and unless the subject is isolated (hard to do candidly with a 35) the results aren't that great. You certainly have to pick and choose your angle and subject carefully.
     
  12. Marc--all you say is true and applicable, but just to point out that the semi-pro models/consumer models don't have quite the agile and sure footed autofocus abilities of the pro models, something that I grapple with all the time on my 20D. Probably the D70 doesn't have quite the same autofocus quickness and reliability as a D200 or D2X. A small difference, but there, nonetheless.
     
  13. The D70 does not have the best AF in the world. I swear my N90s is faster, the view finder is much better thats for sure. Make sure that your D70 is set to use only the central AF point that way you can choose what will be in focus also make sure that the AF assist lamp is working. Apart from that the D70 is what it is the new D80 is supposed to have the D200 AF and a similar view finder so it could be a good upgrade to the D70 in terms of how it functions. I am so tempted by the D80 myself but most of what I shoot are outside B&G portraits usually with a 50mm 1.8 so the D70 usually does just fine.
     
  14. The D200 is closer to the Cam1300 (F100/F5/D1X) autofocus capabilities of than I ever expected. Hooked up to my 300AIS the manual rangefinder focus is almost non existent with the D70, but pretty nice with the D200. The D70 is a great little camera and I can handhold it to some pretty slow speeds, but you may be losing something on the AF end of things (shake, AF, DOF). You might try manual focus and test the results. I rarely get anything useful with groups at f/1.4 because of the DOF and movement. But it can be pretty special when you hit it big.
     
  15. lb-

    lb-

    You just found out for yourself that myth of using fast lenses for low light is just that: a myth.
    oh BS.
    no more a myth than saying a tripod can help to steady a camera or that dragging the shutter can help to reduce dark backgrounds.
    tools and techniques. nothing more.
    unrealistic expectations or an inability to master certain tools and techniques does not make their usefullness myth.
    cheers
     
  16. Mark, sounds like we are in agreement then; wide open is great for shots where you isolate people, most often when they are further away - regardless of light levels. But I am willing to bet you usually have a 24-70/2.8 and flash on a body dangling from your other shoulder for those up close and personal PJ shots. What I am trying to say is: a fast lens is not a replacement for lack of light; when you need a certain DOF, you need a certain DOF. While fast lenses shot wide open have their use at a reception, trying to ditch the flash and simply grabbing a 50/1.4 and opening it wide to get the same shots just won't work.
     
  17. There are unlimited numbers of good pictures available at any aperture, including wide aperture. I know it's a simple suggestion, but... have you tried focusing manually? If your camera's viewfinder is too dim for this AND your camera won't autofocus accurately under these conditions, you may have a camera problem rather than a lens or technique problem.
     
  18. Bob, your first sentence made sense. The second sugests that Lauren's problem is simply one of focussing. As we haven't seen Lauren's images, who is to say she isn't simply trying to take the kind of images that won't work at f/1.4? Just because there are unlimitted good images to be had at f/1.4 doesn't mean any image will work just by focussing right...
     
  19. Thanks everyone for all the answers. I think I may have some combinations of the mentioned problems and will have to continue practicing to figure it out. I have tried manual focusing but can not be sure I trust my eyes. Someone mentioned recomposing. That is something I've had trouble doing - even if I don't lift my finger, the focus goes out when I go to recompose. and I think some of the problems are due to that and my maybe not noticing every time it happens
     
  20. Depending on AF for low-light shooting can be dicey depending on the camera you use and how you use it. Manual focusing with some of the lower-end DSLRs is difficult because the finder is smaller and harder to use (AF body screens aren't as easy to focus as older MF viewfinders, for instance). Takes practice and patience.
     
  21. Lauren--is your camera set to One Shot (it's called something different on the Nikon)? If it is set to Servo, the focus may wander, especially if the subject moves. Anyway, the semi-pro/consumer models have a harder time with this--there is a tendency for the focus to wander even if you set it to One Shot. Got to watch for that. One of the things I hate about my 20D. Another thing is that the focus locks on to something in front of or in back of the intended point because the focus points are actually bigger than what is marked in the viewfinder.
     
  22. Make sure you don't have your camera set to continuous AF. That could be another problem because as you move the camera it will focus on what ever is in the AF frame. So as you focus everything would be OK but in continuous AF the focus is not locked.
     
  23. Nadine and Stuart, I will check those settings. Thanks
     
  24. lb-

    lb-

    Fast lenses, long lenses, tripods, fast shutter speeds, slow shutter speeds, low isos, high isos....... are tools.
    fast lenses and shallow DOF are useful for a particular kind of image
    photography is a wonderful series of technical compromises. I think they teach that in the photography 101 class, right after they teach you what the aperture does. So yes, a shallow dof can be a useful tool, or it can be the compromise you have to work around.
    be aware of your actual dof, don't just know that its "small" or "large" but exactly where it is.
    compose first, focus last
    be aware of the quality of the available light, not just the quantity.
    if your equipment is not suited for low light work change your equipment. saying that f/1.4 isn't useful because it's hard to focus on a low end dslr is like saying on camera flash isn't useful because the flashcubes on your sx-70 won't lightup a large group shot.
    cheers
     
  25. Lauren, I found that my 50 1.4 got foggy wide open. Yours may differ but I never went below f2 with it after that. The Nikon lenses that don't fog that low are the 35 1.4 manual and the 50 1.2 manual. I've never tried the 85 1.4 auto so it may be OK. I got both lenses off of ebay and once shot an entire reception with the 35. The trick is to get a split-image focusing screen. I got mine from Katz-eye and I added on a magnifying eyepiece. With it I can focus at 1.4 but only if nothing is moving. These days I generally use my 35 2.0 auto at weddings and keep the manuals for portrait work.
     
  26. Nadine, I said that. Depending whether the camera is an older model. I've used all the Canons from the 30D on through the 1 series, and know some are better than others. But whatever model, a faster aperture lens helps. Bas, that'd be a bad bet on the 24-70 on a second body hanging from my shoulder. First off, I hate that lens and don't own one anymore, and I use one camera and usually a prime ... most used are the 35/1.4 and 85/1.2. Whether you'll run out of DOF on any given subject depends on how far away you are. If a camera won't focus lock in dim light, what makes people think the focus indicator will aid you while manually focusing? Plus, most of these digital camera AF screens aren't optimized for manual focusing. Lauren, you said ... "Someone mentioned recomposing. That is something I've had trouble doing - even if I don't lift my finger, the focus goes out when I go to recompose. and I think some of the problems are due to that and my maybe not noticing every time it happens". If you focus on something that's not on the same plane of focus of course the main subject will be out of focus when you recompose. If it is on the same plane but farther to the edge of the frame, then that's a different problem ... if you are shooting with a narrow DOF, then recomposing can cause some apparent AF issues that stopping down would mask with greater DOF. The problem is actually one of distance ... which is demonstrated by a simple graph something like this ...
    00IBOI-32599184.jpg
     
  27. Sure like your dog! Looks like he rules the house! Wonderful pics! I like Nadines advice about using flash to stop motion. Also the flash, SB-800, has a built-in auto focus assist for dark situations. Maybe try flipping the flash head away from the subject so the flash senser will still help with auto focus.
     
  28. Point taken, Bas; some pictures are better with more in focus. But I'll give Lauren the benefit of the doubt and imagine that she's aware what will be in & out of focus and has the aesthetic sense to judge correctly when this will work properly.
     
  29. Edward, "I found that my 50 1.4 got foggy wide open" Do you mean literally, you saw fogginess? This occurred with one of my dog shots (now deleted). Marc, thanks, I need to digest that :) Thanks Bob, doesn't every dog rule the house? He's a sweetie, just can look intimidating at times (which is good). I am using sb600, not 800 wonder if it has same capability? As for the little dispute going on, I'm sort of ignoring it as I don't feel it realtes to my needs in my question. I do realize I will have shallow DOF at 1.4 and my reason for using that settig would be either for intentional shallow DOF and just ambient light or when not allowed to use flash in low light situation. My question however isn't whether I should ever use 1.4 or when to use it, but when I do choose it for whatever reason I have trouble focusing.
     
  30. Lucas, I never said a fast lens wasn't usefull; I use (mostly short telephotos) wide open all the time in low light. The "myth" always was that you can swap f/5.6 and your flash for f/1.4. Which you still can't without adjusting the type of picture you take.
    Marc, OK, bad bet. But you get my point that you also have a wide angle, one you probably close down quite often to get some more DOF and take a shot of a group of people. I guess this one wouldn't have worked out so well wide open at f/1.4.
    Cheers, Bas.
     
  31. Another bad bet BAS (see EXIF data panel from my shot that you linked to which was done with a 24/1.4L @ f/1.4 : -) No one is crazy enough to argue that f/1.4 should be used all the time. For certain photographs, it most certainly is wise to stop the aperture down. But that isn't the same as saying that the value of fast aperture lenses in low light is a myth. They are very valuable if you understand the relationship of focal length and distance to subject. Wide lenses inherently offer more DOF than telephoto lenses ... and this includes when they are used wide open. In low light this allows you to capture more ambient light while also dragging the shutter with flash freezing the action ... yet when a wide lens like the 24/1.4 is used, the inherently greater DOF helps hold focus reasonably well even with a group ... as demonstrated by the image BAS linked to above. On Lauren's camera her 50mm provides the equivalent focal length of a 75mm lens because of the 1.5X crop factor ... yet still gives the slightly better DOF of a 50mm. I'd suspect Lauren's displeasure with her images comes from a combination of slower, less accurate AF system and actual user technique. Off center focusing when shooting close with a normal to telephoto lens can be tricky. When shooting wide aperture work I use 2 techniques to overcome the distance phenomena illustrated by my simple chart above: 1) If the light is good enough I'll use one of the focus points at the far end of the viewfinder so the amount of re-composing is minimized. 2) if I need the really sensitive center focus point in the viewfinder because the ambient light sucks, I won't re-compose but instead center the subject and crop off center later. Using a high meg, full frame DSLR provides the luxury of doing that without much penalty when printing the average 8X10 wedding image.
    00IBch-32605284.jpg
     
  32. Haha, Doh! I assumed that was the 35mm lens you spoke of, which wouldn't have quite as much DOF at f/1.4 as a 24mm. :) That's a nice 24mm, BTW. I never used that one, the lack of serious barrel distortion is fantastic. I know no one would be crazy enough to argue it - and nobody does. But it is a classic beginner's mistake to simply open up when the light gets low; I see it all the time in friends just starting out. I assumed Lauren made the same mistake.
     
  33. Just to clarify a point. All focal length lenses have the same depth of field, if the image size remains constant in the viewfinder. This means that distance, and image size in the frame control DoF, more than focal length or F stop. The next issue is choosing a focal length that flatters one's subjects. Getting too close to a subject, with too short a lens will cause distortion. And using a short tele will force distance into the equation. Even though the short tele lens will flatter a human subject, the distance it forces will lessen the DoF. So the answer is to carefully choose subjects when shooting wide open in low light.(for example avoid group shots, or wide panoramas).And always carefully focus on the subject's eyes.
     
  34. Just a bit about AF and a very fast lens - although theoretically a faster lens should allow your camera to attain focus faster due to more light reaching the AF sensors, something that often gets overlooked is that many lenses, especially very fast primes, are somewhat or very soft wide open. Therefore, since a camera is focusing with the lens wide open, it is also trying to focus on that same slightly soft image, and that can make it difficult to find contrast and attain focus.
    For example, my Canon 50 1.4 and 85 1.8 are very soft wide open, and I also find that they struggle to achieve focus in anything less than optimum lighting conditions. On the other hand, my 17-40 f4, which should be even worse since it's much slower and doesn't activate the high-precision AF sensors on my 20D and 5D that work with 2.8 or faster lenses, focuses very quickly and accurately in the same situations that render AF on the 50 and 85 useless. The biggest difference between these lenses? The 17-40 is very sharp wide open, giving the AF sensors a higher contrast image to work with.
     
  35. OK Marc, this has brought up an interesting subject which as a wide open shooter you are most qualified to start I would think. Do you fancy starting up a thread detailing the reasons behind, the technique involved and the do's and dont's of wide open shooting, similar to the flash threads we had started by Nadine? I'm trying to build slideshows for my website and the thing which stands out the most is far too busy backgrounds and that is at f4! I think an in depth discussion of using lenses wide open would be beneficial to the community here, many of whom have no background or do not use shooting wide open as it should be done.
     
  36. Yeah Lauren--what's the dog's name? Try practicing focus on his nose and eyes--put the focus on the nose and then on the eyes to see if you can deliberately put tricky focus where it should be. Did that with my cat with my 50mm f1.4.
     
  37. Ben, I'm swampped with work right now or I'd do it. IMO, it's a matter of practice. Having shot with Leica Ms for many years, you don't actually see the shallow depth of field in the rangefinder window. So, you have to learn about the effect distance to subject has on DOF relative to focal length. Practice, practice, practice. Automation isn't a substitute for practice, especially when it comes to using fast glass wide open. Nadine's exercise above is a good one to practice. What is nice on many newer cameras is the ability to select off center focus points ... which takes a lot of practice to do on the fly. I used to use the center point all the time, but now use the off center-ones after much practice at controlling the selection without taking my eye from the viewfinder. I use a wider lens to increase the DOF while shooting wide open, and a longer lens to isolate the subject ... with selective focus points to get the important part in focus like this ...
    00ICJD-32620984.jpg
     
  38. lauren - big thread. I'm not sure if someone already mentioned this, but many of the canon speedlights have a red focus assist beam that you will notice when you are close. they help focusing in low light...
     
  39. See if a different focus screen helps. I bought the Ee-S for a 5D, and it really helps to snap focus. That way, I can manually focus with more confidence. Don't just aim the focus point anywhere. Help it out. Give it an edge or at least something with high contrast. Especially in low light. I'd avoid using the flash assist for focusing. Seems like that makes focusing slower. And it doesn't work that well for moving subjects, either. The higher end bodies focus faster, but even the lowly Rebel can focus at 1.4 and render sharp eyelashes. Eric
     

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