Nikon Flash Question

Discussion in 'Nikon' started by lekaicasi46, Aug 7, 2021.

  1. Mike, I was not referring to you in particular. I know several nature and wildlife photographers who make a good living from the "hobby". I won't include wedding photographers because most consider it as a job to be retired from some day.
     
    mike_halliwell likes this.
  2. I am not sure that having light at the optimum focus is necessary. In phase detection autofocus, the camera is comparing the phase of light from two different sides of the lens. If the wave fronts are in phase, the image is in focus. Since the camera is looking for a difference, whether the focus at that wave is optimal should not matter. The suboptimal lens performance should be the same for both sides of the lens hence both images and cancel as far as focus is concerned.

    The same should apply to contrast detection AF; the camera is simply trying for the best possible contrast. In fact some flashes use the red light to project a pattern, like a hash symbol, to aid contrast detection.

    I think the reason a red light is used is to disturb the subject and others in the area as little as possible. It is the same reason red lights are used at night to keep night vision - think of the lighting on automobile dash boards or aircraft instrument lighting (at least on older aircraft), or World War II era submarines.
     
  3. Due to chromatic aberration, different wavelengths are focused at different positions relative to the sensor plane. Thus there would be expected some focus error from using red light for focusing vs the ambient light without the focus assist light. But this may be a minor issue compared to not being able to focus at all. If the lens has no CA, all the better.
     
  4. I see what you are saying, but I am not sure it will matter. Here is a link to the way I understand autofocus works (it saves me from writing it out and doing a poorer job of explaining) LINK: Autofocus - Wikipedia .

    Since what is being compared is the phase of the beam from either side of the lens, the color should not matter, Red light from the left will have the same error as from the right and since the phases are compared (subtracted) the error will be subtracted out. Will it be perfect? Probably not, but it will be close enough not to make any difference and as you write it is "a minor issue compared to not being able to focus at all" or I would add, being so slow to focus you miss the shot.
     
  5. The point I'm trying to make is if the lens has longitudinal chromatic aberration, you cannot get all the colours in focus at the same time. If you focus based on a subject lit by a red / infrared light, and achieve perfect focus using that light, then switch to another colour spectrum (white LEDs, for example) to illuminate the subject for taking of the actual picture, the red parts may still be in focus while the blue parts of the scene will be out of focus. However, as said before, whether this is a significant issue is not clear given the difficulty of obtaining a useable picture in very dim conditions in the first place. I know that some of my DSLR cameras (especially D800) had obvious focus errors dependent on the color of the light in the scene when using certain lenses that have significant LoCA, but this has since been alleviated in newer models. But ultimately if you have LoCA in the lens, then it is debatable, which colour should be used for focusing, and a well-corrected lens is inherently easier to use because of this.

    I don't use the AF assist light because it is only active in single shot autofocus mode and I'm always in continuous mode and to go to single shot to get the light would throw off my shooting routine. Additionally some cameras have white light focus assist lights which are quite distracting to the subjects. The red / infrared light is much less noticeable, and that's what I'd use if I could get my head around switching to AF-S instead of AF-C, and then I'd have to remember to switch back - not going to happen. ;-)
     
    bgelfand likes this.
  6. Guys, OP was asking about some flash, isn't it?:)
     
  7. I've got the SB-700 and like it a lot as a compact on-camera flash that can bounce the light. I haven't used the SB-500 or SB-400 so I wouldn't be able to give advice on those.
     
    gabriel_heyman and Nick D. like this.
  8. So I don't know why you chimed in with an 'unprofessional' snipe at those that prefer to use other than Nikon speedlights. Anyone that relies on flash lighting in a professional capacity wouldn't even consider that underpowered little SB-500 toy to be professional kit in any way, shape or form.

    Even the likes of a couple of SB-910s, once they're inside softboxes, are only just powerful enough for something like a head-and-shoulders portrait at fairly close quarters and with an ISO of 100.

    So what would someone sensibly spend a budget of about £600 on? Two SB-910s that'll barely get the job done? Or 5 or 6 YongNuo YN-560 IVs together with a radio trigger, offering more power, flexibility, backup redundancy and greater triggering reliability?

    And which is the more 'professional' decision?
     
    Nick D. likes this.
  9. No contest.

    I have an SB-800, which I use, but hate the menu structure. It's daft.

    and a YN-685 when I occasionally need hi-speed sync.
     
  10. Hmm, you are still hung up on this? I commended only because OP was mentioning it. OP did not ask for info about unproven and unverified DIYs and you supplied plenty. Are these the things your normally use?

    Not sure what you are talking about. Of courses flashes are necessary in many situations and Nikon is a reliable resource for such equipment which are surely better than cheap DIYs in general. I have used and owned/own non-Nikon speedlights such as Metz, Olympus, even Godox, cube lights, LEDs...
     
    Last edited: Aug 16, 2021
  11. "Many of you have been simply chasing "own the latest, greatest gear" as your goal. That's a bit like getting on a vertical climbing machine and not being able to get off: you'll use a lot of energy (money), but you don't actually get anywhere because you just have to immediately do it again, over and over.",- Tom Hogan," - I like the guy.
     
    Mary Doo likes this.
  12. Think no one disputes this. The ultimate goal of course is to produce good results, and one does not need the latest and greatest to do this.

    However, the job would be easier (not impossible) when a good photographer has competent and suitable gear (not necessarily of the highest monetary value) such as a sharp lens and a camera that makes consecutive shots and tracks well when shooting a moving wildlife. Don't you think? On the other hand, the best gear would not be that useful in the hand of some people - for example, the sharp lens may not be focused on the intended subject of the story, the exposure may have blown out highlights or terrible shadows, and the composition is poor or uninteresting.
     
  13. OK, what are these DIYs you're on about?

    Are you meaning independent manufacturers?

    Surely better? Really?

    Purse bias? Deep pockets...:(
     
  14. Go to the 9th post at the beginnng page of thread. Someone was criticizing the mention of Nikon D500 (because OP asked about it, so I said something), saying it could be replaced by "a $5 bargain COB light or even the LED lap in the smart phone". Of course his DIY advice ignored the other functions of a a normal flash. But that's another story.
    No.
    What is surely better? You mean Nikon is better or 3rd party is better? All things being equal (except for the price), Nikon is normally better (subjective) for Nikon cameras but, of course 3rd parties can have excellent well-tested products possibly and at a better price point.
    Not necessarily. Third party products can be expensive too. You should know - you have those Sigma Art lenses.
     
  15. That what I was saying, my $35 Camerons exact replica of SB910 with 2 sec reclining time and the same output power, can be used as commander or slave, even works with my Sony A7-2 in manual mod. We know what we are talking about.
    $ 1149 Sigma Art 24-70mm f/2.8 DG OS HS :)
    $ 2096 Nikon's AF-S NIKKOR 24-70mm f/2.8E ED VR Lens :(
     
    Mary Doo and bgelfand like this.
  16. As mentioned before, you bought this flash at a great price-value and you should be pleased. Added bonus is if this relatively unknown brand is indeed 100% compatible in every way and behaves exactly the way Nikon SB910 does. You made a good choice. Hwvr, also as mentioned before, perception of value is not merely restricted to the price tag for some people. That said, Congratulations on finding a great super value.
     

Share This Page