Flash issue with a7riv.

Discussion in 'Sony/Minolta' started by rodeo_joe|1, May 19, 2020.

  1. Well, I finally took a big, deep breath and bought a Sony a7riv.
    So far I'm quite impressed, after finding where in the menu system to customise the control buttons.

    However - not so impressed with Sony's QC on the hotshoe.

    I initially thought that Sony had disabled use of non-Sony flashes on the camera. I couldn't get a flash or radio trigger to fire in the shoe, even in fully manual mode. The P-C socket worked. So that ruled out a faulty synch circuit.

    Then I poked about on the camera with a DMM in continuity check mode. The lens mount and metal strap lugs were clearly electrically connected, but the metal mount of the hotshoe? Nothing! Not even a high resistance reading.

    Long story short. It appears that paint overspray, or some other coating, was insulating the hotshoe where it should have made 'ground' contact with a flash or trigger. A quick scrape with a craft knife blade removed the paint/coating and I was then able to use a speedlight or radio trigger in the hotshoe. But really, I shouldn't have had to do that.

    So if you buy a Sony Alpha that doesn't fire a flash; have a good look at the contact area of the hotshoe before sending it for repair.

    And Sony: If you're reading. Pay more attention to detail in future. It might save you a few needless returns or warranty repair claims!
     
    Last edited: May 19, 2020
  2. Glad you found that out and fixed it. I wonder if there is any cameras that the PC socket and hot shoe can be enabled/disabled independently? Perhaps the Sony flashes hot foot is abrassive so when you put it in it would work?
     
  3. I have no intention of wasting hundreds of £s to find out, but I suspect that Sony's dedicated flashes use contacts in their daft 'multi interface' as an additional ground connection. So a bit of paint on the hotshoe would be no impediment.

    And in what language does the logo 'ni' equate to 'multi-interface'? Sony really are the mad Knights-that-say-Ni.
    I know that Nikon's P-C socket synch is disabled if the shutter speed is set above the 'X' speed, unless there's an HSS enabled speedlight in the hotshoe, when the P-C socket then continues to work at 1/400th and faster. A strange arrangement, but it shows that the hotshoe and P-C socket can work independently.
     
    Last edited: May 20, 2020
  4. I am impressed you actually did troubleshooting of the electronic circuit connections on a brand new camera. You must have been an electronics bench tech at some time. And the Sony hot shoes looks a bit more intricate and fragile than Canons. So I wonder if the paint over spray was a fluke or will be a common issue with all A7RIVs. I would find it hard to believe they would purposely have a ground connection and paint over it, if they did not intend to use it, why have the ground there at all. The A7RIII seems to have no issue with the Godox.Thanks for the heads up though, may have just been a bad set up on the production line that day, good to know.
     
    Last edited: May 20, 2020
  5. The Sony Multi-Interface has it's place. I don't often use a flash, but purchased a Sony flash just in case. The interface is flawless. I always gave Nikon kudos for their flash automation, but Sony has them beat. It is also compatible with the Sony remote flash controller.

    If you shoot video, the Multi-Interface gives you a digital route to add an external microphone or two. It bypasses the mic preamps and gives a S/N ratio of about 90 dB. The same interface is found on their FS5 cinema camera, and probably others.
     
  6. Well if you know Joe he is always playing with flashes so he knows.
     
  7. FWIW, here's a picture of the offending hotshoe with the part I had to scrape outlined. The opposite handed side needed scraping too.
    Sony hotshoe.jpg
    It did look like bare metal before I scraped it, but obviously wasn't.
    That's good to know, but I doubt I'll ever bother to go that route.

    I have been doing a few performance/rehearsal videos for a budding musician friend lately. I've been using 'wild' sound into a good quality portable mixing-desk style recorder. This allows the sound track to be continuous and consistent while using more than one camera position.

    I see no reason to change this modus operandi, because precise digital timing makes synching wild sound to edited footage an absolute doddle these days. An embedded audio track would probably just get binned anyway. Plus having cables running from mic/mixing-desk to a tiny box on top of the camera doesn't sound like fun.

    WRT a dedicated flash. No thanks! Not at Sony's prices anyway. I've managed to date just using manual or Auto-Aperture mode speedlights, and my studio strobes only have manual control. And Nikon's flakey CLS has put me right off TTL flash control.
     
    Last edited: May 21, 2020
  8. I agree that syncing second source sound to camera video is easy. I do it on a regular basis, and the camera audio is binned in the process. However if you need real-time results, as in blogging and live-streaming, post-processing is not an option. Built-in microphones are arguably worse than those found in smart phones, so many people are turning to auxiliary microphones or external mic preamps. Wires are certainly a hindrance, but the multi-interface shoe can be used with a Sony wireless microphone receiver and a simple adapter.

    I couldn't resist the temptation to build alliteration into the first sentence.

    I've used all the methods cited above for flash, especially with medium format. A genuine Sony flash offers seamless integration with a Sony camera, which is important if you shoot weddings, events, or even grip-and-grab ceremonies. Mostly I use it for fill, which uses so little power that a set of AA batteries lasts for hundreds of frames.
     
  9. There's already an analogue sound input socket on the side of the camera. How much better can the multi-interface shoe be, when you'd be doing really well to get over 60 dB S/N while recording live sound in a non studio environment?
    It may well do, but I have more pressing needs for the 500 quid that's going to cost me. Like new glassware.

    Really though, I can't envisage anything a single dedicated flash can offer me, that the dozen or more speedlights I already own can't.
    TTL? Don't trust it.
    Wireless control? Absolutely pointless with a single flash.
    Setting the flash 'power' from the camera? No need if the flash is sitting right on top of the camera. Bounce flash automation? AA mode has that covered.
    Being suckered into spending thousands on a multi-flash dedicated system? Errm, think I'll pass on that one thanks.
     
    Last edited: May 24, 2020
    Nick D. likes this.
  10. The digital interface will give you a significant advantage in S/N ratio compared to the analog port - 90 dB vs 60 dB. Since the inputs are balanced and low impedance, you can have much longer cable runs to the microphone. Unbalanced inputs are limited to 15 feet, and less is better, before suffering frequency loss and EMF pickup. The biggest problem is level-matching, for a clean signal without clipping.

    Microphones made specifically for the Sony probably work fine, but popular microphones line the Rode AudioMic Pro have a built-in amplifier with an advertised output range adjustable between +/- 10 dB. Ideally you want the level meters in the camera to peak about mid-scale, which is roughly -12 dB measured on the card. If I inject a - 20 dBv signal, I find that I need to turn the camera level all the way down for a mid-scale reading. For minimum noise, you should turn the camera gain to about mid-scale (e.g., 7 of 15), which means the input must be set to -40 dBv. In order to keep from clipping, the AudioMic would have to be used further from the sound source and ideal, which will include more ambient noise.

    If you "don't care" about video, and don't do live-streaming or blogging, this probably doesn't matter. Some people do care, however, so this message may be useful.
     
  11. But only if the analogue preamp and mic combination is capable of > 60 dB S/N ratio, and if the background acoustic noise doesn't swamp any hiss completely. That's not very likely in a live broadcast or Vlogging environment really. Worth investing in a Neumann U47 to inflict some drivel on an internet audience? I don't think so.
     
    Last edited: May 28, 2020
  12. Analog preamp has gone a long way so the noise isn't a problem but it's the mic S/N is still the problem.
     
  13. The microphones I use (Schoeps, Neumann, Sennheiser and DPA) have an equivalent noise level of -78 dB. My preamps have a S/N ratio of 137 dB. In practical situations, amp and mic noise can be ignored. A quiet auditorium typically has a noise level of about 40 dBA, whereas a quiet studio can be as low as 25 dBA. Most of the noise in an auditorium comes from the air handling system. In a poorly designed auditorium or space, all bets are off. Grin and bear it.

    Gain for acoustic instruments is typically about 40 dB (condenser microphones), down to about 25 dB for pianos under the lid. In a well-designed auditorium you can easily hear the air handling noise at these settings, down to sub-sonic frequencies visible in the waveform (these mics respond down to about 3 Hz), which makes it hard to edit precisely. In general, I record with a 40 Hz low-cut, and add 60 or 80 Hz low cut in post.
     
  14. Easily fixed; use an over-hyped and over-rated Rode NT1A. These nasty low-end condenser mics appear to have a built in 80Hz high-pass filter, giving them a bass-free and tinny response that does no credit at all to the Rode brand name.
     
  15. To get the -78dB S/N for the mic you had to go high end. Low end preamp can easily achieve 90dB S/N. So the fact that the camera would accept direct digital isn't all that much advantage.
     
  16. That's relative to an SPL of 90 dB. The maximum SPL is 130 dB. Better mics aren't necessarily quieter, but have a smoother, wider frequency response with less distortion and phase shift at the extremes. The much vaunted U47 distorts considerably off-axis, but is great for high brass, piano and vocals when used properly.

    Aside from a few pipe organs (with 32' pipes), there is very little bass in acoustic instruments below 80 Hz. What you hear as low bass is what your brain constructs from the difference between upper harmonics. Most speakers and headphones tend to break up when presented with low frequencies, giving a tubby sound, largely from room resonances. I cut the bass because the results sound better, cleaner, and bassier.
     
  17. Rodeo, you made a good choice in the A7Riv. Congratulations. Have fun.

    Despite all the techy-talk, I went 2 or 3 years with Sony before I felt a need for a dedicated flash. The tipping point was my son's outdoor wedding, to fill in the shadows. Although I shoot a lot of video, I have never been tempted to plug an extra microphone or preamp into an A7Riii (nor any other camera). It's too easy to do in post, using a multi-track recorder for the master. If I need real-time audio for live-streaming, I feed audio to the switcher or laptop from a mixer.
     
  18. Thanks Ed. I intend to (have fun) if this Covid epidemic ever lets me.
    Well, I can understand spending big bucks for an occasion like that.

    I still use my old pre-digital speedlights for outdoor fill though. The trick is to set Auto-aperture mode a couple of stops wider than the one you're actually using, or set the speedlight ISO faster than what you've set on the camera. That way you 'fool' the speedlight into giving less than a full exposure. I find it works just as well as Nikon's BL TTL setting, although I haven't compared it to Sony's flash system.

    Ah, the joys of 'lockdown'. I'm just hoping we don't get another wave of widespread infections now that our government have ignored prudent medical advice and eased social restrictions - prematurely IMHO. Especially since many people have seen it as a go ahead to do whatever the hell they feel like.

    I hope the rioting and chaos isn't too bad where you are.
     
  19. I have a couple thousand dollars of gear in a building currently under siege in the Chicago loop. Not much I can do about that, but I have backups for everything. It's less than a block from Central Camera, which was looted and completely burned out last weekend. Central was more than a store. It was a national treasure and a familiar haunt of mine for over 50 years.
     
  20. I read about that - senseless and tragic.

    Best of luck then Ed!
     

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