Friday, December 28, 2012

The Taming of the Shoe

The PC Sync connector
Also in this issue:
  • A99's Wireless Flash Delay
  • A Zeiss Full-Frame Alternative
  • Seminar Update

The Taming of the Shoe

Once upon a time there were cold shoes.  Nobody called them that, but that’s what they were -- small brackets mounted onto the camera body onto which you could mount your flashbulb holder.

The original Flash bracket holder,
retroactively labeled the "cold shoe".
Once mounted, you would connect the flashbulb holder electronically to the camera via a PC Sync cord into a PC Sync socket (whose design hasn't changed much over the last century).  Inside the camera there was a mechanical switch which briefly “shorted together” the 2 wires of the PC Sync cable when the shutter was actuated.  It was a very simple and very effective mechanism, which also worked well when the electronic flash was invented.

Adding the circuitry to trigger the flash
now made it a "hot shoe".
“Hey, let’s get rid of that annoying PC Sync cable!” one engineer must have said to himself in the 1960’s, as he
devised what is now known as the “Hot Shoe” (left).  The metal rails on the bracket, coupled with the metal circle in the center, served to provide a replacement for the two wires in the PC Sync cord.  Mind you, at this stage the only thing this provided for was to tell the flash when to fire – no other information was exchanged.  The flash would always output a fixed amount of light, and it was up to the photographer to calculate the distance of the subject and use the appropriate f/stop to ensure proper illumination.   This was often a time-consuming task for each and every shot.

An auto Thyristor flash calculated
proper flash exposure on its own.
In the 1970’s, Thyristor flash circuitry was developed.  Auto-Thyristor flashes had a tiny forward-facing sensor in them (right) that would look at the subject, and when the sensor saw that the subject had enough light it would stop outputting light during the exposure.  (At this point “outputting” became a legitimate word. :-) )  This was a huge leap forward in flash technology, for it meant that the photographer didn't have to calculate or change the f/stop each time the subject changed distances.   (They still work great with digital cameras, as there's no pre-flash needed.  Just make sure your f/stop and ISO are set right.)

More automation meant more
communication pins.  Say goodbye
to standardization!
1980’s: The drawback to the Auto-Thyristor circuits was that if you had a filter in front of the lens, or if you had used a different f/stop, or if your zoom lens would actually change f/stops as you zoomed from wide to telephoto (a common thing!), then the actual amount of light that got through to the film would change, resulting in your flash pictures most likely being underexposed.  To address this problem, in the 1980’s camera companies started to move the flash sensor from the front of the flash to inside the camera, reading the light that got reflected off the film plane.  This new system was dubbed “TTL” (“Through The Lens”), and its main advantage was you could use ANY f/stop, distance, or filter (or combination of filters) and the system would do its best to ensure the flash exposure would still be accurate – no adjustments by the photographer were ever necessary.   And to accommodate this additional communication between the camera and flash, additional connection pins were necessary.

Here’s where things started to get proprietary, for a TTL flash for Nikon would not work on a Canon or a Minolta.  Here’s also where things started to become unreliable, for if the flash was not mounted and secured just perfectly onto the hot shoe, a flash exposure error would almost certainly take place.  (As a wedding photographer I saw this happen to more than one Nikon shooter - and during the days of film they had no idea it occurred until after the event.)

Minolta's solution - much faster mount /
unmount time, and fewer alignment failures.
And so, during their Decade of being Different (1990’s), Minolta decided to re-design the flash hot shoe from the ground up, to address these reliability problems.  (“Hey, there’s no interoperability anymore, so it shouldn't matter!”)  This was a good thing from a technical point of view, since it all but eliminated the kind of "almost mounted" flash failures I had witnessed, plus it made it substantially faster to mount and unmount the flash with confidence.  I liked it a lot, but the new design made it very difficult for Minolta-shooting professionals (both of them) to rent 3rd party flash equipment and radio slaves because suddenly Minolta was incompatible with everything.

When Sony bought Minolta, a flood of market research of non-Minolta/Sony shooters (the folks they were trying to court) told them to "dump the proprietary hot shoe".  And you could tell that Sony wasn't a fan of this shoe either because as time went on (most notably in the NEX-7 and A65 cameras) they let their manufacturing tolerances slip, resulting in accessory flash wobble when attached.  Between that and the flash exposure accuracy problems of the A77, A65, and NEX-7, clearly Sony's attention was elsewhere.

It turns out they had bigger problems to solve.  Sony's various camera divisions were all converging (still cameras could do video, video cameras could do stills), yet there were three distinctly different accessory shoes in use: The Alpha one inherited from Minolta, the "Smart Accessory Terminal" (hastily designed for the NEX), and the Active Interface Shoe used for the handycams (below).  Is there a way to standardize on an accessory interface and still provide new capabilities to all future cameras?


Handycam Active Interface Shoe


The new "Multi-Function
Accessory Shoe" tries to
meet all needs across all
product lines.
Sony's answer to all of these problems is the new Multi-Function Accessory Shoe first introduced in the Alpha 99 and the NEX-6.  It seems to have been designed to respond to all the criticism -- specifically, Alpha owners can now use Pocket Wizards without an adapter.  But it also has a LOT of connector pins allowing for diverse peripherals to attach and communicate with the camera.


These pins, while stiff, look 
vulnerable and I'm not looking 
forward to having to 
pamper my equipment.
What kind of peripherals?  For starters there's the professional audio mixer (the XLR-K1M, which I've used and liked), a future add-on GPS or Wi-Fi, or an add-on EVF or external HDMI display (I assume most future lower-end cameras won't have all these things built-in).  Plus power pins to power all these accessories.

Do I like the new design?  Not especially.  It now takes more time to mount / unmount a flash, and I no longer feel comfortable just throwing the unmounted flash into my camera bag (like I used to when I was a high-pressure wedding photographer) for fear of those little unprotected pins getting bent.  Time will tell just how susceptible these are to damage, but I'll tell you now I'm not looking forward to having to pamper my accessories.  (Preemptive strike: No, I don't use lens caps, either.  They slow me down.)

Wireless Flash Delay

I'm still getting used to my new A99, which offers the best image quality of any camera I've ever owned at any ISO.  I'm overjoyed that the dreaded flash exposure accuracy problem which plagued the A77, A65, and NEX-7 (which went unacknowledged by Sony) has gone away, but it has been replaced with a lesser problem that for me is just a pain: The wireless flash feature has an inexplicably long delay.  (The NEX-7 had this too, but I never expected this camera to be as responsive as a high-end shooter.)  Is this important?  It is for me, but then again most people don't use wireless flash to shoot kids the way I do.  Here's a quick video clearly demonstrating the artifact so you can decide for yourself:




I highlight these problems with a bit of trepidation, since as an engineer I understand just how insanely complex these cameras have become, and I have to acknowledge that Sony got the really hard things right.  (It's just frustrating that they can't seem to re-implement a 30-year-old technology properly.)  The camera also has a flash sync speed of 1/200th of a second when using the PC Sync cord or anything other than a Sony or Minolta accessory flash (the advertised speed is 1/250th of a second.)

Emphasizing these small problems might send the wrong message regarding all the unique positive things this camera has to offer.  (So to balance things out, let me state up front that there's no oil drops on the sensor! :-) )

A Zeiss Full-Frame Alternative

For those of you concerned about the cost and the 2-pound weight of the "Standard" Zeiss 24-70 f/2.8 lens for your full-frame camera, consider this alternative: Konica Minolta once made a 28-75 f/2.8 constant aperture zoom lens that is 98% of the Zeiss optical quality at about half the weight and one-fifth the price.  Pretty good trade-off if you asked me. (There are Sony and Tamron versions too which are more expensive but still great optical performers.  Kurt Munger seems to favor the Tamron version.)

Seminars

Surely you've heard about the seminars by now!  (If not: http://FriedmanArchives.com/seminars)  They seem to leave an impression on all who attend - even those who have attended other seminars in the past.  Here's what's on the calendar for 2013 (exact dates still to be determined):
  • Singapore will occur in March (tentatively March 23-24)
  • Seattle and British Columbia (no, I'm not sure where yet) in June
  • Australia (Brisbane and either Sydney or Melbourne) and Rotorua, New Zealand in October
As mentioned before, I'm restricting the seminars to about 4 major trips a year to maintain a healthy work-life balance.  We can still consider one more for the coming year, and if you're a camera club you can help make it happen sooner.  Contact me at Seminars at Friedman Archives dot com.

Next Month

Next month I'm going to share with you what I've learned about the new frontier of making e-books for the various e-readers (It's not for the faint of heart, and there are NO good tools out there to aid the poor author who doesn't have a background in programming!) (It was a pain even for me, and I used to program for a living!)

I'll also have status updates on the upcoming e-books for the Alpha 99 and NEX-5R and NEX-6.  Stay tuned!

Yours Truly,
Gary Friedman

==============
You didn't think I'd get in a blog post without mentioning Cameracraft Magazine, did you? :-)  http://friedmanarchives.com/cameracraft

47 comments:

  1. Gary!!! In spanish please!!! ;-)(Claudio)

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  2. Great article Gary, really interesting article on the history of flash. The A77 overcooking my shots when using wireless off-camera flash (TTL/HSS) is bothering me a bit - glad to hear that they have resolved this with the A99.

    I wonder if using one of the newer flash models as the commander might reduce the preflash delay you are seeing.

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    1. I tried it with the HVL-F58AM and the HVL-F60AM as the controller - all with the same delay. (I meant to mention that in the video... :-) )

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    2. I tried this combo too. While doing so I found out after triggering FEL (default C button in top left front of A99) the delay is gone. Would the locked flash exposure be good enough as a work around so you can catch the exact expression on children?

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    3. Farmer Dave, I was going to give a flippant remark like "Sure it'll work -- as long as you only need to take one picture!". But I just tried it and discovered that, unlike some Canon models, Flash Exposure Lock locks until you either press the button again or press the Play button. So yes, this works as long as the distance between your subject and flash doesn't change (which is the case with portraits.)

      Well done, sir!

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  3. Nice history of the hot shoe Gary. I was wondering, I know that the BIONZ processor has to do with writing the data to the card, mainly. But since the a900 had dual-processors and the a77 and a99 only have one (albeit probably faster) could that have made a difference?

    -Chance

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    1. No; as every other Sony camera that had a moveable mirror had no problem doing wireless flash quickly.

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    2. Mmm...sounds like a job for the Power Grip II...it recycled faster on the 280PX than most current sony slashed at full throttle...

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  4. As always, wonderful articles! I just with there were more of them. One question... As an engineer, do you think it is possible to have the flash problem of these cameras corrected with a firmware update? I bought an A77 to upgrade my aging A700,(yes, I even bought your book) but ended up returning the camera. I do a lot of off camera flash (heavily influenced my you)and the camera just wasn't cutting it. I'd buy the camera again if this problem was fixed. Anyways, have a safe and healthy New Year. Your friend; Ron

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    1. I'd love to write more but there are only so many hours in a day. :-)

      The only shred of evidence I have that it can be fixed with firmware is the A77 can do it faster with the built-in flash, telling me that it's not a hardware limitation. Of course I hate to make definitive conclusions when I don't actually know the cause of the problem.

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  5. Yep, the HVL-58 also delays badly. Coming from the A700 where I never had that problem, it is something I have to get used to!

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  6. Just a tiny correction
    When you mention Thrysistor Flash, i think the proper wording was Thyristor and this was a new technique used to save power when automatic ( photocell sensor auto flash) flashes were developed.
    Initial computer flashes were actually using up all the power in the capacitor therefore recycling time was always the same.
    All Minolta Autoflashes with a 2 digit No or 100 series in the 3 digit number series were autoflashes but these were without thyristor .
    Only the 200 and 300 series Autoflashes were equipped with the Thyristor technology that reduced recycling times and kept some of the unused power in the capacitor.

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    1. Excellent point! By my memory only a few years had passed between when flashes with sensors were introduced, and when flashes with sensors that would recycle the unused charge (thyristors) units came out. In an attempt to be brief I lumped those two together. (But there's no excuse for me spelling it wrong!)

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  7. Re the sync speed of the A99, in my tests it unfortunately sync fully only at 1/160th (Elinchrom strobes w/PC and/or Skyport connection).
    It is disappointing to see a company like Sony fudging on the specifications of a $2,800 camera.

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    1. I don't think they fudged on the numbers, I think they need to move the code in the firmware that turns on the switching transistor closer to the routine that fires the accessory flash through the "other wires". (Accessory flashes sync at 1/250th of a second just fine.)

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    2. Thank you for the info on the sync, as I was ready to return my A99. I love the EVF for shooting portraits, I can instantly see the result of each shot instead of wondering if my subject blinked.
      I am now retired and after 40 some years of shooting large format, the A850 was my first digital camera. Wonderful, simple to the point camera, but the brief instant of blindness with the mirror up & down again was always bothering me. Now with the EVF I see exactly what I shot.:)
      Btw, Gary, great blog and great book on the RX100!

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  8. Thanks for a very interesting article.

    One thing - I believe the font size of the article text is too small. The comments text size is fine. Previous blogs of yours are fine. I have checked on the latest versions of Firefox and Chrome.
    Please could you fix as it strains my ageing eyes?
    Many thanks.

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    1. Funny you should mention that... I made the font size smaller because of complaints that the site design looked too amateurish. But you're the third person to complain so back it goes. Can't please everyone.

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  9. I had to shoot a Christmas party at the old folks home with my Alpha 35 and HVL F42 flash. It always works fine at home, checking the camera out, but when I get there... I think this time it was the little contacts on the hot shoe. Either no flash or a white-out. The flash was on a bracket, connected with the Sony sync cord, so I ripped that out, went wireless, and raised the pop-up flash. I finally found a mode of settings that would give me good exposures about a minute before I was needed for the shoot. Went home, cleaned the contacts, and it was OK again. Is there an accessory plate that could be inserted between the shoe and the flash to tighten this connection?
    Gary Eickmeier

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    1. Not that I know of, but then again it sounds like the better solution to your problem is regular cleaning of your contacts. :-) (BTW, good to hear from you again, Gary!)

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  10. Great blog Gary, but can you get Oliver to present the next one as he can obviously sniff out a good flash when he sees one :-)

    Steve.

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  11. I'm glad to see both the flash issues being highlighted, they definitely need to be addressed with firmware. I'm down right angry about only getting 1/200 sync speed even with PC sync.

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  12. Gary--
    When will you have a guide to the Sony Nex F3?
    Susan

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    1. Hi, Susan. I have my hands full with the A99 and then the NEX 5R-6 book I'm collaborating on. The demand for the F3 is so low (I've only had about 15 inquiries for it so far) that I had to make a business decision and say "No ebook on this model". Sorry about that.

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  13. Gary-
    Can we expect a straight-forward,in-depth description of the tethering capability of the A99 in your book? This feature has been driving me up a wall as the Sony product line has progressed. The lengths Sony went to to hide information about A99 tethering is crazy, and the Eye-Fi "feature" song&dance Sony did with the A77 was an insult... I can't believe that no Sony cam has even the level of functionality as a lowly D7000. USB tethering will definitely be my make-or-break factor in the decision to invest at the $$ level of the A99 body, in spite of all the other excellent features and IQ.

    Rick

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    1. Hi, Rick. I haven't had a chance to try this option yet, but I plan to write about it in the book: http://dslrsoftware.com/tethered_shoot_lr4_a99_windows.php You can try it for free to see if it meets your needs while waiting for the book. :-)

      I did try Eye-Fi (the pro version) and although it's an impressive technical achievement, it's not really fast enough to be useful (especially if you're shooting raw).

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    2. Thanks for the reply and info, Gary, but i didn't mention two items that complicate the situation. The first would be that my employer is an Apple junkie, so the PC-based solution doesn't work, and the second (tied partially to the Apple situation) is that we don't use Lightroom. We have Phase1 systems, so all of our RAW processing is done in Capture One.

      During a lengthy chat with a Sony rep online, I was told that the A99 is tetherable only through the Remote Camera Control software included in the Image Data Converter package (The functionality of RCC was completely removed from the A77 firmware according to this same Sony Support rep).

      You are very right about pro Eye-Fi; it's not exactly "pro" when it can't handle RAW transfer at any workable speed.

      That all being said, I would really appreciate as much in-depth discussion of all the features and capabilities of RCC with the A99 that you can include in the book, and will most likely buy it for that information whether I end up buying the A99 or not. Thanks.

      Rick

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    3. I tried RCC and couldn't get it to work on my Windows PC. It might end up being a short write-up. :-)

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  14. Intresting discovery you made on this synch delay issue

    This got me to try out my HVL-F20 with the A77 and A700 and you are right, these don't react with the same delay. I even tried the setup with an HVL-F43 as controller on the A77 and it is also much slower than the built-in flash.
    Shame on Sony for letting this happen even with their top of the line equipment.

    Additional comment on the New (old) hot shoe: I just re-used my strobist equipment recently ( Minolta 4000 and 360PX flashes ) and what a pain these are to bolt-on and remove with these thumb screws that either won't lock-up properly and let some slippage happen while shooting or can't be loosened after use.

    Sony all you had to do for those who like the old shoes is to re-make the Minolta FS-1100 with a PC connector or make the FAHS1AM more affordable ( 160$ Cdn or 130$ USD) is a real joke.

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    1. Your report is interesting--and somewhat inconsistent with mine. Using the F20 as trigger, I get the exact results Gary Friedman reports--none on my a850 and significant on my a77. However, when I use an F43 (or an F58) as the trigger on the a77, the delay seems to be the same as his video shows with the built-in flash used as controller--that is, much shorter than the delay using the F20 as controller, albeit (slightly) longer than when the F20 is used as the controller on the a850 (or when I use my Pixel Kings on the a77--which also have no more delay than the F20 on the a850).

      Tom

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    2. Tom, which wireless flash protocol did you test with? The new one ("CTRL+") or the old one? GF

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  15. Excellent Article! I too love wireless flash and the delay would bother me as well.
    I am currently on the fence about purchasing the Phottix Odin TTL flash triggers for Sony and I'm curious if such a delay would occur when triggering off camera flashes using such a system. I guess at this point it is something to ask those few who've taken the 3rd party TTL radio trigger plunge.
    Thanks for bringing this to our attention.

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    1. TTL Radio triggers only repeat the signals they see coming from the camera, so my guess would be they would exhibit the same delay. (But I don't have easy access to a set to try it for myself.) GF

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    2. I asked someone with Phottix Odin triggers to test this on their A99, it does indeed have the same delay.

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  16. I bet the Odin is so well integrated, that a99 thinks an IR transmitter is installed, thereby engaging wireless option in camera... and thereby sending the Odin the delayed protocols.

    Ensure that camera IR wireless is OFF, and let the Odin do all the work. Camera should think there is one flash on hotshoe, and speed things up accordingly, never knowing the Odin is transmitting duplicate faster protocols to the remotes.

    Don't let camera IR and Odin RF protocols interfere with each other. It's worth a try.

    Good review and discussion on Odin here at Dyxum.
    http://www.dyxum.com/dforum/topic94530_post1121645.html#1121645

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  17. On my A77 the Odin has the same delay as on camera TTL using a 56am, what flash where they using??

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  18. I'm glad to find that the slight lag I noted with my new A77/56AM wireless combo is not a product of my recently turning 60. I can live with the small delay so long as it eliminates the annoying contribution of the onboard flash to the exposure so common with my A700 when doing close work. I can now abandon my McGyver-rigged onboard flash filter (2 strips of exposed 35mm film in a split transulcent film canister) and focus on my subject.

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  19. Gary … you forgot to mention Denver … when is the seminar in Denver? :-) You know - the "heartland" - centrally located and easy to get to from anywhere, especially Sedalia. LOL
    Happy New Year,
    Mike

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    1. It was last July, Mike... :-( Get with it!

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  20. Hi Gary.
    Have you any plans to bring your seminars to the UK in the near future.

    Happy near Bruce

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    1. Hi, Bruce. We were just there last September! Plan to return in 2014. Watch this space for more news... GF

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  21. Do Canon/Nikon have similar sorts of problems - which seem pretty big things - flash overexposure on the A77, and so on? I've never looked before, because I've been with Sony/KM/Minolta, since my wonderful 700si (pretty close to 20 years, now).

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  22. Do you have any books gary? i really wish to buy. Enjoyed reading and watching all of your reviews. Thumbs Up!!

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    1. I've written a couple... www.FriedmanArchives.com/ebooks

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