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06-14-2020, 03:42 AM   #1
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Minolta, Pentax and Olympus Dedication the same?

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I've been looking at flash units on Ebay and notice that a Vivitar 550FD (for example) claims dedication to Minolta, Pentax and Olympus : Vivitar 550 FD flashgun dedicated to Minolta, Pentax and Olympus. | eBay

It is no idle boast. Pictures of the back of these things show engraved "M/P/O" and there is no switch that needs setting for the brand.

I do realise that this is a film era unit and I don't expect TTL to work on a Pentax DSLR (except an ist), but at least I'd expect the viewfinder to show flash ready and flash OK signals. But our own reviewers Vivitar 550FD M/P/O reviews - Pentax Camera Accessory Review Database don't agree that the TTL works at all : for example "The flash works fine in auto-thyristor mode, but it doesn't have any TTL capability on a Pentax camera".

I'm looking to buy a cheap unit but TBH not this particular one. But I'm interested in this because it seems to tell us that I can widen my search to any film era Minolta or Olympus dedicated unit, as well as Pentax. Is that true?

Incidentally, I find it very frustrating that many Ebay sellers and even some of our own reviews (including of this unit) do not show the pin layout on the hot shoe. It can tell us a lot about the unit. Many, no most, ads do not show the back of the unit or even give the Guide Number, and I have to work it out by looking at the photo of the slide rule on the back, if there is a picture of it, and sharp enough to read the figures. BTW, the Vivitar 550FD does not have a GN of 550(!) or even 55 in either meters or feet; in fact it is a piffling 24.



06-14-2020, 04:36 AM - 1 Like   #2
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The camera dedication means that the shutter speed will be set to X (1/60, 1/125, whatever) and the aperture will be set according to guide number and ISO. The camera should be in program mode - no idea if auto ISO will play well. TTL word only work on film and *istD cameras.


Using two or three of these in a strobist setup could be fun, but you will also need slave triggers, stands, umbrellas etc. for all that. Using just one mounted on the hotshoe could yield a mixed bag of flash cliches: wrong exposures, low contrast, red eyes, the lot. Your mileage may vary of course. At least it can do bounce flash and a GN of 24 isn't too bad.

Any Pentax body from the K-x onward is pretty good as high ISO. The KP and K1 are stellar in low light, or so I hear. When it comes to a choice between noise and messing around with a flash, I dial in ISO 3200 and do some post processing. But that is just me.
06-14-2020, 05:10 AM   #3
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QuoteOriginally posted by Wasp Quote
Any Pentax body from the K-x onward is pretty good as high ISO. The KP and K1 are stellar in low light, or so I hear. When it comes to a choice between noise and messing around with a flash, I dial in ISO 3200 and do some post processing. But that is just me.
I don't use flash much and, like you, I often just go for higher ISO at least for functional picures. Another interest of mine is working on cars, and I post pictures on a car forum which have been taken under the car or in gloomy conditions, and I don't use flash because it stops me getting the camera into confined places, and even with a pop-up flash on the camera you get hard shadows which are not good for seeing technical detail - soft lighting is best.

However for indoor portraiture, flash adds a sparkle, even though the flash is not technically necessary these days. Moreover I always use bounce flash which in larger rooms needs to be more powerful. I do have a AF280T but I fancy something more powerful, perhaps on a remote tripod.

The question remains, does a Minolta or Olympus dedicated flash of the film era have the same electronic interface to the camera that a Pentax dedicated flash has? In a way I am really only interested in the flash having its own sensor/thyristor control, and giving a flash ready indication - I'm quite capable of setting the camera shutter speed and aperture myself. I just don't want the flash unit to fry my camera electronics. I could probably remove pins from the flash unit shoe if necessary, just leaving the trigger and "flash ready" pins, and I'd be happy.
06-14-2020, 08:37 AM   #4
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QuoteOriginally posted by Lord Lucan Quote
The question remains, does a Minolta or Olympus dedicated flash of the film era have the same electronic interface to the camera that a Pentax dedicated flash has? I just don't want the flash unit to fry my camera electronics. I could probably remove pins from the flash unit shoe if necessary, just leaving the trigger and "flash ready" pins, and I'd be happy.
35mm film era TTL Pentax, Minolta, and Olympus hot shoe pin locations were all different. Older film era flash units used higher voltages than modern units, and I would not recommend mixing a film era flash with a digital camera unless you've got the testing equipment to measure short voltage burst outputs. The risk to your camera is not worth the reward.

Because of their popularity and price, I used Vivitar flash units for years until I learned the hard way, you get what you pay for. I slightly upgraded to Sunpak after that, but after too many problems, only use Pentax units if I need weather sealing, Metz if I don't, or Godox or Yongnuo for cheaper alternatives that won't harm my camera.

Also note, the least reliable camera gear IMExperience are flash units. 6 volts filling a capacitor up to 300 volts and then releasing the Kraken is a small lightning in a box. Buying used flash units takes a lot of faith and the only thing that had the Vivitar name on it that I trust was called Series One.

06-14-2020, 09:32 AM   #5
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QuoteOriginally posted by Alex645 Quote
35mm film era TTL Pentax, Minolta, and Olympus hot shoe pin locations were all different.
I'll confirm that the pin locations are different, at least between Pentax and Minolta. The TTL Minolta cables I have will not carry the TTL and Dedication signals when used on Pentax bodies with a Pentax TTL flash. And the Minolta Maxxums started using a proprietary flash shoe although there are adapters available..
06-14-2020, 11:35 AM - 1 Like   #6
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QuoteOriginally posted by Lord Lucan Quote
But our own reviewers don't agree that the TTL works at all
This is because no matter how many times you say that 1980s-era TTL and p-TTL are completely different technologies, people still confuse them. Pentax DSLRs later than the ist-DS simply do not support the older TTL method to tell the flash when to shut off. So the flash fires at full power, and the camera does whatever it does, and auto-exposure and auto-ISO introduce so many variables that it might appear to work.

I am not where I can get to my collection of Vivitar flashes, but I think I recall something like seven pins on the bottom of the M/P/O models. As Alex645 says, each brand had their own dedicated pin locations, and the Vivitar 550FD addressed this by having ALL of the pins for all of the supported brands. If Vivitar could have stuffed the pins for Canon, Nikon, and Ricoh in there without conflict, they would have made only one version of the flash, instead of two (M/P/O and C/N/R).

Edit: There are three versions of the 550FD - M/P/O, C/R, and N. Some of the other, non-TTL Vivitar flashes of the period only had M/P/O and C/N/R versions.

QuoteOriginally posted by Lord Lucan Quote
The question remains, does a Minolta or Olympus dedicated flash of the film era have the same electronic interface to the camera that a Pentax dedicated flash has? I
The answer is NO. Because each brand has their own "Flash Ready" pin, and that is the ONLY interface from the flash to the camera, a dedicated Minolta or Olympus flash is not going to send a ready signal to a Pentax. However, if the flash has a self-contained auto-mode, where the flash (not, Not, NOT the camera!) determines how much light it sees and shuts off automatically, then the center/FIRE pin on the hotshoe may be sufficient. You would have to ensure that the flash is ready before attempting to take a shot. That said, I have no idea if a dedicated Minolta or Olympus (or Canon or Nikon, for that matter) flash from this era would put signals on any other pins that might confuse a modern Pentax DSLR. The usual warnings about trigger voltages apply - I have never had problems with the 550FD/2800-D family, but the 2800 (different from 2800-D) is notorious for high trigger voltages.

But I will say it again: with this style of "dedicated" "automatic" flash, the flash is NOT changing the settings on the camera. You can move the sliders on the back of the 550FD until your fingers bleed, but the flash does not communicate anything to the camera other than "ready" - and how the camera reacts to that "ready" signal depends on the camera. The sliders on the flash are just a table of settings for you to manually change on the camera to get a usable exposure. The flash then provides what it thinks is the appropriate amount of light.

Last edited by THoog; 06-21-2020 at 07:24 PM.
06-14-2020, 12:15 PM   #7
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My experience with older flashes (Pentax, Canon, and Nikon) is that the only legacy flashes that feature full interaction (minus TTL) with Pentax DSLRs are Pentax flashes like the AF280T. I have a third party flash (Sunpak D444) that has a dedicated pentax mount. If you use flash, the camera will switch the shutter speed to flash sync speed (usually 1/180 sec) and the flash indicator will light up in the viewfinder when the flash is ready, but no other interaction works.

QuoteOriginally posted by Lord Lucan Quote
BTW, the Vivitar 550FD does not have a GN of 550(!) or even 55 in either meters or feet; in fact it is a piffling 24.
Even the guide number is not enough. You also have to know the FOV coverage of the flash. Most of the older flashes are fixed focal flash (often 35mm on FF). Since they can't focus, and hence intensify, their flashes to cover narrower FOV, they have lower GNs. But that doesn't necessarily mean they emit significantly less light or are less powerful.

06-14-2020, 12:29 PM   #8
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QuoteOriginally posted by Alex645 Quote
35mm film era TTL Pentax, Minolta, and Olympus hot shoe pin locations were all different
QuoteOriginally posted by Not a Number Quote
I'll confirm that the pin locations are different, at least between Pentax and Minolta.
So I wonder how Vivitar could have claimed their unit was compatible with all three, TTL and all, with no selector switch? I thought it sounded too good to be true. I do have an old Jessops 300 TTL flash unit, (slight downgrade from Vivitar!) which I have not used for years but which I reviewed here Jessop 300 TTL reviews - Pentax Camera Accessory Review Database . It has a slide switch to select between Pentax, Nikon and Minolta, so presumably they must have different interfaces.
QuoteOriginally posted by Alex645 Quote
I used Vivitar flash units for years .... I slightly upgraded to Sunpak after that,
I understand that Sunpak made the Pentax flashes under contract around the 1980s (eg the AF280T). That's why AFAIK you could not around that time get a Sunpak-branded flash that was Pentax-dedicated, the terms of the contract forbade it. I do have an AF280T and I'm not impressed by the build quality despite the price. But notice the remarkable similarity of the Sunpak 422D of the same era (pictured below) - no co-incidence I think.

I'm well aware of the voltage issue, but it is as well to keep warning people. My father left a nasty little Sunpak unit (GN 18) that resembled this Vivitar 252 Vivitar 252 reviews - Pentax Camera Accessory Review Database. I measured its voltage as about 350v. I put it in a scrap bin rather than risk someone in the future unwittingly ruining a DSLR with it (or electrocuting themselves?), and rather than getting maybe £0.99 for it on Ebay.




Last edited by Lord Lucan; 06-14-2020 at 12:33 PM. Reason: Tpyo
06-14-2020, 12:40 PM   #9
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QuoteOriginally posted by THoog Quote
the Vivitar 550FD addressed this by having ALL of the pins for all of the supported brands.
QuoteOriginally posted by Lord Lucan Quote
So I wonder how Vivitar could have claimed their unit was compatible with all three, TTL and all, with no selector switch? ]
@THoog says the 550FD has all pins and must sense where there is circuit, which brand of camera is being used. Clever and if correct, then you wouldn't have to cut pins off. Again my only concern is high voltage which may or may not be an issue here.
06-14-2020, 01:03 PM   #10
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QuoteOriginally posted by Lord Lucan Quote
It is no idle boast. Pictures of the back of these things show engraved "M/P/O" and there is no switch that needs setting for the brand.
This is true. I have a similar Vivitar 40D flash from that era offering dedication for Sigma Sears, Canon, Nikon, and Ricoh. That said, dedication was extremely limited on my unit and extended to setting sync speed and flash ready in/at viewfinder. It did not provide TTL or auto setting of aperture and such. It has a pin layout that addresses the patterns found on all four brands. Mine satisfies the Ricoh layout with two of the five pins.

The Vivitar 550 FD (three different variants) is more comprehensive and does support TTL on supporting models as it existed at that time. For Pentax that meant analog TTL protocol* using three pins as on the AF280T: X-sync, mode, and ready. Quench is signaled through the mode contact.


Steve

* Supported initially on the Super Program and LX with continued support up through the *istD series of digital cameras.

Last edited by stevebrot; 06-14-2020 at 02:24 PM.
06-14-2020, 01:28 PM   #11
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QuoteOriginally posted by Alex645 Quote
@THoog says the 550FD has all pins and must sense where there is circuit, which brand of camera is being used. Clever and if correct, then you wouldn't have to cut pins off. Again my only concern is high voltage which may or may not be an issue here.
The key might be that the M/P/O variant probably was limited to support of protocols that were essentially similar on cameras having similar contact patterns. The Minolta shoe was very similar to Pentax and the OM-2 shoe unique from either. I suspect that the pins were energized or read as if any of the three supported camera types were attached.


Steve

Last edited by stevebrot; 06-14-2020 at 01:34 PM.
06-14-2020, 01:44 PM   #12
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QuoteOriginally posted by stevebrot Quote
I have a similar Vivitar 40D flash from that era offering dedication for Sigma, Canon, Nikon, and Ricoh
Are you sure that's Sigma and not Sears? I researched all this stuff back in 2014 when I wrote my reviews for the 2800-D and 550FD, and want to say Sears, but don't remember (or really care) any more. I do remember seeing C/N/R and C/N/R/S versions of some Vivitar flashes.
06-14-2020, 02:19 PM   #13
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QuoteOriginally posted by THoog Quote
Are you sure that's Sigma and not Sears? I researched all this stuff back in 2014 when I wrote my reviews for the 2800-D and 550FD, and want to say Sears, but don't remember (or really care) any more. I do remember seeing C/N/R and C/N/R/S versions of some Vivitar flashes.
Good question. Sigma sold a Ricoh XR7 clone at the time, that is why I figured it was Sigma. (Mine is labeled S/C/N/R.)

Edit: I found the manual (thank you Mike Butkus) and it does indeed stand for Sears.


Steve
06-14-2020, 02:46 PM   #14
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Ok, some quick hand-held macro shots of the flash shoes of my Minolta X-700 and Pentax Program Plus. Magnification was the same for both shots so the dimensions should be the same taking into account the sensor plane may not have been exactly parallel with the object's plane.

Program Plus

X-700


Program Plus overlayed on X-700


As you can see the pin spacing is different.
06-14-2020, 05:55 PM   #15
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QuoteOriginally posted by Not a Number Quote
Ok, some quick hand-held macro shots of the flash shoes of my Minolta X-700 and Pentax Program Plus. Magnification was the same for both shots so the dimensions should be the same taking into account the sensor plane may not have been exactly parallel with the object's plane.

Program Plus

X-700


Program Plus overlayed on X-700


As you can see the pin spacing is different.
I found a view of the foot on an eBay listing and there are seven contacts:
  • Two for Pentax
  • Two for Minolta
  • Two for Olympus OM-2n, OM-1n
  • Sync


Steve

Last edited by stevebrot; 06-14-2020 at 06:16 PM.
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