how does the SPIIa:

someonenameddavid · 04-16-2016, 09:20 AM

Work with dedicated flash, and which flash....

Ancient minds wish to know

David

**pathdoc** · 04-16-2016, 09:36 AM

Looking around the web, it seems there was a particular Honeywell flash called the Strobonar which had a particular hookup to this model of Spotmatic II. The effect was similar to that of a thyristor flash such as the AF200Sa, but with the sensor on the camera rather than the flash body.

The instruction manual is available here for a fee via paypal....

Die Cast Pro - Download Pentax Spotmatic IIa Operating Manual

...and here for free.

Pentax Manuals

Ontarian50 · 04-16-2016, 09:44 AM

Does anyone know how rare a model the SP IIa is?

I'm only asking because of the dozens and dozens of Spotmatics that have passed through my hands over the years, not one has been an SP IIa.

It is possible they were only sold in the US, and weren't available up here in Canada anyway? That said, I do see the occasional "Honeywell" branded camera from time to time.

LesDMess · 04-16-2016, 10:02 AM

In the Pentax Forums Pentax Spotmatic IIa review it states, "The Spotmatic IIa adds a flash sensor and dedicated coupling for a Honeywell flash. Having the flash sensor in the camera allowed for easy flash photography also with the flash hand held at a distance from the camera." However, it is not a form of TTL flash so it is a curious concept and I wonder how it works.

Looks like you need the awesome looking Honeywell strobe but likely any manual flash capable strobe would work.

**pathdoc** · 04-16-2016, 10:23 AM

Originally posted by LesDMess

However, it is not a form of TTL flash so it is a curious concept and I wonder how it works.

As I stated above, it's like a thyristor flash but with the thyristor sensor on the camera body and (I suppose) with extra circuitry on what might loosely be called the X-sync bus, to enable the sensor to cut the flash off at the appropriate instant. This theoretically goes one better than having the thyristor sensor on the flash, because you can put the flash anywhere within its brightness and angle coverage and the exposure will still be correct at the camera.

If you try this with a normal flash-mounted regulating thyristor sensor (and I have), quite often you will NOT get a fully exposed picture because the flash is working on the assumption that it is mounted on the camera, roughly equidistant from the film/sensor plane, when all too often it is not.

LesDMess · 04-16-2016, 11:29 AM

Originally posted by pathdoc

If you try this with a normal flash-mounted regulating thyristor sensor (and I have), quite often you will NOT get a fully exposed picture because the flash is working on the assumption that it is mounted on the camera, roughly equidistant from the film/sensor plane, when all too often it is not.

That makes perfect sense for an off the camera - particularly remotely located, flash. Personally I had been using flash meters and manual flash. Now I am using DIY high powered LEDs as continuous light source and it is has it's advantages - like no flash sync limitations.

Ontarian50 · 04-16-2016, 01:46 PM

It does seem like Honeywell wanted to leverage the partnership with Pentax and their own U.S-made flash equipment. I recall seeing the ads in back issues of old camera magazines (I would have been a young kid at the time and not playing with expensive cameras).

However, it really wasn't necessary to put the external sensor "eye" right into a dedicated camera body. Putting the sensor on a hot-shoe mounted module worked just as well for many other manufacturers of handle-mount flashes (Vivitar, Sunpak, Metz, etc.)

So, was it a really short-lived innovation, and the SP IIa disappeared quickly?

**pathdoc** · 04-16-2016, 01:56 PM

IIRC there were and are (for still existing units) issues with light leaks around the sensor. In addition, a specialised body with its added manufacturing expenses probably proved not worth the costs.

**gofour3** · 04-16-2016, 08:05 PM

Originally posted by Ontarian50

It does seem like Honeywell wanted to leverage the partnership with Pentax and their own U.S-made flash equipment

The other negative (besides defacing the camera body) was that Honeywell did not import any Pentax flash models from that period, so for example you could not get the Autorobo flash in the USA.

Phil.

**Baard-Einar** · 04-17-2016, 01:43 AM

Originally posted by gofour3

The other negative (besides defacing the camera body) was that Honeywell did not import any Pentax flash models from that period, so for example you could not get the Autorobo flash in the USA.

Phil.

So thats why the Autorobo flash seems so difficult to find?

**gofour3** · 04-17-2016, 10:27 AM

Originally posted by Baard-Einar

So thats why the Autorobo flash seems so difficult to find?

Yep could be, though I have seen a few here in Vancouver for sale. (I've got three now)

The Autorobo was included in the Canadian price lists from the period.

Phil.

**Baard-Einar** · 04-17-2016, 10:55 PM

Originally posted by gofour3

Yep could be, though I have seen a few here in Vancouver for sale. (I've got three now)

The Autorobo was included in the Canadian price lists from the period.

Phil.

You're lucky. Pentax did not have many flash models at all back in those days. I hope a Autorobo comes my way at some point.

Cheers, baard-einar

**gofour3** · 04-18-2016, 06:49 AM

Originally posted by Baard-Einar

I hope a Autorobo comes my way at some point.

I don't really need three of them, so if you are interested in buying one PM me.

Phil.

04-16-2016, 09:20 AM	#1
someonenameddavid New Member Join Date: Apr 2016 Posts: 5	how does the SPIIa: Work with dedicated flash, and which flash.... Ancient minds wish to know David

04-16-2016, 11:29 AM	#6
LesDMess Pentaxian Join Date: May 2011 Location: Santa Cruz, CA Photos: Albums Posts: 3,089	Originally posted by pathdoc If you try this with a normal flash-mounted regulating thyristor sensor (and I have), quite often you will NOT get a fully exposed picture because the flash is working on the assumption that it is mounted on the camera, roughly equidistant from the film/sensor plane, when all too often it is not. That makes perfect sense for an off the camera - particularly remotely located, flash. Personally I had been using flash meters and manual flash. Now I am using DIY high powered LEDs as continuous light source and it is has it's advantages - like no flash sync limitations. Last edited by LesDMess; 04-16-2016 at 11:37 AM.

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04-16-2016, 09:36 AM	#2
pathdoc Loyal Site Supporter Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Looking around the web, it seems there was a particular Honeywell flash called the Strobonar which had a particular hookup to this model of Spotmatic II. The effect was similar to that of a thyristor flash such as the AF200Sa, but with the sensor on the camera rather than the flash body. The instruction manual is available here for a fee via paypal.... Die Cast Pro - Download Pentax Spotmatic IIa Operating Manual ...and here for free. Pentax Manuals

04-16-2016, 09:44 AM	#3
Ontarian50 Veteran Member Join Date: Mar 2015 Posts: 530	Does anyone know how rare a model the SP IIa is? I'm only asking because of the dozens and dozens of Spotmatics that have passed through my hands over the years, not one has been an SP IIa. It is possible they were only sold in the US, and weren't available up here in Canada anyway? That said, I do see the occasional "Honeywell" branded camera from time to time.

04-16-2016, 10:02 AM	#4
LesDMess Pentaxian Join Date: May 2011 Location: Santa Cruz, CA Photos: Albums Posts: 3,089	In the Pentax Forums Pentax Spotmatic IIa review it states, "The Spotmatic IIa adds a flash sensor and dedicated coupling for a Honeywell flash. Having the flash sensor in the camera allowed for easy flash photography also with the flash hand held at a distance from the camera." However, it is not a form of TTL flash so it is a curious concept and I wonder how it works. Looks like you need the awesome looking Honeywell strobe but likely any manual flash capable strobe would work.

04-16-2016, 10:23 AM	#5
pathdoc Loyal Site Supporter Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Originally posted by LesDMess However, it is not a form of TTL flash so it is a curious concept and I wonder how it works. As I stated above, it's like a thyristor flash but with the thyristor sensor on the camera body and (I suppose) with extra circuitry on what might loosely be called the X-sync bus, to enable the sensor to cut the flash off at the appropriate instant. This theoretically goes one better than having the thyristor sensor on the flash, because you can put the flash anywhere within its brightness and angle coverage and the exposure will still be correct at the camera. If you try this with a normal flash-mounted regulating thyristor sensor (and I have), quite often you will NOT get a fully exposed picture because the flash is working on the assumption that it is mounted on the camera, roughly equidistant from the film/sensor plane, when all too often it is not.

04-16-2016, 01:46 PM	#7
Ontarian50 Veteran Member Join Date: Mar 2015 Posts: 530	It does seem like Honeywell wanted to leverage the partnership with Pentax and their own U.S-made flash equipment. I recall seeing the ads in back issues of old camera magazines (I would have been a young kid at the time and not playing with expensive cameras). However, it really wasn't necessary to put the external sensor "eye" right into a dedicated camera body. Putting the sensor on a hot-shoe mounted module worked just as well for many other manufacturers of handle-mount flashes (Vivitar, Sunpak, Metz, etc.) So, was it a really short-lived innovation, and the SP IIa disappeared quickly?

04-16-2016, 01:56 PM	#8
pathdoc Loyal Site Supporter Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	IIRC there were and are (for still existing units) issues with light leaks around the sensor. In addition, a specialised body with its added manufacturing expenses probably proved not worth the costs.

04-16-2016, 08:05 PM	#9
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 7,772	Originally posted by Ontarian50 It does seem like Honeywell wanted to leverage the partnership with Pentax and their own U.S-made flash equipment The other negative (besides defacing the camera body) was that Honeywell did not import any Pentax flash models from that period, so for example you could not get the Autorobo flash in the USA. Phil.

04-17-2016, 01:43 AM	#10
Baard-Einar Site Supporter Join Date: Jan 2010 Location: Oslo Photos: Gallery Posts: 944	Originally posted by gofour3 The other negative (besides defacing the camera body) was that Honeywell did not import any Pentax flash models from that period, so for example you could not get the Autorobo flash in the USA. Phil. So thats why the Autorobo flash seems so difficult to find?

04-17-2016, 10:27 AM	#11
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 7,772	Originally posted by Baard-Einar So thats why the Autorobo flash seems so difficult to find? Yep could be, though I have seen a few here in Vancouver for sale. (I've got three now) The Autorobo was included in the Canadian price lists from the period. Phil.

04-17-2016, 10:55 PM	#12
Baard-Einar Site Supporter Join Date: Jan 2010 Location: Oslo Photos: Gallery Posts: 944	Originally posted by gofour3 Yep could be, though I have seen a few here in Vancouver for sale. (I've got three now) The Autorobo was included in the Canadian price lists from the period. Phil. You're lucky. Pentax did not have many flash models at all back in those days. I hope a Autorobo comes my way at some point. Cheers, baard-einar

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04-18-2016, 06:49 AM	#13
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 7,772	Originally posted by Baard-Einar I hope a Autorobo comes my way at some point. I don't really need three of them, so if you are interested in buying one PM me. Phil.