[yozza]

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

Has anybody here use this flash before? I am looking at it for my K1000. Is it good and does it have auto Thyristor?

Thanks

[stevebrot]

The df 383 is a TTL flash and was made to support several different systems. It does not feature flash-based "Auto" (auto thyristor).


Steve

[climbmountainway]

A good choice would be the Vivitar 283, or the 285 flash, with available accessories. Yes auto and auto thyristor, with sensor on the flash, not TTL, the ideal unit for the era camera mentioned.

[Lord Lucan]

Has anybody here use this flash before? I am looking at it for my K1000. Is it good and does it have auto Thyristor?

Thanks

A K1000 and a Vivitar DF-383 sound like a serious technical mis-match. The K1000 cannot use the DF-383's best features, and the DF-383 will expect the K1000 to have features it does not possess. The combination will be usable but crippled.

You would be better with a flash unit of the K1000's own era, one that has both an Auto mode (flash has its own sensor) and a manual mode. Good ones can be found cheap as chips on Ebay.

[Dale H. Cook]

A good choice would be the Vivitar 283, or the 285 flash, with available accessories. Yes auto and auto thyristor, with sensor on the flash, not TTL, the ideal unit for the era camera mentioned.

Be aware that a lot of Vivitar 283 and 285 flashes sold on eBay and elsewhere are missing the thyristor module.

[yozza]

A good choice would be the Vivitar 283, or the 285 flash, with available accessories. Yes auto and auto thyristor, with sensor on the flash, not TTL, the ideal unit for the era camera mentioned.

Thanks

---------- Post added 03-31-21 at 05:52 PM ----------

Be aware that a lot of Vivitar 283 and 285 flashes sold on eBay and elsewhere are missing the thyristor module.

I see ones advertised there for the 285 as zoom thyristor? Is that different

[Not a Number]

The sensor module is the round knob on the front. If it is missing or removed there will be a socket. All the current US listings I just checked have the module.

[yozza]

The sensor module is the round knob on the front. If it is missing or removed there will be a socket. All the current US listings I just checked have the module.

Ok so that’s good. I just need to see what zoom thyristor means, versus auto thyristor to be ok. Thanks

[Not a Number]

Just to clarify thyristor is the circuitry that shunts the unused power back to the flash capacitor instead of dumping it. This increases the number of shots per battery and shortens recycle time. The module on the 283 and 285 is actually the light sensor and not the actual thyristor circuit which is inside the flash body. Without the sensor in place the flash fires always at full power.

The major difference between the 283 and 285 is that the 285 has a built-in "zoom" head to change the field of coverage of the flash - narrow for telephoto, wider for wide angle lenses. On the 283 you have to buy a separate lens/filter adapter and variable angle lens kit. Both the 283 and 285 have thyristor circuits.

From the 285 manual:

[Lord Lucan]

The major difference between the 283 and 285 is that the 285 has a built-in "zoom" head

Is there not also a difference that in manual mode the 285 allows several power levels while the 283 only allows full power? - unless you buy an extra module for it *. Having to buy and swap modules for a function I'd expect to be built-in seems a bit weird to me but perhaps reflects how old the design was. The similar but rival Sunpak 383 Super does it better IMHO, and it has a safe voltage.

Beware of putting a Vivitar 283 on a modern camera, the earlier ones have a high trigger voltage which could damage it (but a K1000 would not be affected) and it is a lottery as to which version you get. The Vivitar 285HV is safe I understand, but not the plain 285 without the "HV" (which does not seem to mean "high voltage", quite the opposite!)

* One on Ebay now for £20, more than the units themselves usually sell for. Vivitar VP-1 Varipower Module - For Vivitar 283 Flashgun - Clean & Tested | eBay

[Dale H. Cook]

I would note, as I have often noted here and elsewhere, that I own a few Vivitar 283s which I use only in manual mode. I modify them to put 5 VDC on the shoe and for 12 manually selected flash durations. This is something that only a highly experienced electronic technician should try, as there is still about 300 VDC inside the case. I do not do this for others because at my shop labor rate you could probably buy a new flash for less than I would have to charge.

[Not a Number]

The Vivitar 285HV is safe I understand, but not the plain 285 without the "HV" (which does not seem to mean "high voltage", quite the opposite!)

Most of the "plain" 285s are safe. The one I bought in the 80s measures out at the voltage of the batteries I put in it. The 285HV and 283 accepts a High Voltage battery pack HVP-1 (510v battery) that by-passes the voltage step-up circuitry to give faster recycle times. It would be curious to measure the trigger voltage on when using the HV power supply. The 285 can use the Low Voltage Battery Pack (LVP-2) which uses D cell batteries..

Youtu.be

Youtu.be

Seems like we've had this discussion of sorts before
Old external flashes safe to use on K-S2? - Page 2 - PentaxForums.com

[Lord Lucan]

So the "HV" of some 285s mean they can be used with a high voltage battery pack; that solves something that had been puzzling me. And although only those particular 285s could be used with the HV battery pack, all 283s could - a bit surprising as the 285s otherwise had more features.

It would be curious to measure the trigger voltage on when using the HV power supply.

As those instructions say that you must still have the four AAs in the unit to operate the sync circuit, even when a HV supply is plugged in, I would imagine it makes no difference. I think I would still check though.

[Dale H. Cook]

Seems like we've had this discussion of sorts before

We have had variants of this discussion in a number of threads, but they usually concern DSLR users who want to use a vintage flash - this one is from the opposite direction. I use modified 283s with my K-70 as external flashes. At 2,900 BCPS they are powerful enough for my purposes.

[yozza]

Just to clarify thyristor is the circuitry that shunts the unused power back to the flash capacitor instead of dumping it. This increases the number of shots per battery and shortens recycle time. The module on the 283 and 285 is actually the light sensor and not the actual thyristor circuit which is inside the flash body. Without the sensor in place the flash fires always at full power.

The major difference between the 283 and 285 is that the 285 has a built-in "zoom" head to change the field of coverage of the flash - narrow for telephoto, wider for wide angle lenses. On the 283 you have to buy a separate lens/filter adapter and variable angle lens kit. Both the 283 and 285 have thyristor circuits.

From the 285 manual:

Thankyou very helpful!

---------- Post added 04-01-21 at 07:33 PM ----------

Is there not also a difference that in manual mode the 285 allows several power levels while the 283 only allows full power? - unless you buy an extra module for it *. Having to buy and swap modules for a function I'd expect to be built-in seems a bit weird to me but perhaps reflects how old the design was. The similar but rival Sunpak 383 Super does it better IMHO, and it has a safe voltage.

Beware of putting a Vivitar 283 on a modern camera, the earlier ones have a high trigger voltage which could damage it (but a K1000 would not be affected) and it is a lottery as to which version you get. The Vivitar 285HV is safe I understand, but not the plain 285 without the "HV" (which does not seem to mean "high voltage", quite the opposite!)

Thankyou very helpful

* One on Ebay now for £20, more than the units themselves usually sell for. Vivitar VP-1 Varipower Module - For Vivitar 283 Flashgun - Clean & Tested | eBay

Thanks very helpful