Can I use the Vivitar zoom thyristor 3500 flash with my Nikon d3100?

SOURCE: May I use a Soligor 24D Flash on my new Nikon D40X Digital Camera

You can purchase an off-camera flash sync adaptor at any good camera store, complete with extension cable.   The should work fine.

SOURCE: Can I use my old auto thyristor 550FD on my new Nikon D90 DSLR

Not directly. Get an adapter like the Wein Safe-Sync or a new flash.

SOURCE: how to use vivitar zoom thyristor 285 with nikon

DO NOT ATTEMPT TO USE THIS FLASH ON THE CAMERA OR TEHTER BY WIRE. THe voltage will destroy at least the built-in flash function of your camera. either use a radio slave, an optical slave or you can use it on camera if you use a WEIN safe-synch (approx. $70 USD). If you do not have the users guide for the flash, it can be GOOGLED. Search for "VIVITAR 285 users guide"

SOURCE: Can I safely use a

Yes. The trigger voltage of the Canon 199a, rated by Canon at 6.0V, is low enough to be safe with new digital cameras.

SOURCE: I have a Nikon D3100

That lens will work with the D3100, except for the autofocusing. In order to autofocus with the D3100, you need AF-S lenses, such as the AF-S VR Zoom-NIKKOR 70-300mm f/4.5-5.6G IF-ED or the
AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR.

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