External flash with Instax?

I have a pair of Nissin i60a flashes for Fuji, but they have two slave modes. I was thinking I could put a diffuser or reverse bounce card over the flash in my TL70+ to trigger them. The question really comes down to asking if anyone has some guidelines on external flash with instax film?

At least with my camera I have fully manual control. Want to give some of this a try when family comes over in the next few weeks. Need to order more film too.

I don't have a definitive answer. It would depend on whether the TL70 does "preflashes" to meter the light from the flash and determine the flash level to use for the exposure. These preflashes can falsely trigger slave mode flashes too early. But some cameras with automatic flash work by metering during the flash itself and cutting off the flash duration earlier to lower the flash power. If that technique is used, it should work with your slave flashes.

Back in the day, I'd test flash setups with Polaroid instant film....wait, you have an instant film camera! I'd just do some experimenting!

Good idea to repurpose those flashes as slaves. I did something similar:

hsandler said:

I don't have a definitive answer. It would depend on whether the TL70 does "preflashes" to meter the light from the flash and determine the flash level to use for the exposure. These preflashes can falsely trigger slave mode flashes too early. But some cameras with automatic flash work by metering during the flash itself and cutting off the flash duration earlier to lower the flash power. If that technique is used, it should work with your slave flashes.

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A film camera would inherently not utilize a preflash...the preflash was necessitated by the digital sensor TTL flash redesign, which now requires a preflash to meter the returning light before the shutter opens, so that the camera can measure the light (but NOT metering off the shiny surface of the digital sensor) and send a command to the flash unit for an appropriate amount of light immediately before the shutter opens.
Any film camera utilizing TTL would not command a preflash (nor any film camera depending upon photosensor Auto flash), and any flash unit originally designed for film TTL would not have the capability of responding to a commanded preflash, it would merely flash full power until commanded to interrupt light output by a film TTL body. The TL70 would not command a preflash, of course, its sync terminals merely fire a flash at full power; its flash is likely (its literature makes no claims) not under 'TTL' control but more likely uses an Auto mode photosensor to control output.

In the case of using a digital camera TTL flash unit like the Nissin i60a in slave mode, it likely would work suitably. The i60a, per the user documentation, ...

• supports slave flash both for digital camera wireless (both optical and radio, in 'Sd' setting)
• and for film (optical trigger) with the 'Sf' setting,
  both Sd and Sf mode seem to require manual setting of fractional power output, not control automatically by photosensor control of power
• and 'wireless' setting is for the wireless radio Master-slave capability, which emerged after film TTL.

One should be able to test the i60a by putting it into Sf mode, then using a separate flash (triggered via the test button) to see if it fires the i60a

I had not considered preflash, and I've only taken one extremely poorly exposed flash picture from the internal flash. This testing kind of got sidelined, everyone has been on a rolling flu and rsv round so we never got together. Only so much $1+ a shot I'm willing to waste in testing on my dog. I'll get to it, but need to brush up on my manual flash by guide number, been a very long time since I've used flash this way.

wiltw said:

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Any film camera utilizing TTL would not command a preflash (nor any film camera depending upon photosensor Auto flash), and any flash unit originally designed for film TTL would not have the capability of responding to a commanded preflash, it would merely flash full power until commanded to interrupt light output by a film TTL body. The TL70 would not command a preflash, of course, its sync terminals merely fire a flash at full power; its flash is likely (its literature makes no claims) not under 'TTL' control but more likely uses an Auto mode photosensor to control output.

Click to expand...

While what you said is true almost all the time with film camera and the TL70+ is likely to have a sensor in front of the camera to control the flash and does not have preflash. However, the Nikon F5 when in TTL mode and the metering system is set in matrix mode and the lens supplies distance information (D type lens) and with a Nikon compatible flash it would do a preflash.

Did some reading, and remembering. This flash is GN60 at 200mm zoom setting, which is not needed for the lens in the TL70+. At 50mm setting I see GN of 39. Plug into a calc and get 13.4 meters at iso800 and f8 at full power. Need to build a chart down through the power settings. Also a wrinkle is that I intend to use a flash mounted 8x12 inch Westcott Pocketbox softbox, going to have to experiment to figure out exposure with this, (no flash meter).

I’ve been doing a bit of studio portraiture with Bowens Gemini studio strobes, and Instax works best for me in that scenario at ISO640. The dynamic range is awful compared to negative film, but very handy to consider setups and ratios, if you stubbornly refuse to bring yer DSLR, as I do

Marc

I often use an old Braun 370 or 420 BVC flash. These are computer controlled and adapt automatically https://www.oddcameras.com/braun_370_bvc.htm. There is a control light if the flash light was sufficient, So you can test your setup first without shooting a photo. For the 380 you need a slave cell (synchro eye), the 420 has one built into the flash and there is a little switch near the cable socket to put it in slave mode. Worked for me in most situations without metering or calculations.

Many years ago all I had money for was a 283 and I knew and practiced this stuff with 35mm and 645, but that was a very long time ago.