topic Re: Newer Rebel T7 hot shoe center ping in EOS DSLR & Mirrorless Cameras

Newer Rebel T7 hot shoe center pin

DedTreeJig — Sat, 01 Oct 2022 19:46:21 GMT

I just purchased a Rebel T7. I know the original version did not have the center pin on the hot shoe, however mine does have the center pin. Does anyone know if the center pin is active? Would I be able to use a third-party flash with the camera?

Re: Newer Rebel T7 hot shoe center ping

normadel — Sat, 01 Oct 2022 17:24:40 GMT

Where did you get your info?

A flash shoe without the center pin can't be a hot shoe. The center pin is the "hot" pin. Without it a flash can't be fired. So YES, your center pin is active and live.

You can use a third-party flash meant for Canons, though Canon doesn't recommend it. You can even use a manual flash from the pre-digital days, if it has a trigger voltage no higher than 6 volts. There are varying opinions on how high a trigger voltage is dangerous for the camera, but 6 volts is safe.

Re: Newer Rebel T7 hot shoe center ping

DedTreeJig — Sat, 01 Oct 2022 17:27:09 GMT

Thanks for the information, I really appreciate it.

Re: Newer Rebel T7 hot shoe center ping

jrhoffman75 — Sat, 01 Oct 2022 19:39:45 GMT

For clarity, do you have a T7 or a T7i? I haven't seen any info that Canon made a running change to the T7 and added the center pin.

Even without the center pin the shoe is "hot" since it is powered with signal level voltage, but it will only fire Canon flashes. A "cold shoe" is a flash shoe that will hold a flash unit but there is no signal to it.

Re: Newer Rebel T7 hot shoe center pin

Lotus7 — Sat, 01 Oct 2022 19:48:42 GMT

"A flash shoe without the center pin can't be a hot shoe. The center pin is the "hot" pin. Without it a flash can't be fired."

In fact, many Canon and Sony cameras have Hot Shoes that do not include the center pin. Starting in May 2019, Canon began selling many models using the new 4-contact only hot shoe with NO center pin. Sony did the same even earlier. The new 4-pin hot shoe was/is compatible only with certain Canon-brand flashes.

Apparently, because of the backlash created by elimination of the center pin Canon has re-introduced the center pin contact on some, but not all cameras. There are 3rd party adapters available that allow use of most "traditional" flash units with the "center-pinless" hot shoes, although it's still not advisable to use a flash with a high trigger contact voltage.

Re: Newer Rebel T7 hot shoe center ping

normadel — Sat, 01 Oct 2022 20:45:43 GMT

So the function of a center pin was moved to one of the other four little pins? What Canon flashes can utilize this center-pin-less camera shoe?

The whole idea sounds strange. Why would Canon do this?

Re: Newer Rebel T7 hot shoe center ping

jrhoffman75 — Sat, 01 Oct 2022 20:53:26 GMT

Re: Newer Rebel T7 hot shoe center ping

Lotus7 — Sat, 01 Oct 2022 21:09:24 GMT

"Why would Canon do this?" Probably for exactly the same reason that Canon will not release electronic connectivity data for the RF Lens system to other lens manufacturers. Have you checked the prices of current Canon flash units recently? 🙂

While changes in connectivity standards may bring increased functionality, they also can bring exclusivity and elimination of competition (at least for a while). As always, elimination of competition will almost always bring elevated profits.

Re: Newer Rebel T7 hot shoe center ping

Bellmac — Sat, 07 Jan 2023 20:31:38 GMT

I just purchased a refurbished T7 directly from Canon USA and it has a 5 metal contacts on the shoe, including the large flash trigger contact.

I am trying to get some documentation from Canon on maximum allowable voltage and/or current for flashes. I have a couple of older Vivitar flash units. On my Vivitar 6000AF macro flash (attaches to front of lens), the voltage is a maximum of 6VDC. On my Vivitar 2800, the voltage is 45VDC. I am much more interested in being able to use the 6000AC unit as it has 5 pins and is supposed to provide TTL flash control using camera settings. The 2800 only has a single trigger contact and is a more basic unit, but does provide some automatic flash control.

I only used a multimeter to measure DC voltage. A more thorough test would be to put it on a scope and see if there are any fast voltage and/or current spikes that the multimeter would not see. Sometimes the spikes can do the damage.

I have not found any easy way to contact Canon technical support for some answers. Any ideas would be appreciated.

I see there is a widely sold hot shoe electronic protector, but there is almost no real information available on the device. It is a bit clunky to be stacking devices on the hot shoe and this device seems pretty over-priced and reviews seem mixed.

Re: Newer Rebel T7 hot shoe center ping

MikeSowsun — Sat, 07 Jan 2023 20:56:21 GMT

Modern Canon EOS cameras are safe for up to 250v.

Your T7 has E-TTL and will not work with older film era TTL flash units like the Vivitar 6000.

The Vivitar 2800 is an older ”Thyristor” Auto flash with the light meter sensor on the front. It will work with your T7 but you will have to set the camera to Manual mode and then match the aperture and ISO to the Auto range selected on the flash.

Re: Newer Rebel T7 hot shoe center ping

Bellmac — Sat, 07 Jan 2023 21:28:23 GMT

Thanks for the quick answer Mike. I am not surprised the TTL system in the Vivatar 6000 macro flash might not provide automatic control with the T7. But where do you get the 250 volt number, which is often cited (6 volts used to be the cited value). I cannot find any documentation from Canon. Do you have an authoritative source?

Assuming 250 volts is the rating, what about peaks and current? Any sense of the voltage and current peaks from older flash units. I have some 120VAC studio flashes that I have not even considered yet.

Re: Newer Rebel T7 hot shoe center ping

kvbarkley — Sat, 07 Jan 2023 21:30:48 GMT

250 is the standoff voltage. When the shoe activates it shorts it, so no over voltage. The contacts are designed to handle the current.

Re: Newer Rebel T7 hot shoe center pin

MikeSowsun — Sat, 07 Jan 2023 22:49:07 GMT

Canon redesigned the hot shoe circuitry somewhere around 2004 to make it safe up to 250v.

Here is a reference for you: https://digitaljournalist.org/issue0703/tech-tips.html

Canon cameras that have a PC sync port have this warning in the user manual:

Re: Newer Rebel T7 hot shoe center pin

Bellmac — Sun, 08 Jan 2023 00:46:13 GMT

Really appreciate the effort, but honestly the 2007 reference creates more questions than it answers. It basically says that all EOS Rebel models (which would include my T7/2000D/1500D/KissX90 model) are good for only 6V. Although I appreciate Canon's desire not to disclose proprietary information, to me this kind of information should fall within the category of "product specification". Unfortunately neither the user manual nor published specification for the product provide any information, limitations, or warnings on use of third-party flash units other than the possibility of something other than an Ex Speedlite not working. It says nothing about damage to the camera.

So, as I just said, the 2007 article clearly says that all "EOS Rebel Series" cameras are good for only 6 volts. Am I reading this incorrectly?

Re: Newer Rebel T7 hot shoe center pin

MikeSowsun — Sun, 08 Jan 2023 14:05:16 GMT

Yes, you are reading it incorrectly.

Rebel series Digital SLR cameras (350D, 400D, etc) are good to 250v. Only the 300D and “EOS Rebel Series” FILM SLR cameras were 6v.

Re: Newer Rebel T7 hot shoe center pin

Bellmac — Sun, 08 Jan 2023 14:41:26 GMT

@MikeSowsun wrote:
Yes, you are reading it incorrectly.
You really have to decrypt that listing to figure out what is what. The heading covers both 35mm and digital cameras and I made the assumption that "EOS Rebel Series" included digital cameras. I suspect that others have done the same, which is where the 6 volt limitation came from for the newer DSLR's. Thanks again. So, I think if feel reasonably comfortable trying my old flash units (even if they may not provide maximum functionality). I was mostly interested in being able to try the 6000AF macro flash.