compatibility of ring flashes

[mathbias]

The online descriptions of cheap ring flashes tend to list compatibility with the hot shoe in my Sony a7 iii, but tend not to list their brightness nor recharge time. Expensive ones tend to list compatibility with many cameras but don't mention Sony (and do highlight brightness and recharge time).

How standard is the physical and electrical interface of the hot shoe?

The pictures of the hot shoe contacts, across camera brands, make them appear to be physically compatible, but I haven't found a clear statement of that, and I have no clue about electrically compatible.

I will be buying a ring flash, probably a cheap one (under $100). But I'd like to understand better before making my guess.

 

[NS: Nikon Shooter]

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Hot shoes are not hot shoes … no real standard.

You are right to give importance to compatibility and others. That's
why buying at your local shop makes more sense than online.

 

[ac12]

Ring flash in a hot shoe?
Is it a flash or an LED light?

The only thing close to standard in a hot shoe is the center contact, to fire the flash.
And even that is not standard, as some companies move that contact.

 

[mathbias]

Ring flash in a hot shoe?

All the ring flashes I saw online have the battery holder mounted on the hot shoe and a wire from that battery holder to the ring, which is mounted on the filter threading at the end of the lens. I didn't look at enough models to know if they are all that way.

So the hot shoe controls firing the flash: either control electronics in the battery holder reacts to the hot shoe control and pulses power to the ring, or the battery holder passes through the hot shoe signal plus continuous access to power to control electronics in the ring. I would expect the former, but it doesn't really matter (maybe only a generalist engineer like me would even think about those two possible designs).

I still haven't found a single one that both tells you anything about its brightness and tells you that it is compatible with the Sony a7 iii's hot shoe.

 

[Lez325]

Buy Cheap buy twice- I shoot Sony a9 and 2 x Sony a7Riv's and bought an online ring flash last year - very cheap and cheap results- Invest in the best you can budget for is my advice

here is the one I eventually bought : Its a Nissin

Nissin MF18 Macro Flash - Sony Fit | Wex Photo Video

www.wexphotovideo.com

I get images like these using the above unit

Good hunting


Les

 

[mathbias]

Can you tell me what specifically was wrong with the cheap one you bought, and which one it was?

I don't think I'm going to jump to 6x the cost anyway, but especially not without understanding more first.

One (under $70) I looked at online has manufacturer documentation that says guide number 21 without saying feet or meters. One online seller says 21 feet. Another for the same item says 69 feet (21 meters). More concerning, the user manual says the flash duration is 1/2 second. I hope that's a typo, but don't know how to find out. 1/2 second isn't a flash at all, it's just a light. Aside from that, it has the Sony compatibility and both the 55mm and 62mm adapter rings I need.

 

[mathbias]

I made a fairly random guess and bought one (I can return it if I quickly determine it was a big error). I tried very hard to research the question and failed, then guessed.

I am confused over just about every aspect of it. The instructions were written using English words, but by someone who clearly speaks no English, so every aspect can be learned only by blind experimentation. That is complicated by the poor documentation of the Sony a7 iii, so I don't know what its flash choices actually mean.

I bought an MK-14EXT (guide number 14 meters)

I don't know whether there is some more complicated aspect of hot shoe compatibility. It feels like it attaches securely and it flashes at apparently the right time. I don't know whether some further information transfer between the two is supposed to occur and is missing due to compatibility issues.
The web page and product packaging say this flash is just for Nikon. But the spec page in the manual (which I didn't know pre purchase) says: Canon, Nikon, Pentax,Olympus, Samsung, needs a hotshoe adapter for sony. I assume they mean older Sony models.

I was trying to do initial experiments at 2 meters, F2.8, 1/200, ISO 100 with no other light source. But discovered afterward that my Sony had switched to ISO 12800 (I'm not sure why, but I'll learn). With the flash set to its lowest power 1/128, the images were too bright but not entirely washed out.

I want to switch to rechargeable AA's before I do a ton of experiments. I'd like to find the limit on camera speed (faster than 1/200) for which the flash sync is effective. I need to rediscover (found earlier but can't find again) how the F number goes into the formula for using that 14 guide number. I want to figure out how the various flash modes of the Sony (that I don't really understand) interact with the various flash modes of the MK-14EXT (for which I have near zero clue).

 

[Braineack]

I will be buying a ring flash, probably a cheap one (under $100). But I'd like to understand better before making my guess.

Are you buying it for portrait photography?

(please say no)

 

[mathbias]

Are you buying it for portrait photography?

(please say no)

I'm glad to say no.

I'm pretty ignorant on the topic. But even so, I think I understand good reasons why it would be a terrible choice for portrait photography.

My hope was to fill two objectives with one reasonably priced device (don't yet know whether it will fill either):

Macro: Usually the camera and/or photographer block the light needed for the photo. I thought a ring light had the best chance to not be in my own way.

Plant pictures: The background is a constant problem, depth of focus is only a partial solution. I hope a flash will help in suppressing the background.

I hope my camera is also decent for wildlife photos and vacation panoramas. But I don't think I would be using any flash for those photos. I'll let someone else take all the photos of people.

 

[petrochemist]

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Hot shoes are not hot shoes … no real standard.

You are right to give importance to compatibility and others. That's
why buying at your local shop makes more sense than online.

The International organisation for standards would disagree with you their latest version of the official standard is ISO518:2006

The vast majority of hot shoes share the dimensions of this standard, it's only the more advanced features like TTL (& flash ready indication) that require extra pins & non standard communications. Older flash units can have high trigger voltages that will damage modern cameras, but all will work on the original mechanically switched hot shoes, isolating adapters are available for those who want to use older flashes without damaging their modern cameras.

The exception to this it Minolta & early Sony cameras that did have a hot shoe incompatible with everyone else, but they've since learnt their lesson (or I wouldn't have any Sony cameras)

I think both my ring flashes (old ones) just use basic hot shoe triggering, (shorting the centre pin to the edge). I've ended up getting a LED ring light so I can see to focus, so haven't used a ring flash for over 5 years

 

[ac12]

One thing to watch out for with ring lights is the FLAT lighting.
Because the light is even, all around the lens, some macro shots will look BAD.
This is because you don't have any shadows, so you may not be able to see surface texture.
Just block off one side of the ring light, so the light comes from one side, and you should have some shadows.

 

[mathbias]

Most of the ones I looked at online, including the one I selected, let you set a ratio between the two sides, including the choice of one side being off entirely or being 1/2, 1/4 or 1/8 the power of the other side. Since the instructions are so bad, I am not 100% clear on how that really works (in combination with other features). But I expect it will be plenty for me to add some shadows to macro shots.

 

[petrochemist]

Most of the ones I looked at online, including the one I selected, let you set a ratio between the two sides, including the choice of one side being off entirely or being 1/2, 1/4 or 1/8 the power of the other side. Since the instructions are so bad, I am not 100% clear on how that really works (in combination with other features). But I expect it will be plenty for me to add some shadows to macro shots.

I think the one I used in the late 80's lacked this feature, but even so simply adding a bit of gel (or tracing paper...) over part of the ring restores a degree of modelling. Any photographer worthy of the name should be able to come up with at least half a dozen options for blocking part of the light.
Blocking all the light from one side will create severe shadows that will look every bit as bad as flat light.

 

[mathbias]

Any photographer worthy of the name

I don't want to misrepresent things. I'm not a photographer worthy of the name. I likely never will be. I'm just a guy trying to take some semi-competent photographs.

should be able to come up with at least half a dozen options for blocking part of the light.

That would not be hard if I needed to.

Blocking all the light from one side will create severe shadows that will look every bit as bad as flat light.

Most of my experience has been trying to limit the severe shadows from direct light. I don't expect to ever enter photos in any contests. For my own use, I don't think the flaw of flat light is anywhere near as bad as severe shadows.
This is the first time I've had a ring flash. Having a decent macro lens is also quite new for me. So I'll need to experiment to find out what photos look like with balanced vs. unbalanced use of the ring flash.

I still haven't figured out the best way to support the camera pointing straight down for controlled experiments with macro. I recently got a sturdier tripod, nodal slide and a couple versions of L bracket, and might figure out a better approach than just tipping the ball of the tripod all the way down (which is both unbalanced and difficult to further adjust).

 

[mrca]

I had an alien bee ring light. I didn't use it for on camera shooting as the flat light isnt my style. By no means is it a one trick pony. It could be used as on camera fill or off camera flash with it's soft box or an umbrella but it won't pop 10 times a second like all my einsteins so sold it.