# Flash for 80D, Canon or...?



## SuzukiGS750EZ (Nov 5, 2016)

Hey guys. I'm looking to buy my first flash and learn flash photography. The on board flash leaves much to be desired. I have a few questions. Are there different powered flashes for different situations, or is it more of buying a high powered flash and bringing back the power to the amount of flash you need? Also, are canon flashes best used on canon cameras or are there other flash manufacturers out there that work with canon but provide a better flash?


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## kalgra (Nov 5, 2016)

Yes you can dial back the power on a more powerful flash they are usually just larger and may have more features, faster recycle times, etc. I might suggest getting one of the Yongnuo Canon knock offs. They work just like Canon have pretty much all the same features you will ever want and cost a fraction of the price. I personally like the YN600EX-RT but that is probably over kill if you just want to start out. I do preffer the RT models though they work really well with the Yongnuo Transceivers. You could buy two Yongnuo flashes and a set of triggers for less than a Single Canon flash.


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## kalgra (Nov 5, 2016)

I will add that I have both Canon and Yongnuo flashes which are completely compatible with one another. The Canons are made better and will probably be more durable and reliable in the long run but when you can buy 3 Yongnuos for the price of one Canon who cares.


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## TCampbell (Nov 5, 2016)

Flash is a great way to up-level your photography.  While a flash system can be expensive, the decent starting system will typically cost less than just one decent lens.  The ability to create good lighting can do SO MUCH for an image (money spent to create good lighting will be much more impactful and noticeable that money to get a good lens.)

A few things about flash.

Canon makes a series of flashes that use their "E-TTL" (or E-TTL II) flash system.   The model numbers of these flashes are an indicator of how far you can expect to get adequate lighting from the Canon flash.  

In Canon's system, if you drop the final "0" from the model number (e.g. if it's a 270EX II flash then you drop the 0 to get "27".  If it's a 600EX-RT then you drop the final "0" to get "60") and that number (e.g. "60") is the "guide number" for the flash as measured in METERS.  So a Canon 600EX-RT flash has a guide number of 60 meters.

What's a guide number?

A flash can burst for some maximum out of light output.  Also, the flash has a reflector so that the light fires forward (rather than just a bulb with light traveling in all directions).  Depending on the shape of the reflector and the power of the light will both combine to indicate how far away that light can adequately illuminate a subject.

So the "guide number" system helps you determine how far that is.  But there's a problem.  They don't know what exposure settings you plan to use.  You can change the ISO or you can change the lens aperture and that will affect how much light is required to make the exposure.  So how much is "adequate" to make a good exposure depends on you settings.    SO... the industry picked a baseline value.  

That baseline is f/1.0 and ISO 100.  

So if the flash claims to have a "guide number" of 60 meters, it means that it can provide enough light to make an adequate exposure for a subject 60 meters away from the flash (about 197 feet).  

Now that sounds really impressive... but remember that assumes you have an f/1.0 lens... which of course you do not have (Canon hasn't made one of those in many many years) and even if you owned such a lens, you'd probably be shooting at a higher f-stop.    

But the reason for using f/1.0 as the baseline is because it makes the math really really easy.  All you do is divide the guide number (e.g. 60 meters) by the f-stop you ACTUALLY plan to use for the exposure.    So if we plan to use f/8, then it's 60 meters divided by 8 or  60 ÷ 8 = 7.5 (meters).   That works out to 24.6 (about 25').  

Suddenly that powerful flash that can light up a subject nearly 200' away is only lighting up a subject 25' away when a reasonable f-stop is used.  Of course you can bump up the ISO and increase the coverage distance.... but that's the idea behind the guide number.   BTW, all this assumes the flash fires at "full power" and the flash doesn't have to fire at full power (you can cut it to 1/2 power, 1/4 power, 1/8 power, etc.)

That's the basic idea behind comparing flash power for speed lite flashes (studio strobes are different and typically use watt/seconds instead of guide numbers.)

It gets a bit more complicated because lighting is often modified to soften the look (shadow to highlight transitions are gradual and gentle -- rather than abrupt line with a well-defined transition point).  That might involve shooting through a diffusion screen to broaden the light source (such as using a soft-box or a shoot-through umbrella), or bouncing the light off a ceiling.    The reason this is more complicated is because that light modifier is going to "eat" some of your light.  It's not unusual for the fabric in the softbox or shoot-through umbrella to "eat" a stop of light (or more).  This means you usually have to test your modifier to find out how it affects your shot.  If I'm bouncing off a ceiling then not only do I have to consider that the light is traveling farther before it reaches my subject, the ceiling is also a "scattering surface" (meaning light that strikes it does not bounce off the ceiling as if it were a mirror... (like a billiard ball hitting a bumper and bouncing in away opposite the angle from which it arrived) but will "scatter" in all directions (it would be more like the billiard ball exploded into millions of miniature billiard balls and when in every direction.)

Now suddenly the flash is seeming even less powerful and you're getting a bit confused as to just how a photographer would even know what settings to use for flash photography.  (knowing what to use without having to guess is really just based on doing some tests so you know your flash... when "manually" controlling the flash.)

While a lot of photographers do prefer to manually control their flashes (and for years that's all we had), "smart" flash systems have evolved over the years and are fairly good today.  The current Canon system is E-TTL II.

This system uses a computer to determine how much power should be needed to capture a shot.  It works by taking a "pre flash" (think of that as a test shot) except the shutter is closed on the camera when it does this.  The pre-flash fires at a specific known amount of power.  The camera "meters" the dark (no flash) scene, fires the flash at a known power level and meters the same scene again with the flash.  It calculates the difference between how the scene metered with no flash vs. the pre-flash and uses that to determine how much ACTUAL power should be used for the shot.  The camera then opens the shutter and takes the flash exposure.  This all happens SO FAST that you'd swear the light only flashed once.  The camera & flash are working together to set appropriate power level for the flash.

Canon's flashes aren't cheap.  

Probably the most common flash for an 80D is the Canon 430EX III-RT (guide number of 43 meters).  It's a very good, solid, reliable flash.  About $250.
The flagship flash of Canon's line is the 600EX II-RT (the RT suffix designates that it can be radio controlled).  It's about $530.  
I have a pair of 600EX-RT's (the originals, not the "II") and Canon's on-camera trigger/controller which they call the ST-E3-RT.

The radio system advantage is that off-camera flashes can be hidden behind objects and do not require "line of sight" to trigger the off-camera flashes (there are optical systems which are cheaper but they require "line of sight" and there are many situations in which this can be a challenge.)

There are 3rd party flashes which are MUCH cheaper (sub $100) and you can build a system with them.  Some of them have some level of Canon E-TTL compatibility (sometimes it's only partial compatibility and not all features of E-TTL may be implemented.)

To learn more about the Canon system, I highly recommend you pick up a copy of Syl Arena's book "Speedliter's Handbook".

You can learn a great deal about flash technology in general by following the "Strobist" blog at strobist.blogspot.com


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## kalgra (Nov 5, 2016)

Really good information and even better explanation. Thanks for sharing @TCampbell


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## SuzukiGS750EZ (Nov 5, 2016)

Thank you so much TCampbell, reading all of that made sense of the research i already read and confused myself 0n. Guide numbers make A LOT more sense now and envisioning the light/light loss makes more sense. I had been looking at the 430 EXIIIRT actually, but i didn't want to purchase before asking. I think i will go with canon flashes since i now fully understand TTL as well, which makes sense as to why when using onboard flash the flash would send out a flicker of light before shooting.


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## OGsPhotography (Nov 19, 2016)

Good informative thread! TC !!!

I love my YN 560s, they are manual but I dont mind doing a few test shots every shoot.


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## Drive-By-Shooter (Dec 23, 2016)

the low price attracted me to a yongnuo.  local saleswoman said they don't last.  she was right, it did not last 6 months.  fortunately b&h took it back anyhow.  never had any failure from nikon or, years ago, vivitar, metz or braun.


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## goooner (Dec 23, 2016)

Great info TC. I have a 430 EX II, but it does not work as a slave (can't trigger it with light). I used the yungnuo triggers with it and it worked well. After changing to Nikon I got a SB800 quite cheap from Ebay, and it works very well. Got a cheap METZ which also works very well, and both can be triggered on different channels using my on camera flash. I got both flashes for less than $150.

So check ebay or used flashes at your local camera shop.


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