Flash Advice

[RbnDave]

Here is another newbie question. What is the difference between the Canon 550EX and the 420EX? I've looked at the product descriptions of both over on amazon and the only difference I see is the 550EX can work as a master flash. Am i missing anything? I don't ever plan on more than one flash or any sort of master slave setup. Is the 420EX all I will need?

Thanks

Dave

[robertwgross]

If you are sure that you won't use more than one flash, then the 420EX might be the best choice. Otherwise, the Master/Slave stuff can be handy.

The 550EX has a bigger guide number (brighter flash = longer effective flash range).

The 550EX is physically larger and weighs more.

The 550EX has a pull-down diffuser panel that spreads the light wider, if you want.

The 550EX allows you to set fractional light strengths, like 1/2, 1/4, 1/8, ...

There are other advanced features as well.

You didn't mention what camera this is for, so it is hard to cover this completely.

---Bob Gross---

[scottbergerphoto]

At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. That's a difference of 13 Meters or about 40 Feet. That also translates into a greater ability to do bounce flash off walls and ceilings.
The 550EX can also be shot in Manual Mode, the 420EX cannot.
As already mentioned, the 550 can serve as the master of a wireless ETTL array.
The 420EX is a great flash. The 550 just gives you more flexibility and power.
Scott

[Vegas Poboy]

The info from everyone above is correct but here is my little 2 cents to add. The 550 is a fully adjustable flash, the 420 is auto only. The only way to make any adjustments with the 420 is to use the flash compensation within the camera itself and that will adjust 2 stops either way. If you plan on being creative with flash I highly recommend purchasing the 550. I have both, purchasing the 550 last and if I had to do it again I would purchase two 550 instead of the 420.
hopefully this helps
Poboy

[RichardtheSane]

Vegas Poboy wrote:
The only way to make any adjustments with the 420 is to use the flash compensation within the camera itself
I guess that is kinda unlucky if you have an DRebel then.

[cowman345]

Can you trigger the 550ex and a 420ex off camera with the onboard flash on a 10D, for instance? or must the 550ex be mounted on the camera directly for it to serve as a master to the 420ex? It seems kind of limiting to mandate frontal fill flash in order to use it as a master. I know you can buy an infared master for around 200 bucks, but is there any way around this?

-dave-

[Malaxos1]

RichardtheSane wrote:
Vegas Poboy wrote:
The only way to make any adjustments with the 420 is to use the flash compensation within the camera itself
I guess that is kinda unlucky if you have an DRebel then.


if it's for the Rebel then I would get the 550EX. I bought the 420 EX for my Digital Rebel and it's great, the only problem is that I cannot adjust the flash out put. The problem with thw D Rebel and 420EX combo is that neither the camera or flash have flash compensation. Therefore you take what you get when it comes to flash intensity...Dean

[robertwgross]

scottbergerphoto wrote:
At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. That's a difference of 13 Meters or about 40 Feet. That also translates into a greater ability to do bounce flash off walls and ceilings.


Scott, do you want to re-think that?

55 or 42 are the guide numbers. Divide the guide number by the aperture to get meters. Your numbers are good only if you use an f/1.0 lens aperture.

---Bob Gross---

[scottbergerphoto]

cowman345 wrote:
Can you trigger the 550ex and a 420ex off camera with the onboard flash on a 10D, for instance? or must the 550ex be mounted on the camera directly for it to serve as a master to the 420ex? It seems kind of limiting to mandate frontal fill flash in order to use it as a master. I know you can buy an infared master for around 200 bucks, but is there any way around this?

-dave-

The communication between the 550Ex and the 420Ex in wireless mode is not done as a typical slave/master. The 550 uses a series of light pulses to tell the 420 when and how much to fire. It is all controlled by the camera. You can move the 550 off the hot shoe with a Canon "Off the Camera Shoe Cord 2". That way you maintain the wireless ETTL between the 550 and 420. The on camera flash will not fire the 550 unless you put it in Manual Flash Mode and attach a slave. You would then have to do the same to the 420, but you have no ability to control its output (max each time). To use the 550/420 combination off the camera without the 550 corded, I believe you need the infrared transmitter(STE2).
Scott

[robertwgross]

cowman345 wrote:
Can you trigger the 550ex and a 420ex off camera with the onboard flash on a 10D, for instance? or must the 550ex be mounted on the camera directly for it to serve as a master to the 420ex? It seems kind of limiting to mandate frontal fill flash in order to use it as a master. I know you can buy an infared master for around 200 bucks, but is there any way around this?

-dave-


I mount my 550EX on a flash bracket and connect to the hot shoe via proper cable. In that case, the 550EX is neither master nor slave.

In the next case, I do the same thing to mount the 550EX, but I flip it to Master. Then I have the 420EX sitting out several feet the other direction set for Slave.

In the last case, I mount the STE2 transmitter on the camera, so it is the Master. Then I set up the 550EX to be one slave to the left and the 420EX to be one slave to the right.

Those, in general, are your options. I don't fool around with generic optical slave triggers.

---Bob Gross---

[CanonUser]

There is a misconception that 550 & 420 represent flash range in meter. Actually, it's range in Feet Unit times 10.

Regards,
Alan

[scottbergerphoto]

robertwgross wrote:
scottbergerphoto wrote:
At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. That's a difference of 13 Meters or about 40 Feet. That also translates into a greater ability to do bounce flash off walls and ceilings.


Scott, do you want to re-think that?

55 or 42 are the guide numbers. Divide the guide number by the aperture to get meters. Your numbers are good only if you use an f/1.0 lens aperture.

---Bob Gross---

No I don't Bob.
I was using the Canon provided Guide Numbers as a reference. Feel free to check your Flash or Camera Manual for the flash specifications. They are in fact expressed in Meters or Feet at ISO 100. Yes I am aware that Distance = GN/f stop. I didn't think it was necessary to spell it out for each f stop. If you read my posts in the following link, you'll see that I already went into detail how to calculate effective distance for a given Guide Number. It's about half way down the page you were just looking at.
http://www.photography-on-the.net/forum/showthread.php?t=21430
Scott

[scottbergerphoto]

canonuser wrote:
There is a misconception that 550 & 420 represent flash range in meter. Actually, it's range in Feet Unit times 10.

Regards,
Alan
Sorry Alan, your incorrect. The Guide Number of the 550 EX in Meters at ISO 100 is 55 and that of the 420EX in Meters is 42. As a reference, consider that the 10D's on camera flash has a Guide Number of 13 Meters or 43 Feet. Why would some one spend over $300 for the 550EX just to get a Guide Number of 55 Feet, just 12 feet more then the on camera flash?
You can refer to http://photonotes.org/articles/eos-flash/ Part 1, page 22. "550 is the maximum guide number-output of the flash in meters-multiplied by 10 to make it sound cooler".
Scott

[robertwgross]

scottbergerphoto wrote:
At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. That's a difference of 13 Meters or about 40 Feet.

Well, I'll help you re-think this statement.

It is just wrong.

You can add clarifications of what you really meant or what you wrote elsewhere, but this statement is just wrong.

---Bob Gross---

[scottbergerphoto]

robertwgross wrote:
scottbergerphoto wrote:
At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. That's a difference of 13 Meters or about 40 Feet.

Well, I'll help you re-think this statement.

It is just wrong.

You can add clarifications of what you really meant or what you wrote elsewhere, but this statement is just wrong.

---Bob Gross---

Bob,
Let me quote two experts instead of getting into a pissing match with you. In "Mastering Flash Photography" by Susan McCartney, Page 14, "The standard manufacturers' GN rating, listed in all flash manuals, measures the power and range of a flash, in feet(or meters), used in combination with ISO 100 film"
or
how about " Electronic Flash Information" by Toomas Tamm, "The distance and the aperture value for proper exposure are connected by this formula: subject distance * f stop value = constant =GN. This constant is called the Guide Number (GN for short). Since f-stop values have no units attached, the guide numbers are expressed in units of length (feet in the U.S., meters elsewhere)."
End of story,
Scott

[robertwgross]

Scott, I agree with the experts.

I do not agree with your earlier statements. Some of us knew what you meant to say, but you didn't state it correctly to be foolproof.

---Bob Gross---

[scottbergerphoto]

robertwgross wrote:
but you didn't state it correctly to be foolproof.

---Bob Gross---
You give yourself away Bob. As I have said before, you troll in the backgroud waiting to pounce when you think you've caught someone in an error or misstatement. Get a life!
Glad I'm not you,
Scott

[robertwgross]

Scott, I figured out how you can make your advice workable.

Your original statement:
"At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. "

Change to read:
"At ISO 100, the 550EX can go 55 meters divided by the aperture number, and the 420EX can go 42 meters divided by the aperture number."

So, Scott, I am sorry that you made the misstatement. I don't like to see wrong advice going out in this forum. Some of us knew what you were trying to say, and that is why I gave you a chance to straighten it out.

Instead, you went defensive. Wow.

---Bob Gross---

[PacAce]

robertwgross wrote:
Scott, I figured out how you can make your advice workable.

Your original statement:
"At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. "

Change to read:
"At ISO 100, the 550EX can go 55 meters divided by the aperture number, and the 420EX can go 42 meters divided by the aperture number."

So, Scott, I am sorry that you made the misstatement. I don't like to see wrong advice going out in this forum. Some of us knew what you were trying to say, and that is why I gave you a chance to straighten it out.

Instead, you went defensive. Wow.

---Bob Gross---

I must agree with Bob in this case. Scott, your statement was completely misleading, especially when given to someone who may not know that the aperture being used will make a big difference in the actual "mileage" you get out of the GN number of 55 or 42.

[robertwgross]

PacAce wrote:
I must agree with Bob in this case. Scott, your statement was completely misleading, especially when given to someone who may not know that the aperture being used will make a big difference in the actual "mileage" you get out of the GN number of 55 or 42.


Maybe not completely misleading, but just not an accurate explanation to the original poster. Agreed, some of us kind of knew what Scott meant, but we were not the readers that the clarification was intended for.

---Bob Gross---

[scottbergerphoto]

PacAce wrote:
robertwgross wrote:
Scott, I figured out how you can make your advice workable.

Your original statement:
"At Iso 100 the 550 can go 55 meters the 420 can go 42 meters. "

Change to read:
"At ISO 100, the 550EX can go 55 meters divided by the aperture number, and the 420EX can go 42 meters divided by the aperture number."

So, Scott, I am sorry that you made the misstatement. I don't like to see wrong advice going out in this forum. Some of us knew what you were trying to say, and that is why I gave you a chance to straighten it out.

Instead, you went defensive. Wow.

---Bob Gross---

I must agree with Bob in this case. Scott, your statement was completely misleading, especially when given to someone who may not know that the aperture being used will make a big difference in the actual "mileage" you get out of the GN number of 55 or 42.

Sorry PaceAce, I disagree, but I appeciate the non deprecatory tone of your post (listening Bob?). My intent was to demonstrate for the questioner how to use the Guide Number to compare the maximum power of two flashes, not how to calculate an effective maximum distance for a given f stop. I believe I did that.
There should always be room for disagreement in this kind of public forum. What I find as unacceptable, is the condescending, self congratulatory comments in the guise of information, offered by some.
Scott

[scottbergerphoto]

robertwgross wrote:

The 550EX has a bigger guide number (brighter flash = longer effective flash range).

---Bob Gross---
If I was you Bob, I would point out that this statement is just as misleading, because you don't state that the effective flash distance is longer for the same f stop.
At f/4 the 550Ex has almost the same effective distance as the 420 at f/2.8(the 420 would actually go a few feet further). But we don't say that do we? No, because it is understood when talking about Guide Numbers.
Scott

[Belmondo]

I don't have a dog in this fight, so it doesn't matter much to me which of you is the most correct.

In defense of both of you, I feel obliged to say that the user's manual for my 550EX is the most intimidating piece of literature in my library. The 10D manual is bad enough, but I still have at least a reasonable handle on 90% or more of it because to a large extent, it makes sense.

Flash? No way. It's not science.....it's black art. There are no equations, really. There are magic incantations and spells that make it all work. I hope to learn it someday, but for now, my most effective techniques are to cross my fingers and pray.

[RbnDave]

Thanks for the advice guys. I came home from the bar last night and checked this thread before I went to bed. Man had it ever grown.

I should have been more specific with my first post. I will be using the flash on my 10D.

After reading all your posts, I think I will wait untill I can afford the 550EX to buy a flash.

Dave

[samdring]

Get a life Scott
Bob's wit may, occasionally be ascerbic, bit his wit is ALWAYS wit

[Belmondo]

If Bob's wit was wit only half the time, what would that make Bob?

One of life's imponderables.:D :D :D :D :D, etc. etc.

Tom

[Scottes]

scottbergerphoto wrote:
The 550EX can also be shot in Manual Mode, the 420EX cannot.

I don't understand this statement. I shoot the 420EX on my 10D in manual mode all the time. Setting 1/60 f/5.6 90mm across the room and the picture is perfect. Granted, setting 1/200 f/11 is was a bit dark, so 1/125 f/8 worked much better. But they were all manual.

With any of those setting the exposure level indicator showed that the picture was going to be grossly underexposed, they weren't.

[scottbergerphoto]

scottes wrote:
scottbergerphoto wrote:
The 550EX can also be shot in Manual Mode, the 420EX cannot.

I don't understand this statement. I shoot the 420EX on my 10D in manual mode all the time. Setting 1/60 f/5.6 90mm across the room and the picture is perfect. Granted, setting 1/200 f/11 is was a bit dark, so 1/125 f/8 worked much better. But they were all manual.

With any of those setting the exposure level indicator showed that the picture was going to be grossly underexposed, they weren't.

You are confusing the Manual Exposure Mode of the camera, which sets Aperture and Shutter Speed Manually, but has no direct control of flash output, vs. Manual Flash Mode, which has its controls located on the flash and lets you set the flash output directly on the flash. When you set the camera to M mode you are manually controlling the ambient light exposure not the flash. The camera controls the flash output via ETTL. This is not affected by shutter speed and only indirectly affected by Aperture, in that smaller Apertures result in shorter distances the flash can travel. That relationship is expressed as : Distance = Guide Number of Flash/ f stop. That is why your pictures at f5.6 from across the room were fine ( 42M /5.6 = 7.5Meters) and at smaller apertures weren't (42M/11 = 3.8Meters) You were too far for the flash to be effective.
Your meter was telling you that with available ambient light without flash, your picture would be underexposed. It can't tell you in advance how well the subject will be exposed when the flash fires. You need a separate flash meter to see that. In Manual Flash Mode the camera isn't involved in setting the level of flash output. You set the flash output on the flash and have to use a separate flash meter to adjust it. Let me know if you have more questions.
Scott

[robertwgross]

belmondo wrote:
If Bob's wit was wit only half the time, what would that make Bob?


... grossly underexposed?

---Bob Gross---

[Belmondo]

robertwgross wrote:
belmondo wrote:
If Bob's wit was wit only half the time, what would that make Bob?


... grossly underexposed?

---Bob Gross---



Very cute. Please note: my question was purely hypothetical---you're a wit all the time. (At least some of us think so.)

[freddiebear48]

:DWhat about the 580 EX? Is it worth the price?

[PacAce]

:DWhat about the 580 EX? Is it worth the price?
Only you can answer that. It's got all the features of the 550EX except that it's a little more powerful GN=58 vs the 550EX's GN=55; it takes the camera's crop/magnification factor into consideration when zooming the flash head (on cameras that support it); it recycles a little faster and it has a more streamlined body although it's not much smaller than the 550EX. For some people, these extras are worth the $80 ($60 with the current rebate program) or so difference in price between the two flashes. For others, it's not.

[tim]

Flash? No way. It's not science.....it's black art.

I definitey agree with this. A single external flash is bad enough, reading about studio strobes etc they seem relatively difficult, I think I may do a class some time to learn them. Or maybe i'll buy some and a book and see what happens - i've manged to figure everything else out so far, with help from people here.