tests done for max flash power -SB900 SB700 yongnuo 560III

rocketman122

Senior Member
Browncoat, its not the part to add the pictures/vid, but its just thrown around, like a kind of statement thats of distrust. I did the test for myself because my best bud thinks the 560III arent as strong as his 910 which he said he tested. so wanted to size it up against what I have and its the SB900. then I said Ill try to do them all.
I specifically hate that statement. doing a video and uploading takes time also. I only drink wine and dont smoke.

I did measure 1m from the flash head edge to the middle of the rounded light meter head. meaning, the light meter has a bublous head and I measured it to half the distance of the head. you will understand in the vid I will upload.

I will take my friends 910 and see how it performs because I think the flash I have may be just a bit tired and worn out a bit. batts are brand new recharged overnight. will also do the SB800 SB28 568 (when I get it back from repair from taiwan) the metz 58 AF2 and see they stack up. will do them all the same. I simply wanted a standard across all of them to test their brute power at full 1/1. nothing more. not recycle times, not power at the farthest settings. just strength at the 35mm 1/1 iso 100 setting
 

WayneF

Senior Member
Rocketman, I obviously owe you an apology, since you did clearly state the flash distance was one meter, and somehow that went right by me. Somehow I never realized it. It was my mistake, sorry.

So I think your procedure was great, but the results seem off.

If SB-900, ISO 100, full power, FX, 35 mm zoom, the guide number is 34 (meters, manual page F-19), and metered exposure should be f/34 at one meter.
Your metered number was more than one stop low?

And the SB-700, ISO 100, full power, FX, 35mm zoom, the guide number is 28 (meters, manual page H-23) and metered exposure should be f/28 at one meter.

Yongnuo 560 manual (at end) says Guide Number 39, or f/39.

Exactly matching the exact number is not a realistic expectation, but it should have been greatly closer.

Since all three were off, I'm suspecting the meter, maybe the wrong dome on it, or low batteries, or not metering in center of flash beam, or something?

Maybe it was not direct flash? Bounce could serve as a valid comparison, but the manual Guide Number chart I am trying to use to verify is Direct Flash only.

Seems to me a picture (of the meter on its stand) with the camera near the flash position, exposed at the metered fstop, should strongly demonstrate the result accuracy.

If the flash were defective, and only feebly trying, still the meter should meter this and the picture should be exposed well.

But if the meter was not seeing it right, the picture would not be right.

If the manuals guide number chart number were simply used at the appropriate flash distance, the picture ought to be pretty good. That is the point of it. GN = Distance x fstop number.
 
Last edited:

Eyelight

Senior Member
I'm more or less just listening to this thread in an effort to learn more about modern lights. But seems to me there would be a number of variables that would be difficult to control when comparing one flash unit against a different brand/model. And seems the testing would need to be in a room without any reflective surfaces, if the aim is to test only the power output of the light.

A flash going off is like a sneeze. The bulk of the light may go in one general direction, but light goes everywhere, bounces off everything within range. Seems this would be accentuated by tight quarters and a short test distance.

But this is mostly my imagination, which as we know can wander off in odd directions at times.
 

WayneF

Senior Member
I'm more or less just listening to this thread in an effort to learn more about modern lights. But seems to me there would be a number of variables that would be difficult to control when comparing one flash unit against a different brand/model. And seems the testing would need to be in a room without any reflective surfaces, if the aim is to test only the power output of the light.

Mine is just one opinion, but yes, close reflecting walls can add to what the light meter sees. A big and high bare room is a good thing. Maybe a warehouse. Maybe outdoors in the night. :)

But if all flashes are carefully in the same situation, the effect and comparison should be the same. If trying to establish an absolute number, yes, the room might slightly affect the number. But a comparison still seems valid, if done equally for all flashes.
 

aroy

Senior Member
Just like audio speakers are tested in an anechoic chamber, flash units should be tested in open field, so that there is no reflected light to muddy the results. I still think that testing at 5 meters should give results consistent with real life situation, as well as reducing the error margin due to distance measurements, but if you have no space then that is it. The tests were done by Rocketman122 for his own need, and if he is satisfied, that is it.

Any way, how ever you do the tests, if the conditions are same for all the flashes, their relative performance is all that we are gauging, and whether it is 1m or 10m, as long as we know where they stand relative to each other it is fine.
 

Browncoat

Senior Member
Browncoat, its not the part to add the pictures/vid, but its just thrown around, like a kind of statement thats of distrust.

This is exactly where I'm coming from on asking for pics/vid.

"Distrust" is a strong word, and I'm not trying to imply that I distrust you. That's too personal, and this isn't personal. It's about credibility. Unless I'm very much mistaken, @WayneF has implied credibility also. Something just seems kind of off with this testing, and without being able to see how the test was performed, it's difficult to accept these results.

Verification = Validation + Credibility.
 

rocketman122

Senior Member
Ill get back later but had 2 weddings today and yesterday. did a vide for the SB700 and it was consistant but the Sb900, the first flash is a bit weak like the test I did when I posted and the 2nd came in much stronger. and this confuses me and I did video it but I didnt get it the 2nd time and I want to check and video this for you guys to see. I will do the SB800 as well.
 

David1954

New member
Hi newby here, I just recently bought a d7100. So far love it ! It just amazes me how much there is to learn. I have not purchased a flash yet , I'm leaning toward the sb700, but budget is tight do to all recent purchases ( camera , lenses ect. ) . Can you recommend a flash other than sb700 or should I just wait until I can buy that one ? Thank you ! David1954
 

WayneF

Senior Member
Hi newby here, I just recently bought a d7100. So far love it ! It just amazes me how much there is to learn. I have not purchased a flash yet , I'm leaning toward the sb700, but budget is tight do to all recent purchases ( camera , lenses ect. ) . Can you recommend a flash other than sb700 or should I just wait until I can buy that one ? Thank you ! David1954

If price is a concern, see Review of the Yongnuo YN565EX Speedlight

It will do what a SB-700 does, with more power, for 1/3 the price.
 

rocketman122

Senior Member
Hi newby here, I just recently bought a d7100. So far love it ! It just amazes me how much there is to learn. I have not purchased a flash yet , I'm leaning toward the sb700, but budget is tight do to all recent purchases ( camera , lenses ect. ) . Can you recommend a flash other than sb700 or should I just wait until I can buy that one ? Thank you ! David1954


Sb700 is fast. faster to recycle than the SB900 910 and 800 at full power. but it is the weaker of them all. not by much though. small thing packs quite a punch though.

if you plan on shooting faster than 1/250 of a second (HSS-usually done outdoors) then the yongnuo 568 can do that. the 565 cant but does have a battery port for an external battery pack...if you ever need one. on power, the 565/568 are on the same level and recycling as the 900/910/800.

had some word from yongnuo a few months ago they are in testing phases of the 568 mark II. not sure when itll be out though.

for me personally, I prefer to have a nikon flash on the camera. this is from someone who owns nikon and the 568.

if you need wireless firing, a la CLS, which I think is just crap, id personally just get some cheap radio slaves. like night and day. tons to choose from and a KA set is commlite G430 that go for $25 shipped. I have 2 sets as a backup to my 6 YN622n.

got news from my friend at flashhavoc.com that godox will be releasing some killer products in the 2nd half of this year so might throw all my flashes out except the nikon sb700/900 for my on camera flash.

so bottom line is either suck it up and go SB700, or yn565 or 568. I only have experience with these- BUT! there are products by neewer, triopo, nissin, and godox you should look into. im pretty set in what I need flash/slave wise and im not completely happy as I need specific needs for my wedding shoots im not getting completely from my gear. will have to keep my eye open though.

I will get back to this test ive started but this wedding season is tiring me. wow the damn blistering heat tires me out. cheers!
 
Top