Any advice on cheap flashes

Lou Jost · Post by **Lou Jost** » Sat Jan 16, 2016 9:22 pm

Are you serious? Currently all it takes to use the flash on my a6000 is to pop the flash out. Would that really work?!

Yes, it works, and very well. The flashes come with little stands so they can be set up in an instant. And they don't even need line of sight to your pop-up camera flash. They can be triggered by strong secondary reflections from the camera's flash. I have the Yongnuo radio controller but I much prefer the optical slave.

One thing to be careful of is to make sure your camera flash does not strongly illuminate the subject. There is a very slight delay between master and slave flash, and if both master and slave are strongly illuminating a vibrating subject, you can get ghosting.

The triggering time for the optical slave is faster than that for the radio slave. That means if you are using multiple Yongnuos, with one of them being used to control the others, they will not all fire together. The master will fire first and then the slaves. Again, this can cause ghosting if the subject is not absolutely still, at least if magnification is 10x or more.

Charles Krebs · Post by **Charles Krebs** » Sat Jan 16, 2016 10:23 pm

While the YN-560's have good optical slaves, you need to consider your "built-in" flash modes if you intend on using it to trip your "remote" YN-560 flashes optically. The built-in flash on quite a few cameras (and I believe this is the case with the Sony A6000) can not be set to a manual mode. As a result each shot will very likely have the in-camera flash going off at full power. So battery life and recycle times can quickly become an issue with stacking.

If your camera built-in flash does allow for manual mode at reduced power settings then it is a good way of "tripping" the remote flashes.

One nice thing about the 560-TX is that you can increase or decrease the power settings as you wish from the unit on the camera. This may not always be a big deal, but if you ever have a flash positioned in an awkward location, or set so that you can't readily see the control panel on the back of the flash, it is a really nice feature.

ChrisR · Post by **ChrisR** » Sun Jan 17, 2016 1:58 am

Reminder - it has to be manual. If it's iTTL there may be a pre-flash which allows the camera to decide the duration of the main flash.
You can't see it because it's too quickly followed by the main flash, but your slaves probably will see it. It can screw things up

Lou Jost · Post by **Lou Jost** » Sun Jan 17, 2016 4:49 am

Yes, I forgot that some cameras might not allow you to set their flashes to manual. All of mine allow this. I set them to about 1/32 or 1/64 power usually. Depending on the positioning of the slaves, 1/128 power might not be enough to trip the slaves, in my experience.

Koorosh · Post by **Koorosh** » Sun Jan 17, 2016 8:17 am

OK I just checked. The only options are flash, rear synch or front synch (or wireless, but it's greyed out). All three are full flash.
Maybe I should get the controller.
Oh and I have looked it up, but I'm not quite sure if what I'm seeing is right or not: are there external power packs for the flash? I don't like the sound of recharging batteries all the time.
As for the flash running down battery on the camera, I'm running it through a mains supply so that's not an issue.
And so the optical slave is literally triggered by the burst of light from the flash? Does that mean that the flash and camera shots won't be synchronised?

Lou Jost · Post by **Lou Jost** » Sun Jan 17, 2016 8:54 am

On my Nikon and Panasonic cameras, the optical slave is fast enough that it triggers the flash before the second curtain begins to close, so you can (and should) use second-curtain sync. I can imagine that a slower triggering method (like RF) might not be fast enough to be able to use second-curtain sync.

I don't have external packs for the Yongnuos, but they do have what looks like a power connector.

mawyatt · Post by **mawyatt** » Sun Jan 17, 2016 8:59 am

Lou,

I have measured the delay of 2 different RF triggers, see thread for a graph of one of these RF triggers (Neewer). The delay is between 1.2 and 1.4ms which is quite long IMO. Optically trigger delays should be below 100us I would think. I plan on attempting delay measurements on the 2.4GHz RF triggers later.

Cheers,

Mike

Lou Jost · Post by **Lou Jost** » Sun Jan 17, 2016 9:07 am

Mike, it will be great to see actual data on that! Do you know the delay between the second-curtain flash trigger signal and the actual drop of that second curtain?

Koorosh · Post by **Koorosh** » Sun Jan 17, 2016 10:24 am

So when you use a radio signal to use the flashes, is there some compensating calculation in the camera and between the flashes that allows the two to synch to each other, or do you have to use longer exposures?
I only have experience using flashes with a Canon 700D and an Mt24 ex. I think there was a limit to 1/125th of a second and you couldn't go any lower. Saying that, it was attached to the hotshoe.
But is ths essence the same?

Lou Jost · Post by **Lou Jost** » Sun Jan 17, 2016 10:31 am

Obviously you can't use faster shutter speeds than the synch speed of the camera. You MAY need to use the next available slower speed, and MAY need to avoid second-curtain sync, if your triggering chain has a long time delay. But as I said before, in my limited experience (just two camera brands), optical slaves are fast enough to avoid these problems. I am not so sure about RF slaves, which as Mike just mentioned (with real data!!), are ten times slower.

mawyatt · Post by **mawyatt** » Sun Jan 17, 2016 11:21 am

Lou Jost wrote:Mike, it will be great to see actual data on that! Do you know the delay between the second-curtain flash trigger signal and the actual drop of that second curtain?

Lou,

Here's an example. I just completed another test with a different RF Trigger (Viltrox JY-02) that also operates at 433MHz and got a similar result. So from this limited data set I think it's safe to say that the 433MHz RF triggers have about 1.2~1.4ms delay.

Best,

Mike

Koorosh · Post by **Koorosh** » Sun Jan 17, 2016 12:45 pm

Nice

So is it that when using flash where there is a delay, if you use say 1/125th of a second, the actual pulse of light caught by the exposure is much shorter because the image is dominated by the bright flash just before the second shutter close?

Obviously you can't use a shutter speed faster than the synch, but what I was wondering was whether cameras and flashes have built in programming that works to account for each other. e.g. if it takes half a second (obviously not that long) for the signal to produce the flash, get the camera to wait a little time before starting the exposure.

If that problem can be resolved without having to add complicated programming (which I assume must be different if using different flashes and cameras etc) by the short and very bright pulse dominating the exposure just before it closes, then it makes sense to leave it. I guess.

Lou Jost · Post by **Lou Jost** » Sun Jan 17, 2016 1:11 pm

If there is NO delay, the bright flash dominates the exposure.

If the delay is too long, then the fall of the second shutter curtain will block the flash's light from some part of the sensor.

As I said above though, the delay with the Yongnuo's optical slave is completely unimportant.

Koorosh · Post by **Koorosh** » Sun Jan 17, 2016 2:00 pm

Ok thank you.
And thank you to everyone else- glad to be getting away with the cost of eneloops and a single flash for less than the 200 odd I thought I would be spending!

I will probably add another flash at some point but I'm already spending more than I have.
Budget = 0, final spend = 135... That's including a 100mm lens and 12 batteries with a charger though.

Charles Krebs · Post by **Charles Krebs** » Sun Jan 17, 2016 3:06 pm

ChrisR

Reminder - it has to be manual. If it's iTTL there may be a pre-flash which allows the camera to decide the duration of the main flash.
You can't see it because it's too quickly followed by the main flash, but your slaves probably will see it. It can screw things up

The Yongnuo flash units (and some others) have two optical slave settings. The second one can be used if the triggering flash emits a "pre-flash". Don't know about other manufacturers flash signals, but the second slave setting on the Yongnuo does well in ignoring a Canon TTL "pre-flash".

Koorosh

Oh and I have looked it up, but I'm not quite sure if what I'm seeing is right or not: are there external power packs for the flash? I don't like the sound of recharging batteries all the time.

There is a high-voltage input on these flash units (~300V). Yongnuo makes an 8"AA" external battery pact that will supply this and plug in. It provides nearly instant recycling and greater capacity. But you are then dealing with 12 "AA" per flash! (And will want to be careful about overheating in some circumstances).

There is one option for "plug-and-play" AC power that I am aware of. But it costs $135.
http://www.innovatronix.com/index.php/p ... -speedfire

Actually I am aware of one other... a Quantum AC Turbo with a CZ2 cable. But this will set you back over $300.

Vivitar made an AC unit (SB-4) for their 283 and 285. They are still available used and inexpensive (abouot $15). The HV voltage output is about right, but the plug is different and I don't know of anyone who has hacked this (or if this is even possible) to a Canon/Nikon/Yongnuo flash unit with the HV input.

These flash units are pretty efficient. Unless you find yourself using them at full or 1/2 power (not likely) you should be able to get by with a couple of sets of rechargeable AA's.