Can somebody explain how the asymmetrical power distibution of the Ranger RX Speed AS works in combination with either the A or S type flash heads?

I mean, when do you have a 100% (17-1100 w/s) power output? And when do you have 2:1 ratio output? Is it related to the number of heads or output ports you are using at the same time?

Many thanks

you have a 100% (17-1100 w/s) power output when you have 1 head connected to A port. AS ratio you get when you connect 2 heads. You can also have 300-7w/s output if you connect 1 head to port B.

Daan,

On the AS unit, the B channel can only deliver 33% of the available power, with or without additional head. The A channel can deliver 100% of the power available, except if there is another head connected to the B channel. In which case, the A channel can only deliver 66%.
Percentages will remain constant as variator is changed up or down the power scale.

One head only:
A Channel = 100% (17-1100) ws
B Channel = 33% (5.7-366) ws

Two heads (A & B)
A Channel = 66% (11.4-733) ws
B Channel = 33% (5.7-366) ws

Couple of other points to add :

1. A (Action) head has half the flash duration as the S (Standard) head.
2. Either head in the B channel will produce half the flash duration as they would in the A channel.
3. If a A (Action) head is used on the A channel and the S (Standard) head on the B channel the flash duration from either head will be basically the same.
4. My unofficial testing (posted in a previous thread) has shown that A (Action) head produces basically the same output as the S (Standard) head at the same power level. Within tenths as I recall. This amounts to virtually no difference in the light ratios produced if the A (Action) and S (Standard) heads are used in combination with each other on either A or B channels.

Good luck.

gzasinets and Carmen, thanks for explaining this to me

A couple of other things:

How about flash recycling times? Will they be the same for the A and B channel when used in ratio? IIRC in the fast recycling mode, the A channel has a 0.3-3 sec output and the B channel has a 0.19-1.2 sec output. Do these numbers change when both channels are used at the same time?

I don't think it matters for recycling times if you use either the A or S head on one port only, correct?

Daan,

Recycle time has to do with how long it takes to refill capacitors, the energy reserves of the system. Capacitors are in the pack, not the heads. Thus it makes no difference which head or how many you use, only the amount over power that is used or needed by the pack. Recycle times will improve proportionately as the main variator is reduced from maximum to minimum power regardless of type or number of heads. The B channel recycle specs are faster because it has less capacity to fill. I suspect that A channel at 33% will recycle about the same, although I have not tested and cannot say for certain. The main advantage to using the B channel with one head on the Ranger AS for me is to take advantage of faster flash duration and the lower power range. Recycle times and capacity are very good on this pack for a portable unit.

Good luck.

Carmen Miranda wrote:
Daan,

Recycle time has to do with how long it takes to refill capacitors, the energy reserves of the system. Capacitors are in the pack, not the heads. Thus it makes no difference which head or how many you use, only the amount over power that is used or needed by the pack. Recycle times will improve proportionately as the main variator is reduced from maximum to minimum power regardless of type or number of heads. The B channel recycle specs are faster because it has less capacity to fill. I suspect that A channel at 33% will recycle about the same, although I have not tested and cannot say for certain. The main advantage to using the B channel with one head on the Ranger AS for me is to take advantage of faster flash duration and the lower power range. Recycle times and capacity are very good on this pack for a portable unit.

Good luck.

Yeah, the B channel with one head seems very fast in both recycling times and flash duration. I was just wondering what would happen to the recycling times when you have both channel A and B occupied at the same time.

Thanks

Daan,
imagine there are 3 bundles of caps in the pack. Chanel A is wired to all 3 bundles (100%) while B is connected to only 1 bundle (=33%).

Hence B is limited to draw from this 366 Ws bundle. No wonder that flushing and reloading is much faster than of the total 1100Ws.

'Asymmetric' packs' output variator combines 'voltage regulation' for all caps and 'capacitor bank switching' as a way to reduce power.

Keep in mind that the higher the voltage, the faster the flash. Let's assume you wish an output of 366 Ws. For chanel A this means to reduce the caps' voltage to a large degree, hence increasing the flash duration. For chanel B this means 'full cap voltage' = shortest flash duration. Result: B is always faster at reduced variator settings.

Peter, thanks for the explanation...

So, channel B has a faster recycling time than channel A (according to specs). Which is logical since it has less power than channel A. So when you have a strobe plugged in both channel A and B, the strobe in channel B is faster recharged than the strobe in channel A, right? So the strobe in channel B has to wait for the strobe in channel A to be recycled before both can fire..?

I have to say - this is the best discussion about the capabilities of the Ranger AS system that I have read anywhere. Written in plain language, too, so newbies to battery-operated studio lighting can understand it. Bookmarked for future reference (the Ranger is in my future ).

I was under the impression that using a combination of A and S heads would allow you to change the ratios, going from a 2:1 to a 4:1 (S in Achan and B in Bchan) and 1:1 (B in Achan and S in Bchan).

I forget where I heard this, but if there is any real world evidence to support or disprove this, I would be very interested to know.

Tomagado wrote:
I was under the impression that using a combination of A and S heads would allow you to change the ratios, going from a 2:1 to a 4:1 (S in Achan and B in Bchan) and 1:1 (B in Achan and S in Bchan).

I forget where I heard this, but if there is any real world evidence to support or disprove this, I would be very interested to know.

Tomagado,

I also remember the discussion which was based on the assumption that the short flash duration heads might be less efficient. After hearing this a couple of times, I did some testing myself and posted the results with pictures of the set up. I've done a search to find the thread but I can't seem to find it. I believe this was back in April or May this year.

In any event, I found there was no appreciable difference between the heads in output. I think the A head I tested was only a couple of 1/10th's less than the S head throughout the as I recall.

The other difference between these two heads as I recall, is their anticipated longevity. The shorter flash duration head generally accepted to have a shorter life than the standard. I don't know how significant this difference is in real life however. I'm still doing the testing.

Good luck.

Daan B wrote:
So when you have a strobe plugged in both channel A and B, the strobe in channel B is faster recharged than the strobe in channel A, right? So the strobe in channel B has to wait for the strobe in channel A to be recycled before both can fire..?

No, strobes don't fill their own capacity, the pack does. The strobe heads are ready to fire simultaneously when the pack is fully charged to the level commanded by the variator.
Once the pack's capacitors are fully charged to the amount specified by the variator, the pack simply discharges 66% power to the A channel and 33% to the B channel. That percentage always remains the same on a 2:1 asymmetric pack, whether the pack is set to it's minimum or maximum output.

Percentage (ratio) can vary on a fully independent asymmetric pack (break out your wallets boys), but heads in either case, will still fire simultaneously once the pack is fully charged to it's maximum requirement.

How and which capacitors fill up first is really a moot point. It is the amount all the capacitors have to charge as specified by the variator that makes the difference in recycle time when two heads are used.

Good luck.

Carmen Miranda wrote:
Tomagado wrote:
I was under the impression that using a combination of A and S heads would allow you to change the ratios, going from a 2:1 to a 4:1 (S in Achan and B in Bchan) and 1:1 (B in Achan and S in Bchan).

I forget where I heard this, but if there is any real world evidence to support or disprove this, I would be very interested to know.

Tomagado,

I also remember the discussion which was based on the assumption that the short flash duration heads might be less efficient. After hearing this a couple of times, I did some testing myself and posted the results with pictures of the set up. I've done a search to find the thread but I can't seem to find it. I believe this was back in April or May this year.

In any event, I found there was no appreciable difference between the heads in output. I think the A head I tested was only a couple of 1/10th's less than the S head throughout the as I recall.

The other difference between these two heads as I recall, is their anticipated longevity. The shorter flash duration head generally accepted to have a shorter life than the standard. I don't know how significant this difference is in real life however. I'm still doing the testing.

Good luck.


Thank you so much , this information is very useful

Cheers,
Thomas

So, I'm a little confused myself now. If I have only 1 head attached to channel A, I only get 66% of the 1100 watts or is that only when I have 2 heads attached? Or put another way, if I have one head on A do I get all 1100 watts?

Thanks

Gregg Heckler wrote:
So, I'm a little confused myself now. If I have only 1 head attached to channel A, I only get 66% of the 1100 watts or is that only when I have 2 heads attached? Or put another way, if I have one head on A do I get all 1100 watts?

Thanks

One head attached to channel A will give you 100% = 1100 w/s (see Carmen's post ^^^)

Carmen Miranda wrote:
My unofficial testing (posted in a previous thread) has shown that A (Action) head produces basically the same output as the S (Standard) head at the same power level. Within tenths as I recall. This amounts to virtually no difference in the light ratios produced if the A (Action) and S (Standard) heads are used in combination with each other on either A or B channels.


Good to know, since there are some people who insist that the A head is only faster because it's about a stop less powerful for each particular setting... (and I'm picking up a Ranger RX Speed AS kit with Freelite A head tomorrow ).

Do you have a link to your tests, Carmen?

rudiphoto wrote:
Do you have a link to your tests, Carmen?

http://www.fredmiranda.com/forum/topic/684548/0?keyword=x#6142346

Have fun with your new big boy toy.

I intend to, Carmen, I intend to!

Carmen Miranda wrote:
3. If a A (Action) head is used on the A channel and the S (Standard) head on the B channel the flash duration from either head will be basically the same.



Only if they're alone, on different packs! If they're on the same pack, the A head in port A will flash at 1/4310 sec and the S head in port B will flash at 1/2310 sec.