RETRA Strobe Thread

4 minutes ago, mjrovner said:

Many thanks all! Still undecided but this is all super helpful. I was thinking 40% on the Primes vs. 40% on the Pros was apples to apples, but as you point out that's wrong. Maybe they should publish recycle times to comparable W/Secs?

I think that's too big an ask, you MIGHT be able to calculate it, but the number may not be worth the paper it's printed on,  the ability to measure state of charge of the capacitor is probably not all that precise.  My gut feel is those Ws /second numbers are close enough to judge as being the same for our purposes, even if you did get an accurate number what would you do with it?   How would you translate it into -  "I can produce so many 1/4 or 1/2 power flashes per second" for example?  The only real way to do that is test the strobes. 

Stuart, the point of the W-sec calculations was to show that within our ability to measure a back of the envelope calculation shows the two strobes were adding energy to the strobes capacitors at about the same rate.  I only used Ws as a measure for energy input to the capacitor, the Prime has 2/3 of the capacity of the Pro is the basic assumption based upon the specs. 

1 minute ago, ChrisRoss said:

Stuart, the point of the W-sec calculations was to show that within our ability to measure a back of the envelope calculation shows the two strobes were adding energy to the strobes capacitors at about the same rate.  I only used Ws as a measure for energy input to the capacitor, the Prime has 2/3 of the capacity of the Pro is the basic assumption based upon the specs. 

Yes, I totally get that. I was responding to mjrovner's comment about publishing cycle times in W-sec.

Where else can one go to be able to nerd out on strobology? I love it!

Both flashguns have same recycle speed.

The Pro versions have larger capacitors which is why at full power they will give out more light than the Prime version. Because more energy is released it will take more time to refill the larger capacitors.

Due to larger capacitors the Pro version is able to produce more equivalent power flashes in a row. Imagine a bucket of water, the Prime version is made from two buckets of water and would be able to fill 20 glasses whereas the Pro version can hold 3 buckets and would be able to fill 30 glasses.

It's not possible to give recycle time in energy/second because the charging curve is not linear and this value is always changing. It's similar to electric cars and their batteries which charge very fast to about 70-80% capacity and slowly reach the last 20-30%.

Thanks Oskar!

On 7/11/2021 at 10:07 AM, Oskar@RetraUWT said:

Both flashguns have same recycle speed.

The Pro versions have larger capacitors which is why at full power they will give out more light than the Prime version. Because more energy is released it will take more time to refill the larger capacitors.

Due to larger capacitors the Pro version is able to produce more equivalent power flashes in a row. Imagine a bucket of water, the Prime version is made from two buckets of water and would be able to fill 20 glasses whereas the Pro version can hold 3 buckets and would be able to fill 30 glasses.

It's not possible to give recycle time in energy/second because the charging curve is not linear and this value is always changing. It's similar to electric cars and their batteries which charge very fast to about 70-80% capacity and slowly reach the last 20-30%.
 

So, as a rough calculation, for recycling anything up to 100 w/s, the Prime and Pro will take basically the same time to recycle, as the Pro is only recycling to 2/3 of its capacity, and the Pro will take longer only to reach its full capacity?   If so, then you could set the Pro to 2/3 on the output dial and have, essentially, a "Prime" equivalent performance?

Also, question about the battery capacity check function on my new Pro-X.  The manual says the battery check is calibrated for "Eneloops".  Does this mean it will not be accurate for Eneloop Pros?

I hope to shoot these new babies this weekend!

Correct. The pilot light is also weaker on the Prime versions, at 50% power on the Pro version you get about the same output on the pilot light as on the Prime at 100%.

It's meant for both types of eneloops as they have a similar voltage drop when discharging.

I have not been able to get mine in the water yet, so this may not help, but I went with primes.   I have never needed full power out of Z240 or Z330 strobes, and as I understand it, one gets more flashes per battery change for the primes as opposed to the pro, which I thought more valuable than more power that I did not really need for my style of photography.

But I can't base this on any actual use.  Time will tell.

Pilot light power is unimportant to me.

I'm coming up on 150 dives with my Primes. Yep, there are times when I question whether I should have spent the extra and got the Pros. But, in reality, I've never been in a situation with them where I thought I needed more power.

Similarly with the pilot light which I use a lot (especially with a snoot). Even in fairly shallow sunlight water I can usually aim the snoot with the pilot light.

Having had Z220s/240s for around 20 years, moving to the Retras felt almost like a sneaky betrayal. But, have to say, I love them and they are a great "investment". The quality of the light is terrific and the ability to shape and steer the light through the snoot and reflector is brilliant. AA batteries, superchargers, bayonet fittings for all the attachments, robust .... what's there not to love!

I'm sure you will be delighted with your Primes, Draq. 

7 hours ago, Draq said:

one gets more flashes per battery change for the primes as opposed to the pro

The Pro version has larger capacitors and delivers more energy but if you set both flashguns to give the same exposure they have the same battery consumption. Basically if you used the Pro version up to about 50% power you would have the performance of the Prime in terms of light output and energy consumption. The added benefit of the Pro (due to larger capacitors) is that you can make more flashes in a row which I explained earlier with the buckets of water analogy.

What would be helpful is an official rating of sustained FPS either strobe is capable of producing at each power level, with and without superchargers. For example, per my own testing, Retra Pro with supercharger is capable of sustaining 3fps at up to 50% power level, and 8fps at up to 6% power level. I'm guessing that a Prime with supercharger would be able to fire continuously at 3fps at up to 75% power, but I don't have one to test.

Both flashguns will achieve the same sustained fps because the recycle speed is the same. The key word is "sustained". If you need this information it is available from recycle time: 1fps = power/recycle time

Please note that power in the tech-spec is relative to the available power output of the flashgun. 80% power is not the same on the Pro and Prime versions in terms of actual light output.

By "flashes in a row" I meant a very quick sequence, a short burst for which there is no time to really recharge the capacitors. Usually these are action shots that only last for 1 second or less. During that 1 second of action the Pro versions have the ability to light up more images at the same exposure because of their larger capacitors.

Which is exactly why i ordered the Pros.

7 hours ago, Oskar@RetraUWT said:

The Pro version has larger capacitors and delivers more energy but if you set both flashguns to give the same exposure they have the same battery consumption. Basically if you used the Pro version up to about 50% power you would have the performance of the Prime in terms of light output and energy consumption. The added benefit of the Pro (due to larger capacitors) is that you can make more flashes in a row which I explained earlier with the buckets of water analogy.

Well, I guess all I did was save a bit of money, then.  Had I understood that better, I might have opted for the pro, but I am sure the prime will be fine.

Guys

I've been shooting my Retra Prime strobes now for about 12 months and coming up on 150 dives. As you might have seen from previous posts I rate them highly - truth be told, I'm approaching Fan Boy status.

For pretty much all of my macro dives (105mm or 60mm lenses) I use Retra's LSD snoot. The combination is, I think, unbeatable if you want snoot macro images. The spotting light is perfect and fine tuning using the Retra LSD slides is tremendous for controlling the fall of light on the image.

I've been mulling over whether for snoot purposes it was worth splurging and getting a Pro for the extra power. You know how that ear and mind worm thing works? Cut a long story short, of course I did. An "investment", right?

I've now used the Pro for about 10 dives - all with the LSD. Sint Maarten, where I dive, is usually pretty clear and well-light water and, truth be told, I was struggling a bit to see whether the extra power of the Pro made that much difference. So I ran some tests at home and will post side by side images of the Pro and the Prime and the same power settings:

All images are shot at 125/f18 ISO 100.

Top image is always with a Pro-X with LSD - the bottom image is exactly the same with a Prime

My take: if you are using the small holes on the masks, the Pro version is definitely better. Maybe not so much difference for the wider mask holes.

And one final thought: shooting at +3 really chews through the batteries. I'd suggest a Supercharger is almost an essential accessory for snoot shooting.

So first pair of images: Strobes set at +3 and using the smallest, single round hole  of the Retra mask set -

Next two are shot with a +0 setting 

Next two at +0 but with the largest mask circle

And finally both at +3

Interesting Tim, cheers for those - coming from  a soon to be Retra owner!

Mike

No probs, Mike.

I really rate them highly. Just keep an eye on the batteries! With the Inon Z240s I could reckon on 3 dives a day between charges. Not with the Retras. Two at most.

I think the Supercharger is a Must-Have if you are using a snoot.