Wetpixel strobe review

[adamhanlon 0]

 

I have just posted the Wetpixel review of the Inon Z330, Retra Flash and Symbiosis SS2 strobes on the front page:

 

http://wetpixel.com/articles/strobe-tests-inon-z330-retra-flash-and-symbiosis-ss2

 

If you are just coming to this, please check out the extensive threads on the Z330 and Retra Flashes too:

 

Z330: http://wetpixel.com/forums/index.php?showtopic=61091

 

Retra Flash: http://wetpixel.com/forums/index.php?showtopic=59574

 

Perhaps we can amalgamate the threads and add personal experiences to this thread?

 

Adam

[Nicool 26]

Thanks for the extensive review Adam!

On the methodology can you confirm how you’ve done the extensive battery test in water bucket? Shooting lots of continuous full power flashes wouldn’t have been possible (well, depending on the frequency) on the Z240 due to heating, so it looks like Inon did address well the heating issue on Z330?

 

 

Envoyé de mon iPhone en utilisant Tapatalk

[adamhanlon 0]

I can confirm that I did the battery testing by cycling the strobes at full power with them being triggered as soon as the ready lights illuminate.

 

The strobes were in bucket of water at room temperature.

 

Adam

[hellhole 21]

The z330 now has a warning sticker in the box that tells you. That if u fire (more then) 10 flashes... U have to wait 5 min before firing again

[Bumbi.dombovari 3]

Adam!

1 Joule is correctly equal to 1 Ws and not 1W / s

 

Bumbi

[Bumbi.dombovari 3]

and more:

The guide number has a unit of measurement: for distance. Feet or meter. Manufacturers do not even say it, but it's a mistake because it's not 33 feet or 33 meter. The guide numbers of the flashes in the article are given in feet.

 

Bumbi

[tursiops 81]

and more:

The guide number has a unit of measurement: for distance. Feet or meter. Manufacturers do not even say it, but it's a mistake because it's not 33 feet or 33 meter. The guide numbers of the flashes in the article are given in feet.

 

Bumbi

Let me say this a little differently and in more detail, because I'm sure many people are confused about it.

 

The Guide Number (GN) is what you divide by the distance-to-subject to get an f-stop. The distance to subject can be in feet or meters. So, if you are 10 ft away with a GN of 33, you should use f/3.3. But, if you are a meters person, like most of the world (!), the GN should be given as 10, so when you divide by 3m (i.e, 10 ft) you still get an f-stop of 3.3.

 

Because f-stops are a ratio of lens focal length to lens opening, the f-stop has no units, it is a pure ratio of two lengths. So when you multiply distance x f-stop = GN, you still have units of distance, be they ft or meters. This means the GN MUST HAVE ITS UNITS ATTACHED -- feet or meters -- or it is incorrect and potentially will give you greatly underexposed pictures. .

 

Using the example of GN33 and assuming it works for meters, and you are 3m away, you will use f/11. But the correct f-stop is 3.3, because the GN is in feet. So you are underexposing by a factor of over eleven (11/3.3 squared).....good luck.

[adamhanlon 0]

 

 

The z330 now has a warning sticker in the box that tells you. That if u fire (more then) 10 flashes... U have to wait 5 min before firing again

 

This is very interesting and there was certainly no such notice with the strobes supplied for this review. Could you take a picture of it?

 

I can state that I have seriously violated this guideline repeatedly and there has been no obvious negative effect on the Z330s or their performance! I did 4 back to back battery tests of the strobes, cycling at full power soon as the ready light appeared... that's around 1000 flashes with no break in between!

 

In terms of guide numbers, I think we should, in this instance, perhaps simply look at them as a non specific and hence fairly generic way of comparing strobe output. As mentioned, I was quoting manufacturers specifications, which (I think) did not list units.

 

I note that the unit is Ws rather then W/s and thank you for this correction.

 

Adam

[tursiops 81]

 

 

In terms of guide numbers, I think we should, in this instance, perhaps simply look at them as a non specific and hence fairly generic way of comparing strobe output. As mentioned, I was quoting manufacturers specifications, which (I think) did not list units.

 

 

What's worse is when the manufacturers themselves get confused. From the Sea and Sea website, http://www.seaandsea.com/

"Maximum guide number is a powerful 32 (ISO 100, meter)."

 

From the Retra website, where they ignore the GN units and get the Energy rating wrong

TECH SPEC:

• 100W/s
• GN30 in comparison with two strobes - see comparison here
• GN18 (absolute measurement on land)

And so on.

[SMY 15]

Adam,

 

thanks a lot for the very helpful anaysis work.. You helped me a lot to make my decisison....

 

Sascha

[rwe 4]

Because f-stops are a ratio of lens focal length to lens opening, the f-stop has no units, it is a pure ratio of two lengths.

 

From a purist point of view, f-stop does have units. As an example, mm focal length/mm effective aperture diameter. Since the 2 lengths are referring to different parameters, they do not cancel. While I realize that ignoring the units greatly simplifies communications, as a chemist, I find that many professionals can't solve problems by simple unit conversions because they think things like vapor/liquid distribution constants (concentration vapor/concentration liquid) also have no units.

[tursiops 81]

 

From a purist point of view, f-stop does have units. As an example, mm focal length/mm effective aperture diameter. Since the 2 lengths are referring to different parameters, they do not cancel. While I realize that ignoring the units greatly simplifies communications, as a chemist, I find that many professionals can't solve problems by simple unit conversions because they think things like vapor/liquid distribution constants (concentration vapor/concentration liquid) also have no units.

LOL. I guess this is the difference between mathematics and chemistry.

[Nicool 26]

Since Adam was asking for personal experience i’ll shared mine with a pair of Retras which i borrowed for about 1700 shots over 6 dives (some dives 2h40 long with action, i am not shooting that crazy )

My current strobes being Inon z240 x2, here is my subjective take on the Retras:

 

Pros for retras:

-maintenance: much quicker to swap batteries as i am leaving the oring in and grease it every 10 openings only

-simplicity of usage

-no acc button/magnet that can get stuck/corroded and mess-up my photos

-fiber optics routing (rear mounting ball easier i find)

-battery indicator... though i like in principle the idea, in reality it didn’t turn too reliable, and after exchanges with Retra it appeared it was due to me using very old batteries (1st gen eneloop). I bought some new eneloop pros but couldn’t try them as i had to return the strobes before.

-ease to mount various diffusers

-resistance to overheating - though i haven’t tested it that much but trust that aluminium housing helps cooling strobes down

 

Cons:

-batteries drain if left in strobe turned off! Again this may not happen with my fresh eneloop pros, but with my inons i had the habit to leave batteries in between dives (usually i dive once a week on weekend only) and that wasn’t a problem with inons

-strobe angle: probably just subjective, but i was shooting with shark diffusers (didn’t get the wide angle diffusers) which are supposed to preserve the retra’s original 110deg, but i felt like the coverage was lower than with my Z240s and diffuser (although 110 degrees).

 

Now i am left to choose between Retra and Inons and still not sure what to do :-)

The over-heating issue of the Inons was big concern for me but Adam’s review indicates this is solved... although i wish Inon didn’t keep that statement on letting strobe cool down if the problem really got addressed!

Also, not sure how useful the rotating Inon shade is.

Thinking... thinking...

 

 

Envoyé de mon iPhone en utilisant Tapatalk

[errbrr 73]

The batteries left the retra appear to drain quite fast while off, even with brand new eneloops. It's annoying because I normally load batteries into strobes for travel to reduce the number of spare batteries I'm carrying. With the retras I then take them out and put fresh ones in on arrival. Then again, Z240s could have been doing the same thing and with no battery indicator I wouldn't know. I rarely run the Z240s flat with changing the batteries before every dive and have never had a problem with them going flat after only a few shots.

[SMY 15]

With the help of the review, I decided now to give the Inons a chance.....and wait for the colour diffusors to come, too. What I still haven't understood is, why the battery compartment needs an inner and outer cap....others have it in one piece....

 

Sascha

[Draq 118]

With the help of the review, I decided now to give the Inons a chance.....and wait for the colour diffusors to come, too. What I still haven't understood is, why the battery compartment needs an inner and outer cap....others have it in one piece....

 

Sascha

 

It is the system Inon has used for years. From a technical standpoint, the inner piece is not really a cap as much as it is the contacts for the batteries. It isn't waterproof. It appears that Inon has not changed the battery compartment at all. I think they should have re-designed it so that a flooded compartment could not flood the strobe. I think that is the one real weakness of these, although I have used Inon strobes for a long time with no problem and would not let it deter me from buying these. I think the color diffusers may be out already. Backscatter lists them on their site.

[ChrisRoss 150]

If you are using the battery indicator to judge what is going on be careful as it could just be self discharge, The capacity voltage curve of the NiMH type battery is very flat so difficult to judge% charge based on voltage, which I am assuming what is being used with the charge indicator. The best way to judge would be to take two sets of known good eneloops or your battery of choice of about the same age. Charge them up put one set in the flash, the other out, wait your week then recharge them both together and see if the set in the flash takes longer to recharge indicating more drain.

Edited February 22, 2018 by ChrisRoss

[Draq 118]

If you are using the battery indicator to judge what is going on be careful as it could just be self discharge, The capacity voltage curve of the NiMH type battery is very flat so difficult to judge% charge based on voltage, which I am assuming what is being used with the charge indicator. The best way to judge would be to take two sets of known good eneloops or your battery of choice of about the same age. Charge them up put one set in the flash, the other out, wait your week then recharge them both together and see if the set in the flash takes longer to recharge indicating more drain.

 

I have no idea about this. just asking. If what you say above is true, then would that suggest the charge indicator lights are unreliable in general?

[ChrisRoss 150]

In general yes, if it is based purely on voltage, the cells typically experience a small drop and then voltage remains pretty much flat till it is is all but empty then drops rapidly. The indicator will give some representation but due to the small voltage changes involved is only an approximation.

 

If you are storing for a period of time it is possible that the drop you see from is the initial rapid drop from about 1.4V to about 1.22. From this point on the voltage drops very slowly from maybe 1.22 to maybe 1.18 then drops rapidly. This may be enough to cause the power signal to drop from 4 to 3 lights on. but in reality only represents something like 5% of the battery capacity. Before concluding this is a problem I suggest you need to compare to batteries charged at the same time, but not stored in the flash.

[hellhole 21]

 

This is very interesting and there was certainly no such notice with the strobes supplied for this review. Could you take a picture of it?

 

I can state that I have seriously violated this guideline repeatedly and there has been no obvious negative effect on the Z330s or their performance! I did 4 back to back battery tests of the strobes, cycling at full power soon as the ready light appeared... that's around 1000 flashes with no break in between!

 

In terms of guide numbers, I think we should, in this instance, perhaps simply look at them as a non specific and hence fairly generic way of comparing strobe output. As mentioned, I was quoting manufacturers specifications, which (I think) did not list units.

 

I note that the unit is Ws rather then W/s and thank you for this correction.

 

Adam

Here...

[Oskar@RetraUWT 54]

Thank you very much Adam for making the review!

 

I will try to answer some comments below.

 

From the Retra website, where they ignore the GN units and get the Energy rating wrong

TECH SPEC:

• 100W/s
• GN30 in comparison with two strobes - see comparison here
• GN18 (absolute measurement on land)

And so on.

 

Thank you "tursiops" for noticing the mistake in the energy formula, it should of course be multiplied (*) and not divided (/).

In the comparison we stated that the GN calculation was done at 1 meter. We've amended that as well so it is now clear directly in the specs.

 

 

-battery indicator... though i like in principle the idea, in reality it didn’t turn too reliable, and after exchanges with Retra it appeared it was due to me using very old batteries (1st gen eneloop). I bought some new eneloop pros but couldn’t try them as i had to return the strobes before.

Cons:
-batteries drain if left in strobe turned off! Again this may not happen with my fresh eneloop pros, but with my inons i had the habit to leave batteries in between dives (usually i dive once a week on weekend only) and that wasn’t a problem with inons

 

Thank you "Nicool" for sharing your experience!

- In our case the battery indicator is based on voltage and is calibrated roughly for both types of eneloop batteries. If the batteries are older their voltage will drop more quickly under load and the indicator will show less lights after a few shots. With new batteries it should drop less and the indicator should provide a better insight where the batteries are on charge.

- Our practical instructions state that our strobe will consume a little bit of energy in OFF position and we do not recommend leaving batteries inside for longer periods of time. There is an unofficial way to overcome this if you want to leave the batteries inside the compartment: Leave the strobe in ON mode and unscrew the battery compartment lid until the strobe shuts down, unscrew for another turn to make sure there will be no contact and put the strobe in OFF position.

Thank you all very much and looking forward to keeping in touch.

[Nicool 26]

Thanks again Oskar for answering questions of the community here! Based on our earlier emails exchanges plus discussion here, i guess a good way to find out more precisely if the batteries are still good for 1 more dive is to do 2 - 3 test shots on-land and check again the battery indicator. If it still shows the same, good.

In fact, i was doing something similar with my Inons z240: turning them on, doing 2 shots at full power - 1.5 stops (just because it’s a power level i often use) and make sure each time that the red ready light would come back instantaneously. If taking time, i would change batteries.

 

Back to the comparison between the new strobes on the market, there is one element of behavior that is for me important: if the capacitor didn’t have sufficient time to charge, at the next shooting attempt i am expecting the strobe wouldn’t produce any light, giving priority to producing the exact amount of light required as opposed to producing « something ».

The benefit in such a behavior (at least what i see on the Z240s) is that during action and when i don’t have time to look at strobes ready light, i’ll quickly find out if some of my photos are unlit when reviewing on the screen, and then i’ll reduce flash output if i see the strobes aren’t keeping up the pace.

 

Adam or anyone, can you confirm that the strobes tested behave like that?

 

 

Envoyé de mon iPhone en utilisant Tapatalk

[Nicool 26]

Thanks again Oskar for answering questions of the community here! Based on our earlier emails exchanges plus discussion here, i guess a good way to find out more precisely if the batteries are still good for 1 more dive is to do 2 - 3 test shots on-land and check again the battery indicator. If it still shows the same, good.

In fact, i was doing something similar with my Inons z240: turning them on, doing 2 shots at full power - 1.5 stops (just because it’s a power level i often use) and make sure each time that the red ready light would come back instantaneously. If taking time, i would change batteries.

 

Back to the comparison between the new strobes on the market, there is one element of behavior that is for me important: if the capacitor didn’t have sufficient time to charge, at the next shooting attempt i am expecting the strobe wouldn’t produce any light, giving priority to producing the exact amount of light required as opposed to producing « something ».

The benefit in such a behavior (at least what i see on the Z240s) is that during action and when i don’t have time to look at strobes ready light, i’ll quickly find out if some of my photos are unlit when reviewing on the screen, and then i’ll reduce flash output if i see the strobes aren’t keeping up the pace.

 

Adam or anyone, can you confirm that the strobes tested behave like that?

 

 

Envoyé de mon iPhone en utilisant Tapatalk

In fact, thinking twice about it i am not too sure what would be my favorite strobe behavior in regards to capacitor not fully charged, but i'd still like to know how the Retra and Inon are supposed to behave in that regards.

cheers

Nicolas

[Oskar@RetraUWT 54]

In fact, thinking twice about it i am not too sure what would be my favorite strobe behavior in regards to capacitor not fully charged, but i'd still like to know how the Retra and Inon are supposed to behave in that regards.

 

If there is something fast going on and you are unable to wait for the complete recycle time you usually want to get some light onto the scene instead of having a dark image, later possibly solving it in post production. The Retra Flash will fire before the ready light is on.

[trimix125 73]

Hi,
if you want to avoid discharge during travelling, and leaving the batteries inside the strobe, simply cut a piece of thin plastic ( like the wrapping from the eeneloops ) that will fit on the batteries but as well under the batterie compartment cap and put it there, before closing the cap.
Done that with my Inon D2000 for travelling and it worked fine.

Thanks for the work that is done for the testing.
But still not sure which i will choose ;-)))

Regards,
Wolfgang