Preview: Retra Strobe by Alex Mustard

by adamhanlon Wednesday, February 1st, 2017

RETRA Flash-Preview

By Alex Mustard

This is not a normal review. This product is not yet production ready and it has not yet been underwater. However, we feel it is worth covering on Wetpixel because it is an exciting new addition to the underwater photography market-place and because it will be available from today for significantly discounted pre-orders. Furthermore, there are many companies that make housings, strobe arms and lights, but relatively few that make strobes. So a new, serious entry to the market is noteworthy.

Retra Flash. Compact design, lots of power. Diffuser is mounted with bayonet, which allows other accessories to be attached easily.

Retra are a European company best know for their optical snoots and other innovative accessories for the underwater photographer, such as the uTrigger underwater remote release. This strobe is a new venture for them.

I first heard from Retra about this strobe in mid-2015, gave feedback on an early prototype in early 2016 and took a working prototype with me this year to the Bahamas. That trip allowed me to compare it with all other major strobes (we had Seacam 150, Subtronic 270, Sea & Sea YS 250, Ikelite DS161, Inon Z240 and Sea & Sea D1 with us in Bimini) and to get some final feedback from the underwater photographers I was diving with - potential customers. Despite this involvement with the product, I am keen to state that I have not been paid for my opinions and don’t benefit in any way from future sales of this product.

Retra Flash. Simple, large, easy to use controls. Options of electronic and optical synch (TTL available with optical synch).

Anyone who has read Underwater Photography Masterclass will know my obsession with quality of light and the value of wide, soft illumination for underwater images. This is partly because ambient light has these characteristic underwater and partly because we work so close to our subjects that light has little distance to spread and soften. Not only does wide, soft light make subjects look better, it also makes strobe positioning and aiming slightly less critical, so makes you look like a better photographer too!

Soft, even illumination brings out the best in most underwater wide angle subjects.

I am pleased to say that the Retra Flash has been designed by underwater photographers with this attitude first and foremost. Retra have spent a lot of effort on their reflector and diffuser to produce a wide, even illumination. The key to great light from an underwater strobe is to have as wide a spread of the brightest illumination as possible. I.E. to have almost the same amount of light reaching the subject in the centre of the beam and the edges.

Comparison between the beam coverage of the Retra Flash and INON Z240, Sea & Sea YS 250, Ikelite DS 161, Seacam 150 and Subtronic 270 (all fitted with manufacturer’s diffusers, except Subtronic which does not have them). All photos taken at 5000K on camera, so warmer strobes appear more orange and cooler strobes are more blue.

Another exciting factor in the design is that the diffuser mounts to the strobe with a bayonet, which is clearly designed to make it very easy to add other accessories to modify the light from the Retra Flash for other types of lighting for different shots, including using optics as in Retra’s LSD snoots.

The ability to adjust my quality of light is one of the main reasons I use Seacam strobes. I use the diffusers (a) for close focus wide angle, I take them off (b) for big scene wide angle and big animals, and add the black beam restrictor rings (c) to give my light a hard edge for inward lighting and in low viz. Retra plan to take this philosophy to the next level.

The Retra Flash is clearly designed as a performance upgrade for photographers currently shooting INON or Sea & Sea D1/D2 etc strobes. It is a similar size to both, although housed in a tough aluminium casing, and uses Sea & Sea electronic synch cables or fibre optics. It even takes 4 x AA batteries meaning you can even continue with the same chargers. But the Retra strobe out-guns its Japanese rivals with much wider, more even light and a bit more power (I was told that the test unit was turned down). The compact size is not only a value for travel, but also aids strobe positioning for shots where the strobes need to be tucked in close to the lens.

Size comparisons of the Retra Flash with INON Z240

Seacam 150

Subtronic Mega Colour.

Guide Numbers are often used as a measure of strobe power. But they can be very misleading because they simply tell us how bright the centre of the beam is. I’ve already said that far more important is how wide the bright part of the beam spreads, and the wider you spread a beam the lower the Guide Number (as anyone who has ever eaten strawberry jam will attest – the more you spread it, the thinner it gets).

The easiest way to achieve a high Guide Number is to narrow the beam angle. Nikon’s land flash the SB-910 has the massive Guide Number of 53 (in metres, ISO 100), but only when the flash head is zoomed in to only cover the narrow frame of telephoto lens! When the Sea & Sea D1 was released it was marketed as having the same guide number as the much bigger, more expensive Sea & Sea YS-250 (my test below actually found it 1/3 stop greater), but it of course has far less power than its big brother (it achieves the Guide Number because it has a narrow beam). The solution many Sea & Sea D1 owners use is to add a dome diffuser, which increases the angle of coverage, but also drops the Guide Number considerably.

The Retra Flash I was testing was slightly powered down from the production models. But it still produced the same Guide Number as the Z240, YS250 and DS161 (see below), while giving a much wider spread of light than the Z240 in particular. The Sea & Sea D1 recorded a slightly higher Guide Number in my tests, but had a noticeably narrower coverage than even the INON Z240. The Seacam and Subtronic strobes, which to me seem to use the same flash tube, are a step on again in power, coverage (and price).

GUIDE NUMBERS MEASURED FROM PHOTOS (ISO 100, in Metres)

Inon Z240 with diffuser – 16
Retra Strobe with diffuser – 16
Sea & Sea YS250 with diffuser – 16
Ikelite DS161with diffuser– 16
Sea & Sea D1 with diffuser – 18
Seacam 150 with diffuser - 22
Subtronic 270 no diffuser – 25
Seacam 150 no diffuser – 25

There are a few other neat features. The strobe features a line of 4 LEDs to show battery power remaining. The aiming light is wide angle, so it can also double as a focus light. It has two powers (up to 300 lumen) and is centrally positioned for optimum performance with snoots. The sTTL mode, that I did not test, has +/-2 stop adjustability.

Retra are announcing their new strobe today and plan to start delivering it in May/June 2017. It is planned to retail at €699 Euros (excluding VAT, but including Express Worldwide DHL Shipping). There are discounts for early orders. Order before the end of Feb and it is €499, order before end of March and it is €549, and before the end of April it is €599 Euros.

The only problem I found with the strobe was that it would not fire through Nauticam’s latest housing electronics (tried it on three different NA-D5 housings) with the electronic synch cable (Seacam strobes also will not fire). All other strobes (Inon, Sea & Sea, Ikelite, Subtronic) fired with electronic cables on the Nauticam housing. And all the strobes fired without problem on other housings with standard electronic circuits.

In conclusion, it appears from these dry tests that Retra has hit their target. This strobe packs the punch and the wide spread soft light of much larger strobes, like the Ikelite DS161 and Sea & Sea YS 250, in a compact package. The fact it uses 4 x AA batteries, optical or Sea & Sea electronic synch cables, makes it a straightforward upgrade for Inon Z240 and Sea & Sea D1 users. The travel and photography friendly size may also tempt users of bigger strobes. And if that does not, the availability of accessories to modify the light will certainly appeal to photographers who care about both quantity and quality of light.

What I can’t answer in a dry review is what the strobes are like to use underwater. Will the 4 x AA batteries be enough to ensure fast recycle times at typical settings? And most critical of all, how reliable will the strobe be? On that last point, Retra seem confident and offering a two year warranty with each flash.

I’d like to thank Retra, Peter de Maagt, Theresa Guise, Martyn Guess, Martina Engels Dunmore and Nadia Aly for lending me strobes for this test.

Alex Mustard. January 2017

Retra Flash tech-spec:

● 100W/s
● 2.5s recycle time (4x eneloop pro)
● 200x full power flash (4x eneloop pro)
● 3 hour with pilot light
● 5500K color temperature (4700K with wide diffuser)
● 95º beam angle (110º with wide diffuser)
● 9 manual exposure levels
● S-TTL with +/- 2 F-stop adjustment
● Slave mode with smart pre-flash cancellation
● 300 lumen pilot light
● 4 level smart battery indicator
● S&S 5 pin, S6, N5 connector options
● Inon, Sea&Sea dual optical connector
● Length = 120mm
● Diameter = 102,5mm
● Weight = 650g (without batteries)
● Underwater weight = -50g
● -100m depth rating
● 2 year extendable Retra Warranty

For more information, please see the Retra website

Hello everyone!

Since there have been a lot of inquiries this week I just wanted to give a quick update:

Right now we are super busy with the pre-production run of the new Retra Flash. At the end of this month we will publish an extensive update on the progress and we will also announce some of the accessories. We are very excited to show you what we've done!

The shipping schedule has been delayed a little bit and we expect to start shipping at end of June/early July. An exact shipping date will be published in the update.

We'll be in touch soon...

Thanks

Posted by Oskar@RetraUWT on 2017-05-17 09:45:36

Thank you for your order!

Posted by Oskar@RetraUWT on 2017-03-02 20:01:57

Thank you, we will continue the debate there.

Posted by Oskar@RetraUWT on 2017-03-02 20:01:18

Hi Retra, I started a thread in the Lighting forum called Retra Strobes. I hope that will be a central clearinghouse for questions and answers on these.

Posted by floridaguy on 2017-02-28 13:20:12

My YS-D1 cracked around the battery housing and can't be fixed. Well, I just ordered 2 of these plus one LSD. Will sell my D1 when they arrive. Really, the prices you are offering look excellent. Can't wait until June. Please keep us posted on progress. Why can't you post a thread in the lighting forum? I will start one and you can post in that.

Posted by floridaguy on 2017-02-28 13:13:39

Hi Liz, thank you for your order!

Posted by Oskar@RetraUWT on 2017-02-26 20:52:44

I use it for photos where I don't want the on camera strobes lighting the foreground. Off camera light only creates great backlighting and a few more options. But the only way to achieve it is to find another method of strobe triggering. So far I have used a small LED torch held by the model to set off the triggerfish. It's not the best system for sure.

I have ordered two! Looking forward to their arrival in June.

Posted by Liz Rogers on 2017-02-26 12:41:10

I'm debating on buying a Symbiosis SS-2 now or waiting for these. Has anyone compared the Symbiosis SS-2 flash size/intensity to the 240, YS250 or DS161?

Posted by Stapler on 2017-02-13 04:07:19

Hi John, I have asked Adam Hanlon about this and he said that I can answer any questions which will arise in the forum but I can not create a thread by myself.

Posted by Oskar@RetraUWT on 2017-02-07 05:20:47

Hi John, I will check with Adam Hanlon.

Thanks

Posted by Oskar@RetraUWT on 2017-02-05 01:59:31

For ease of access and updates, unless it violates a forum rule, I think perhaps opening a thread in the lighting forum to update progress and answer questions would be a nice way to continue this discussion...

Posted by John on 2017-02-04 12:03:51

You're welcome.

There is no need to take off the o-ring every time you open/close the battery compartment lid. Lubrication should be kept to a minimum.

Thanks

Posted by Oskar@RetraUWT on 2017-02-04 07:34:58

Thanks Oskar, my other questions were already asked and answered with others below :)
While i appreciate it is difficult to include a vacuum check system in a strobe design, i still think it's very useful, because it should significantly help reduce the chances of a battery compartment flood.
It's good to know the Retra Flash could still be repaired after such a flood, but the bottom line is if it happens during a remote dive trip, the dive trip is still ruined.
Hence i remain convinced of the value of vaccuum checks on strobes :)

Around that topic i'd have one more question: what will be the recommended practice in oring maintenance?
Does the oring need to be taken off and lubricated each time the battery box is opened?

Posted by Nicool on 2017-02-04 06:08:30

Hi Nicolas, thank you for your feedback.

A vacuum check is valuable when the seals are being opened and closed regularly and a user error can cause flooding.

With the Retra Flash the battery compartment and the connector pins are both sealed away from the rest of the strobe which means you can not critically damage the strobe with user error. If water get's inside the main compartment it will be covered by warranty.

Let me know if you have any further questions/suggestions or check the comments below if they were already answered.

Thanks

Posted by Oskar@RetraUWT on 2017-02-03 23:28:24

Hi Oskar,
I think protection to flood is very important(for te peace of mind it brings to the photographer): if there is any chance to integrate a vaccuum check with retra strobe or with your future strobes, this would be very valuable.

Regards
Nicolas

Posted by Nicool on 2017-02-03 14:57:22

Hi Erik, the additional battery pack will be for standard AA batteries.

Posted by Oskar@RetraUWT on 2017-02-02 12:50:37

How will you charge the battery pack?

Posted by Erik on 2017-02-02 11:59:44

I didn’t test this as the Retra flash was still an early prototype

Posted by Alex Mustard on 2017-02-02 02:37:13

We are aiming for the price to be around €99,00EUR (excluding VAT).

Posted by Oskar@RetraUWT on 2017-02-02 02:23:23

Oskar what would the cost be for the additional battery pack?

Posted by Mark Gray on 2017-02-02 02:17:58

You can trigger the Retra Flash optically (SL mode) or via electrical cable (ON mode). I'm curious to know why you need a test button for cave photography?

The silver button in the middle controls the pilot light.

Posted by Oskar@RetraUWT on 2017-02-02 01:27:45

Hi Domenico, thank you for your questions.

The battery compartment is determined by the size of the batteries and their organisation inside the housing. We are using an arrangement that follows the curvature of the housing.

The colored indicator light will illuminate the dials and the markings so they will be visible on night dives. One of the biggest advantages of the Retra Flash is that the markings are very big and clear so they are easy to read.

Let me know if you have any further questions or check the comments if they were already answered.

Thanks

Posted by Oskar@RetraUWT on 2017-02-02 01:24:29

Hi Mark, thank you for your questions!

1. Currently we have the option of S&S 5 pin or S6 or N5 connectors. We will probably include the Ikelite as well. The connectors will be exchangeable and you will be able to buy them separately.
2. We will give the specifications when the battery pack is available - before we start shipping the strobe. You can expect the time to be around 1,5s for a full power recycle with AA eneloops.
3. Full power flash quantity with the additional battery pack will be determined once it will be officially announced. You can expect the number to be at least 300.
4. The additional battery pack will be for standard AA batteries.
5. Yes, the additional battery pack will not require any modification of the strobe.
6. We are already offering a domed diffuser which has very uniform coverage as Alex showed above in comparison to other strobes. Although I must add that not all of the accessories that will be included with the strobe are presented at the moment. At least another collar for reducing the angle of light will be added.

Let me know if you have any further questions or check the comments below if they were already answered.

Thanks

Posted by Oskar@RetraUWT on 2017-02-02 01:20:19

Hi Matt, right now the recycle time is 2,5s at full power on 4x AA eneloop pro's. We are planing an additional battery pack which will be announced before shipping the strobe. It should dramatically reduce the recycle time (around 1,5s). We will make a more detailed comparison with other strobes so make sure to follow.

Thanks

Posted by Oskar@RetraUWT on 2017-02-02 01:06:26

Hi Oskar, some basic questions, the flash's body looks very minimal with a tiny space dedicated to the battery compartment, this seems to reduce the risk of flooding in theory so it means that all other producers so far made bulky battery compartments for no reasons? One of the main reason I hate my YS-D1 is the knobs turns by themselves just looking at them, on the other hand I loved my YS-D2 illuminated knobs before they flooded on my second dive with them. Are your knobs illuminated this is essential feature for me. Thanks

Posted by Domenico Luzzi on 2017-02-01 22:11:18

Hi Oskar, I have a few questions regarding your new strobe:

1.What hard wired sync cord connection will the strobe have?
2.What will be the recycle time of the strobe with the additional battery pack?
3. How many shots will the additional battery pack deliver?
4. Will the additional battery pack be user changeable AA or will be a dedicated battery pack similar to Ikelite ds125/160?
5. Will it be easy to change the additional battery pack back to standard strobe battery configuration?
6.Will you be making a Dome diffuser for this strobe?

Look foreward to your answers,

Regards Mark

Posted by Mark Gray on 2017-02-01 16:08:32

How does the recycle time compare to the YS-250 at full and half power?

Posted by Matt Morgan on 2017-02-01 14:31:06

Sometimes my photography distresses me :-)

A test fire button would be very useful, especially for the caves. I can see using the SOS feature for this. What is the silver post in the middle of all the buttons?

Great to hear about the overheating protection.

Posted by Liz Rogers on 2017-02-01 14:11:43

Hi Liz

We have built-in heat fuses which temporarily disable the strobe if it gets to hot in certain critical areas, including the batteries. This means you can't damage the strobe with repeated flashes. It turns itself off until it's cooled down. Aluminium housing helps a lot.

SOS mode is purely for releasing light signals in distress. It's not designed for photography purposes.

Thanks

Posted by Oskar@RetraUWT on 2017-02-01 13:58:24

Hi Erik, thank you for the compliments and the questions.

We have only indicated the main power levels without the middle options. The production version will have these markings. And yes, they will all click.

That is correct. S-TTL is +/- 2EV in 0.5 steps.

The battery compartment has a single o-ring but the inside of the strobe is sealed separately. The electrical connector also has sealed pins. If water gets inside the strobe (excluding battery compartment and space around connector pins) it is covered by our warranty.

We are using a singular linear flash tube made from quartz glass.

Not all accessories which will be included in the package are featured at the oment. Besides the wide angle diffuser we are planing at least another collar to narrow the light beam. More info will come as we get closer to shipping.

Thanks

Posted by Oskar@RetraUWT on 2017-02-01 13:50:41

Two questions from me as well:
1. How is the strobe protected against overheating, especially with repeated full power shooting in tropical waters and dry firing? I have burnt out the flash tubes on my Inon Z240s a couple of times.
2. Will SOS mode function as a test button? So I could trigger the strobe just by turning to the SOS setting? Is this at full power?

Posted by Liz Rogers on 2017-02-01 13:46:27

Hi John thank you for your questions.

I am sorry if the text is confusing - of course we will include a user manual!

ON is manual mode with triggering only via an electrical cable. It is the most basic mode and does not require pre-flash cancellation.

SL (optical slave mode) triggers only via optical cable and normally it triggers the flash upon detection of short pulsed light - flash. The smart pre-flash cancellation can be enabled with a separate control while in SL mode. It will probably be a long press of the pilot light button.

We are using a singular linear flash tube and a singular LED pilot light.

We have only indicated the main power levels without the middle options. The production version will have these markings.

If something is not clear please let me know, I am happy to explain.

Posted by Oskar@RetraUWT on 2017-02-01 13:43:17

Hi,
I have an LSD Retra and I am very happy with the Quality.
I have some questions....
1) Exposure Levels. It looks like there are only 5 steps. However, it states 9 Levels. Therefore, I assume that only every other exposure Level is printed on the Strobe and there is a click between the printed steps. Correct?
2) If my guess of 1) is correct. It would then indiretly imply that the S-TTL is +/-2EV in 0.5 steps. Correct?
3) How many O-rings does the Battery Compartement have?
4) Flashtube: what is the shape?
5) Accessories: What are the plans?
Will you do a short narrowing tube for "inward lightning"?

/Erik

Posted by Erik on 2017-02-01 13:33:19

Your webpage says no owner's manual necessary, but I seem to be a bit dense. I assume that if using the strobe via optical fiber, setting it to "on" will result in a full power dump when triggered optically, and is adjustable by two stops up or down. Your description on your webpage says there are 9 manual power levels. I don't understand how that would work with the controls on the strobe.

My camera does use a pre-flash that can be turned off, so if I want to use the strobe in manual mode I assume I need to turn off the pre-flash on the camera. You mentioned that manual use of the strobe required an electrical connection but I assume it also works via optical cable if the pre-flash is disabled. Is that right?

It appears to me that instead of a typical flash tube, your strobe uses LEDs arranged in a rectangle. Is that right?

Thanks

Posted by John on 2017-02-01 13:04:28

That's correct. Electrical cables will only work in manual mode on the Retra Flash.

Posted by Oskar@RetraUWT on 2017-02-01 09:36:45

Ah so won't work with electrical cables on the ikelite then with TTL on the camera.

Posted by Michael Wicks on 2017-02-01 09:26:55

Hi Michael, thank you for your question.

The TTL on the Retra Flash is going to be based on optical fibres which means it will work like a S-TTL (slave TTL). It is more similar to what Inon or Sea&Sea are offering.

Posted by Oskar@RetraUWT on 2017-02-01 09:13:36

Will the TTL work similar to that as the DS161 on the ikelite housing?

Posted by Michael Wicks on 2017-02-01 09:03:57

If you want to use your on board flash and connect with optical fibres you just set the strobe to "SL" and use the right knob for adjusting the power output.

If you have an electrical cable connected you set the strobe to "ON" and use the right knob for adjusting the power output.

Posted by Oskar@RetraUWT on 2017-02-01 08:57:57

So what setting works for manual setting on the camera, manual on the strobe and optical firing through the cameras on board flash set to low power? That is the only setting I ever use, and probably many others, I guess.

Posted by Bent Christensen on 2017-02-01 08:44:43

No problem, you can ask me anything.

ON is manual mode with triggering via an electrical cable. It is the most basic mode and does not require pre-flash cancellation.

The smart pre-flash cancellation is intended only for SL (optical slave mode) and only if you have a camera which can only fire with pre-flash. These are generally small compact cameras.

Posted by Oskar@RetraUWT on 2017-02-01 07:22:08

Final questions now ;). I looked at your home page and the settings. Will "On" be what is manual for Z240? I assume there is a pure manual option. Also, the Icons need some pin-pushing in order to work with Canon dslr. Does your strobe work out of the box, or is there some settings available for ignoring pre-flashes when used in normal manual mode? If that is even a problem, thinking about it I guess that manual shooting shouldn't have pre-flashes?

Posted by Bent Christensen on 2017-02-01 07:12:35

Yes, the Retra Flash can be optically triggered in SL (slave) mode. This mode also offers smart pre-flash cancellation if you are using a compact camera with mandatory pre-flash.

The Retra Flash weighs 650g without the batteries.

The standard 1" ball mount is included.

They can be ordered here: https://www.retra-uwt.com/coll...

Posted by Oskar@RetraUWT on 2017-02-01 05:46:57

Thanks! I guess that they can be used without cables as well and then triggered by another strobe, is that correct? How much do a strobe weigh? Is the ball connector included? Finally, where can they be ordered?

Posted by Bent Christensen on 2017-02-01 05:39:41

Hi Bent, thank you for your questions.

Inon and Sea&Sea optical connectors are both compatible. The optical connector is threaded for Inon and the cap for the optical connector has a hole for the Sea&Sea plug.

The battery compartment is sealed so you can't flood the inside of the strobe. It's the same for the electrical connector. If water get's inside the strobe it's going to be covered by warranty.

Posted by Oskar@RetraUWT on 2017-02-01 05:29:49

What kind of optical cables will be necessary? And will the battery compartment be sealed against the electronics?

Posted by Bent Christensen on 2017-02-01 05:14:07

I would like to mention that the problem of connectivity with the latest Nauticam housing is only with the prototype. The production version of the Retra Flash will be compatible with these housings just the same as Z-240's, YS-D1's and all the rest.

Posted by Oskar@RetraUWT on 2017-02-01 02:47:56

Hi Everybody, I am Oskar Zupancic, founder and managing director at Retra. If you have any questions regarding the new Retra Flash I am happy to answer. I will be checking this commentary regularly.

Posted by Oskar@RetraUWT on 2017-02-01 02:46:12