Oskar - Retra UWT

Backscatter (BS) recently published a comparison of more than thirty underwater strobes. It is an impressive amount of work and contains genuinely useful data. We have now gone through that data in detail, repeated several measurements ourselves, and published our findings here: https://www.retra-uwt.com/blogs/news/a-closer-look-at-backscatters-strobe-test-retra-uwt We found several issues that we think deserve discussion: Guide numbers are plotted on a linear scale, which makes differences between powerful strobes appear larger than they are in photographic terms. We replotted the data in F-stops. The beam viewer uses different exposure settings for some strobes and does not normalize their centre brightness, so it should not be treated as a calibrated beam comparison. There are almost no error bars, variance figures or trial counts, making it difficult to tell whether smaller differences are meaningful. We could not reproduce the reported Retra Maxi color-temperature behaviour or its reported Boost recycle time. The Isotta RED64 guide-number result appears inconsistent with BS’s own beam images and flash-duration data. There is also a commercial context worth acknowledging. BS is both a retailer comparing products it sells and the owner of a strobe brand included in the comparison. That does not automatically make the data invalid, but it does make transparency about methods, uncertainty and commercial interests particularly important. This commercial focus is also visible in the content BS produces for its website and social media. The commanding majority of its promotional effort is focused on its own branded products. Including many competing brands in the test is commercially useful for BS. It creates the impression that they have a complete overview of the market and can offer neutral advice on almost every available strobe. Many customers come to BS precisely because they are undecided and want guidance. Once BS is accepted as the authority with all the data, it becomes much easier for them to steer those customers towards their own products. This does not automatically mean that the data is false, but it is an important reason to examine how the testing and presentation may support that sales strategy. The same standard applies to us. Retra manufactures two of the strobes discussed in the test, so we are not a neutral third party either. We have disclosed that interest and included our methods, measurements and reasoning so they can be challenged directly. Our intention is not to dismiss BS’s work. We would like to see the questionable readings checked, the charts improved and more information about measurement uncertainty published. If anyone finds an error in our analysis, please point it out. We will correct it. I’m interested to hear how others interpret the data, particularly the color-temperature results, the RED64 reading and whether guide-number charts should be presented in F-stops.

Thank you, Dave. We’ve fixed the legends and improved readability on mobile devices. If anyone else has any suggestions, please let us know. We’re planning to publish the article next week. https://www.retra-uwt.com/pages/a-closer-look-at-backscatters-strobe-test-retra-uwt

Our commentary of the test will be published soon, here is a preview: https://www.retra-uwt.com/pages/a-closer-look-at-backscatters-strobe-test-retra-uwt

Quick heads-up for anyone who has been on the fence about the new Retra Maxi strobes: Launch pricing for both versions (with and without the video light) ends on September 1st. After that, prices will increase, so this is the last chance to order at the current launch price: https://www.retra-uwt.com/products/retra-maxi

Europe and Australia recently struck a trade deal making almost all import/export tarrif free. Especially strobes and accessories (tarrif codes 9006.61 and 9006.99) are now free of any tarrif charges except local GST which currently sits at 10% making the final price even more affordable than in Europe where average VAT rate is around 22%. Shipping is fast too, 2-3 working days to most locations from EU to AU. Repairs are rarely required but in case something brakes the turnaround would be 2 weeks from pickup to delivery. The same team that designs and produces the strobe will also service/repair it to guarantee the highest quality.

Hi, please copy/paste your issue to our email: help@retra-uwt.com This is by far the fastest and the most reliable way of getting any issue resolved with any Retra product. P.S.: sounds like a sensor malfunction, there are potential temporary workarounds.

Note for potential buyers: These strobes remain covered under our factory warranty until May 2026. The warranty can also be extended by an additional 2.5 years, until November 2028, through our RetraCare+ program: https://www.retra-uwt.com/pages/retracare-warranty This ensures continued coverage and peace of mind for the next owner.

I think this is a good question for Dave who is reviewing the strobes. Drop a comment here: https://waterpixels.net/forums/topic/3192-preview-of-the-retra-maxi-strobe

@Dave_Hicks is testing the new Maxi strobes quite intensively and is sharing his first impressions here: https://waterpixels.net/forums/topic/3192-preview-of-the-retra-maxi-strobe If you would like to see him test anything specific you can ask in the comments.

The battery contacts in the Maxi have multiple layers of anti corrosive coating with a silver coloured finish, designed specifically to protect the connection points. Historically we have not encountered issues with this coating unless there was water ingress or a short circuit caused by a damaged battery or incorrect battery orientation. Incorrect orientation is not possible in the Maxi battery compartment and the new li ion batteries typically include short circuit protection. If water enters the compartment the contacts can get damaged, although in all past cases users were able to clean them well enough for the strobe to power on and remain usable. Any replacements (if necessary) were carried out only after they had successfully completed their diving trip.

Hi! The battery contacts have multiple layers of anti corrosive coating with a silver coloured finish, designed specifically to protect the connection points. We have not encountered issues with this coating unless there was water ingress or a short circuit caused by a damaged battery or incorrect battery orientation. Incorrect orientation is not possible in the Maxi battery compartment and the new li ion batteries typically include short circuit protection. If water enters the compartment the contacts can get damaged, although in all past cases users were able to clean them well enough for the strobe to power on and remain usable. Any replacements (if necessary) were carried out only after they had successfully completed their diving trip.

We recommend the Wide angle diffusers for the Maxi, primarily because the Maxi has cooler light output by default and those diffusers help warm it up. Quality of light is coverage, color temperature and distribution.

Hi Dave, would you be interested in doing an independent review? I think Matt can send you his pair when he is not using them. Please send me a message and we will work out the details. The Maxi strobe is optimized for high GN and lithium performance instead of the refined light quality and compact size of our Pro series strobes. There are obvious differences in the light they produce, comparison below. The Maxi reaches about 80% of the light quality that our Pro series strobes offer.

All Retra Flashes from the very first version stay powered on until they are switched off. This design comes from real use in the field, where a photographer may wait for hours for a single shot and prefers not to touch the strobe so the animal is not disturbed. Once the strobe is on, it continually tops up the capacitors so it is always ready to fire, and this naturally uses some battery power. With the 8xAA battery pack, the stand by time is around 24 hours, which is also stated in the data sheet. The trade off is that if you forget to switch the strobe off, it will eventually run the batteries down. We are considering adding a timer option for users who would like the strobe to switch itself off automatically. Thank you for your feedback.

By the way, we have 4 units of the previous-generation Pro Max strobes left. Please write to our email if you’re interested.