My review of the Retra Maxi strobe is now available at Inside Scuba as part of issue #66.

I started this review with some initial previews here on WaterPixels and really appreciate the input and ideas from everyone here. As I worked on this I decided that a long term review was the direction I wanted to take. Not just a few dives or a single trip, but experience with it over months and over 100 dives and very diverse environments. In the end I shot with the Maxi's from Dec 2025 to the end of June 2026 when I wrote the review in early July. Then a few weeks of editing and revision followed by a couple more getting it ready for publishing by Inside Scuba.

Thanks to Andy Deitsch & Byron Conroy for agreeing to publish the article!

Inside Scuba

Long Term Review of the Retra Maxi Strobe

Dave Hicks tests the Retra Maxi strobe across 100+ dives in Raja Ampat and the Pacific Northwest, comparing it head-to-head with the Backscatter HF-1.

Thank you, excellent review.

I too had the problem on my second dive that one of my strobes would not turn off, the focus light was on but the strobe would not flash. I thought it had leaked and I rushed back to the boat, pulled the batteries. No leak! Reinstalled batteries and the strobe functioned normally. Upon getting back to the resort I emailed Retra and within an hour they answered assuring me there was no problem and to reload my software to 1.0. My eyes rolled back because I am NOT and computer person and I figured this would be an ordeal! Nope! Connected to the Retra App, downloaded the software, easy! Problem solved.

There is a learning curve with the Maxi due to their power and ultra wide beam especially with the diffuser. I have to put the strobes further out, turn them outward more and sweep them further back (behind the dome) to keep them and reflections out of my dome or even the more narrow FOV of the WWL. Also, unlike with previous strobes I have owned, borrowed, whatever, this is the first time I kept turning them down, down.

The Maxi strobes just do not feel large in the water, I got used to them quickly and was able to remove an outer float arm and replace that float arm with a plain arm.

The XStar 5000 batteries I am using just go and go and go!

Pool day prep for the NA-R50 for upcoming Maldives trip.

Edited August 10Aug 10 by Nemrod

2 hours ago, Nemrod said:

Thank you, excellent review.

I too had the problem on my second dive that one of my strobes would not turn off, the focus light was on but the strobe would not flash. I thought it had leaked and I rushed back to the boat, pulled the batteries. No leak! Reinstalled batteries and the strobe functioned normally. Upon getting back to the resort I emailed Retra and within an hour they answered assuring me there was no problem and to reload my software to 1.0. My eyes rolled back because I am NOT and computer person and I figured this would be an ordeal! Nope! Connected to the Retra App, downloaded the software, easy! Problem solved.

There is a learning curve with the Maxi due to their power and ultra wide beam especially with the diffuser. I have to put the strobes further out, turn them outward more and sweep them further back (behind the dome) to keep them and reflections out of my dome or even the more narrow FOV of the WWL. Also, unlike with previous strobes I have owned, borrowed, whatever, this is the first time I kept turning them down, down.

The Maxi strobes just do not feel large in the water, I got used to them quickly and was able to remove an outer float arm and replace that float arm with a plain arm.

The XStar 5000 batteries I am using just go and go and go!

Pool day prep for the NA-R50 for upcoming Maldives trip.

Great, glad you liked the review! You've already bought some Maxi's, so hopefully some other readers will use this to help with their buying decisions.

Your next step might be to buy some 12 and 16 inch arm segments. These can really help you get more value and flexibility from your strobes. Counter intuitively, one benefit of long arms that I take advantage frequently is effective inward lighting. For CFWA situations this is my go to move. You can get the strobes far enough away to avoid flare and glow, but you are able to get dramatic lighting without backscatter even in really poor clarity water conditions. (ask me how I know!) Long arms also enable better coverage for really large reef scenes, particularly when shooting vertical.

Edited August 10Aug 10 by Dave_Hicks

How are the ball mounts held on?

5 minutes ago, Grantmac said:

How are the ball mounts held on?

If you mean the ball mount on the Maxi, it's a 5mm hex nut through the ball.

I hadn't really looked at it previously. It comes attached as far as I know.

Edited August 10Aug 10 by Dave_Hicks

16 minutes ago, Grantmac said:

How are the ball mounts held on?

There is a single screw through the middle of the ball mount that goes into a sturdy thread in the strobe case. There is a plastic gasket to isolate (for corrosion) and an anti-rotation pin. Very solid mounting.

Excellent review @Dave_Hicks ! Very fair and well written. Terrific images as well!

Hope this is just the first of many more to come.

12 hours ago, Nemrod said:

There is a single screw through the middle of the ball mount that goes into a sturdy thread in the strobe case. There is a plastic gasket to isolate (for corrosion) and an anti-rotation pin. Very solid mounting.

The mount is very solid. Oskar told me once you cannot over-tighten them either. Not that I’ve tried!

The ball mount does not come installed. They were in a separate bag with the grease and spares and an Allen key. My recommendation is to remove the ball mount for transport to conserve on space and to remove the ball mount after a dive trip so that trapped saltwater there will not seize the threads or cause corrosion. A little dab of silicone grease will help as an anti-seize. This is not a fault or defect nor a complaint, just normal maintenance on an expensive item you will want to enjoy for many years.

Edited August 11Aug 11 by Nemrod

1 hour ago, Nemrod said:

The ball mount does not come installed. They were in a separate bag with the grease and spares and an Allen key. My recommendation is to remove the ball mount for transport to conserve on space and to remove the ball mount after a dive trip so that trapped saltwater there will not seize the threads or cause corrosion. A little dab of silicone grease will help as an anti-seize. This is not a fault or defect nor a complaint, just normal maintenance on an expensive item you will want to enjoy for many years.

Good to know. The review Maxi's didn't come in original packaging.

Sure, take them off if it saves space. I've never actually done that in about 20 years of traveling with strobes. I take mounts off of my camera housings very often as they significantly increases their space requirements.

@Dave_Hicks What an excelent review. You covered more than I could ever think of, evidenced with great pictures.

And I learned something new, never thought reduction rings would benefit wide angle photography in particle rich water. Sounsds logical, I often get lightened spots in the corners. It will try that out as soon as I can.

Ok, one comment. You noted that thant the Maxis are 5500-6000K and you have 4500K diffusers. On Retras website I only could find a -500K one (Wide Angle Diffuser).

Thanks for the comments. I am glad you liked the review and found it inforative!

Retra states in their product page for the Maxi that it is 4500k with the wide angle diffuser. And it looks like they updated the page to state the native color temp as well.

The Retra Maxi delivers GN46 and a color temperature of ~6200K. With the optional Wide Angle diffuser, it provides 160º coverage at ~4500K. Optimized for GN performance, this powerful strobe captures distant subjects with exceptional light output.

3 hours ago, Floris Bennema said:

@Dave_Hicks What an excelent review. You covered more than I could ever think of, evidenced with great pictures.

And I learned something new, never thought reduction rings would benefit wide angle photography in particle rich water. Sounsds logical, I often get lightened spots in the corners. It will try that out as soon as I can.

Ok, one comment. You noted that thant the Maxis are 5500-6000K and you have 4500K diffusers. On Retras website I only could find a -500K one (Wide Angle Diffuser).

I noticed a significant reduction in Backscatter first dive with my new Retras fitted with reduction rings. It's not a magic cure all and I can still manage to take a frame filled with Backscatter if I'm not concentrating but it's so much easier now to produce a frame without excessive backscatter.

@Dave_Hicks with the Maxi's - what power levels are you typically using when doing macro shooting nudis etc using the Nikkor 105mm?

9 hours ago, CCRphoto said:

@Dave_Hicks with the Maxi's - what power levels are you typically using when doing macro shooting nudis etc using the Nikkor 105mm?

Probably about 1/4 power, level 2 on the dial.

Here is one of a group of striped nudis (8-10cm each) devouring a Sea Pen. Shot with the curved port 60mm @ f14. Level 2 or 2.5 on the Maxis, using reduction rings.

Edited August 17Aug 17 by Dave_Hicks

2 hours ago, Dave_Hicks said:

Probably about 1/4 power, level 2 on the dial.

Here is one of a group of striped nudis (8-10cm each) devouring a Sea Pen. Shot with the curved port 60mm @ f14. Level 2 or 2.5 on the Maxis, using reduction rings.

Cheers - that is useful information for some image ideas that I am working on.

From the article:

"The battery compartment is confidently sealed with two heavy-duty Buna rubber O-rings. Most other strobes on the market, such as the Backscatter HF-1, are sealed with thinner and more delicate silicone O-rings."

The replacement o-rings I have received from Retra were labeled EPDM as are the Maxi ones on this page: https://www.retra-uwt.com/en-us/products/o-rings-for-retra-flash-battery-compartment

They should have a less obscure place to provide this specification as well as here.

Here is one of many o-ring material info pages: https://www.theoringstore.com/store/index.php?main_page=page_4

Scroll down to see the good and bad of the various types. Looks like one of the worse types is silicone. One of the fatal factors of the Nikonos RS. I have a story about this as well.

I have been using my Retra fairly intensely for a couple of weeks thanks to some good weather that just turned nasty yesterday - the lake (in the pix) is already up by three feet. Getting in some post-p!

I have a few setting data points. At +3 (power level) I was able to take a pic every 3 seconds (time by intervalometer) and got about 1500 shots on a full charge (stopped shooting on the blinking red signal a couple of times) . My last shoot (Saturday, two days ago) I was able to watch the ready light (see pic) which did not go out when shooting 5 frames per second at 0 (power level). I drained the battery in my D4S (Z9 gen battery - version-d) before the Retra batteries died doing 5 fps bursts (via remote cord which you can see in the pic). Is there significance to the ready light not going out during a burst? (directed at Oskar). Retra needs to provide guidance on max FPS for different power settings in the User Manual app IMHO.

The red blurry things in these pix (taken with an ipad - HEICs imported into LR) are Sockeye Salmon.

2 hours ago, Tom Kline said:

From the article:

"The battery compartment is confidently sealed with two heavy-duty Buna rubber O-rings. Most other strobes on the market, such as the Backscatter HF-1, are sealed with thinner and more delicate silicone O-rings."

The replacement o-rings I have received from Retra were labeled EPDM as are the Maxi ones on this page: https://www.retra-uwt.com/en-us/products/o-rings-for-retra-flash-battery-compartment

They should have a less obscure place to provide this specification as well as here.

Here is one of many o-ring material info pages: https://www.theoringstore.com/store/index.php?main_page=page_4

Scroll down to see the good and bad of the various types. Looks like one of the worse types is silicone. One of the fatal factors of the Nikonos RS. I have a story about this as well.

Wondering how you conclude Silicone o-rings are one of the worst? The only downside you might consider is the low tear strength which they mention, but that is only an issue for dynamic seals - this might include anything that has a rotating shaft on a housing, but if it's lubricated prperly this won't cause an issue.

EPDM is probably a better choice than Buna-N as it is more resistant to sunlight. Both EPDM and silicone seem like reasonable choices for o-rings in UW photo gear to me.

2 hours ago, Chris Ross said:

Wondering how you conclude Silicone o-rings are one of the worst? The only downside you might consider is the low tear strength which they mention, but that is only an issue for dynamic seals - this might include anything that has a rotating shaft on a housing, but if it's lubricated prperly this won't cause an issue.

EPDM is probably a better choice than Buna-N as it is more resistant to sunlight. Both EPDM and silicone seem like reasonable choices for o-rings in UW photo gear to me.

Experience.

I used the Nikonos RS for a decade and had several close calls starting with the first time I used it when I did not know that silicone grease should not be used. Silicone grease was the most easy type to get in the US. For example Aquacraft sold 1 oz tubs (if I recall the amount correctly - they were about 2 " in diameter and and inch high). A tub (cost about $10; 1980s) would last for several years. Easy to handle and use - just stick ones finger into the grease after removing the lid. Aquacraft sold lots of small scuba accessories and were sold in most scuba shops. OTOH the teeny tiny Nikonos tubes were better used as a toothpaste tube prop for Barbies and Kens. I recall having one slip through the mesh of my mesh bag with various other loose parts (save a dive etc.) taken to a dive site and then get stepped on - squish!! More than once I had the tubes land between the two haves of equipment cases next to the hinge. The tubes were so small they fell out of compartments and onto the hinge area very easily. Another squish. By the time the RS came out I had long sworn off using the those Nikonos tubes. Silicone grease worked just fine on pre-RS Nikonos cameras.

As well I believe the Inon strobes (I have numerous Z220 model strobes) use silicone o-rings for the battery compartment. Two + decades of experience. I have had them extrude and tear. There is a warning about them extruding on the strobe but that can be hard see (lots of dimly lit spaces, night etc.). I suspect Inon uses them because of the plastic body of the strobe. A hard o-ring might crack it.

Lens ports and main o-rings are not static, they do move. The RS ones rolled in the groove as evidenced by the distribution of crude on them after a use in water with suspended sediments.

Edited August 18Aug 18 by Tom Kline

1 hour ago, Tom Kline said:

Experience.

I used the Nikonos RS for a decade and had several close calls starting with the first time I used it when I did not know that silicone grease should not be used. Silicone grease was the most easy type to get in the US. For example Aquacraft sold 1 oz tubs (if I recall the amount correctly - they were about 2 " in diameter and and inch high). A tub (cost about $10; 1980s) would last for several years. Easy to handle and use - just stick ones finger into the grease after removing the lid. Aquacraft sold lots of small scuba accessories and were sold in most scuba shops. OTOH the teeny tiny Nikonos tubes were better used as a toothpaste tube prop for Barbies and Kens. I recall having one slip through the mesh of my mesh bag with various other loose parts (save a dive etc.) taken to a dive site and then get stepped on - squish!! More than once I had the tubes land between the two haves of equipment cases next to the hinge. The tubes were so small they fell out of compartments and onto the hinge area very easily. Another squish. By the time the RS came out I had long sworn off using the those Nikonos tubes. Silicone grease worked just fine on pre-RS Nikonos cameras.

As well I believe the Inon strobes (I have numerous Z220 model strobes) use silicone o-rings for the battery compartment. Two + decades of experience. I have had them extrude and tear. There is a warning about them extruding on the strobe but that can be hard see (lots of dimly lit spaces, night etc.). I suspect Inon uses them because of the plastic body of the strobe. A hard o-ring might crack it.

Lens ports and main o-rings are not static, they do move. The RS ones rolled in the groove as evidenced by the distribution of crude on them after a use in water with suspended sediments.

This is why I just use PTFE (white) Tribolube lubricant for 100% of my camera gear. As you say you can't use silicon grease on silicone o-rings. It will make them swell up, fail, and flood your gear eventually. So I just never use silicone lube on cameras. A 2oz tube of PTFE Tribolube costs about $60-$80 and will last for many years and 100's of uses a tiny dab at a time. And it will work fine on Silicone o-rings, Buna Rubber, or EDPM rings. As best I can tell it is identical to what Nauticam supplies for their silicone o-rings.

Edited August 18Aug 18 by Dave_Hicks

2 hours ago, Dave_Hicks said:

This is why I just use PTFE (white) Tribolube lubricant for 100% of my camera gear. As you say you can't use silicon grease on silicone o-rings. It will make them swell up, fail, and flood your gear eventually. So I just never use silicone lube on cameras. A 2oz tube of PTFE Tribolube costs about $60-$80 and will last for many years and 100's of uses a tiny dab at a time. And it will work fine on Silicone o-rings, Buna Rubber, or EDPM rings. As best I can tell it is identical to what Nauticam supplies for their silicone o-rings.

Agree, just because using the wrong lube gives you a problem doesn't mean that silicone is bad for o-rings. A great many housings use Silicone o-rings including Nauticam, Marelux, Sea and Sea, INON strobes - any coloured o-ring is going to be silicone.

On the topic of dynamic seals, this is not insert and twist or piston style o-rings where you screw a cap on it refers to parts that are always in motion or regularly in motion, one example might be the shutter lever on Nauticam housing where the shaft rotates to activate, but even that is not really that dynamic, dynamic o-rings examples of dynamic o-rings where silicone might be a problem include hydraulic and pneumatic actuators, pump shaft seals and even scuba regulators that use a piston.

On INON o-rings the secret is sufficient lube. Housings it's a mere breath of lube just to get it shiny. On INON o-rings where you are screwing on the lid, I'm a bit more generous, you can feedl the difference once you apply enough.

11 hours ago, Tom Kline said:

Experience.

I used the Nikonos RS for a decade and had several close calls starting with the first time I used it when I did not know that silicone grease should not be used. Silicone grease was the most easy type to get in the US. For example Aquacraft sold 1 oz tubs (if I recall the amount correctly - they were about 2 " in diameter and and inch high). A tub (cost about $10; 1980s) would last for several years. Easy to handle and use - just stick ones finger into the grease after removing the lid. Aquacraft sold lots of small scuba accessories and were sold in most scuba shops. OTOH the teeny tiny Nikonos tubes were better used as a toothpaste tube prop for Barbies and Kens. I recall having one slip through the mesh of my mesh bag with various other loose parts (save a dive etc.) taken to a dive site and then get stepped on - squish!! More than once I had the tubes land between the two haves of equipment cases next to the hinge. The tubes were so small they fell out of compartments and onto the hinge area very easily. Another squish. By the time the RS came out I had long sworn off using the those Nikonos tubes. Silicone grease worked just fine on pre-RS Nikonos cameras.

As well I believe the Inon strobes (I have numerous Z220 model strobes) use silicone o-rings for the battery compartment. Two + decades of experience. I have had them extrude and tear. There is a warning about them extruding on the strobe but that can be hard see (lots of dimly lit spaces, night etc.). I suspect Inon uses them because of the plastic body of the strobe. A hard o-ring might crack it.

Lens ports and main o-rings are not static, they do move. The RS ones rolled in the groove as evidenced by the distribution of crude on them after a use in water with suspended sediments.

Off topic - I remember the first time that someone came into Jim & Cathy's with an RS and we all were thinking that it was one hell of an upgrade from a Nik V!

10 hours ago, Dave_Hicks said:

This is why I just use PTFE (white) Tribolube lubricant for 100% of my camera gear. As you say you can't use silicon grease on silicone o-rings. It will make them swell up, fail, and flood your gear eventually. So I just never use silicone lube on cameras. A 2oz tube of PTFE Tribolube costs about $60-$80 and will last for many years and 100's of uses a tiny dab at a time. And it will work fine on Silicone o-rings, Buna Rubber, or EDPM rings. As best I can tell it is identical to what Nauticam supplies for their silicone o-rings.

That - and by using Tribolube for the camera too you can't accidentally put silicone grease on something that goes in your rebreather - I've seen what happens when someone does!

11 hours ago, Tom Kline said:

the teeny tiny Nikonos tubes were better used as a toothpaste tube prop for Barbies and Kens

Kinda wonder if Tom still has the RS. Or the Ken and Barbie dolls...... Action Man, anyone?

Sorry, back to lubes.... and Retra Maxis

7 minutes ago, CCRphoto said:

That - and by using Tribolube for the camera too you can't accidentally put silicone grease on something that goes in your rebreather - I've seen what happens when someone does!

Actually, I DO use silicone on the rebreathers! It eats silicone for breakfast. It has lots of lots of very big o-rings in the Loop with bayonet fittings. Hoses, heads, canisters, lungs. They are all rubber/edpm and fine with silicone. This is all low-pressure ambient level so even 100% O2 is not an issue. I do use Tribolube when I service the regulators, MAV, etc. I treat all regulators like they must be O2 clean, even if some of them are just air.

I know some CCR units have silicone o-rings, but that just seems like a bad idea to me.

Edited August 18Aug 18 by Dave_Hicks