Info Backscatter Hybrid Flash HF-01: preliminary review

[WS007]

Sorry, not sure what you mean by unbiased? The photos of the wall chart in the pool are unedited from the camera.

Thank you for taking the time to respond, Jim...

What I mean is that the reference photos are probably not just taken and put totally unprocessed directly into the videos.
Likely, the photos get processed before putting them into the video (adjustment of brightness, contrast etc.) and later also the entire video gets adjusted to make it look good in the internet...

=> The reason why I am asking is, that there is a very interesting tread in "waterpixel", where people take screenshots of the Backscatter videos and analyse the distribution of brightness for comparison of different brands of flashes:

Backscatter In-Water Strobe Beam Testing

waterpixels.net

=> This interesting comparison would be much more meaningful, in case you could provide the totally unprocessed test images for analysis (they do not need to be the raw files, JPEG or TIFF will also do it, but there must not be any adjustments/processing)...

Wolfgang

 

[stuartv]

Just be aware you won't get 10fps and TTL together. TTL has preflashes for metering which slow the whole process down. This is true of any flash with TTL, topside or underwater.

You also have to be aware of the power output the strobe. If the TTL is at the upper end of the output range for the scene you are shooting then it will be slower and conversely if the scene doesn't need a ton of strobe light, then the recycle will be faster.

If you really need to shoot fast, then do manual. If you want TTL to move faster then up your ISO and shutter speed.

I totally understand. I foresee programming a custom button so that I can shoot with TTL normally, but press-and-hold to switch to full manual with maximum frame rate for *ahem* rapidly evolving scenes. lol!

Others have already posted about the benefits of multiple chargers for backup so I won't go there but just to say I've seen things go sideways in the field that was no fault of the charger.

The reason we sell the specific XTAR 2 bay charger at Backscatter is we pair it with the QC3.0 USB power brick so that it will perform at the maximum charge rate. It's 2A in each slot and if you just charge 1 battery in 1 slot it's 3A. To keep the math simple that means it charges a 6000mah battery from dead in 3 hours for 2 batteries in 2 slots, and 2 hours with 1 battery in 1 slot with the other left open. Most 4 bay chargers will charge between .5 and 1A, meaning 6 or 12 hours. There is a 4 bay charger that can do 2A in 2 slots and 3A in 1 slot if the others are left empty, but then you are back in the same boat (pardon the pun) as the 2 slot charger, plus that charger has to be manually set up to do that.

Understood on that, too. I ordered a 4-bay that works just as you described. Max charging current if only using 1 bay, less if using 2, and only 1A per bay, when using all 4.

I'd still rather have 2 of those than 2 x 2-bay chargers.

Most of the time, I expect my current workflow to continue to be using one set of batteries for a whole day, then putting them on the charger at the end of the day, so they have all night to charge. Speed won't be a factor and I'd rather charge more slowly anyway, just to reduce any possible heat that may build up.

Plus, a normal day for me should leave these 21700 batteries with more than half their charge remaining, so charge should be fairly quick, even at 1A. With the Eneloop Pros I have been using, they are usually done charging before I even go to bed, so I can assemble my camera rig for the next day before I go to bed.

If I am ever in a time crunch, I can use the 2 x 4-bay chargers to charge 2 batteries each, just as I could with a 2-bay.

Also, once I am in possession and have vetted everything, I will get a complete spare set of batteries.

So, I stand by my desire to be able to buy a 4-bay charger from you along with the batteries and the rest. I mean, it is sort of moot for me personally, now. But, I already have a customer that heard me talking about these strobes and wants me to order a set for them (my shop is a Backscatter dealer). Right now, I will be advising them to buy a 4-bay charger elsewhere, as I have done. Actually, I will advise them to buy 8 batteries (to have spares) with the strobes, and 2 x 4-bay chargers from elsewhere - if their budget extends to such.

In the future, I'd rather be able to order them a complete package from Backscatter. Call it a Pro kit. 8 x batteries and 2 x 4-bay chargers.

 

[Diver-6873]

My HF-1s are supposed to be delivered today. I hope to have a couple of dives with them on Friday and Saturday and will share first impressions.

I included 2 pairs of the recommended 21700's with my order. I look forward to seeing how well the strobe holds up with three-four dives a day. I just returned from Palau and most days I managed 250-350 shots a day. At God's Pocket in April with 3 dives/day I hit 400 a couple of times. Never full power, so I'm optimistic they will deliver a full days work.

(BTW shooting a Z8 in Palau one day I shot over 800 frames on a single battery (most without strobes) and ended with 21% in the camera battery. We can put to bed the worries about Z8 battery life!)

I've been using a Nitecore 4 cell charger that supports 21700s since I got the BS MF-2 strobe. It's USB-C powered which is great since almost all my dive/camera chargers are USB powered now. I drive all the chargers with a compact 65w USB source.

View attachment 845663

I link the idea of that Nitecore 4x charger for both strobe as well as torch batteries. The only issue I see that that if I read the specs right it only supports 3000mA per slot - am I mis-understanding or don’t we need more for most batteries these days. My 18650s are 3400mA and my 21700s are 5000mA ?

 

[stuartv]

I link the idea of that Nitecore 4x charger for both strobe as well as torch batteries. The only issue I see that that if I read the specs right it only supports 3000mA per slot - am I mis-understanding or don’t we need more for most batteries these days. My 18650s are 3400mA and my 21700s are 5000mA ?

You are mixing up charging current and capacity.

These 21700s for these strobes are 5300 mA-HOURS. That is their capacity. They can deliver 5.3A (5300 mA) for 1 hour.

The charging current of, for example, 3A is just how quickly it will charge. Feeding the battery a 3A current will charge it more quickly than feeding it a 1A current. Either way, it will charge the battery to its full 4.2V.

 

[bvanant]

I think most battery guys think charging at 0.5C is appropriate for a given battery. For a 3400 mAh battery charge at 1700 mA.
Bill

 

[Backscatter::Jim]

Thank you for taking the time to respond, Jim...

What I mean is that the reference photos are probably not just taken and put totally unprocessed directly into the videos.
Likely, the photos get processed before putting them into the video (adjustment of brightness, contrast etc.) and later also the entire video gets adjusted to make it look good in the internet...

=> The reason why I am asking is, that there is a very interesting tread in "waterpixel", where people take screenshots of the Backscatter videos and analyse the distribution of brightness for comparison of different brands of flashes:

Backscatter In-Water Strobe Beam Testing

waterpixels.net

=> This interesting comparison would be much more meaningful, in case you could provide the totally unprocessed test images for analysis (they do not need to be the raw files, JPEG or TIFF will also do it, but there must not be any adjustments/processing)...

Wolfgang

A few points of order...

The photos are unprocessed from the camera except for dropping in to the video timeline. No other edits were done. No contrast, no exposure, no nothing. The screen shots on Waterpixels look correct.

The way the video is edited is that we have the main A camera (which is Thomas speaking), a B camera of the closeups and product shots, and another channel for the still images. This way we can color correct for the studio lighting of camera A and B separately without affecting any of the other channels. So the photos of the wall are on a different channel that does not have any editing or correction, there is no global correction to the video because there re different cameras and lenses and lighting used for various shots and it would be impossible to apply a global color correction.

The wall chart is 1 meter away from the strobe. We use a meter stick to measure this. The camera is placed 1 more meter away from the flash. We make sure the the flash is square to the target by taking test shots and we use a level to make sure it is pointed straight. This takes more time than you could ever possibly imagine.

The camera is an a1 with a Nauticam WWL-1. Same for all tests. We choose the a1 so we can get higher flash sync speeds. Shutter is at 1/320 as some strobes are on the limit for flash duration approaching 1/400 and we wanted to capture the whole duration. This is why the Ike 230 video has 2 photos in it, 1 at 1/320 and 1 at 1/100 so it can show the full flash duration at max power. The Waterpixels post shows the one at 1/100 with more ambient light. ISO is 100, F22 for all shots.

In a perfect world we would have access to a pool at night so that we would not be competing with any ambient light.

The guide numbers are measured with a Sekonic light meter 858D-U in our own custom made underwater housing made just for this pool testing purpose. This is at 1 meter and we take painstaking measurements to make sure it is exact and that the strobe is square to the light meter. Setting on the light meter is ISO 100.

Sorry I can't share file formats right now as I'm in Little Cayman prepping for the shootout and James and other Backscatter staff are stuck in various airports due to flight cancellations on the way to the shootout, but as I said above the screen shots are looking correct.

An in air test of an underwater strobe is useless to determine how it would perform underwater. Optics, domes, and reflectors all have an effect when combines with water, which is why we started doing these pool tests after we made our light meter housing.

We want these tests to be as standardized as possible and take great pains in that effort. This way when someone calls up Backscatter we can give them the best objective advice on the differing products to find the best one that suits them. As stated in these videos, we're not sure how each individual manufacturer tests their gear, so we decided to make our own standard test to do a direct comparison.

Please let me know if you guys have any more questions. And yes there are more strobe tests coming, please be patient.

Feel free to share this over on Waterpixels as I don't have an account yet.

 

[WS007]

A few points of order...

The photos are unprocessed from the camera except for dropping in to the video timeline. No other edits were done. No contrast, no exposure, no nothing. The screen shots on Waterpixels look correct.

The way the video is edited is that we have the main A camera (which is Thomas speaking), a B camera of the closeups and product shots, and another channel for the still images. This way we can color correct for the studio lighting of camera A and B separately without affecting any of the other channels. So the photos of the wall are on a different channel that does not have any editing or correction, there is no global correction to the video because there re different cameras and lenses and lighting used for various shots and it would be impossible to apply a global color correction.

The wall chart is 1 meter away from the strobe. We use a meter stick to measure this. The camera is placed 1 more meter away from the flash. We make sure the the flash is square to the target by taking test shots and we use a level to make sure it is pointed straight. This takes more time than you could ever possibly imagine.

The camera is an a1 with a Nauticam WWL-1. Same for all tests. We choose the a1 so we can get higher flash sync speeds. Shutter is at 1/320 as some strobes are on the limit for flash duration approaching 1/400 and we wanted to capture the whole duration. This is why the Ike 230 video has 2 photos in it, 1 at 1/320 and 1 at 1/100 so it can show the full flash duration at max power. The Waterpixels post shows the one at 1/100 with more ambient light. ISO is 100, F22 for all shots.

In a perfect world we would have access to a pool at night so that we would not be competing with any ambient light.

The guide numbers are measured with a Sekonic light meter 858D-U in our own custom made underwater housing made just for this pool testing purpose. This is at 1 meter and we take painstaking measurements to make sure it is exact and that the strobe is square to the light meter. Setting on the light meter is ISO 100.

Sorry I can't share file formats right now as I'm in Little Cayman prepping for the shootout and James and other Backscatter staff are stuck in various airports due to flight cancellations on the way to the shootout, but as I said above the screen shots are looking correct.

An in air test of an underwater strobe is useless to determine how it would perform underwater. Optics, domes, and reflectors all have an effect when combines with water, which is why we started doing these pool tests after we made our light meter housing.

We want these tests to be as standardized as possible and take great pains in that effort. This way when someone calls up Backscatter we can give them the best objective advice on the differing products to find the best one that suits them. As stated in these videos, we're not sure how each individual manufacturer tests their gear, so we decided to make our own standard test to do a direct comparison.

Please let me know if you guys have any more questions. And yes there are more strobe tests coming, please be patient.

Feel free to share this over on Waterpixels as I don't have an account yet.

Great thanks, Jim ...

Just one more question: What are the angles of the different zones (the rings in the test image)?

 

[Backscatter::Jim]

Just one more question: What are the angles of the different zones (the rings in the test image)?

30 60 90 120

 

[dreifish]

@Backscatter::Jim -- thanks a lot for sharing some of the testing details -- the work you guys are doing at Backscatter is really appreciated, and definitely have some idea of how much work it is to rigorously do comparison tests!

Any chance you might prioritize the in-depth review of the Seacam 160Ds? In your "Best Underwater Strobes" article, you already conclude that the Seacams have " the absolute best wide angle beam quality, electronic TTL, and most hardcore fast-shooting performance" and "the brightest, widest, most even beam with the most natural edge falloff of any strobe that we tested" so I assume you've already done at least some preliminary tests. It would be great if you could supplement your qualitative observations with some quantitative numbers on guide number, beam coverage in water, color temperature, flash duration and flash recycling times.

The strobes are in a very different price category than the the HF-1s (and most other strobes). I think many in the community would appreciate having some standardized measurements to really be able to understand what improvements (and tradeoffs!) you're getting if you spend 2-3x the money!

 

[Nemrod]

Very good info from Backscatter and very good info from all, thanks.