Backscatter In-Water Strobe Beam Testing

[DreiFish]

[DreiFish]

Now drawing some conclusions:

 

1. YS-D3 vs HF-1, both with flat diffusers -- similar coverage, but the HF-1 is almost a stop brighter.

 

2. YS-D3 with flat diffuser vs Retra Pro Max with no diffuser - very similar!

 

 

3. Retra Pro Max vs. DS230 - similar coverage, but DS230 is almost a stop brighter, and perhaps also brighter at the edges.

 

 

HF-1 with flat diffuser vs. DS230 -- HF-1 is maybe 1/3 stop brighter in the center, but  DS230 has a more even, wider beam.

 

HF-1 with dome diffuser vs. DS230 -- Similar, but DS230 just edges out the HF-1 in terms of evenness. 

 

 

I'd really love to see Backscatter test the Seacam 160D and Marelux Apollo 3. Based on Retra's tests though, I would expect the Seacam 160D to perform pretty similar to the Retra Pro Max though. Maybe 1/3 stop brighter?

 

 

My conclusion? DS230 has the best combination of power, coverage and color temperature. The price and weight are also attractive for a 'big' circular flash tube strobe. But HF-1 is also pretty impressive for versatility (and probably better recycling times and battery capacity). YS-D3 still has the advantage that at 730g it's considerably lighter than the other 5 strobes in this list, and also the cheapest. Retra.. well, it has a lot of different light modifying accessories. 

Edited June 11 by DreiFish

[OldManK]

As I'm currently deep in research to pick out my first set of strobes, your comparisons here (And the Google sheet with data) are super appreciated!

[Dave_Hicks]

What this tells me is that diffusers are a major detriment. I don't know why anyone bothers to use them. 

[Andrej Oblak]

3 hours ago, Dave_Hicks said:

What this tells me is that diffusers are a major detriment. I don't know why anyone bothers to use them. 

 

I'd use it to:

• Widen the beam
• Soften the light
• Reduce hotspots
• Change color of the light

[Architeuthis]

Thanks, very interesting comparison... 👍

 

Is it known to what angles (° field of view) the four different circles in the test image correspond?

Also, what is the distance between flash and test image (the more distance the more even the light distribution will be; YS-D3 without diffuser looks like a catastrophy, I would say completely unusable (maybe the distance is much too short and does not reflect real life conditions?)?

 

I find the results sobering. Only DS230 seem to deliver reasonable light distribution, the other flashes seem to deliver a hot spot in the middle, even with dome diffusers...😐

 

Were these images taken from the Backscatter videos? Do we know whether they do harsh postprocessing to make the entire videos looking nice in the Internet - many postprocessing manipulations will change the test images and make them unusable: e.g. the more the contrast slider is activated, the greater the difference in brightness between center and  border will become. These manipulations may well be very different from video to video, depending on the person and the mood of the person who is doing it...

(I hope the flashes perform better in real life and try to find arguments, still waiting for my pre-odered HF-1s...😊)

 

 

Wolfgang

 

[TimG]

1 hour ago, Andrej Oblak said:

 

I'd use it to:

• Widen the beam
• Soften the light
• Reduce hotspots
• Change color of the light

 

Yeah, I'm with Andrej: looks to me that the diffusers soften and widen the beam. Without the diffuser there is very sharp edges with a distinct hot spot. Yes, there is a loss of power but the quality of light looks better, to me, with the diffusers.

 

[Chris Ross]

1 hour ago, Architeuthis said:

Thanks, very interesting comparison... 👍

 

Is it known to what angles (° field of view) the four different circles in the test image correspond?

Also, what is the distance between flash and test image (the more distance the more even the light distribution will be; YS-D3 without diffuser looks like a catastrophy, I would say completely unusable (maybe the distance is much too short and does not reflect real life conditions?)?

 

I find the results sobering. Only DS230 seem to deliver reasonable light distribution, the other flashes seem to deliver a hot spot in the middle, even with dome diffusers...😐

 

Were these images taken from the Backscatter videos? Do we know whether they do harsh postprocessing to make the entire videos looking nice in the Internet - many postprocessing manipulations will change the test images and make them unusable: e.g. the more the contrast slider is activated, the greater the difference in brightness between center and  border will become. These manipulations may well be very different from video to video, depending on the person and the mood of the person who is doing it...

(I hope the flashes perform better in real life and try to find arguments, still waiting for my pre-odered HF-1s...😊)

 

 

Wolfgang

 

To my eye the Retra looks most even but it is difficult to judge with different centre brightnesses I think the photos really need to be converted to plots to judge properly.  I think also for example the retra has the target a bit folded so the bits angled away from the camera seem darkened.  You can see in the plot provided, I think its from Retra the RF pro mirrors the seacam and the curve is flatter than the DS-161 ikelite flash

[Architeuthis]

1 hour ago, Chris Ross said:

To my eye the Retra looks most even but it is difficult to judge with different centre brightnesses I think the photos really need to be converted to plots to judge properly.  I think also for example the retra has the target a bit folded so the bits angled away from the camera seem darkened.  You can see in the plot provided, I think its from Retra the RF pro mirrors the seacam and the curve is flatter than the DS-161 ikelite flash

 

I fully agree that there should be some measurements, e.g. histograms (e.g. distance from center vs. intensity). Screenshots from videos are not suitable, the measured values depend a lot on postprocessing and how the video is viewed. It should be done from original, standardized, test shots in water and at distances that are realistic...

 

Dreifish does a great job, I enjoy to see this comparison, but the comparison would be much more meaningful, when would be able to use the original testshots (in case they were done by Backscatter under standardized conditions)...

 

 

I think the graph shown comes from the "Retra study": https://www.retra-uwt.com/pages/flashgun-light-comparison

Retra say that the strobes were positioned 60cm away from a screen in air ((!); even the beam angle will differ in water compared to air. Not to speak about even or uneven distribution of intensity)).

 

Please have a look at the intensity distribution in the figure with the original test photos, especially YS-D2 and Z330 without diffusers:

 

=> I have both YS-D2 and Z330 strobes, but I never have observed such a weird intensity distribution UW. It must be an artifact, produced by using the strobes in air.

=> To me the entire "study" is nonsense. Maybe one can use the original table for comparison, were parameters supplied by the manufacturers are listed. The measurements are not worth anything (sorry to say, but this is the case)...

 

 

Wolfgang

 

P.S.: I do not doubt that the Retras are excellent strobes. I think that Retra does not have it necessary to publish such "studies" to promote their strobes...

 

Edited June 11 by Architeuthis

[Architeuthis]

Here I have found some graphs from Backscatter, unfortunately mostly not the recent strobe generation (brightness vs. angle): https://www.backscatter.com/reviews/post/Retra-Flash-Underwater-Strobe-Test-and-Review

 

I guess this is from the test shots (or similar shots) that Backscatter shows in the videos (and Dreifish uses for his comparison)...

I hope it does not violate copyright, as I cite the source above (if yes, please delete):

 

Here the graph w/o diffusers (brightness is given in f-stops, so f/22 is a the reference and f/16 means -1/f-stop and f/11 means -2/f-stops (?); beam angle is given in degree (°), I guess degree from center (or is it entire angle of view (?)):

 

When compared to other pro-level strobes the Retra performed quite well in terms of brightness and consistency.

 

 

And here the measurements from the test photos made with diffusers:

 

Even with diffusers, the Retra still rises to the top of the test results.

 

=> The measured intensity falloff (in e.g. % from value in the center) is pretty similar for all the strobes tested without diffusers, in the range of approx. -1.5 f-stops from center to 90° (the Retra model tested has the steepest falloff).

=> When warm and white diffusers are used, the Retra model has still approx. -1.5 f-stop falloff (from center to 90°). All other strobes (and Retra with shark diffusers) improve to the range of approx. -0.5 f-stops to -1 f-stops falloff...

 

[Chris Ross]

55 minutes ago, Architeuthis said:

 

=> The measured intensity falloff (in e.g. % from value in the center) is pretty similar for all the strobes tested without diffusers, in the range of approx. -1.5 f-stops from center to 90° (the Retra model tested has the steepest falloff).

=> When warm and white diffusers are used, the Retra model has still approx. -1.5 f-stop falloff (from center to 90°). All other strobes (and Retra with shark diffusers) improve to the range of approx. -0.5 f-stops to -1 f-stops falloff...

 

I plotted up the brightness from the centre and the square just inside each ring plus the outermost square at the level of the "X"axis horizontally out from the centre.  The X axis of the plot is arbitrary values with ) being centre and 1, 2 and 3 being the 3 rings on the target.    Imported each jpeg in PS, convert to greyscale then LAB colour to get luminance values.  Here is the plot:

 

You can see the YS-D3 has more dramatic fall off  and the Retra has the same brightness at points 3 and 4 even though it started off with lower luminance in the centre.  The ikelite has roughly the same curve shape as the YS-D3 just brighter through out the range.  Basically this means the Retra spreads its light out more evenly with less fall off.  You need the plot to judge the difference because the human eye is terrible at such comparisons. 

 

Basically what this means that at constant centre brightness, the Retra has the brightest edge to the light cones.

[Architeuthis]

41 minutes ago, Chris Ross said:

I plotted up the brightness from the centre and the square just inside each ring plus the outermost square at the level of the "X"axis horizontally out from the centre.  The X axis of the plot is arbitrary values with ) being centre and 1, 2 and 3 being the 3 rings on the target.    Imported each jpeg in PS, convert to greyscale then LAB colour to get luminance values.  Here is the plot:

 

You can see the YS-D3 has more dramatic fall off  and the Retra has the same brightness at points 3 and 4 even though it started off with lower luminance in the centre.  The ikelite has roughly the same curve shape as the YS-D3 just brigther through out the range.  Basically this means the Retra spreads its light out more evenly with less fall off.  YOu need the plot to judge the difference because the human eye is terrible at such comparisons. 

 

Basically what this means that at constant centre brightness, the Retra has the brightest edge to the light cones.

 

Thank you Chris, interesting!

 

 

Is it this with or without diffusers (which diffuser if any)?

Could you please also make a graph with HF-1 (with and w/o diffusers)?

 

In case you normalize the brightness of each individual strobe/diffuser combination to the value at "0" (x-axis), the center, The even/uneven light distribution would be even better visible for everybody.

Intensity comparison could be made separately from the even/uneven brightness distributions, just by comparing the absolute values in the center, e.g. bar diagrams...

 

 

=> I do not want to be the party-crasher, I hav a little bad feeling when I write this, BUT there is still a massive problem in all this comparison: Both when viewing the images and also when making quantitative measurements from them (the measurements provide, no doubt, comparable numbers. These numbers are, however, just the result of the intensity values on the processed image; we need, however, the unprocessed images in order to be able to compare..

 

=> A meaningful comparison and analysis of the test images is only possible, when the totally unprocessed RAW files are compared, no processing at all. (in addition, the photos have to be taken at strictly standardized conditions. e.g. distance, clarity of water, camera settings (ISO, shutter, aperture) - hopefully Backscatter is doing so...).

 

 

It would be great if Backscatter would make the original raw files available...

 

 

Wolfgang

 

Edited June 11 by Architeuthis

[shokwaav]

4 minutes ago, Architeuthis said:

=> A meaningful comparison and analysis of the test images is only possible, when the totally unprocessed RAW files are compared, no processing at all. (in addition, the photos have to be taken at strictly standardized conditions. e.g. distance, clarity of water, camera settings (ISO, shutter, aperture) - hopefully Backscatter is doing so...).

 

They mention that they do standardise some stuff, namely measuring the actual guide number with a light meter with their specified settings and distance here: https://youtu.be/-g_vCijzNdA?t=837

 

However, just looking at their photos, it's clear that some settings regarding the Ikelite photos are different from the other photos just by looking at the sides of the swimming pool.

 

I think comparing the f stops between the edges and the centre can be compared within the same image (assuming no post processing was performed), but comparing the brightness between different images will be difficult unless Backscatter can provide the standardised settings. 

 

[Dave_Hicks]

7 hours ago, Andrej Oblak said:

 

I'd use it to:

• Widen the beam - Use longer arms 
• Soften the light - Turn down the power level
• Reduce hotspots - Turn down the power level more!
• Change color of the light - This is the one good use if you include Gels, otherwise adjust WB

 

My responses in Red.

 

I've been shooting underwater for a long time now and experimented with many strobes, diffusers, etc. At the end of the day, you can adjust your strobe position, angle, and power levels to achieve the results you desire.

 

Diffusers are like wearing ear-plugs at a concert and sunglasses at a movie. If you need them then it's too loud or too bright. When shooting with strobes YOU have full control of the power knob. Use it as needed.

[Dave_Hicks]

I think these strobe power tests would be a lot more interesting if they included strobes set at 1/2 power. I rarely shoot at full power as it includes too many negatives like flare and backscatter in all but the most perfect water conditions.

 

I have a pair of the new HF-1 strobes expected to be delivered this week, and what I really want to take advantage of is the ability to fire at least 3 frames per second. This would typically be at 1/2 to 1/4 power levels. 

[DreiFish]

7 hours ago, Architeuthis said:

Is it known to what angles (° field of view) the four different circles in the test image correspond?

Also, what is the distance between flash and test image (the more distance the more even the light distribution will be; YS-D3 without diffuser looks like a catastrophy, I would say completely unusable (maybe the distance is much too short and does not reflect real life conditions?)?

 

AFAIK, Backscatter hasn't described the test environment for this light fall-off test, but I would presume the distance from strobe-to-chart is consistent between the strobes. I would also hope the camera used is also.  I also would like to know what the distance is and what angle of view the different circles represent. @James Emery -- could you share some of these details? 

 

7 hours ago, Architeuthis said:

 

Were these images taken from the Backscatter videos? Do we know whether they do harsh postprocessing to make the entire videos looking nice in the Internet - many postprocessing manipulations will change the test images and make them unusable: e.g. the more the contrast slider is activated, the greater the difference in brightness between center and  border will become. These manipulations may well be very different from video to video, depending on the person and the mood of the person who is doing it...

 

@James Emery -- is there any way Backscatter could provide the raw files here or on Backscatter.com? These are indeed screen-grabs from the videos, and how they were processed is an unknown variable. Again, I would hope that the light intensity hasn't been adjusted between different strobes, but I suspect there's been at least white balancing applied to most of the videos (the images appear neutral and exactly the same color temperature except for the Ikelite DS232 shot, which is very blue. So at least white balance seems to have been adjusted. If anything, the DS232 should be the warmest of all of these strobes according to Backscatter's own color temperature tests.

[DreiFish]

4 hours ago, Architeuthis said:

 

I think the graph shown comes from the "Retra study": https://www.retra-uwt.com/pages/flashgun-light-comparison

Retra say that the strobes were positioned 60cm away from a screen in air ((!); even the beam angle will differ in water compared to air. Not to speak about even or uneven distribution of intensity)).

 

Please have a look at the intensity distribution in the figure with the original test photos, especially YS-D2 and Z330 without diffusers:

 

=> I have both YS-D2 and Z330 strobes, but I never have observed such a weird intensity distribution UW. It must be an artifact, produced by using the strobes in air.

=> To me the entire "study" is nonsense. Maybe one can use the original table for comparison, were parameters supplied by the manufacturers are listed. The measurements are not worth anything (sorry to say, but this is the case)...

 

 Yes, that's where the graph comes from. I would caution against equating the YS-D2 results to the YS-D3.. it seems they are different beasts. The YS-D2 may well have produced more even light distribution without a diffuser. 

 

I too wish Retra could've further elaborated their testing methodology and want to point out also that this is an older test, not of the latest Retra models (though Retra themselves has claimed the light quality should've remained constant)

[DreiFish]

3 hours ago, Architeuthis said:

Here I have found some graphs from Backscatter, unfortunately mostly not the recent strobe generation (brightness vs. angle): https://www.backscatter.com/reviews/post/Retra-Flash-Underwater-Strobe-Test-and-Review

 

I guess this is from the test shots (or similar shots) that Backscatter shows in the videos (and Dreifish uses for his comparison)...

I hope it does not violate copyright, as I cite the source above (if yes, please delete):

 

Here the graph w/o diffusers (brightness is given in f-stops, so f/22 is a the reference and f/16 means -1/f-stop and f/11 means -2/f-stops (?); beam angle is given in degree (°), I guess degree from center (or is it entire angle of view (?)):

 

When compared to other pro-level strobes the Retra performed quite well in terms of brightness and consistency.

 

 

And here the measurements from the test photos made with diffusers:

 

Even with diffusers, the Retra still rises to the top of the test results.

 

=> The measured intensity falloff (in e.g. % from value in the center) is pretty similar for all the strobes tested without diffusers, in the range of approx. -1.5 f-stops from center to 90° (the Retra model tested has the steepest falloff).

=> When warm and white diffusers are used, the Retra model has still approx. -1.5 f-stop falloff (from center to 90°). All other strobes (and Retra with shark diffusers) improve to the range of approx. -0.5 f-stops to -1 f-stops falloff...

 

 

Please keep in mind that this is the original Retra flash, which used a single linear (not circular) flash tube. No reason to think it tells us anything about the current circular flash tube Retra models or that the DS161 is similar in light intensity or spread to the newer DS230/232.

[DreiFish]

2 hours ago, Chris Ross said:

I plotted up the brightness from the centre and the square just inside each ring plus the outermost square at the level of the "X"axis horizontally out from the centre.  The X axis of the plot is arbitrary values with ) being centre and 1, 2 and 3 being the 3 rings on the target.    Imported each jpeg in PS, convert to greyscale then LAB colour to get luminance values.  Here is the plot:

 

You can see the YS-D3 has more dramatic fall off  and the Retra has the same brightness at points 3 and 4 even though it started off with lower luminance in the centre.  The ikelite has roughly the same curve shape as the YS-D3 just brighter through out the range.  Basically this means the Retra spreads its light out more evenly with less fall off.  You need the plot to judge the difference because the human eye is terrible at such comparisons. 

 

Basically what this means that at constant centre brightness, the Retra has the brightest edge to the light cones.

 

Which YS-D3 screenshot did you map this for? With or without diffuser? Would be great to supplement this also with the 3 different YS-D3 diffuser options and the 3 HF-1 diffuser options.

[DreiFish]

1 hour ago, shokwaav said:

 

They mention that they do standardise some stuff, namely measuring the actual guide number with a light meter with their specified settings and distance here: https://youtu.be/-g_vCijzNdA?t=837

 

However, just looking at their photos, it's clear that some settings regarding the Ikelite photos are different from the other photos just by looking at the sides of the swimming pool.

 

I think comparing the f stops between the edges and the centre can be compared within the same image (assuming no post processing was performed), but comparing the brightness between different images will be difficult unless Backscatter can provide the standardised settings. 

 

 

Agreed -- the other images are at least white balanced to the same color temperature. The DS230 image is not. However, I believe the brightness hasn't been manipulated, as it accords with Backscatter's separately reported comparative GN tests at center of the strobe (GN22 for Retra, GN29 for DS230, GN32 for the YS-D3 and GN40 for the HF-1).

[DreiFish]

24 minutes ago, Dave_Hicks said:

 

My responses in Red.

 

I've been shooting underwater for a long time now and experimented with many strobes, diffusers, etc. At the end of the day, you can adjust your strobe position, angle, and power levels to achieve the results you desire.

 

Diffusers are like wearing ear-plugs at a concert and sunglasses at a movie. If you need them then it's too loud or too bright. When shooting with strobes YOU have full control of the power knob. Use it as needed.

 

David, respectfully, your proposed solutions don't actually solve the problems.

 

1. Using longer strobe arms doesn't replicate the effect of diffusers in spreading out the light intensity evenly across the lit subject. You just end up with 2 still distinct hotspots spread further apart. 

 

2. Turning down the power doesn't soften the light. You end up with the exact same central hotspot and proportional intensity fall-off towards the edges, just from a lower intensity starting point.

 

3. See #2 above. Reducing the strobe power doesn't reduce the hotspot, because the hotspot is a result of the proportional light fall-off towards the edges. 

 

4. You can indeed change color temperature using gels, at the expense of light intensity. The HF-1s with the 5500k filters will produce light of similar color temperature with the DS230 for example, but you'll probably lose about 1/2 stop of light intensity. So if using gels on the cooler lights to match the color temperature of the warmer ones, the DS230 will be noticeably brighter. I (and others) have explained in other threads why using a custom white balance (in camera or in post) to adjust for cooler strobes is not a solution. The issue isn't the specific color temperature of the strobe -- it's the relative difference in color temperature between the strobe and the ambient light. With warmer strobes, that relative difference is greater, leading to increased color contrast between your subject and the background. You can't achieve that with global white balance adjustments -- only with separate selective adjustments for the subject and background using masks. 

 

So no.. respectfully again, diffusers (and warming gels) are not ike wearing ear-plugs at a concert and sunglasses at a movie. They're a specific tool that can be quite beneficial to achieving certain aesthetic results in your images that you can't achieve without them. Whether that aesthetic result is important to your particular type of aesthetic is a separate question, but they are definitely valuable tools in the arsenal for many underwater photographers looking to achieve a certain look.

 

18 minutes ago, Dave_Hicks said:

I think these strobe power tests would be a lot more interesting if they included strobes set at 1/2 power. I rarely shoot at full power as it includes too many negatives like flare and backscatter in all but the most perfect water conditions.

 

I have a pair of the new HF-1 strobes expected to be delivered this week, and what I really want to take advantage of is the ability to fire at least 3 frames per second. This would typically be at 1/2 to 1/4 power levels. 

 

The relative light fall-off towards the edges is going to be exactly the same at full power, 1/2 power, 1/4th power, or whatever other power level you test it at. There's no magic that reduces backscatter and flare at 1/2 power vs shooting at full power. That's all down to strobe placement and the needed strobe power relative to the desired exposure. Also, it's relative -- the HF1 at 1/2 power for example should produce similar light intensity to the YS-D3s at full power.

[Dave_Hicks]

2 minutes ago, DreiFish said:

 

David, respectfully, your proposed solutions don't actually solve the problems.

 

1. Using longer strobe arms doesn't replicate the effect of diffusers in spreading out the light intensity evenly across the lit subject. You just end up with 2 still distinct hotspots spread further apart. 

 

2. Turning down the power doesn't soften the light. You end up with the exact same central hotspot and proportional intensity fall-off towards the edges, just from a lower intensity starting point.

 

3. See #2 above. Reducing the strobe power doesn't reduce the hotspot, because the hotspot is a result of the proportional light fall-off towards the edges. 

 

4. You can indeed change color temperature using gels, at the expense of light intensity. The HF-1s with the 5500k filters will produce light of similar color temperature with the DS230 for example, but you'll probably lose about 1/2 stop of light intensity. So if using gels on the cooler lights to match the color temperature of the warmer ones, the DS230 will be noticeably brighter. I (and others) have explained in other threads why using a custom white balance (in camera or in post) to adjust for cooler strobes is not a solution. The issue isn't the specific color temperature of the strobe -- it's the relative difference in color temperature between the strobe and the ambient light. With warmer strobes, that relative difference is greater, leading to increased color contrast between your subject and the background. You can't achieve that with global white balance adjustments -- only with separate selective adjustments for the subject and background using masks. 

 

So no.. respectfully again, diffusers (and warming gels) are not ike wearing ear-plugs at a concert and sunglasses at a movie. They're a specific tool that can be quite beneficial to achieving certain aesthetic results in your images that you can't achieve without them. Whether that aesthetic result is important to your particular type of aesthetic is a separate question, but they are definitely valuable tools in the arsenal for many underwater photographers looking to achieve a certain look.

 

 

The relative light fall-off towards the edges is going to be exactly the same at full power, 1/2 power, 1/4th power, or whatever other power level you test it at. There's no magic that reduces backscatter and flare at 1/2 power vs shooting at full power. That's all down to strobe placement and the needed strobe power relative to the desired exposure. Also, it's relative -- the HF1 at 1/2 power for example should produce similar light intensity to the YS-D3s at full power.

 

Can you share a real world photo that shows the negative impact of a hotspot?

[DreiFish]

5 minutes ago, Dave_Hicks said:

 

Can you share a real world photo that shows the negative impact of a hotspot?

I try to avoid taking such photos, but here's a comparison shot showing the 'hotspot' effect of undiffused Inon S-220s vs Marelux Apollo 3 strobes with diffuser. 

 

 

 

 

[Dave_Hicks]

1 hour ago, DreiFish said:

 

The relative light fall-off towards the edges is going to be exactly the same at full power, 1/2 power, 1/4th power, or whatever other power level you test it at. There's no magic that reduces backscatter and flare at 1/2 power vs shooting at full power. That's all down to strobe placement and the needed strobe power relative to the desired exposure. Also, it's relative -- the HF1 at 1/2 power for example should produce similar light intensity to the YS-D3s at full power.

 

My point (which I didn't make clearly) is that I would be interested in seeing how these strobes perform on the 1st, 2nd, 3rd shot in a 1 second burst. Are all 3 (or 12, 20, 30) shots delivering a similar level of illumination or is there are power drop off with later shots? How do the various strobes perform in these burst shot modes?

 

With new strobes coming on the market with more power, Li-on cells, and the ability to support more than one shot per second, this is going to be the new, and actually relevant metric to judge these strobes.

 

I've shot Ikelike DS-125, DS-161, Inon 330, and Retra strobes over the years. I'd be hard pressed say that one delivered better image results than another. I moved between models based on portability, useability, and reliability over the years. I never found any of these strobes to be dramatically better in producing useful images than the others. I do feel very limited by not being able to take more than one shot per second in high speed action situations, and look forward to experimenting with this ability.

 

Edited June 11 by Dave_Hicks

[Dave_Hicks]

19 minutes ago, DreiFish said:

I try to avoid taking such photos, but here's a comparison shot showing the 'hotspot' effect of undiffused Inon S-220s vs Marelux Apollo 3 strobes with diffuser. 

 

 

 

 

 

These are both pretty poor quality images that are not properly illuminated or exposed. Assuming you didn't crop, the shot below with the brighter area is take from a closer position than the one above which might explain illumination difference. I can't tell which one of these has a diffuser on it.

 

Regardless, Inon 220's don't have any right to be making useful images of a scene that wide even if they aspire to WA. I don't know enough about the Marelux models to comment.