Inon Z-330 vs circular tube strobes

Hey all

I've been shooting Inon Z-330 for some years now (from 2018), but now I started to contemplate about upgrading to bigger, more powerful strobes with warmer and more even light. Don't get me wrong, I'm super happy with Inons, they've been reliable all these years and are generally powerful enough for my use. I've also done some very beautiful (in my opinion, of course) photos with them, you can check some of them on my FB profile. But what bothers me are these two things:

• Lots of backscatter on the edges of the frame. I always pull the strobes well behind the housing and point them outwards, but this means that I have to crank them up to get enough light in the middle of the picture frame. I'm kind of under impression that strobes with circular flash tube don't have this problem, or at least is not so pronounced, since the light is more even across the beam range, so you don't have to crank them up that much to get enough light to the edges of the light cone.
• Somewhat cool temperature of light, even if I use 4600K diffusers. This is noticable mostly if I have to push the strobes hard when shooting with a sunball in the picture frame. My understanding is that if I push flash tubes hard, they will emit cooler light than with regular settings. For example take a look at the attached photo below. Strobes were set to approx. -1 or maybe -1/2, I used 4600K diffusers, but the diver's skin looks kind of blueish

I've already done my homework and checked multiple reviews (Reef Photo comparison of strobes, Retra's flashgun light comparison, Adam's video about light quality, etc.) and it all seems nice and pretty straightforward that I should upgrade. But before I spend 4000€ on a new lighting system, just to find out that I didn't gain anything major, I wanted to open a discussion here on what are your thoughts about this. My main questions / talking points for you are:

• Are my assumptions above correct and will these issues be resolved if I move to bigger strobes with a circular flash tubes?
• Did you do a similar migration and did you see any noticeable difference in the quality of your photos?
• Would a better diffuser for Inon Z-330 resolve this problem with much less money spent?

Basically I'm deciding between Retra Flash Pro X and OneUW 160x. Retra is cheaper, offers more accessories, and by buying it I support my fellow countrymen, but has a really slow recharge time, especially without superchargers, which are a non-negligible additional cost. OneUW on the other hand seems an embodiment of power and warmth (4600K), beautiful design, but is a bit more expensive (but not that much if you consider Retra Pro X + supercharger) and I'm kind of afraid that the support may be worse. Just a hunch, since I don't often hear anything about them, such as new accessories released, strobe upgrade, etc. Which one would you choose?

1 hour ago, Andrej Oblak said:

Hey all

I've been shooting Inon Z-330 for some years now (from 2018), but now I started to contemplate about upgrading to bigger, more powerful strobes with warmer and more even light. Don't get me wrong, I'm super happy with Inons, they've been reliable all these years and are generally powerful enough for my use. I've also done some very beautiful (in my opinion, of course) photos with them, you can check some of them on my FB profile. But what bothers me are these two things:

• Lots of backscatter on the edges of the frame. I always pull the strobes well behind the housing and point them outwards, but this means that I have to crank them up to get enough light in the middle of the picture frame. I'm kind of under impression that strobes with circular flash tube don't have this problem, or at least is not so pronounced, since the light is more even across the beam range, so you don't have to crank them up that much to get enough light to the edges of the light cone.
• Somewhat cool temperature of light, even if I use 4600K diffusers. This is noticable mostly if I have to push the strobes hard when shooting with a sunball in the picture frame. My understanding is that if I push flash tubes hard, they will emit cooler light than with regular settings. For example take a look at the attached photo below. Strobes were set to approx. -1 or maybe -1/2, I used 4600K diffusers, but the diver's skin looks kind of blueish

I've already done my homework and checked multiple reviews (Reef Photo comparison of strobes, Retra's flashgun light comparison, Adam's video about light quality, etc.) and it all seems nice and pretty straightforward that I should upgrade. But before I spend 4000€ on a new lighting system, just to find out that I didn't gain anything major, I wanted to open a discussion here on what are your thoughts about this. My main questions / talking points for you are:

• Are my assumptions above correct and will these issues be resolved if I move to bigger strobes with a circular flash tubes?
• Did you do a similar migration and did you see any noticeable difference in the quality of your photos?
• Would a better diffuser for Inon Z-330 resolve this problem with much less money spent?

Basically I'm deciding between Retra Flash Pro X and OneUW 160x. Retra is cheaper, offers more accessories, and by buying it I support my fellow countrymen, but has a really slow recharge time, especially without superchargers, which are a non-negligible additional cost. OneUW on the other hand seems an embodiment of power and warmth (4600K), beautiful design, but is a bit more expensive (but not that much if you consider Retra Pro X + supercharger) and I'm kind of afraid that the support may be worse. Just a hunch, since I don't often hear anything about them, such as new accessories released, strobe upgrade, etc. Which one would you choose?

• Lots of backscatter on the edges of the frame. I always pull the strobes well behind the housing and point them outwards, but this means that I have to crank them up to get enough light in the middle of the picture frame. I'm kind of under impression that strobes with circular flash tube don't have this problem, or at least is not so pronounced, since the light is more even across the beam range, so you don't have to crank them up that much to get enough light to the edges of the light cone.

Shape of the light tube has nothing to do with backscatter at the edges. Backscatter happens when light bounces on a suspended particle reflects and comes back to the lens. It is not possible to eliminate backscatter with very wide lens as the lens sees everything including your strobes and the impact of the light beam with water that happens near the strobe. The more powerful your strobe more you get a cloud near it when it fires.

Wider more uniform beams have increased diffusion so actually may produce more backscatter. 

• Somewhat cool temperature of light, even if I use 4600K diffusers. This is noticable mostly if I have to push the strobes hard when shooting with a sunball in the picture frame. My understanding is that if I push flash tubes hard, they will emit cooler light than with regular settings. For example take a look at the attached photo below. Strobes were set to approx. -1 or maybe -1/2, I used 4600K diffusers, but the diver's skin looks kind of blueish

Warmer strobes create a bluer water they have impact on the background more than they do on the foreground that you can white balance anyway. It is true that some shots of the Z330 look very cold though

1 hour ago, Interceptor121 said:

Wider more uniform beams have increased diffusion so actually may produce more backscatter.

Don Silcock in his review of OneUW 160x for Indopacificimages found out just the opposite - that this strobe produced less backscatter than others. It's not clear, though, which strobe he based this comparison on.

My reasoning for this (I may be wrong, however) is the following: to reduce the backscatter you need to pull strobes backwards and point them outwards. Because intensity of light decreases on the edges of the beam for strobes with a straight flash tube, you need to crank up the power, to get enough light in the center of the frame. This causes the beam on the edge of the picture frame (center of the beam) be stronger than necessary, which lights up all the particles in the water. Following this logic if a strobe has more even beam, you don't need to crank it up that much, to get enough light in the center of the frame, consequently backscatter won't be as pronounced at the edges of the picture frame.

40 minutes ago, Andrej Oblak said:

Don Silcock in his review of OneUW 160x for Indopacificimages found out just the opposite - that this strobe produced less backscatter than others. It's not clear, though, which strobe he based this comparison on.

My reasoning for this (I may be wrong, however) is the following: to reduce the backscatter you need to pull strobes backwards and point them outwards. Because intensity of light decreases on the edges of the beam for strobes with a straight flash tube, you need to crank up the power, to get enough light in the center of the frame. This causes the beam on the edge of the picture frame (center of the beam) be stronger than necessary, which lights up all the particles in the water. Following this logic if a strobe has more even beam, you don't need to crank it up that much, to get enough light in the center of the frame, consequently backscatter won't be as pronounced at the edges of the picture frame.

That article demonstrates that the writer does not understand how strobes are built as he assumed dome shaped front means wider beams which is not the case. The part where he thinks he is measuring strobe power by shooting burst is quite interesting with some real misconceptions of all sorts. Anyway let's move on.

Dome front of the strobe does not create more even light and has no effect on beam angle. The reason for having a dome shape has to do with cooling and making the front more resistant to depth pressure. The oneUW strobe has a circular element and a very good reflector design this results in a wide even beam. Retra also have a good design with a circular beam

None of those have a dome to increase angle of coverage but for the reasons above (mechanical)

Pulling the strobes backwards compared to the dome line makes sure you don't see the strobes in the image or the potential scatter in front of the light. However with a narrower lens as the field of view is reduced you don't actually need to do that.

Angling the strobes outwards just means the centre of the frame will have less light than the edges. Depending on what you shoot this may or not result in a reduction of backscatter. You will then be forced to increase the power however strobes loose a lot of power in the edges due to a number of reasons so you may end up just with a dark image. At the end of the day a big wide angle scene needs light full stop. Angling the strobes outwards means an extensive dark area in front of the lens which generally is not what you want and can't be corrected by increasing power simply because you ran out of angle of coverage

Backscatter is generated by the field of view of the lens intersecting with the strobes beam angle and therefore depends mostly on conditions. There are other techniques that may still illuminate the target but reduce backscatter for example inward lighting which also ends up with edge illumination however at the least the two strobes add up in the centre at close range which means less water and at the end less particles and also the illumination is prominent near the lens not far from it

I have three suggestions that will largely solve this problem.

1) Get longer arms. For very wide angle work I use 3 arm segments. 12"+16"+16" (30cm+40cm+40cm)

2) Angle your strobes inward, pointing toward the dome, inline or behind the dome. Slightly rotate outward as needed. This will reduce backscatter by reducing illumination behind the subject just like pointing outward. However, you may get more core (vs edge) light on your subject.

3) Turn down the strobe power and turn up the ISO. I usually set ISO 250-320 and 1/4 to 1/2 power for shots like you posted. 

2 hours ago, davehicks said:

I have three suggestions that will largely solve this problem.

1) Get longer arms. For very wide angle work I use 3 arm segments. 12"+16"+16" (30cm+40cm+40cm)

2) Angle your strobes inward, pointing toward the dome, inline or behind the dome. Slightly rotate outward as needed. This will reduce backscatter by reducing illumination behind the subject just like pointing outward. However, you may get more core (vs edge) light on your subject.

3) Turn down the strobe power and turn up the ISO. I usually set ISO 250-320 and 1/4 to 1/2 power for shots like you posted. 

2 when the subject is far away will increase backscatter actually if the subject is further away from where the beams meet

Generally you shoot inward as you get close the rule is very simple as you get close you close the angle as you go further you open it but pointing outwards as a proxy of not having longer arms does not really work well as it deprives the centre of the frame of light and normally there is where you have your most interesting things

The sample photo was a close in diver.

When using a very wide lens like a 15mm FE you don't take many photos that are far away. 

Here is a photo I took last week using the technique i described.

The sample photo was a close in diver.
When using a very wide lens like a 15mm FE you don't take many photos that are far away. 
Here is a photo I took last week using the technique i described.
 
 

3 hours ago, davehicks said:

I have three suggestions that will largely solve this problem.

1) Get longer arms. For very wide angle work I use 3 arm segments. 12"+16"+16" (30cm+40cm+40cm)

2) Angle your strobes inward, pointing toward the dome, inline or behind the dome. Slightly rotate outward as needed. This will reduce backscatter by reducing illumination behind the subject just like pointing outward. However, you may get more core (vs edge) light on your subject.

3) Turn down the strobe power and turn up the ISO. I usually set ISO 250-320 and 1/4 to 1/2 power for shots like you posted. 

Thanks for the tips, Dave, I'll sure try them out next time. As for 3) I've been practicing this for a while now and it really makes a difference. My default setting for deeper dives (40m and deeper) is ISO 800, 20-40m is ISO 400 and shallower than 20m it's ISO 200. I start out with this, then adjust as needed. But please note that I dive mostly in Adriatic sea where the water is quite murky and dark in depths, so your experience and settings may vary if you're used to shooting in tropical waters only.

But guys, please, let's not change this topic to discussions on backscatter only. It is an issue for sure, but my main question was if the improvement in quality of light with bigger strobes is noticeable and worth the substantial investment.

2 hours ago, Andrej Oblak said:

 

But guys, please, let's not change this topic to discussions on backscatter only. It is an issue for sure, but my main question was if the improvement in quality of light with bigger strobes is noticeable and worth the substantial investment.

Quality of light is generally measured in terms of color rendering index. Unfortunately this is not tested for strobes while it is available for LED lights. There is much more to a light source than the average color temperature and in some cases some light frequencies are stronger than other and have peaks that ultimately make the perceived quality drop.

This factor is irrespective of the shape of the front of the strobe it has to do with the light bulb itself and the reflector

From what I have seen the Z330 look cooler than the old Z240 and the YS-D3 looks cooler than the old YS-D2

This article from reefphoto is pretty bad to draw conclusions on angle of coverage etc but the images do give you an idea about the light color and confirm that your Z330 is pretty 'cool'

https://reefphoto.com/blogs/trending/how-good-are-the-current-strobes-for-light-intensity-and-coverage

I like the light colour of my YS-D2 very much and I do not use any warming filter with them

Here is another recent photo that I took in my home waters of Puget Sound, which is cold green and full of particulate on the best of days. 

I took this photo with the same setup as with the Fiji photo, but with lower strobe power as it is dark and very silty. This would be 1/4 power on the left and 1/8th on the right.

You can get plenty of good light with an Inon 330, and without creating a lot of flare or backscatter.

7 hours ago, davehicks said:

Here is another recent photo that I took in my home waters of Puget Sound, which is cold green and full of particulate on the best of days. 

I took this photo with the same setup as with the Fiji photo, but with lower strobe power as it is dark and very silty. This would be 1/4 power on the left and 1/8th on the right.

You can get plenty of good light with an Inon 330, and a oid creating a lot of flare or backscatter.

 

Nice outcome considering the conditions.

On 9/25/2022 at 6:01 PM, davehicks said:

Here is another recent photo that I took in my home waters of Puget Sound, which is cold green and full of particulate on the best of days. 

I took this photo with the same setup as with the Fiji photo, but with lower strobe power as it is dark and very silty. This would be 1/4 power on the left and 1/8th on the right.

You can get plenty of good light with an Inon 330, and without creating a lot of flare or backscatter.

 

Not to hijack the thread but dang, this photo makes me want to dive the PS region even more now.  I really want to get some images of Wolf Eels and now I want an image of Giant Pacific Octos.

Tell me if this helps!

Nice pics, Dave!

https://www.dpreview.com/forums/post/15932666There's been a lot of discussion around what causes backscatter and dome fronts etc and what they may or may not do. 

On the subject of backscatter there are two factors in play, lighting angles leaving an unlit area between strobe and camera and also the inverse square law - close by particles lit up by the strobe beam show as much brighter than more distant particles and combine this with the depth of field and whether or not the particles are in focus.  Positioning your strobes so the lens can't see the particles very close to the strobe that get lit up very brightly is an important part of it.  Positioning your strobes back behind the plane of the port is to solve this issue. 

On Don Silcock's review. I know Don and he's a very exacting type of guy with regards to image quality .  Leaving aside whether or not his theories about the dome shape and flash power testing are correct - I regard that as somewhat irrelevant when you have some results to look at and the commentary on the quality of the light.  You don't need to understand why something is happening to appreciate the results.  I've seen it mentioned a few times - the softness of the light seems to wrap around the subject.  The backscatter result  also seems to be real - I have shot in those water and particulates are a real problem.   I believe Don previously used YS-250 and Ikelite strobes and still uses INON strobes for macro.  So the improvement he is seeing is over YS-250/ikelite.  I'm sure you can setup INON strobes to get less backscatter - but does it introduce other limitations?

On quality of light - CRI is not measured on strobes most likely as it's not an issue they are very similar in performance to tungsten lights.  But there's more to quality of light than CRI, there is also softness and evenness of light and this is what seems to be discussed 

There is of course a whole long thread on the Retra strobes, which early on Alex Mustard reviews them and talks at length about light quality on the original retra :  http://www.wetpixel.com/articles/preview-retra-strobe-by-alex-mustard 

AdamHanlon reviewed the new Retra Pro later on and similarly proaised the light quality:   https://wetpixel.com/articles/strobe-review-scubalamp-d-max-and-retra-pro-flash/P4

There is also this review from Walt Stearns who posts here on WP on the Retra prime having previously been a user of the Z330.  https://www.scubadivermag.com/retra-prime-underwater-flash/

On the colour temperature,  that should be solely about water colour.  You WB in raw processing to get the subject looking right and the the resultant is the water colour.  Of course it always possible the diffusers are not doing as good a job as a strobe tube of the desired colour temperature.  As mentioned a strobe should have a CRI of around 100.  Adding a coloured diffuser may reduce this CRI?  Here is a thread talking about CRI of strobes.  https://www.dpreview.com/forums/post/15932666

 Note that the circular tubes generally by nature have lower colour temperature and probably have different glass/coatings to bring the colour temperature to the lower point.

https://www.dpreview.com/forums/post/15932666There's been a lot of discussion around what causes backscatter and dome fronts etc and what they may or may not do. 

On the subject of backscatter there are two factors in play, lighting angles leaving an unlit area between strobe and camera and also the inverse square law - close by particles lit up by the strobe beam show as much brighter than more distant particles and combine this with the depth of field and whether or not the particles are in focus.  Positioning your strobes so the lens can't see the particles very close to the strobe that get lit up very brightly is an important part of it.  Positioning your strobes back behind the plane of the port is to solve this issue. 

On Don Silcock's review. I know Don and he's a very exacting type of guy with regards to image quality .  Leaving aside whether or not his theories about the dome shape and flash power testing are correct - I regard that as somewhat irrelevant when you have some results to look at and the commentary on the quality of the light.  You don't need to understand why something is happening to appreciate the results.  I've seen it mentioned a few times - the softness of the light seems to wrap around the subject.  The backscatter result  also seems to be real - I have shot in those water and particulates are a real problem.   I believe Don previously used YS-250 and Ikelite strobes and still uses INON strobes for macro.  So the improvement he is seeing is over YS-250/ikelite.  I'm sure you can setup INON strobes to get less backscatter - but does it introduce other limitations?

On quality of light - CRI is not measured on strobes most likely as it's not an issue they are very similar in performance to tungsten lights.  But there's more to quality of light than CRI, there is also softness and evenness of light and this is what seems to be discussed 

There is of course a whole long thread on the Retra strobes, which early on Alex Mustard reviews them and talks at length about light quality :  http://www.wetpixel.com/articles/preview-retra-strobe-by-alex-mustard

On the colour temperature,  that should be solely about water colour.  You WB in raw processing to get the subject looking right and the the resultant is the water colour.  Of course it always possible the diffusers are not doing as good a job as a strobe tube of the desired colour temperature.  As mentioned a strobe should have a CRI of around 100.  Adding a coloured diffuser may reduce this CRI?  Here is a thread talking about CRI of strobes.  https://www.dpreview.com/forums/post/15932666

 Note that the circular tubes generally by nature have lower colour temperature and probably have different glass/coatings to bring the colour temperature to the lower point.

The CRI or a tungsten bulb i.e. an old school light bulb is near 100

That doesn’t mean that the CRI of a flashlight is near 100 because there is a reflector and the plastic/glass that covers the bulb that do not transmit everything equally

Having said that if you have ever taken studio shots you will know that nobody would ever fire a flashlight directly to the target without a light modifier as what matters are the shadows

Shadows define the character of an image

Unfortunately underwater we can’t take softboxes or even position lights and camera as it should be due to water and physical limitations

The OneUw and to an extent the retra are very similar to a mains powered studio flash but of course smaller

Filters and anything you put in front of the strobes do impact CRI as they select what light frequencies to attenuate

In short you get what you pay for but as dave hicks shows the most important part is to know how to use your equipment

Sent from my iPhone using Tapatalk

100 CRI is a perfect back body and a tungsten filament is quite close to that - close enough that people don't measure and strobes are the in a similar ball park - the Xenon gas in the tube is not emitting like a black body and the glass and coating chosen to cut some UV and otherwise modify the light to be close to a black body in emission characteristics, the whole package will be chosen to provide this characteristic and also to achieve the desired colour temperature.  The circular tubes seems to "burn" slower and cooler so have a lower colour temperature than linear bulbs naturally which can be modified further by reflectors and coatings on the tube and glass type.  In any case the starting point is a lot closer to a black body than most other light sources (like LEDs which are monochromatic in their basic form).  I think xenon tubes are close enough to perfect that no one bothers measuring them.

59 minutes ago, ChrisRoss said:

100 CRI is a perfect back body and a tungsten filament is quite close to that - close enough that people don't measure and strobes are the in a similar ball park - the Xenon gas in the tube is not emitting like a black body and the glass and coating chosen to cut some UV and otherwise modify the light to be close to a black body in emission characteristics, the whole package will be chosen to provide this characteristic and also to achieve the desired colour temperature.  The circular tubes seems to "burn" slower and cooler so have a lower colour temperature than linear bulbs naturally which can be modified further by reflectors and coatings on the tube and glass type.  In any case the starting point is a lot closer to a black body than most other light sources (like LEDs which are monochromatic in their basic form).  I think xenon tubes are close enough to perfect that no one bothers measuring them.

Nobody bothers measuring them as it is very difficult to measure a flash vs continuous light.

If all flashs were equal there would not be a reason why cheap ones product ugly light and expensive ones nice light

The same that happens on land goes underwater

Users are fixated on the bulb and do not look at the whole system, it is the combination of bulb, reflector, front port that makes the beam not just the bulb

I think a perfect example of this is Ikelite they have circular bulbs however I think the design is a bit dated and falls way behind some of the newer strobes but also some of the old strobes. The Sea and Sea YS-D250 being the first large scale Japanese product that were indeed very well designed but heavier and more expensive to make.

Seacam first and OneUW and Retra later show how the end to end design can turn into a better outcome but there is more than the shape of the bulb

I also agree with David Hicks that technique is far more important and you can get good results from the Z330 and from any strobe for that matter if you know how to position the strobes

I would urge the op to try what David and I have recommended which is to use inward lighting and forget about the color temperature for a moment as that is not going to change the subject as you correctly pointed out

1 hour ago, Interceptor121 said:

If all flashs were equal there would not be a reason why cheap ones product ugly light and expensive ones nice light

Shhhh. Don’t help everyone to understand how important light is in underwater photography. I've often credited the Sea & Sea's marketing for allowing me a successful career in underwater photography!