Krontalk

Chronos => Chronos User Discussion => Topic started by: thebishop on September 15, 2017, 03:06:30 AM

Title: Let's talk lighting
Post by: thebishop on September 15, 2017, 03:06:30 AM
I just put in a preorder for the camera and are now wondering what people are using for artificial lighting?

Of course there are many factors playing, but looking at around 4K fps with minimal gain settings to reduce image noise, with say f4 aperture, what have people used successfully?

I am going to try with the Manfrotto LYKOS Daylight (https://www.bhphotovideo.com/c/product/1204246-REG/manfrotto_mll1500_d_lykos_daylight_on_camera_led.html?c3api=2572%2C113041717267&gclid=EAIaIQobChMI6bzn7fem1gIVSIGyCh2YZQfIEAAYAyAAEgKWVvD_BwE)
and if anyone is interested I will share the experience, but would be very interested to learn about other people experience with lighting.
Title: Re: Let's talk lighting
Post by: ptrautne on September 15, 2017, 07:48:09 AM
I have had good luck with the following LED lights

https://www.amazon.com/gp/product/B018NKRQ4Q/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B01K1CGKC8/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B004I6OSPK/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

https://www.kickstarter.com/projects/415736264/litratorch-worlds-most-versatile-adventure-ready-l?ref=user_menu
Title: Re: Let's talk lighting
Post by: Martin on September 15, 2017, 08:52:19 AM
Hi Bishop,

it all comes down to personal preference regarding tint/kelvin range/CRI but one aspect is very important to keep in mind/verify: no PWM driven light sources in or even near your setup.

You'll want very constant current and voltage driven (driver = controller) LED lights, else you'll notice pulsating brightness changes throughout your video.

I will tripod-mount several high CRI, (very) high output flashlights from my night-(geo)caching collection and see if that'll be enough ;)

For example this (amazing) person tests these lights thoroughly, including tests for any traces of PWM (Pulse Width Modulation): http://flashlightreviews.ca/reviews.htm
Not sure if this is a subject in every studio lights review?

All the best
Martin
Title: Re: Let's talk lighting
Post by: thebishop on September 15, 2017, 11:21:40 AM
I hope the Manfrotto is stable, they make a big deal of "non-flickering" everywhere...

1600 lux @ 1m is perhaps not enough though, but will start with that and see how far it takes me, the Godox one seemed quite reasonable too.

Unfortunately, the cheap "big light" is mostly unavailable for me for the next 6 months or so... The downside of living a bit too far up north.

Any other experiences would be interesting, I guess it should be possible to actually calculate the amount of light that would be needed for a given set of video parameters for a reasonable exposure, but too complex for me right now.
Title: Re: Let's talk lighting
Post by: tesla500 on September 15, 2017, 02:00:15 PM
As a rough estimate, for a color camera, you'll need about 7 lux per fps at f/2 and 360 degree shutter.

So at 4000fps, you'd need about 4000fps * 7 = 28,000 lux. If you want to run f/4, you'll need 4x as much light, so 110,000 lux which is about noon day sunlight

I'm afraid you'll need far more light than those Manfrotto lights will provide, unless you're putting them right next to the subject. At 1m (3') distance you'd need 18 of those lights for f/2 4000fps
Title: Re: Let's talk lighting
Post by: jasonfish on September 15, 2017, 04:29:16 PM
I've been using one of the Stratus LEDs with a benchtop power supply. It's plenty bright, but a real hassle to power. My PS only supplies 5.1A, which is barely enough. The other option is a pre-made 24v 7A wall wart, but I'd probably have to order 5 or 6 of the things to find one that doesn't induce flicker.

They have a wall wart on their site, but it's not yet available for sale. In the meantime they suggest a 6s hobby LiPo, but that means buying another charger, not to mention the need to recharge every hour.

I'm seriously considering that Godox.
Title: Re: Let's talk lighting
Post by: thebishop on September 15, 2017, 10:57:56 PM
As a rough estimate, for a color camera, you'll need about 7 lux per fps at f/2 and 360 degree shutter.

So at 4000fps, you'd need about 4000fps * 7 = 28,000 lux. If you want to run f/4, you'll need 4x as much light, so 110,000 lux which is about noon day sunlight

I'm afraid you'll need far more light than those Manfrotto lights will provide, unless you're putting them right next to the subject. At 1m (3') distance you'd need 18 of those lights for f/2 4000fps

Thanks a lot for that estimate, much appreciated!

I will try to change my preorder to a monochrome version then to make it easier to light the scene, then I can stop caring about CRI too, perhaps there are some cheaper/brighter light sources if that is a non-issue, will need to google a bit...

I would like to run with less than 360 shutter too (I want to use the camera for archery shot analysis primarily, want to see the arrow clearly as it leaves the bow).

I can put the lights slightly less than 1m from the archer, but not closer (need some safety distance).

Perhaps it is ok with som gain as well, I haven't seen enough comparable footage with/without gain yet to know if it is ok.
Title: Re: Let's talk lighting
Post by: thebishop on September 15, 2017, 11:18:19 PM
So looking at the Godox with the NG-10X fresnel attachment - according to an Amazon reviewer that gave about 30,000lux @ 1m, so two of those and going black-white should make f/4@4kfps more or less in range (preferably three to get down from 360 shutter...). Will continue to loo a bit more... :-)
Title: Re: Let's talk lighting
Post by: sam on September 16, 2017, 06:10:41 AM
Inspired by tesla500, I rigged up lights with the Chanzon 100W led modules ( here (https://www.aliexpress.com/item/Chanzon-LED-Bulb-1W-3W-5W-10W-20W-30W-50W-100W-High-Power-Epistar-Chips-COB/32811656870.html?ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10130_10068_10344_10342_10343_10340_10341_10307_10137_10060_10155_10154_10056_10055_10054_10059_9911_100031_10099_10338_10339_10103_10102_440_10052_10053_10142_10107_10050_10051_10324_10325_10326_10084_513_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_143_10312_10313_10314_10078_10079_10073-9911,searchweb201603_14,ppcSwitch_7&btsid=c97891e8-72f9-495d-91f6-4494a2028c30&algo_expid=d738e639-9dfe-4250-9fd2-8b435d5031ca-1&algo_pvid=d738e639-9dfe-4250-9fd2-8b435d5031ca) now, but this link moves around...).

I drive each of them with one of these constant current boost converters (http://www.ebay.com/itm/DC-DC-boost-converter-Constant-Current-Mobile-Power-supply-250W-10A-LED-Driver-/181940997254?hash=item2a5c874c86:g:ZlsAAOSwxN5WVAXJ) each.  This is probably overkill, but these are so cheap...  I mount the LEDs to the front of a cpu water cooling block, and the drivers to the back.  Right now I'm driving 3x100W LEDs, a water pump, and fan for the radiator with a 500W ATX power supply. 

Overall, this is ~25k lumens for ~$100.  It stays plenty cool, and works well, but I think there's lots of room for improvement.  And of course, now that my camera has arrived, it doesn't seem bright enough any more!
Title: Re: Let's talk lighting
Post by: wilheldp on September 16, 2017, 01:34:02 PM
So looking at the Godox with the NG-10X fresnel attachment - according to an Amazon reviewer that gave about 30,000lux @ 1m, so two of those and going black-white should make f/4@4kfps more or less in range (preferably three to get down from 360 shutter...). Will continue to loo a bit more... :-)

I bought that exact setup.  I haven't had a chance to use it with the camera yet (mine will hopefully ship next week), but I did some testing on the light and lens.  http://forum.krontech.ca/index.php?topic=5.msg364#msg364 (http://forum.krontech.ca/index.php?topic=5.msg364#msg364)
Title: Re: Let's talk lighting
Post by: thebishop on September 16, 2017, 09:36:05 PM
I've been using one of the Stratus LEDs with a benchtop power supply. It's plenty bright, but a real hassle to power. My PS only supplies 5.1A, which is barely enough. The other option is a pre-made 24v 7A wall wart, but I'd probably have to order 5 or 6 of the things to find one that doesn't induce flicker.

The Stratus in 2 x 10-array configs would have been excellent, but having seen the video for putting it together ("don't do this, or you will fry all driver boards", "avoid this, or the thing will literally explode") and only having basic aptitude for electrical work, I'd avoid it :-) But thanks for the link, it could definitely have been one possibility.
Title: Re: Let's talk lighting
Post by: thebishop on September 16, 2017, 09:41:20 PM
I bought that exact setup.  I haven't had a chance to use it with the camera yet (mine will hopefully ship next week), but I did some testing on the light and lens.  http://forum.krontech.ca/index.php?topic=5.msg364#msg364 (http://forum.krontech.ca/index.php?topic=5.msg364#msg364)

Thanks! I missed that thread, very helpful, great with the quantified measurements. Hope for non-flickering! Looking forward to hearing about your experience when you get the camera!
Title: Re: Let's talk lighting
Post by: jasonfish on September 16, 2017, 10:09:06 PM
...or you will fry all driver boards...

Did that on my first one. :)
Title: Re: Let's talk lighting
Post by: thebishop on September 17, 2017, 02:19:33 AM
I went with 3 x Godox (200) + fresnels, will let you know how it works if interested when received lighting + camera - now the wait begins... :-)
Title: Re: Let's talk lighting
Post by: Electra on September 18, 2017, 12:30:13 AM
At least for smaller areas, a friend borrowed my camera and their lights were two or three 25 and 40W  LED 'spot lights'.. The kind with a grid of 3W LEDs each with their own lens. They are fairly cheap, waterproof(Not always a worry) and because they have a narrow beam, you can get a lot of light on a subject, at least up to about 8-9k fps and from a distance of about half 30cm to half a meter.
And at least at half a meter, the 40W 30 degree 'spot' outperforms my 100W  120 degree LED flood.

Huge powerful LED floods are great if you have large subjects or large splatter areas(Upside down mowers in your garage are a good example.:) but if your subject is fairly small, you can get away with a lot less light if you have good focus.  Or you can take a lot of light and make it much brighter... :)
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 18, 2017, 06:16:35 AM
I've got 6 of these for close-ups:

https://www.amazon.co.uk/gp/product/B01GFWWSWE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

and 3 x 24V 5 amp power supplies.

I don't think they'll give enough light for a large outdoor area with very high frame rate. I'm interested to see how those Godox lights work out.
What we need is an affordable 1-2kW LED or HMI light. Might investigate the cheaper end of the market i.e. China
Title: Re: Let's talk lighting
Post by: thebishop on September 18, 2017, 06:41:38 AM
I'll let you know how the Godox works out - I want to light up essentially the size of the upper body of an archer and be able to have a decent DOF (and minimum 4K fps, preferably more, but then I can probably do more close-up...) - we'll see how far the setup will work.

I'll post results when I've been able to get delivery of all the gear!

Agree that an affordable 1-2kW LED rig would be fantastic... :-)
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 18, 2017, 07:05:31 AM
I've had a look at the Godox range and ordered one of their LED1000 panels. If it really puts out the equivalent of 1kW, it's good value.

Might need to supplement it with a spot or two though. There are some second hand Arri 650s on Ebay around 150 which might fit the bill, but I'd much rather use LED if possible.

If the Godox 200 gives good results I might get one of those, but >500W output would be better.
Title: Re: Let's talk lighting
Post by: jasonfish on September 18, 2017, 09:49:52 AM
Wonder how these would work out. Sure, they're floodlights, but anything's a spotlight if placed close enough to the subject. :)

https://www.amazon.com/Morsen-50000LM-Outdoor-Lighting-Daylight/dp/B01MDUTTTQ
https://www.amazon.com/Super-Bright-Floodlight-Waterproof-Spotlights/dp/B01IOW3E5S

They are pretty huge though.
Title: Re: Let's talk lighting
Post by: Camoit on September 18, 2017, 01:04:13 PM
I'm going to do some testing With Dave Bunge. He owns a grip service company.
So in time I should have an idea of what lights to use that you won't see the 60 cycle flash effect. 
That is super annoying.
The guy has been in the film lighting business for 30 years so he is one of the go to guys when it comes to lighting.

http://www.sacramentogrip.com/
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 19, 2017, 05:05:40 AM
Wonder how these would work out. Sure, they're floodlights, but anything's a spotlight if placed close enough to the subject. :)

https://www.amazon.com/Morsen-50000LM-Outdoor-Lighting-Daylight/dp/B01MDUTTTQ
https://www.amazon.com/Super-Bright-Floodlight-Waterproof-Spotlights/dp/B01IOW3E5S

They are pretty huge though.

I think you'll get flicker with a lot of those LED floodlights. I have a few different types and they all flicker.

My Godox 1000 arrives tomorrow. I've set up an objective comparison between the lights I have for the Chronos. If all of us could post frame grabs using our lights and the same settings I've used, we could get a better idea of how they compare in use. I've done some already with the LED spots I have.

Here's a (reduced) frame grab using the 1280 x 1024 setting of the scene:

(https://i.imgur.com/8rl7Aoo.jpg)

I'm using the Computar 12.5-75 lens with the camera 1.5m from the subject and the lights 1.0m from the subject. I thought a greyscale/colour test card and matt black object such as a lens would make a good subject as most people with cameras of some sort are likely to have these. 

I'm going to take multiple test recordings with various levels of lighting and put all the resulting frame grabs onto one page so it's easy to see what lighting is required at different camera settings. The settings I'm using for each lighting level is:

1: 1280x1024, 1057fps, 476.1us
2: 640x360, 5904fps, 85.21us
3: 640 x 96, 21650fps, 23.14us

0db gain, aperture set just below zebra level or wide open if there's not enough light to require stopping down. WB and  BL set.

Title: Re: Let's talk lighting
Post by: jasonfish on September 19, 2017, 08:01:47 PM
Took my two Stratus LEDs, removed their controller boards and replaced them with a couple boost converters:

https://www.amazon.com/gp/product/B019SYX7BM

Because, ya know, what's the worst that can happen? ;)

With the Stratus boards:
Requires 24-28v @ 6-7A+ (for what??)
The lamp gets fed 27v
The fan gets 6v

With the new boards:
Requires 12v @ 2A (much easier to find)
The lamp still gets 27v, pulls 0.8-1A
The fan gets 12v (runs faster, lamp stays cooler)

With two of these lights placed 1m from the subject, I set the Chronos frame rate to 8,000fps, the shutter to 50%, and still had to stop the f1.8 lens down about halfway.

More trials to come, but after running for 30 mins, the heatsinks are cool to the touch, no flicker, and no change in amp draw.
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 21, 2017, 07:03:09 AM
That sounds pretty good. I've done some tests and even with a Godox 1000 Panel and 6 x 48W LED spots, I'm only at f4.
Here are my results:

(https://i.imgur.com/iOcsoTp.jpg)

Conclusion: Need more lights!
Title: Re: Let's talk lighting
Post by: thebishop on September 21, 2017, 12:27:56 PM
It is kind of funny, I looked around and retrieved my old light meter (Minolta Auto Meter V F) - can actually be useful again :-)
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 27, 2017, 06:23:58 AM
Took my two Stratus LEDs, removed their controller boards and replaced them with a couple boost converters:

https://www.amazon.com/gp/product/B019SYX7BM

Because, ya know, what's the worst that can happen? ;)

With the Stratus boards:
Requires 24-28v @ 6-7A+ (for what??)
The lamp gets fed 27v
The fan gets 6v

With the new boards:
Requires 12v @ 2A (much easier to find)
The lamp still gets 27v, pulls 0.8-1A
The fan gets 12v (runs faster, lamp stays cooler)

With two of these lights placed 1m from the subject, I set the Chronos frame rate to 8,000fps, the shutter to 50%, and still had to stop the f1.8 lens down about halfway.

More trials to come, but after running for 30 mins, the heatsinks are cool to the touch, no flicker, and no change in amp draw.

I've just ordered some of these Stratus lights. For the money, nothing else seems to come close to the output once you add the parabolic reflectors.
I can get 200W 24V power supplies so I think I'll use those rather then mess around replacing the controller boards, as it will still give me the option of running off 6S LIPO batteries if I need to in the future.

Interested in hearing whether you have any long term issues they way you've done it.
Title: Re: Let's talk lighting
Post by: jasonfish on September 27, 2017, 10:31:19 AM
I think you'll be happy, they really are fantastic lights.

And it should be stated that I don't not like their boards. I blew out one board when dinking around one night, so emailed the maker for troubleshooting help. We identified the bad component so I could try to find a replacement locally, and I ordered a second light direct from them. When it arrived, the tech had included a new component in the bag. Wonderful service!

Turns out that the first board ultimately had more problems than just that component (all my fault). So I had one working light, and one dead one.

The only reason I "replaced" their boards is that I already had a few of those converters in the lab and figured it was worth trying to revive the first light. After realizing that it worked just as well with far "simpler" input requirements, I swapped out the second working board as well.

So I have no bad feelings about their boards, and love the support I got. I just happened to go a different route that works better for me with the parts I have.

Stratus LEDs are amazing. Give them money. :)
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 27, 2017, 10:50:26 AM


Stratus LEDs are amazing. Give them money. :)

I have! I've got 4 coming and 4 x 24V 200W PSUs. That should be enough light to get me going I hope!
Title: Re: Let's talk lighting
Post by: NoDak on September 27, 2017, 06:25:22 PM
Inspired by tesla500, I rigged up lights with the Chanzon 100W led modules ( here (https://www.aliexpress.com/item/Chanzon-LED-Bulb-1W-3W-5W-10W-20W-30W-50W-100W-High-Power-Epistar-Chips-COB/32811656870.html?ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10130_10068_10344_10342_10343_10340_10341_10307_10137_10060_10155_10154_10056_10055_10054_10059_9911_100031_10099_10338_10339_10103_10102_440_10052_10053_10142_10107_10050_10051_10324_10325_10326_10084_513_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_143_10312_10313_10314_10078_10079_10073-9911,searchweb201603_14,ppcSwitch_7&btsid=c97891e8-72f9-495d-91f6-4494a2028c30&algo_expid=d738e639-9dfe-4250-9fd2-8b435d5031ca-1&algo_pvid=d738e639-9dfe-4250-9fd2-8b435d5031ca) now, but this link moves around...).

I drive each of them with one of these constant current boost converters (http://www.ebay.com/itm/DC-DC-boost-converter-Constant-Current-Mobile-Power-supply-250W-10A-LED-Driver-/181940997254?hash=item2a5c874c86:g:ZlsAAOSwxN5WVAXJ) each.  This is probably overkill, but these are so cheap...  I mount the LEDs to the front of a cpu water cooling block, and the drivers to the back.  Right now I'm driving 3x100W LEDs, a water pump, and fan for the radiator with a 500W ATX power supply. 

Overall, this is ~25k lumens for ~$100.  It stays plenty cool, and works well, but I think there's lots of room for improvement.  And of course, now that my camera has arrived, it doesn't seem bright enough any more!

Hmmmmmmmmm. I wonder if we still have that crapload of old Socket 478 heatsinks at work. :D I'm sure the boss would be okay with me getting rid of them.

Okay, so one heat-sink per module.

I use the drivers that you linked.

I found a US-ish seller of those modules on eBay. http://www.ebay.com/itm/100W-watts-High-Power-SMD-LED-Chip-Lamp-Beads-White-Red-Blue-Green-RGB-UV-Light-/122046201688?var=&hash=item1c6a853f58:m:mBExdbhCP8WUQFmi4PpsUQw

Should I go with White or Cool white? 6,000k-6,500k vs 10,000k-15,000k? Yea it's $20 more than the aliexpress one, buuuuuut I'll prefer to get a US reseller.

Power supply, hmmmm. We have a bunch of old 24 VAC CCTV power supplies. Things are moving to PoE IP cameras, so we probably won't ever use them. I think they are 8 amps at 24 volts. Would need to add a bridge rectifier for sure.

Would I need to add a capacitor for the ripple this would create or do I need to not be a cheap-ass and get a proper switching PSU?

24 volt would probably be better than 12v to reduce the amperage required in the wiring.

I could just use the car battery I have for starting my generator and only switch on all the LEDs when I am about to trigger the camera. :-\

Do those drivers output the same voltage regardless of input voltage? Or do I need to have it always powered by 12v or 24v? I am guessing it's one or the other.

80,000 Lumens and probably blowing breakers.  ;D Even better, since it will be one module per heat-sink means that I can aim and mount them individually
Title: Re: Let's talk lighting
Post by: jasonfish on September 27, 2017, 07:02:38 PM
The boards I bought from Amazon, similar to sam's, have a constant voltage dial and a peak current dial. So yes, constant output voltage regardless of input.
Title: Re: Let's talk lighting
Post by: NoDak on September 27, 2017, 07:34:59 PM
The boards I bought from Amazon, similar to sam's, have a constant voltage dial and a peak current dial. So yes, constant output voltage regardless of input.

Nice, good to have options.

I see that you solder the driver directly to the module. (Not a problem, I can solder.) How do you go about calibrating them? Do you calibrate the voltage before you connect anything, then connect it to the module with alligator clips, calibrate the amperage with a multi-meter, solder it all down, then Loc-tite the screws in place? Or is there another way?
Title: Re: Let's talk lighting
Post by: jasonfish on September 27, 2017, 09:00:30 PM
Mine have screw terminals, so no soldering. I have a few of each of these, they seem interchangeable:

https://www.amazon.com/gp/product/B00MIJL4OC
https://www.amazon.com/gp/product/B019SYX7BM
(and many others, some with V and A displays built in, which will be in my next order)

1) Attach your source, set the output V with the Voltage screw
2) Unscrew the Current screw all the way (it'll tick tick tick but won't actually stop)
3) Connect your vmeter in series with the lamp
4) Check the LED spec sheet for amps
5) Increase the Current screw until flicker stops and you get solid light output, note the amp draw and double check the LED spec sheet
(I actually gave an extra half turn of the CC screw to avoid starving the LED)

If you think you may have bumped or moved one of the screws, check it all again. Better safe than smoky.
Title: Re: Let's talk lighting
Post by: NoDak on September 27, 2017, 10:29:36 PM
Ah, the eBay ones don't have screw terminals.

In the long run it may be better to buy the ones you link with screw terminals. Makes calibration and such easy, as does replacing modules should the need arise.
Title: Re: Let's talk lighting
Post by: Fyodor on September 27, 2017, 11:48:25 PM
I just bought the LED panels from ebay, as well as the converters and some water cooling blocks. Lets see if I as a mechanic can get these electronics to work... :D

That will take a while... "guaranteed delivery" within 60 days :o
Title: Re: Let's talk lighting
Post by: thebishop on September 29, 2017, 06:10:03 AM
Initial feedback from actually shooting with the Godox 200 (x3) now - there seems to be no discernible flicker when shooting at 8K fps, so I think it looks as a good alternative. Haven't done more than initial "let's plug everything together and get some random test video done", but have hopes it will work ok also for my final intended use case.

Looks promising!
Title: Re: Let's talk lighting
Post by: jasonfish on September 29, 2017, 09:30:50 AM
Darn it bishop, and here I was happy with my hacky Stratus lights. Now I might have to spend money again. grrr
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 29, 2017, 10:08:01 AM
Those Godox lights are good value, but each Stratus module + reflector + PSU is costing me 110 including shipping to the UK, so you get more lumens for your money and I quite like the modular approach.

If I bolt 4 x Stratus modules together into one fitting, that's going to give me 56,000 lumens. 3 of those fittings is going to put out a lot of light for under 1500 all in. 

Title: Re: Let's talk lighting
Post by: jasonfish on September 29, 2017, 05:08:47 PM
and I quite like the modular approach.

If you mean the ability to light from multiple angles, I agree: that's been fun to play with. Maybe one Godox as the primary, plus the two Stratus. ;)
Title: Re: Let's talk lighting
Post by: John DeLonghi on September 30, 2017, 03:36:21 AM
and I quite like the modular approach.

If you mean the ability to light from multiple angles, I agree: that's been fun to play with. Maybe one Godox as the primary, plus the two Stratus. ;)

Also the flexibility to bolt several modules together to make larger lighting units which mount on a single lighting stand.

One of the problems when you have multiple lights all up close to the subject is fitting all the lighting stands into a small area!
Title: Re: Let's talk lighting
Post by: NoDak on October 01, 2017, 01:21:39 AM
Anyone found a good cheap 110v AC constant current driver? The killer expensive part is the 110V to 12 or 24 V PSU.  :-\
Title: Re: Let's talk lighting
Post by: John DeLonghi on October 17, 2017, 11:09:24 AM
4 of the Stratus lights have just arrived.

Still waiting for the 24V PSUs to get here (cheapest I could find was 48 each but hey ho), but  I've tried them out on a bench PSU which maxes out at 17V, and they're looking very usable.

Different colour temperature to the other LED spotlights I've been using, but that shouldn't notice too much. It's often difficult to get LED lights from different manufacturers to match exactly.

I'm going to make a cover for them to protect the PCB better. Should be trying them with the Chronos next week sometime.
Title: Re: Let's talk lighting
Post by: Explodify on October 26, 2017, 05:55:12 PM
Anyone have good recommendations from Amazon in the Sub 200$ range? I have tried a few and no luck. The Stratus I got went out after maybe 4 uses so I am hesitant to use them. Anyone used halogen lights or something of that nature?
Title: Re: Let's talk lighting
Post by: John DeLonghi on October 27, 2017, 01:39:53 AM
Anyone have good recommendations from Amazon in the Sub 200$ range? I have tried a few and no luck. The Stratus I got went out after maybe 4 uses so I am hesitant to use them. Anyone used halogen lights or something of that nature?

How were you powering it? Have you contacted Stratus about it?
Title: Re: Let's talk lighting
Post by: Explodify on October 29, 2017, 01:18:50 PM
Anyone have good recommendations from Amazon in the Sub 200$ range? I have tried a few and no luck. The Stratus I got went out after maybe 4 uses so I am hesitant to use them. Anyone used halogen lights or something of that nature?

How were you powering it? Have you contacted Stratus about it?

Yep found that the issue was the battery. Running 2v per cell. Went and got a 24v 7+amp now working fine. So bought another light to make things better!
Title: Re: Let's talk lighting
Post by: John DeLonghi on October 30, 2017, 03:34:28 AM
I'm still waiting for my 24V PSUs to arrive for the 4 I've got. Planning to use them this Wednesday for the first time, so they better turn up tomorrow!

I might actually be able to stop the lens down a few stops!
Title: Re: Let's talk lighting
Post by: NoDak on October 30, 2017, 05:41:55 PM
I got screwed by Amazon. Bought a bunch of the 48 watt automotive LEDs. They claim 48 watts, they actually use only 8 watts.

https://www.amazon.com/gp/product/B01M7TG8ID/ref=od_aui_detailpages01?ie=UTF8&psc=1

 >:(

Getting ready to return these units. Might have to go with a build-it-yourself approach.
Title: Re: Let's talk lighting
Post by: John DeLonghi on October 31, 2017, 02:11:44 AM
I got screwed by Amazon. Bought a bunch of the 48 watt automotive LEDs. They claim 48 watts, they actually use only 8 watts.

https://www.amazon.com/gp/product/B01M7TG8ID/ref=od_aui_detailpages01?ie=UTF8&psc=1

 >:(

Getting ready to return these units. Might have to go with a build-it-yourself approach.

To be fair to them, they don't claim they consume 48W in power, they say they are 48W LED output power.
All those LED spots of different types use '3W' LEDs in various arrays, so on that lamp they are using 16 x 3W = 48W.

I have four of those same spots and they're not to bad really, probably fairly close to the claimed LED output power, but they don't compare to the 100W Stratus.
Title: Re: Let's talk lighting
Post by: NoDak on October 31, 2017, 07:47:04 PM
I got screwed by Amazon. Bought a bunch of the 48 watt automotive LEDs. They claim 48 watts, they actually use only 8 watts.

https://www.amazon.com/gp/product/B01M7TG8ID/ref=od_aui_detailpages01?ie=UTF8&psc=1

 >:(

Getting ready to return these units. Might have to go with a build-it-yourself approach.

To be fair to them, they don't claim they consume 48W in power, they say they are 48W LED output power.
All those LED spots of different types use '3W' LEDs in various arrays, so on that lamp they are using 16 x 3W = 48W.

I have four of those same spots and they're not to bad really, probably fairly close to the claimed LED output power, but they don't compare to the 100W Stratus.
They should then claim 48 watt equivalent, like all the incandescent replacement LEDs do.
Title: Re: Let's talk lighting
Post by: John DeLonghi on November 01, 2017, 02:04:02 AM
If only all manufacturers of lamps adhered to a common standard, life would be so much easier, but they don't and you'd still get exaggerated claims from the Chinese who generally don't care about misrepresenting their product's specifications.
Title: Re: Let's talk lighting
Post by: Fyodor on November 10, 2017, 12:54:52 AM
As suggested above, I bought some 100W LEDS, drivers, water cooling... but actually couldn't find the time to assemble it all together. Electronics is not my comfort zone anyway.

When we did some test runs in our lab at work this Wednesday, I brought my Chronos andmy boss brought some old foto studio lights with 1000W halogen burner!

Surprisingly that was absolutely flicker free!

Because halogen is considered outdated these days, these lights are very cheap (I now bought 3 on ebay for 40 total incl. shipping) and give a very good warm white light.

The downside is, that the cheaper ones don't have built in fans, and can be used for 5 minutes only before they need to cool down. But that's why I bought three of them ;).
Title: Re: Let's talk lighting
Post by: thebishop on November 10, 2017, 05:44:19 AM
Feedback on the godox: no flicker at 9k FPS at least, so looks good so far!
Title: Re: Let's talk lighting
Post by: John DeLonghi on January 05, 2018, 08:25:23 AM
I've just been doing some more tests with the Stratus lights and I've noticed some flicker at high frame rates I didn't see before.

I'm going to try a different power supply on one to see if that makes any difference but above 7000fps it's quite noticeable at the moment. Strange I didn't notice it before.

I've got an Aputure 300D LED light I'm comparing against the Stratus and I was surprised to find that even using a fresnel on the 300D, the Stratus holds it own against a light costing 7 times the price, but the flicker could be a problem if i can't solve it.

Incidentally, the Aputure also flickers if I set it below 100%, but I doubt I'll ever want to run it on anything other than full power with the Chronos.

Has anyone else using the Stratus seen flicker?
Title: Re: Let's talk lighting
Post by: John DeLonghi on January 10, 2018, 09:53:15 AM
Stratus have a new driver board and I've just taken delivery of some and swapped one of the existing boards with a new one.

I've gone up to 38.57kfps with 2.830us exposure and can't see any flicker now. I'm just about to upgrade the other 3 Stratus lights I have with the new driver boards.

The new boards are clearly labelled "100W LED Driver V2" on the back so you can tell if you have the ver. 1 or ver. 2 boards.

I'd say the 4 x Stratus and 1 x Aputure 300D is going to be a good lighting kit.
There's a lot of light there and it all packs up into a couple of cases and will not stress a domestic circuit. It should all run off a 2KW generator if necessary.