(1 to 100 of 399 replies)
midwestphotoexchange 6:26am, 8 March 2009
Discussion thread for LumoPro 120

(Original post edited to conform to Flickr TOS by DH)
1 3 4
(1 to 100 of 399 replies)
VibrantPhotographs 8 years ago
Sounds cool... Looking forward to more info.
petepixxx Posted 8 years ago. Edited by petepixxx (member) 8 years ago
Nice description! Especially the slave flash off/on. I didn't catch it at first read cause I didn't expect that feature in a flash, only studio lights. Many studio/home users will like that!

Let's get a few important extras out of the way..

1) Foot strengh? plastic or metal? Do they make a stronger plastic now, or what? I don't trust it.

2) Are the dimension of the flashhead the size bigger or smaller or just right as the 285?

3) Please-Please-Please-Please! tell my you have idiot lights for power settings like the YN460! wimper....

May I note that this "release" was @ 1:26 AM? Expecting a lot of immediate response?? NightOwls! And wedding photographers downloading the days shoot, I'll bet...
mjpatey 8 years ago
Yay! Can't wait to see some test shots and impressions. :-)
celticview 8 years ago
i second with petepixxx! any photos of the unit?
Eric L 5112 8 years ago
Can't wait to see it!

Does it have the 285's gel slot?
loudtiger 8 years ago
pix of flash please
Nionyn_ PRO 8 years ago
Sounds really very good, Moishe. Just what a lot of people have been wanting.
Good luck!
midwestphotoexchange Posted 8 years ago. Edited by midwestphotoexchange (member) 8 years ago
midwestphotoexchange 8 years ago

1) Foot strengh? plastic or metal? Plastic, very sturdy.

2) Are the dimension of the flashhead the size bigger or smaller or just right as the 285? Smaller than the 285, which is good as many modifiers do not fit the 285. The flash head is aproximately the size of an SB-24.

3) Please-Please-Please-Please! tell my you have idiot lights for power settings like the YN460! wimper.... No idiot lights. The power settings are clearly marked, Full, 1/2, 1/4 etc.
petepixxx Posted 8 years ago. Edited by petepixxx (member) 8 years ago
@MPE--..No idiot lights. Drat!

But I'll bet the switches have a nice secure detent/click to them to "feel" in the dark (or while watching the client), as with the Sunpak 383. Yes?

Sent the pic off the NASA for enhancement. Quick pShop results (here) are beautiful!! ;)
sighsl 8 years ago
What kind of cycle time can we expect after a full power flash with freshly charged NiMh cells?
Looks nice.
mjpatey 8 years ago
If it works as advertised, it's the perfect niche product for me... I've gotten so used to dialing in the flash manually, that this would save a couple hundred bucks in automagic features I don't really need.

I wonder when beta testers are going to start posting impressions and samples? In particular, I'd be interested in NiMH battery life as compared with an SB-24 and 285HV.
fredlau316 8 years ago
I found the website, but I think it's still under construction
rudy__ 8 years ago
Nice feature set. Sync ports: Miniphone and PC :)
Luminon Photography PRO 8 years ago
If this flash REALLY puts out similar light to name brands that have GN ratings almost twice as high you should use the higher GN. All you're doing by trying to be the one and only flash maker using the "correct" numbers is ensuring that you will not sell as many flashes. Most people will go to your website and simply see "GN 80" and think this is a puny, el' cheapo imported flash and not buy it.

IMHO you've created a winner and I want to see you make a fair and equitable profit by bringing us this option. Just my 2 cents worth of marketing advice.
petepixxx 8 years ago
Profit? WhatMeWorry? As long as I can stock up before the crash...
David Sr. - 8 years ago

Warranty period?
midwestphotoexchange 8 years ago
Luminon said:
If this flash REALLY puts out similar light to name brands that have GN ratings almost twice as high you should use the higher GN. All you're doing by trying to be the one and only flash maker using the "correct" numbers is ensuring that you will not sell as many flashes. Most people will go to your website and simply see "GN 80" and think this is a puny, el' cheapo imported flash and not buy it.

I really went back and forth on this one. The name LP120 actually comes from the specs from the manufacturer who listed it with a 120GN. I think I will publish the specs just as I did above, with the details:
GN: 80 (True value, no EV compensation inflation, equivalent to Vivitar 285HV)

sighsl said:
What kind of cycle time can we expect after a full power flash with freshly charged NiMh cells?

I don't remember from the tests. I will post the results Monday or Tuesday, along with the life expectancy with NiMh and Alk batteries.

petepixxx said:
But I'll bet the switches have a nice secure detent/click to them to "feel" in the dark (or while watching the client), as with the Sunpak 383. Yes?
Correct, you can feel it sliding into place. Get to know the flash for an hour and you should have no problem setting flash ratios in the dark.
The Notorious DKE 8 years ago
I can't wait to order one (or two).
midwestphotoexchange 8 years ago
Here are a few pics from Beta Tester - Carlos Benjamin

petepixxx 8 years ago
Now that is interesting! Using 2x four position switches! More stable from less throw? Stronger? Probably! Any other benefits?
David Sr. - 8 years ago
Carlos.. Carlos.. Carlos... the umbrella isn't really in the swivel backwards is it? ;-))

Moishe, this looks pretty nice..

Is the PC port a screw-lock type? It looks like it but I can't tell from the photos. If it is, that would be a valuable fact to add to the specs.
midwestphotoexchange 8 years ago
@David Sr: The PC is not a screw-lock type.
sampoonsh 8 years ago
Hi Moishe,

Did you try putting on Prokit? How does it perform?


Jake Lichty Photo 8 years ago
Will this flash be safe to use on camera?
wangster411 PRO 8 years ago
Looks very nice. I didn't see any trigger voltage listed, but now a days, I don't think anyone makes any crazy high voltage stuff any more? I suspect somewhere between 6v to 12v?
midwestphotoexchange 8 years ago
@sam: It fits very well on the Speedlite Pro kit. We have a couple complete Strobist kits coming out that will include both!

@Daywalker.11: The flash is safe for use on a camera. I think I measured voltage around 8-9v, but I will run another test when I get it today.

@petepixxx: The other benefit for having 2 separate switches is that the product will be available this week rather than another 6 months down the line, had I decided to change it. I think you are correct that it is a bit more stable with the 2 separate switches.

The flash is due into the store later today. We will be running Q/C over the next couple days. I'll do my best to try to break and/or fry it!

midwestphotoexchange 8 years ago
Just came in the door! Bright red box, silver letters. Props to Chris Kay for the box design, it looks great!

Got one on the desk of every employee here trying to fry it.
So far so good.

CotswoldPhoto Posted 8 years ago. Edited by CotswoldPhoto (member) 8 years ago
Oh Moishe. That Lumopro website is awful. Sorry, it has to be said.

iframes, tables for layout and it goes on. Now, I'm a passable photog, no better than that! But I can web design. I just can't be bothered as I don't need the money or hassle. In fact, I recently took down my own site to reduce the hassle. My brother has one I did (www.spotlighton.co.uk) but he has messed with the top banner since.

What's different with my designs?

1. They almost always work on any browser (can't say always can we?).
2. They are text reader friendly and meet Disability Act requirements (if in Firefox, switch off the images and css, and you can still read it!)
3. And my designs aren't too bad (I'm not a graphic designer!)

But ... message me, for the sake of (good) web designers everywhere. No charge.
W.G.W. 8 years ago
only thing its missing is a DC jack for a SLA battery pack. Although im guessing there is enough room in there to add in my own.
petepixxx Posted 8 years ago. Edited by petepixxx (member) 8 years ago
OT: @ClevaTreva it's always fun to read a webpage where I don't recognize the cities, counties, districts, or even zip codes (oops, Post codes!). Makes me realise why the world is so fragmented.
petepixxx Posted 8 years ago. Edited by petepixxx (member) 8 years ago
Do you think the SLA that has worked forever for the Vivitar 283 / Sunpak 120J will work OK for this flash? I'm trying to get standardized with some many more flashes now.

CotswoldPhoto 8 years ago
OT: @petepixxx The area spotlighton covers is a delightful very northern part of Scotland. It is very beautiful - well worth a visit, loads of photography opportunities (landscapes and twee villages). It's where the Royal Family send their sprogs to school (at least the boys!) - Gordonstoun (my brother's house backs on to the school grounds).
midwestphotoexchange 8 years ago
First tests are going very well. Got 20 around the store, every employee firing them continuously at full power. There is a ready light on the back of the flash that lights green to identify that the flash has fired. It does not give that confirmation when it is on full power. Of course at full power, it's pretty obvious when it fires...

I took one unit and set out to break it. Testing all angles, 3 ft on industrial carpet, nothing, 6ft. nothing, 3ft on hard wood floors, nothing, 6ft on hard wood floors, the red cover on the front broke off. No loss of function. After droping it a couple times at 6ft one of the contacts in the battery compartment dislodged. Stuck my finger in and repositioned it. Took it out to the parking lot. 3 ft on concrete, nothing, 6 ft battery contact gets dislodged and the battery door breaks off. Repositioned the contact, taped the battery door back on and kept trying at 6 ft. After 5 drops at different angles, the body finally cracked. It still works sometimes but it's pretty much finished.
Put it on a swivel, put on pressure to break the shoe. Don't have the gear to measure force, but it took some pressure before I was able to break the shoe. WHen it finally broke, it was just the side of the foot which is held down to the swivel. Put on pressure and broke the other side, same thing. Unscrewed the shoe and put a new one on (soldier iron necessary, we'll do it for you if you break your shoe.) and it worked fine.

Voltage measured between 7.25v and 8.25v on all units. Safe.

There is one thing I can see that we are going to get a lot of calls about. It's in the manual, but who reads those? There is a switch on the front for turning the optical slave off and on. If the slave is ON, any other method of sync (hotshoe or either of the sync ports) do not work. When you turn the slave off, they switch back on. Pretty neat, but I can hear the phone ringing right now.

Still have around 10 tests to run. Will have to wait until tomorrow.

elv0000 8 years ago
Looks nice!, what is the recycle time like?
masontrullinger 8 years ago

This is super awesome and commendable of you and your crew for developing this product. I run all my flashes off of SLA batteries. Is the battery door removable? Or do you plan on offering an accessory door with a hole for a cord to stick through? I guess I could just drill a hole in the door but that might limit the resale value.

I love the price point and the features. I think you really nailed it. I'm not sure what all the Armatar guys did to their modified 285s but is there any easy way to convert this flash to barebulb?

JASPhoto 8 years ago
Will you be putting out an HV version? Hopefully useing Nikon or Vivitar or sunpak connection.
strobist PRO 8 years ago
I have to add my props to Moishe for taking on this project. It fills a big hole that has been there for a long time.

It is not meant to be an "everything" flash. It is designed to have the key features that are needed for good, off-camera shooting, without the price-bumping features that crank up the costs on the flagship flashes.
midwestphotoexchange 8 years ago
@Mason: No removable door. No idea on the barebulb. I've got a couple questions for you, can you give me a call?

@jasphoto: I am planning another version. Will probably be 1-2 years down the line. Will include all the current features, +1 stop of light, TTL (Canon/Nikon.) I'll look at the HV and a removable door.

@elv0000: Full power, Alkolines: 5 secs. to reach full charge. I haven't tested the NiMh's in the production batch yet. It was around 3-3.5 seconds with the samples.

carlos.benjamin 8 years ago
Can I just say that I loved using this flash. For quick setup in a controlled environment I only have to drag out one pair of PWs and hook them up, the rest of the flashes can go on optical. This is the most consistent optical device I've ever used.

In the photos above I used a cord from Radio Shack that didn't cost me $25.00 which is what I paid for the sync cords (very short) that I have purchased in the past. I think I paid about six bucks and got six foot cords. Sweet! That sync port should have been available years ago from major manufacturers so we don't have to buy a hybrid to go between PWs and sync ports.

And yes, the umbrella is in backwards. I was trying for a key light up high with a little fill from below. Didn't work as well as I'd envisioned it, but the flash is providing its own light from camera right with a Sunpak 383 providing light from camera left.

The switches are great for low light shooting situations. I can quickly tell if I'm below half power by moving the switch on the right to the left. If it doesn't move I'm into the next switch. With the sunpaks I would have to move the switch all the way to one end or the other and then walk it back up or down to the setting I wanted.

I also liked the fact that it zooms and swivels. With sunpaks you got swivel but no zoom. With Vivs you got zoom but no swivel. Now you get both in a single unit. You get four ways to trigger in a single unit.

At any rate these couldn't come at a better time as I need to replace a couple of the sunpaks that aren't working right. I'd be buying some anyway, but now I need them instead of just wanting them and that makes the sale to the wife much smoother.......

Sam - used the ProKit and the number six on this flash and everything fit very nicely.

Moishe - If you're considering the removable door I'd try to have the Lumopro folks engineer it so that it's hinged but you can take it off or leave it swinging on the hinge. I've got a flash with a removable door and it seems like every time I change batteries I'm thinking, "Now, where'd I put that door?" I could live with a hole in the door if it means I don't have to go hunting for it. Or maybe you could get some additional income selling replacement doors to folks like me......

Oh, and save me at least two of these.
very1silent PRO Posted 8 years ago. Edited by very1silent (member) 8 years ago
Any idea what the flash duration is from these? Will it drop nicely at low power like most other AA battery flashes?

You might want to prominently display the fact that you've got a 7-8 volt trigger voltage. That's just high enough that some of the older Canon digital cameras (300D, 10D) won't tolerate it — they've got a sync voltage limit of 6 volts.
carlos.benjamin 8 years ago
I also showed this around to several of the folks in the AZStrobist group and all were impressed with the design. I showed it to Joel Grimes as well and he liked it.
petepixxx 8 years ago
Does MPE sell lanyards for battery doors? Cheaper than strong thread and a little glue?
ScottJ 8 years ago
It's amazing how much that thing (from the front, anyway, and in general form factor) looks a lot like a Sigma EF430.
sampoonsh 8 years ago
Hi Carlos,

Great! I'd love to see the combination of this flash and Prokit work impeccably. Its price positioning and functionality really have me hooked. Look forward to getting one soon.


brian oley 8 years ago
Does the optical slave ignore TTL preflashes and fire correctly only on the actual shot?

What does the wide angle adapter look like? Does it hold filters in place like the one on the 285hv?

This thing looks freaking awesome... I'll likely be getting one.
midwestphotoexchange 8 years ago
@brian: The optical slave does NOT ignore the TTL preflash. You will have to disable this function on your on-camera or on-board flash. Check your manual for instructions on how to do this (not directed specifically at you.)

The wide angle adapter is just an insert that snaps into the slightly recessed head. I have thought about putting a filter under there, but I'm afraid it would melt being sandwitched so tightly against the flash head. Anyone who has an SB-800 with the gels knows what I'm talking about. There is a slit at the top of the head that would allow you to insert the SB-800 gels or better yet, cut a template to slide in out of our gel kits.

Very cool; demand to concept to production.

I have no need for one currently, but if I am in the market I would seriously consider! Plus, you guys have all my money from my last two lens purchases! :)

Best of luck with this!
Connahhh 8 years ago
Flash durations at full power please!
midwestphotoexchange Posted 8 years ago. Edited by midwestphotoexchange (member) 8 years ago
strobist PRO 8 years ago
FWIW, I am not going to blog about these until tomorrow. This effectively gives anyone involved in this discussion a head start and a guaranteed slot in the first run if things get crazy tomorrow.

The first run was a decent size, but it is very possible that they will sell out in pretty short order if a flash like this resonates with the general readership.

Not hyping, because (a) I do not like to do that, and (b) I have no direct skin in the game anyway (MPEX is an advertiser, of course, but this is not any kind of product partnership -- other than the upstream info involved in designing it.)

Just a heads-up, so anyone who wants to make sure they get one, can do so.

Next run will take 6-7 weeks, IIRC, and it will probably be a bit before a reasonably good supply chain equilibrium will be there.

Thanks not only to Moishe for addressing this key unavailability in the flash world, but to you guys for being a constant source of valuable info and feedback on all things lighting.

ddyer-bennet 8 years ago
This is a great idea! I've currently got an SB-800 and an old Vivitar 285 doing my off-camera duties (sometimes both at once, using the built-in on my D700). The price on this is gonna make me move up to three off-camera lights sooner than I would otherwise have done.

The guide-number discussion is fascinating. I've been watching studio flash get random watt-second ratings for decades, but I maybe haven't paid enough attention to optimism in guide-number ratings for on-camera flash. I'm treating "same as 285" as holy writ (since it's so easy to measure with a flash meter or a digital camera), and that's a decent answer. For a single on-camera flash it's a bit weak (most of them are), but for one player in a set of off-camera flashes it's fine. If I need to tan my models I can haul out the White Lightning x1600 heads.
The Eye of Brad 8 years ago
just ordered mine, the website was running slow, ordered over the phone. I have 3 broken 285hv's right now. Granted all of those broke during crowded shots from people or objects hitting the light stands and them taking a 6+ foot fall onto concrete. We shall see how the LP120 holds up to my reckless abandon.
strobist PRO 8 years ago

If you like, MPEX can hit them with a hammer several times before shipping them to you, just to acclimate them to you.

To all-

ALSO, to any BETA testers of the flash, I would very much appreciate your feedback in this thread, as would any potential purchasers.
fredlau316 Posted 8 years ago. Edited by fredlau316 (member) 8 years ago
Is this flash made in China by YINYAN?
I found some similar model to LP120, but only 2 manual output
and of course, no pc port
CY-380AF and CY-32TWZ
midwestphotoexchange Posted 8 years ago. Edited by midwestphotoexchange (member) 8 years ago
@fredlau316: It is made in China, not by Yinyan. The body style is popular, I think there are several manufacturers that use it.

I'm working on flash duration tests right now, will advise, but it might be a while.

I was just beginning my hunt for some Vivitar 285HVs... so this is relevant to my interests.
midwestphotoexchange 8 years ago
Website launched:


Let me know if anyone has any suggestions or comments on the site.

sighsl 8 years ago
Something I would like to know... Is what the maximum voltage is that's acceptable at the battery inputs. I ask for a couple reasons and ideally I would like to know the actual specs as it has been built/designed, however the results of a test would be acceptable as well..

One reason I'd like to know is for the ability to use Lithium/Iron Disulfide (Li/FeS2) AA cells such as the Energizer Ultimate Lithium L91. These cells put out 1.6 volts or so per cell at low discharge rates(< 1amp) they are primary batteries (not recchargeable) but will put out close to 2 amp hours or more even at relatively high discharge rates. have a very long shelf life, and are very light. (these cells are expensive, but nice to have in your camera bag for emergencies) So, given the voltage, four of these will put out say 6.4 volts.

Another is I'd like to build a external battery pack, from high capacity NiMH cells... Ideally I'd like to use 6 cell packs, the voltage on a 6 cell pack like this would go as high as say 7.6 volts and be able to put out over 4 amp hours. If 7.6v is too high then I'd want to do 5 cell packs, this would be around 6.3volts.... ( or very similar to 4 cells of the Li/FeS2 AA cells described above).

The general question is... what's the highest voltage the circuit can take without melting or otherwise being destroyed? (also assuming the power source can put out as much current as the circuit will take, such as would be the case with the NiMH cells/pack.)
midwestphotoexchange 8 years ago
@sighsl: I'll see what I can find.
carlos.benjamin 8 years ago
Woohoo! Got mine ordered too......

Moishe - I don't think too many people are hitting this thread because the title doesn't mean anything to them. I'd think if you drop the Q&A and replaced it with "built with strobists in mind" or something similar you'd see more people in here. Of course, once David blogs about it the title won't really matter.......

As for the website..... Don't care for the animation on the splash page. Too much crossover on the fade, you don't really get to see an image without the previous image still fading out or the next one fading in. Other than that it's a nice, clean site without distractions. I like that.....
The Eye of Brad 8 years ago
I would like the website better if the LP604 was ever in stock.
I have tried to add one of those to my order each time I called, always told they are on backorder.

strobist PRO 8 years ago

Maybe they know how rough you plan to be on them...
midwestphotoexchange 8 years ago
Amen Brad. I apoligize for that. I'm working on it.
The Notorious DKE 8 years ago
Still waiting for the recycle times to be posted.
very1silent PRO 8 years ago
A typo on the new web site. At lumopro.com/LP120.html there's the word "dimensions:" on the right side of the page, but no actual dimensions listed. This is true of most items listed.

It would be nice to have full and complete specs listed on the pages too -- things like flash output, sync voltage, maximum weight for stands, etc.
midwestphotoexchange 8 years ago
@very1: What do you mean by flash output? Is there more that is needed than the GN? I'm working on the rest. Sync voltage is between 7.5-8.5V.
very1silent PRO 8 years ago
midwestphotoexchange: lumopro.com/LP120.html does not include GN or any other measure of output.

In the future, few people who look at the lumopro.com website are going to read this thread. I know what you claim the guide number to be, but people looking at that web site next month won't.
The Eye of Brad 8 years ago
Good point, but I have never broken a light stand, Just Flashes, Triggers, modifiers, assistants, small animals, and 1 lens.
midwestphotoexchange 8 years ago
Recycle time: Alkoline AA, 5 seconds at full power. Will be faster with some NiMh batteries. At 1/32 power, I pressed it as fast as I could for a couple minutes and it wore my thumb out before I made it any further.
The Eye of Brad 8 years ago

I am looking forward to seeing how even the power is as 1/4 when using burst mode (6fps) to capture action.

I am also interested to see how fast these can sync with PW hypersync and just general overcranking of sync speed.

The test after that will be to slap it on my LX3 and see how it does at 1/2000

Lots of things to test with them. Like light spread at the zoom levels, etc.
midwestphotoexchange 8 years ago
I need help determining the flash duration of the LP120. If there is anyone out there who has done this work on a regular basis and feels they can reliably document results, please contact me. I see a shiny red box in your future...

badtz_maru 8 years ago
I knew someone would get around to this eventually, I need to find myself some venture capital darn it. My one question is, will they take a quantum battery or turbo without having to hax? Otherwise so long as these puppies work as advertised, I see a couple in my future.
midwestphotoexchange 8 years ago
I've got no word on the Quantum batteries. I'm going to send a couple off to them to see what they think. I think there is already a battery insert that will at least in shape fit the flash, but I don't know about compatibility. There is no High Voltage outlet on this model.

Bike43 8 years ago
Q: Midwest Photo Exchange stole my girlfriend and I cannot forgive them, can I buy the flash anywhere else?

I have another GF now, though not as good. would you consider a swap ?
prlutes 8 years ago
So... i'm still learning kinda about all this off camera lighting and strobes.... this may have been asked because ive forced myself to keep my eyes open to read this article/comments and easily could have looked it over but....

How is the recycle time? i mean i was thinking about buying 430's for my first off camera flash setup but i really wasn't trying to spend that much on strobes before i got a little more comfortable with the whole situation. This seems like a great product and for the price you can't beat it.

Thanks in advance!
eduardo_frances Posted 8 years ago. Edited by eduardo_frances (member) 8 years ago
to me the best feature is the 1/8 jack, you can get the cable in any audio store, radio shack, etc. And if you decide you want to do things wired FlashZebra has the hotshoe to 1/8 jack for your camera I think -also Pocketwizards and Cybersyncs use 1/8 jacks, I don't really know why camera and lighting manufacturers keep using the sh***y PC port-
abdul10000 8 years ago
What is the color temperature on this flash like, is it close to the Vivitar 285HV? Will there be any difference in color temperature using those two flashes together?
thomasmcinnis [deleted] 8 years ago
Reading about this is the best thing to happen to me all day. Good work guys! Will be ordering next pay day :)
MikeD 8 years ago

how about being able to integrate this flash with Al Jacob's Black Box and a Quantum cable?

BTW, great work with these. great forward thinking!!!!

oriktigt 8 years ago
How is it with the t0.5 for different power outputs?
Mikko Reinikainen 8 years ago
Moishe: If the slave is ON, any other method of sync (hotshoe or either of the sync ports) do not work.

This doesn't sound like a useful feature, more like a design flaw.

I can think of many cases where it is useful to have BOTH electrical and optical triggering in use, but no case where it would be useful to disable the electrical sync ports.

If you ever make a revised version, it should be (IMHO):
- electrical sync ports (hotshoe, PC-sync, miniplug jack) always ON
- optical slave switchable ON/OFF


Oh, about the girlfriend. My wife tells you can keep her, thank you very much.
kreego PRO 8 years ago
Kudos to Charlie Sorrel at Wired, who just wrote about the unit, mentioning David and Moishe at the same time...

Cheap, Manual Flashgun: Built by Strobists, for Strobists

David Sr. - Posted 8 years ago. Edited by David Sr. - (member) 8 years ago
Mikko - Ditto!

I have no doubt we will see a hack (mod) on this.
David Sr. - 8 years ago
@ Kreego - your link didn;t work for me...

Here's where I found it....
kreego PRO 8 years ago
@David Sr. - my bad - got my tabs mixed up ;-) That's the right link you posted - thanks!

zeal4life4me 8 years ago
Will be looking for how we can use with an External Battery Pack of some sort: this is Important for some.

Moishe, do you plan to make "improvements" due to the great feedback on this thread?
cdburgerjr 8 years ago
I already have 3 flashes and I might buy these just on principle. :-)

No, really, maybe not. But I do have to remark: FINALLY, someone that decides on moving away from the PC cord!

Why in the *bleep* world does everyone insist on using that *bleep* PC plug format that *bleep* EVERYBODY knows is *bleep* ??!!?? And then Sunpak had a great chance on the 383, but they blow it with that *bleep* proprietary mini-plug thing that comes with a PC adapter cord??!!?? Just *bleep*.

Sorry, just had to get that off my chest. :-)


P.S. Yes, FlashZebra got my business.
jonberge 8 years ago

I'm a PhD candidate in Electrical Engineering and an amateur photog, I have access to a lab and the equipment needed to do flash duration testing. If you are interested, please drop me a line, I'm in Ontario Canada.
midwestphotoexchange 8 years ago
@Mikko: DH agrees with you that this is not a useful feature. To have the optical slave active at the same time as the sync ports would help to insure that the flash will actually fire (by one means or another.) From my perspective, I'm looking at the wedding, press and other location photographers. Having them separate insures that amateurs and pro photographers are not firing your flashes and using your light while you have it wired or are using radio slaves. Not that you don't like to share, but you only have so much battery life. I really like your suggestion above which would seem to make everyone happy. I'll look at doing that in the next model. Thanks for the idea!

RE: Quantum and other external battery packs. The manufacturer does not recommend using anything over 6.5v for batteries. I am going to send a unit off to Quantum to see what they think.

@zeal: I have never found much value in this or other threads making suggestions as to how I should build my products. I just decide what I want to create and make everyone believe that is what they need. Seriously though, as I wrote above, this would not have been possible without you all and threads and personal discussions like this one. I am already working on another version of the flash and I can see at least 3 things THAT I HADN"T THOUGHT OF that will likely be making an appearance. The factory has already advised that the necessary circuitry to support a voltage range is available.

Re: Flash Duration: Factory states 1/1000 - 1/20000

Re: Color Temperture: Factory states: Daylight...duh. I'll get my color meter out.

petepixxx 8 years ago
@moishe -- Re: Color Temperture: Factory states: Daylight...duh. I'll get my color meter out.

Could you please check to see if color temp is the same on all exposures? And when HOT!

Just thinking of ABs color change at low settings...

midwestphotoexchange 8 years ago
@petepixxx: Working on it.
Nick McCarthy 8 years ago
Sweet! I had a Vivitar285HV randomly die on me recently (Quality control issues?)

So I just ordered 2 of these LumoPro LP120s to go along with my still working rock-solid Vivitar 285, and I'm finally up to a 3 light setup!

I'll report back on how they work back once they ship.
Pascal Scheffers 8 years ago
I hate relying on factory numbers, so the inner geek in me decided to see what I could find out myself. I wasted some time on a flash duration experiment, just to see if you can measure it. It seems you can, somewhat accurately. I took the IR photodiode (not optimal) from the Microsoft media center remote receiver which has a convenient mono 3.5mm jack. I just plugged that into the microphone jack and recorded the 'audio' with Audacity. When you fire the flash, you see nice little peaks in the wave form, tiny ones for 1/128th power, a really long one for full power.

I did this for the Canon 550ex, but unfortunately, I cannot find any numbers to (probably) invalidate mine:

flashpower: flashduration = in seconds = in fractions of a seconds.
1/128: 2.26900 - 2.26915 = 0.00015 = 1/ 6666
1/64: 9.34082 - 9.340975 = 0.000155 = 1/ 6500
1/32: 13.23372 - 13.23390 = 0.00018 = 1/ 5555
1/16: 16.28896 - 16.28916 = 0.0002 = 1/ 5000
1/8: 19.21016 - 19.210475 = 0.000315 = 1/ 3175
1/4: 22.031225 - 22.031725 = 0.0005 = 1/2000
1/2: 25.232175 - 25.233245 = 0.00107 = 1 / 935
1/1: 29.279795 - 29.320 = sensor overload?
1/1: 3.063695 - 3.06640 = 0.003 = 1/370
1/1: 4.4668 - 4.4695 = 0.0027 = 1/370

Take these with a grain of salt. Or a bucket full. The photodiode used is really, really unknown. I mean, it is intended to capture IR, not visible light. There doesn't seem to be a proper IR filter on it, though, so it should be okay but... This would probably work better with just a bare photodiode hooked up to the microphone port of a computer.

Is that full power 1/370 number anywhere near what you see in real life? It seems very suspect. At full power the waveform looks very different from the others, you can clearly see that for all the others the light is cut-off, but full power just goes on and on and on and on... If I look at the area under the curve, 80% of the light is emitted in at most half of that, so about 1/800th of a second.

Now I do need at least one more flash and the LP120 fits the bill nicely, then I could do a similar experiment for the LP120 and at the very least give comparative numbers. But shipping to the Netherlands... ouch.

Any suggestions to turn this into a very accurate measurement using cheap, strobist-style, tools?
chikabelley 8 years ago
Well done Moishe. Great to see them up and in running.
joneikifi Posted 8 years ago. Edited by joneikifi (member) 8 years ago
Here's the tool I used to measure my flash durations:

Flash speed measurement by joneikifi

And the results:

Flash duration measurement results by joneikifi

Better results with a smaller pull down resistor:

Better results with a smaller resistor by joneikifi
Pascal Scheffers 8 years ago
@joneikifi: how incredibly neat. Did you have to do your own plots, or does the little computer come with software too?

Your graphs look much smoother, my sample rate was 44100Hz, but otherwise quite similar.
joneikifi 8 years ago
@PascalScheffers: Had to write my own software and do the plots in a spreadsheet. Arduinos are handy for all kinds of testing and prototyping.

The graphs are smoother than I like but a $30 microcontroller board is pretty cheap as far as oscilloscopes go, and it gets the results.
1 3 4
(1 to 100 of 399 replies)
Groups Beta