_________1

Chuck, you are an ASS!

Hal, don't shout.

Daniele, run your own tests before buying the Grigull. Test them with your favourite film. If they work for your application, then they are good lights.

I see your Grigull metal halide CDM discharge lights now. It is called the littlefloodlight.

 

Desisti has something similar called the CD 15F Fresnel. B&H sells it for $817.00, the lamp sells for $66.95.

 

Note that Desisti is an Italian company which given the scheme of things in the USA may have its products marked up a little higher than elsewhere.

 

So, if your friend is selling you a set of used lights at Euro 800 each, he or she is selling them to you at their original new selling price. I'd say that you'd be paying too much for a set of used lights.

Grigull appears to make fluorescent light banks currently. Your Fresnel does not appear on its website.

 

If it is an HMI Fresnel (except that the smallest HMI I know is 125w), ask if it comes with an electronic ballast or a magnetic ballast.

 

The closest things I can find are the K5600 Joker, Arri Pocket Par, Frezzi Sun Gun. The luminaire alone costs about $1250 to $1450. The electronic ballast falls in the same price range.

 

If it is a tungsten-halogen aka quartz-halogen with a dichroic filter to convert 3200K to 5500K, then it is too expensive.

Your aperture controls your flash exposure. At f2.8, you should get a shallow depth of field. The shutter speed controls the ambient light exposure.

 

You say that 1/250th sec is not fast enough. Are your backgrounds overexposed?

 

If they are and you need that f2.8 for shallow depth of field and proper flash exposure, your only recourse is to slip an ND filter over the lens and turn up your flash by the requisite amount.

 

For example, if your background is overexposed by 1 stop at 1/250th sec and f2.8 is the correct flash exposure, you use a 1-stop ND filter over your lens, set the shutter speed at 1/250th sec and then increase your flash output by 1-stop.

 

Someone please correct me if I am wrong.

Peter Lindbergh has been known to use Briese 220cm Focus Giant Brolly. Otherwise, sunlight raw or diffused through silks, or high wattage HMIs (12KW, 18KW), usually Fresnels.

Ellis, there are no 5K nor 10K HMIs :(

Dupont IMRON automotive paint.

Against the folly of men, even the gods themselves despair.

You need serious help. Over 93 idiotic responses or questions. Some kind of record.

My sincere and profuse apologies to you, Brooks. I got carried away.

 

I maintain my stance and disagree vigorously with Richard C, Ken and Tom.

This will attract an infra-dig quip from Jay, I'm sure.

www.demarchelier.com

 

www.peterlindbergh.com

 

www.stevenkleinstudio.com

 

www.artandcommerce.com

 

www.mfilomeno.com

 

www.jedroot.com

 

http://www.rasource.com/photographersreps.htm

 

http://www.rasource.com/photographersrepsnational.htm

 

Have fun surfing the sites, daniele.

Heh, heh, Helen. Love that pancake lantern. Tell me more about your experience with it. Did you get the small, medium or large pancake? How do you like it compared with the plain jane Chimera Chinese Lantern? Tried it with and without the skirts?

No, you are not, Ken. If you are, you'd recognise bad physics and bad logic the moment you see it.

 

You are insisting on nonsense as fact and obviously have no experience in flash or know what you are talking about.

 

And if you really are a flash engineer, then please let me know which manufacturer you work for so that I'd be sure to avoid its products. Not Norman, I hope?

 

Profoto will not make the claims that you do because they know it is bollocks when they read it.

 

It is spelled 'PEAK'.

 

Thank you for your link. A repairman's guide. Very helpful. You obviously haven't read the article yourself or you won't be making such claims. Even the author of that website dares not make such claims.

 

60 000watts out of a pocket disposable flash! What have you been smoking?

 

As I maintained, you are no flash engineer.

Look at this: www.georgeholz.com .

I am sure Profoto would like to learn your secrets, Ken, of how to generate 672 000 watts of its Acute2 1200ws pack or better yet, 2 640 000 watts out of its Pro 7a 1200ws pack. I am sure Balcar, Broncolor, et al. will bid up to find out your secrets.

 

THINK about it.

I am sorry. You guys really need to talk to a flash engineer to disabuse yourself of these 'facts'.

Flash duration has everything to do with it when you are talking about flash.

 

Again drawing on your example: at 1/200th sec shutter speed, the equivalent wattage of the continuous light source is 200 000w then. You claim that this is equivalent to 1/100th sec shutter speed and 100 000w continuous light source which is equivalent to a 1000ws flash.

 

If you know anything about flash, given any aperture f-stop X, the light output at 1/100th sec shutter speed is equal to 1/200sec shutter speed because flash is a fixed quantum of light. (See why we cannot talk about flash without talking about its duration?) You agree that flash electrical power (since we are concerned with electrical power at this point) is independent of shutter speed.

 

So you are saying that a 1000ws sec flash is equivalent to a 100 000w hotlight at 1/100th sec. And a 1000ws flash is equivalent to a 200 000w hotlight at 1/200th sec. In that case, if I use a shutter speed at 1/200th sec, I will see a flash output twice of that at 1/100th sec.

 

Thus according to your analogy, with an adjustment in shutter speed (as if it has anything to do with it), I should be getting twice the flash output if I halve my shutter speed which clearly cannot be if you understand flash.

 

Think about it a little and you will see where you made an erroneous assumption. We are essentially comparing apples to oranges although they are both fruit.

 

Or talk to a flash engineer.

 

The conclusion is that you cannot make sense of equivalencies between flash and continuous light by looking at their power rating. Saying that a 1000ws flash is equivalent to a 100 000w at 1/100th sec shutter speed is just plain wrong.

A characteristic of those who shoot with the Pentax 67 is their penchant for natural or continuous light. That means okay, natural light or quartz-halogen or HMI/MSR or KinoFlo continuous light sources. The slow flash sync speed of the Pentax 67 necessitates that, somewhat. Of course, the use of natural light sources impart a certain characteristic to their photographs which is quite different from using flash. I guess sometimes the choice of our tools go someway towards determining how our photographs 'look'. It is the sum total of the photographer and his tools :^)

www.georgeholz.com .

 

George Holz shot the Tequila Sauza Original Sin calendar with it. I am pretty sure Ellen Von Unswerth uses it too.

What the world really needs is a good 1J flash which tucks behind your ear.

My dear Richard Cochran

 

I admire you for your effort but I am afraid that you are seriously misinformed. You have done nothing more than watt-seconds equivalencies. However, you cannot use that and draw your conclusions about your erroneous correlation between flash and hotlights.

 

1) You cannot squeeze a quart out of a pintpot. Where did your logic fail? Let me take your quoted example: you claim that a 1000ws flash is equivalent to 100 000w hotlight in 1/100th sec. Fair enough. Let's us then shorten the flash from 1 second to 1/100th sec. That is to say, is a 1000ws flash equivalent to a flash at 100 000w in 1/100th sec? What about a 1000 000w in 1/1000th sec? As time tends to zero, the wattage tends to infinity. Can any flash produce an infinity of wattage? No.

 

A flash is a power or energy storage device. Now power = voltagexcurrent. If power tends to infinity, either voltage or current tends to infinity. That cannot be so in a real world capacitor; it just cannot swing an infinite amount of voltage or current.

 

 

The electrical output of a flash is determined by its rise and decay curves based on its flash duration and amplitude. If you look at flash packs of any provenance, you will find that a 1200ws pack, puts out 1200w tops, for example. Indeed at its maximum output, flash duration is usually the longest. Conversely, at its shortest flash duration, its output is usually its lowest.

 

Following your analogy, if flash duration becomes shorter, wattage should increase proportionately. This cannot be because the storage capacitors can only hold a finite amount of energy or power and finite voltage and/or current swing.

 

Is a 1000ws flash equivalent to a 100 000w in 1/100th sec hotlight? Not in a long shot. Simply because it is meaningless to talk about such equivalencies. (Look at a real world flash, say the Profoto Acute2 1200ws pack. At 1200w maximum output, it has a flash duration of 1/560th sec. Going by your example, it should be generating 672 000w at 1/560th sec. Clearly not.)

 

You need to take down your article because you are disseminating well-meaning but utter misinformation. Think about it long and hard. Or talk to a flash manufacturer.

 

To Richard Wu, I am afraid that ithere is no correlation at all. Flash is more efficient in turning watts into lumens than Q-H or HMI/MSR luminaires. It is a general guideline and one cannot take watt-seconds equivalencies and draw the conclusions that Richard Cochran erroneously did.

 

Someone could take a flash in a Fresnel head and a Fresnel hotlight for example and do a test. It still won't tell you anything about the correlation in light output because different makes have different efficiencies. Even the flash manufacturers cannot come to agreement on a standard to measure light output.

 

Hmm, perhaps it is time for an experiment.

My vote is for Chimera or Plume. www.chimeralighting.com , www.plumeltd.com .