Which basic kit to consider buying

[goatee]

I don't know what this proves but it gave me a chance to play with my light meter. I know there is a certain amount of rounding goes on to get the f-stop but at 5ft from the strobe at full power ISO 100 1/160 and taking 20 readings without moving they all gave f16. So I imagine this shows consistancy.

Lessons learnt:
1. Do not look towards the flash and expect to be able to read the numbers
2. Allow the flash to recharge between readings (At first I thought the lamps were dying getting lower and lower as I repeatadly triggered the light meter without waiting )

But how can I measure colour temp (without buying a meter) is there a way to use the custom white balance of the camera?

That sounds good.

To check colour temperature, shoot a white piece of paper to set a custom wb, and then shoot a number of shots. The colour should be identical (or near as damnit) in all the shots. I'm not sure if there's a more scientific way to check the colour temp in the shots.

 

[Garry Edwards]

That sounds good.

To check colour temperature, shoot a white piece of paper to set a custom wb, and then shoot a number of shots. The colour should be identical (or near as damnit) in all the shots. I'm not sure if there's a more scientific way to check the colour temp in the shots.

That's a pretty good non-equipment way of testing. A small but important refinement; view each image in ACR and use the white balance tool to correct the white balance and get a precise measurement of correction needed.

When checking the accuracy of repeat flash power, use a similar method. Consumer meters aren't usually accurate enough to check just by checking meter readings, and anyway meter readings fluctuate and so can cancel out or exaggerate flash error.

n.b. all testing should be done immediately the flash head indicates that it's ready - with some heads it really is ready, some others are shall we say optimistic

I'd be interested in seeing whether these Stable Imaging kits really are as good as they seem. Very few really are.

 

[Tyrone Shoelaces]

Another brand to consider: http://www.alienbees.com/

I know a few people who've been using them for a while (years) and only have good things to say about them.

I also know a few people who've never used them and only have bad things to say about them.

I took a punt and so far I'm very happy with my decision and the customer service you get from AB is American style.

 

[mortm]

This is great I not only learn to get to grips with my new Sekonic but get to play with white balance... which I must admit I have ran from up to now. I've just had half a bottle of red so having learnt from past experience I know not to write much at the moment. The last time I did on another forum I found I had managed to upset half the diving population. But I'm a bit excited, so a couple of questions and honestly if I some how insult anyone it's the drink talking.

1. Do I need to fill the frame with white or are we talking spot metering. I know what white balance is but have never gone there, guess it's time I did.

2. Does ACR come as standard with Photoshop. I know someone who has Photoshop so could do as Gary says. (I actually feel a bit embarrassed calling Mr Edwards, Gary.. he is a bit of a legend)

3. Trouble with knowing when the strobes are ready is the indicator light is on the back, I used one elephant, two elephant..

I think it would be great to have a consumer testing procedure write up for such kits... Mr Edwards? Oh and can you please make it a Dummy's guide for people like me.

And lastly thank you for letting me get involved, I think I will learn loads doing this. Off to read the manual regarding white balance now.

Mel

 

[Garry Edwards]

This is great I not only learn to get to grips with my new Sekonic but get to play with white balance... which I must admit I have ran from up to now. I've just had half a bottle of red so having learnt from past experience I know not to write much at the moment. The last time I did on another forum I found I had managed to upset half the diving population. But I'm a bit excited, so a couple of questions and honestly if I some how insult anyone it's the drink talking.

1. Do I need to fill the frame with white or are we talking spot metering. I know what white balance is but have never gone there, guess it's time I did.

2. Does ACR come as standard with Photoshop. I know someone who has Photoshop so could do as Gary says. (I actually feel a bit embarrassed calling Mr Edwards, Gary.. he is a bit of a legend)

3. Trouble with knowing when the strobes are ready is the indicator light is on the back, I used one elephant, two elephant..

I think it would be great to have a consumer testing procedure write up for such kits... Mr Edwards? Oh and can you please make it a Dummy's guide for people like me.

And lastly thank you for letting me get involved, I think I will learn loads doing this. Off to read the manual regarding white balance now.

Mel

Mel,

I'm certainly no legend but please don't call me Gary - My name's Garry

It's called a colour target. It doesn't need to be white (in fact white can be a very bad choice, because if it's overlit ACR won't be able to read it. Grey is best, black is fine. What matters is its neutrality, i.e. its lack of colour.

No, you don't have to fill the frame with it, it just has to be large enough to place the eyedropper tool on it, to sample the colour and, from there, to correct the white balance.

ACR is included in Photoshop CS2, CS3. Other editing programmes capable of converting raw images have their own version, all work in much the same way.

I wouldn't mind writing a simple guide on how to test flash equipment - I've actually carried out some pretty thorough testing on a couple of makes, would be happy to do more makes but, sadly, not many manufacturers are happy to supply me with equipment to test:thumbsdown:

 

[mortm]

Sorry Garry.. see what a little bit of wine does.

I will give the white balance a go tomorrow. From what you are saying I see we are not looking for accuracy in white, but consistency. So what ever the colour we want a uniform reading. I have never used ACR but I will try to get what we are looking for. I will take a few raw images with an area of neutral colour under the same conditions, take it into ACR, use the eye dropper to grab the colour then hunt out white balance controls/settings to see what I can find and use that colour as the white balance reference to see the adjustment needed. Then after doing this with a few sample shots see how the adjustment values compare. If they are close we are good if not we are bad. How many shots should I take to give a good guide do you think?

I hope I have got this nearly correct and you aren't feeling like this :bang:

 

[Garry Edwards]

Sorry From what you are saying I see we are not looking for accuracy in white, but consistency. So what ever the colour we want a uniform reading. IHow many shots should I take to give a good guide do you think?

Spot on. 5 shots should be enough, at each power setting.
Quite often, colour varies at different power settings as well as between shots. Very often, especially with the 'bargain basement' lights, there are substantial (and IMO totally unacceptable) variations at different settings. In practical terms, what this means is that if you have a key light at say full powr and a fill light at 1/8th power they can be outputting 2 entirely different colours, which can't be corrected on computer. It's easy to see the difference in colour when there's a difference of only 50K - never mind the 200K that some manufacturers boast about...

Reducing power can also have a serious effect on output consistency. When power output is very low it's generally very variable too. With some makes that I could mention (but had better not) they simply have too wide a range of adjustment, presumably to make them look better on paper, but they are unusuable at the minimum setting.

 

[mortm]

OK I will need confirmation I have done this correct.

The word auto to me means out of your control so the first thing I did was set the cameras white balance to a set value and manually focused the camera.

My general procedure was as follows.

Take the shots in raw format, open with Photoshop and then in ACR use the White Balance Tool eye dropper to sample within a small square drawn on grey card and note down the resulting custom temperature. But my results were as follows:

F10 1/160 ISO100 50mm (5 test readings with L-308S all F10)
Shot 1 - 4750
Shot 2 - 4750
Shot 3 - 4750
Shot 4 - 4750
Shot 5 - 4750

F5.6 1/160 ISO100 50mm (5 test readings with L-308S all F5.6)
Shot 1 - 4600
Shot 2 - 4600
Shot 3 - 4600
Shot 4 - 4600
Shot 5 - 4600

I'm guessing I've got this wrong?

 

[Garry Edwards]

The lens, ISO, shutter speed are irrelevant (as long as you use the same lens for each test) and the exposure is only barely relevant.

If you were using flash for these tests, then the results are good in terms of shot-to-shot consistency but a difference of 150K when you changed the power setting by just 1.5 stops isn't good at all.

Based just on the testing you've carried out so far, it doesn't look as if the lights produce accurate colour at all settings. I would be interesting to measure the differences at all power settings but I doubt whether the importers would be happy to see them

 

[mortm]

Your wish is my comand

I have had to change the lens as I was unable to get lower than F5.6 with the rubish I had attached. I have started from scratch which has become a pain as I moved from my A100 to my A350 only to find the RAW files weren't recognised by ACR, hopefully getting that sorted now. Have taken a new batch from 1/8th to full and am using a different grey as the one I was using was the back of a notepad and it's rough recycled quality anoyed me. Will post results shortly all going well with ACR.

P.S would we really expect kits like this to be perfect?

Mel

 

[mortm]

Test 2:

N.B the power dial goes slightly less than 1/8 and slightly more than Full hence the halves. Should have paid better attention and set to exact markings.

minimum power (under 1/8) F3.2 - 4950, 4950, 4950, 4950, 4950
1/4 power F5.6 - 5000, 5000, 5000...
1/2 power F8 - 5050, 5050, 5050...
Full Power F13 - 5150, 5150, 5150...

So the full power range gives a difference of 200 over 4 Stops so roughly 50 per stop.

If anyone wants the sample RAW files pm your email but don't expect me to send them all at 13.5mb each. But will send 1 of each.

 

[Garry Edwards]

Given the price of these lights, those results aren't bad - at least they seem to be consistent at any given power setting.

200K difference between full and 1/8th though is a lot, to a certain extent you'll be able to correct it by using a CC lighting gel, if you don't then you'll end up with uncorrectable colour differences when you use more than one light at different power settings.

To go back to your earlier question "P.S would we really expect kits like this to be perfect?" No, you should only expect to get what you pay for. Personally though I'd rather pay more and get more.

 

[mortm]

Personally though I'd rather pay more and get more

Rich and clever... single

Ok here is part of the response from Neil at Stable Imaging:

With regards the variation in colour temperature it honestly is to be expected. The variation is to do with the speed of the flash duration, the faster the speed the less variation. Going from full to eighth power you would normally expect a variation between 200 to 300k but even though worth taking into account it will not make a significant difference. The only people who go on about such things are those that own Bowens Esprite Gemini or the like with their enviable flash duration ... but not so low a price. High speed tubes = high pocket prices. You will not get a kit anywhere near this price that doesn't have a temp variation like this, it is impossible not to with the cheaper tubes.

I went through a number of manufacturers and lamp makes and added a few changes to get them to what I believe great little kits that allow everyone to get involved in studio lighting. One of the weirdest things was related to the power variation, originally I had the variable control also control the modelling lamp, a bit of a gimmick on a 50w bulb but didn't think it would do any harm, but it did it reduced the flash guide number! So that went, a gimmick isn't worth it if it is going to lower performance.

I will have some new lights coming out shortly, once the exchange rate picks up. These will be the start of a more professional range. First in the line up is a 300w with 150w modelling light. What will make this special is a recycle time of 0.9s and fan cooling along with a price I intend on keeping as close to £100 as I possibly can.. oh and a flash duration of 1/500 – 1/1200. OK not up to the 1/2380 of the Bowens but pretty good.

 

[Garry Edwards]

Rich and clever... single

QUOTE]
Not rich, not clever and not single

Interesting response - as Mandy Rice Davies once famously said "He would say that wouldn't he"

His explanation is technically flawed, He's 100% right about cost but there is far more to consistent colour temperature than flash duration. The quality/capacity of the capicitors is the most important single factor.
it will not make a significant difference.
We'll just have to disagree on that one. A difference of 50K is significant in my book, although we need to buy Bron to get much better than that and most of us can't justify that kind of expense. There are makes available at reasonable prices that are significantly better than 200K differential over a much greater range of adjustment but I'm not knocking the guy for selling these lights - there's a place in the market for all sorts of products.

Anyway, you now know how to check lights for colour consistency without buying an expensive colour temperature meter

 

[mortm]

Yes and I've learnt a bit about white balance, had my first taste of ACR and given my meter a good workout.

Here is a link Neil sent over:

http://www.warehouseexpress.com/Home/default.aspx?/Saves/guides/colourtemp.html

I know he wouldn't say something just for the sake of selling he has always been honest in the past but I'm sure there is a lot more to it. But I still believe this kit is great value and more than enough to learn with and get good results. It still gets my recommendation. I guess we would need to get hold of the other kits in this price range to do a comparison. I know someone with a Mr Studio kit but I wouldn't bother testing that as it melted out of shape from the modelling light. I will see what I can do as I think a comparison of the budget kits would be very helpful to the hobbiest.

Maybe Goatee could test his new lights the same way

Thanks for your help Garry

And your safe, I'm getting married next year, see I'm even training to get ready for the big day LINK

Mel

 

[mortm]

Another interesting read taken from here:

Consistency

It doesn't matter how inexpensive a light is if it's unacceptably inconsistent. If you don't get consistent light output, you won't get consistently lit and exposed images.

As with reliability, extreme consistency (within 1/25th of an f-stop or better) also tends to cost more than reasonable consistency (1/5th of a stop or so).

Most existing pack systems are accurate within 1/5th stop or better (mostly better), with shot-to-shot variances well under 1/10th of a stop. Most midline monolights have similar reliability. At the lower end, many monolights may have much larger shot-to-shot variations. Typically, as price goes up, variation goes down.

Another aspect of consistency is color temperature. Most units from a given manufacturer will have the same base color temperature, but not all manufacturers use the same baseline; it may vary from roughly 5000K to 6500K or so. If the temperatures are sufficiently different between different lights (main vs key, for example), it may be noticable, and a single custom white balance won't address the mismatch; it will only average the two, still leaving one warmer and one cooler.

Additionally, most units output light of slightly different color temperatures at different power levels. Some inexpensive units may vary by 1000K or more between full and minimumm power, or even vary color temperature from shot-to-shot even at the same power. (Usually this happens at the lowest power settings.) Better units have smaller variances.

For casual shooting, this is rarely significant. For instances such as product photography or catalog work where exact color matching is critical, it can be very important.

1000k and I was worried about 200.

Found someone saying the Bees mentioned here give a shift of 500K

I think this data should be part of the specs given.

 

[mortm]

Here is a look at the Elinchrome D-Lite2 and Alienbees AB400

They had a 200K drop from full to 1/16

I think a lot can be found on the net already, but I am feeling a lot less worried about my 200k... wish that was money.

I will stop posting my findings here unless anyone is interested as I think we may have digressed... well I may have anyway :nono:

 

[Garry Edwards]

Hmmn...
I'm not questioning his integrity, it just seems to me that his knowledge is probably more likely to come from the www than from a physics degree.

I'll stick with my own position here - a difference in colour of 200K IS significant. A difference of 1000K is ridiculous. A difference of -50K is too expensive for most people.

Of course, we all have different standards, different requirements and photograph different types of subjects. I accept that most people shooting portraits of friends and family will be happy with a difference of 200K.

Me? I get paid to take photos, so they have to be right. Generally, clients can see when it's wrong even if they don't understand why it's wrong. The same thing applies to the 'distort' tool in PS - it can be used to emulate large format camera movements but clients can tell the difference so, if they're prepared to pay I shoot on 5"x4". If they're not prepared to pay for large forma I explain why they should and leave the decision to them.

One point in the article you linked to is spot on - it doesn't matter how good the lights are, if you fit an old, yellowed softbox (or umbrella) over the top then the colour will be way off

 

[mortm]

Hi Garry, sorry didn't mean to imply you were questioning anyone's integrity.

I just want to see if it is possible to determine what we should expect in the consumer studio kits, If I was spending big bucks then yes I would want a lot less temp shift and no doubt if i was in your field it would be essential, but then I probably doubt I would be using a Sony a350. Hopefully people with the lesser price kits will read this check theirs out and post the results. At my level I think there are a lot more important things effecting my photography than change in temperature... mainly lack of skill. But projects like this help. I wouldn't have even known there was a difference if I hadn't come across this post. So now when I am ready to move on to more expensive lights I know some of the things to look out for.

Mel

 

[mortm]

I blame goatee he started all this white balance talk and where is he now aye

 

[mortm]

After a bit of searching, and yes I know I was going to wait until anyone said they were interested but I'm sure someone one day will do a search for this info.

Here are some readings from various kits and some camera mount flashes taken from the net, the first three using a Minolta Colour Meter:

Profoto Compact 600 Plus Monolights
Power - Color Temperature - F/Stop

1/1 - 5070*K - f/32
1/2 - 4990*K - f/22
1/4 - 4920*K - f/16
1/8 - 4830*K - f/11
1/16 - 4720*K - f/6.7

White Lightning x1600
Power - Color Temperature - F/Stop

1/1 - 5220*K - f/32
1/2 - 5090*K - f/22
1/4 - 5020*K - f/16
1/8 - 4970*K - f/13
1/16 - 4880*K - f/8
1/32 - 4800*K - f/5.6

Elinchrom Style 600 S
Power - Color Temperature - F/Stop

1/1 - 5090*K - f/27
1/2 - 4920*K - f/19
1/4 - 4830*K - f/16
1/8 - 4760*K - f/11
1/16 - 4720*K - f/8
1/32 - 4620*K - f/5.6

Calumet Genesis 400
Power Temp
1/1 --- 6100k --- (f-16)
1/2 --- 6000k --- (f-11)
1/4 --- 5900k --- (f-8.0)
1/8 --- 5800k --- (f-5.6)

Alienbees B1600
1/1 - 5200
1/16 - 4850

Canon 580EXII Speedlite
1/1 - 5400
1/16 - 5600

Sigma EF-500 DG Super
1/1 - 5250
1/16 - 5500

Sunpak 383
1/1 - 5250
1/16 - 5550

You will be pleased to know I have started to get bored with myself as well

 

[goatee]

I blame goatee he started all this white balance talk and where is he now aye

lol - well, for me, consistency from shot to shot, when not changing the power settings is what's important for me - if I need to change power settings, I'll shoot a grey/white/black card, to check colour temp.

I'll give it a go next time I have my lights out.

After a bit of searching, and yes I know I was going to wait until anyone said they were interested but I'm sure someone one day will do a search for this info.

Here are some readings from various kits and some camera mount flashes taken from the net, the first three using a Minolta Colour Meter:

snip

If the Elinchroms are showing such a colour shift, then I would be delighted with the results that the Stable Imaging kit has given.

One question - do your lights have the option of a beep to show when the lights are charged? It can make a big difference if you want to take several shots - e.g. with kids who move around quite quickly.

 

[Garry Edwards]

Interesting figures. The Minolta Color IIIF meter has always been the professional tool but when Kenro took over the Minolta range they dropped the colour meter, and dropped all support for it too, which is bad news for those of us who own one. The good news is that Sekonic have now announced their own replacement

I think the figures are interesting (assuming that they are actually correct, my own testing figures are different) because the Profoto and Elinchrom show up pretty badly, especially at the lower outputs, and they shouldn't be as bad as they appear to be.

I think, to get a useful interpretation, you should only take a 3 stop (1 - 1/8th) or 4 stop (1 - 1/16th) range because when lights are reduced to just 1/32nd power the colour shift is always unacceptable, and so is the power consistency. If I was the cynical type I might think that manufacturers only make them reduce that far to give the impression that their lights are better...

You can safely disregard the figures from hotshoe flashes because the flash only has one power setting - full - and the reduced exposure is obtained by shutting the flash off early, resulting in a shorter flash duration. In other words, the capacitor does the same work at all power settings.

 

[goatee]

I think, to get a useful interpretation, you should only take a 3 stop (1 - 1/8th) or 4 stop (1 - 1/16th) range because when lights are reduced to just 1/32nd power the colour shift is always unacceptable, and so is the power consistency. If I was the cynical type I might think that manufacturers only make them reduce that far to give the impression that their lights are better...

So presumably :rules: buying lights with only a 3 stop range, isn't a problem, if they perform so poorly when the power is less than 1/8th power.

 

[Garry Edwards]

So presumably :rules: buying lights with only a 3 stop range, isn't a problem, if they perform so poorly when the power is less than 1/8th power.

It is a problem, just not as big a problem. And how big a problem depends partly on the type of shots you produce.

Quote from your earlier post well, for me, consistency from shot to shot, when not changing the power settings is what's important for me - if I need to change power settings, I'll shoot a grey/white/black card, to check colour temp.
Unfortunately that doesn't help if you're using more than one light. The temp from say the key light might be considerably higher than that of another light set at lower power, so the subject will be lit with light of two very different colours and so will be different colours in different places.

 

[mortm]

Welcome back goatee

option of a beep to show when the lights are charged?

No, up until I got the light meter I wasn't that bothered but now as I have to stand in front of the lights where I can't see the ready light it is a bit of an issue... not that it will keep me up at night... unlike colour temperature and white balance, I'm just glad I can never remember my dreams as I bet I dreamt about it last night.

If you do the test the right grey card is important, the speckled grey form the back of a notebook wasn't a good idea. I ended up using the back of my Sony manual. It may not be neutral grey but for this test at least it was uniform. Think I will have to get some dedicated card now I'm on a mission. But not that of a mission that I am going to buy a colour meter, boy they are expensive.

 

[mortm]

I have placed an image in my gallery showing 5150 against 4950. Basically small sections taken from 2 of my test images and sewn together.

 

[goatee]

Unfortunately that doesn't help if you're using more than one light. The temp from say the key light might be considerably higher than that of another light set at lower power, so the subject will be lit with light of two very different colours and so will be different colours in different places.

I gotcha - and yes, you're right. I'll experiment and see what difference a couple of 100 k makes to skin tones.

 

[kalibre]

Cheers mortm for all of the info. Like I mentioned ealier in the thread I'm after a budget 3 head kit as well so all the info I can get is good!

goatee: I've now checked out the EX MKII and am quite impressed for the money. The specs I must have looked at previously must have been for the MKI.

I'd be really interested if you could post smiliar tests to mortm but with the EXs. I'd offer to give you a hand but I'm bl^^dy miles away!

Thanks again.

 

[mortm]

Words from an editor of Digital Photo regarding the tests carried out on budget lighting kits:

We didn't test the colour temperature of the flash output as we felt this would go beyond the scope of a budget unit test. If absolute colour temperature is critical (say for *very* accurate pro product shots or similar), it'd make sense to invest in a high-end pro studio lighting set-up rather than budget monoblocs. The budget here would run into four figures, and would feature gear that would be beyond the needs of most readers. Our aim was to introduce affordable studio flash, and establish a fair & objective testing method that would directlt compare the units and reveal the best value kit. Different colour temperatures may be possible at different power settings, but to be honest, it's unlikely to be a cause for concern for most digital photographers - including professionals. By the time your camera's interpreted, processed (and in most cases, invented) the colour data, and then you've tweaked the hue, saturation and colour temp in a RAW converter, and then you've tweaked the file again in Photoshop, you're unlikely to have thoroughly accurate and objective RGB file. If it's for professional use, your image will then be subjected to a CMYK conversion for print which will force some colours out of the picture altogether. There's a bit of a domino effect to it all, and there's a lot more can go wrong at the processing stage than a light that's 200K too warm. The best bet's to buy the best kit you can afford, and get to know its strengths and weaknesses really well so you can get the best performance out of it.

Maybe we... or is it just me.. are going overboard. But hey it's all learning.

Kalibre - Any simple questions regarding the Stable Imaging kit fire away and I will do my best. I may do a review soon if i get the time.

 

[Garry Edwards]

Words from an editor of Digital Photo regarding the tests carried out on budget lighting kits:



Maybe we... or is it just me.. are going overboard. But hey it's all learning.

Kalibre - Any simple questions regarding the Stable Imaging kit fire away and I will do my best. I may do a review soon if i get the time.

I like that excerpt - it's hilarious

You may see things differently, but bear in mind that magazines exist for one purpose only - to sell advertising space...
And the last thing they want to do is to upset their customers!
The ONLY mag I've ever read that seems to me to tell the truth, warts and all, is AP

And, just in case anyone was wondering, I'm listed as a 'Trader' simply because I sell my Photolearn tutorials and videos - I don't sell lighting equipment

 

[kalibre]

Words from an editor of Digital Photo regarding the tests carried out on budget lighting kits:



Maybe we... or is it just me.. are going overboard. But hey it's all learning.

Kalibre - Any simple questions regarding the Stable Imaging kit fire away and I will do my best. I may do a review soon if i get the time.

Thanks mortm, I've checked your gallery and the 200k difference isn't as bad as I thought i'd would be. Obviously in multi light multi power level setups this won't be correctable (as others have said) but certainly for my amateur needs I think it would do just fine.

I've looked at the stable imaging and although I'm sure they'd do the job, I'm looking to get multiple accessories and build on them in the future, so support and brand is quite important (I know Interfit isn't a great brand but hey).

 

[mortm]

Also you would never have a situation like in the image, the camera would generally be set to match the main light and difference would for be lost.. to us novices anyway.

I've never heard anything wrong with Interfit, my decision was limited budget and I had used a friends and they suited me, give me plenty to play with. I'm sure you will be happy with your Interfits they get good magazine reviews. You will have to do the colour temp test and let me know the results.

 

[kalibre]

Will do. Won't be ordering until 20th of Oct when I get back from hols, but I'll let you know once I've had a play, unless goatee posts the details first.

 

[goatee]

I would hope to be able to do it before then - give me a couple of weeks though, (being realistic).

 

[mortm]

Quick question. Could you use the custom white balance on the camera to check colour temp difference. i.e. take the reading from the custom white balance setting on the camera at each power setting?

 

[kalibre]

Quick question. Could you use the custom white balance on the camera to check colour temp difference. i.e. take the reading from the custom white balance setting on the camera at each power setting?

Not on Nikon kit as far as I'm aware. It'll set it but won't give you a reading.....

 

[mortm]

Oh so limited to certain cameras. The Aplaha gives a reading which I could use and save having to go through importing to ACR etc. Thought I may have found an easier way to encourage people to perform the test. Never mind.

 

[Carlsbad]

After a bit of searching, and yes I know I was going to wait until anyone said they were interested but I'm sure someone one day will do a search for this info.

Here are some readings from various kits and some camera mount flashes taken from the net, the first three using a Minolta Colour Meter:
...

Calumet Genesis 400
Power Temp
1/1 --- 6100k --- (f-16)
1/2 --- 6000k --- (f-11)
1/4 --- 5900k --- (f-8.0)
1/8 --- 5800k --- (f-5.6)

Alienbees B1600
1/1 - 5200
1/16 - 4850
...

I had much better experience with Genesis 400 than with otherwise excellent Alien Bees in terms of WB inconsistency.
See for yourself:
http:

 

[mortm]

Good work

Did you get a chance to take them through ACR and check the difference in temp?