marcus g

The use of a stepless mechanical slider or a digital readout adjustable in 1/10 steps is more of a design choice. Using the latter, it is easy to adjust the flash energy according to the reading from a digital light meter. Of course, both technologies will give good pictures with a digital camera.

As I understand it, the term 'digital precision' - when used by flash manufacturers - is more about the precision in light intensity from shot to shot. To give an example, the old flash unit Elinchrom 500 allows flashing when the charge cycle has reached 90% of the set voltage. This roughly translates to a worst-case light variation of 0.3 f-stops. A newer unit, like the Profoto D4, has an energy stability better than 1/100 f-stop from shot to shot. (These are just examples that I happen to know about. I do not know the corresponding characteristics for the Elinchrom units you mention.)

The need for energy precision depends on usage - if you are commissioned to take 500 similar product shots for a catalog, it will be valuable, but not so much for a portrait session resulting in a few pictures that are to be individually photoshopped.

I am not a professional photographer, and you may very well get better answers in this thread.

Thanks for offering to give advice! There is also another guy who has posted a partial schematic of a Bowens monolite 400 on the web: http://eddy.uni-duisburg.de/akurz/foto/flash.html

I do not have Bowens units myself, but I'm very curious about different flash circuits. Hans, you posted photos of the inside of a Bowens 800E under another topic in this forum. From these images, I see two 50W resistors mounted on one side. Are these the flash adjustment resistors you mentioned above, or are they used to limit charge current when recycling?

Also, would you happen to have a schematic or service manual to any more modern flash unit (in digital format)? The brand is not important, as long as it is one with fast recycle to full power (<2s).

I would be very interested in seeing how things are done in current

designs. Best wishes from Paris, France

Dear all,

I'm beginning to get really tempted to buy a D70 in the near future.

There are two things that I'm wondering about, that maybe some of you

Nikon-fans could answer?

#1 I would buy a body only, as I already have Nikkor lenses for my

35mm camera. These are the AF28-85/f3.5-4.5, the AF85mm/1.8 and the

AF75-240mm/f4.5-5.6D. The latter one is cheap plastic, but the first

two should be pro grade. Will this lens collection work well with the

D70, or is there some advantage to the new DX lenses that I will be

missing? (I know that I'll be limited to 28x1.5 = 42mm at the short

end but I primarily like to shoot in an amateur studio, and rarely

try wide-angle landscapes.)

#2 In the promotional PDF brochure available from Nikons website, it

is stated that 'images can be downloaded from the camera to a computer

while shooting'. Can this be done using the software supplied with the

D70?

This also leads to another thing I have been wondering, as I have no

previous experience from shooting digital: For a studio shoot, I think

that it would be really neat to hook the camera to a laptop computer

by a long USB cable, in such a way that RAW files would be transferred

to the computer (with a few GB of free space) automatically while

shooting - without fiddling with several memory cards etc. This would

be a feature that had no counterpart in film photography. Am I only

dreaming here, or is it possible to arrange such a setup - with the

D70? (The idea is that one should not have to touch the computer while

shooting this way.)

I'm thankful for any responses!

I'm the guy who did the homebrew project. From reading this thread, I must say that I agree with many things written above.

First and most important: Never, ever fiddle with things like this unless you are absolutely sure that you know exactly what you are doing!! The safety issue cannot be overstated! If you build a capacitor bank and charge it, be sure have a safe method of discharging the caps through a power resistor before touching anything. Check out www.repairfaq.org for more info on handling dangerous voltages.

Of course, the reason for making a homebrew design is to 90% the

fun of figuring it out, planning and building it, and to 10% the

prospect of having a working setup for photographic use afterwards.

Naturally, this is not something to do just to avoid paying for a factory-made unit.

Good stuff do not appear on Ebay as often in Europe, as it appears to do in the US. As far as I can tell, getting Bowens monolights for $62 sounds unbeatable. If you are not as passionate about DIY tinkering as me, getting used gear is undoubtedly the best way.

Regarding capacitors, I realize that I may seem to be suffering from some kind of mania, as so many of them are needed to build a powerful strobe. But for me it was not as hard work as it may seem. Most of the caps come from just one visit to a local minilab, where they had a huge box of used-up disposable cameras. They were only happy that I hauled it away for them. Building the capacitor banks was just a matter of hours. I found some satisfacion in using this solution, but I do not expect anyone else to do the same.

If anyone is still with me, I could mention that I will have time to continue work on the studio lights in a few months. The power pack is sturdy enough, but I will completely redesign the lamp heads to have aluminium housings, and proper wide-angle reflectors. I will also buy proper light stands. The stuff shown on my page is way too flimsy for serious use.

I have bought a small supply of bigger flashtubes (1400Ws) for a much better price than the elinchrom tubes. I will use these to build one or two more powerful monolights, with modelling lamps that can track the flash energy and so on. But this will happen at some point in the future. Before then, I will try to improve my photography (!)

Once again, be very, very careful with experiments like this!

Best wishes!