200w or 250w?

[Donald Miller]

The 4550 VCCE XLG that I have does have the 250 watt lamp...it is not recommended to switch wattages from the lower wattage to the higher wattage lamp according to the mfg. The problem is one of heat build up from what I understand.

[J D Clark]

I have to admit I have used a 250w lamp in the 4500 II that I have -- it occurred to me that the brighter lamp would result in shorter exposure times, so the heat buildup with be corresponding less. So, I charted the time/temperature pairs for both lamps up to about five minutes, and found that the 250w lamp was indeed hotter, but not outrageously so, and about to the same temperature if you take into account the shorter exposure time.

So, I ended up using the 250w in my 4500 -- and tried to make sure that I didn't spend too much time framing and focussing.

As far as I can tell, the power supplies for a 4500 and 4550 are the same. Of course, this is against the manufacturer's recommendations.

Finally, I don't know how the light output per wattage works, but the 250w lamp *did* have more than 25% increased output, it was more like about a stop increase. Perhaps it was an old 200 versus a new 250, but I was pleasantly surprised (but didn't chart the actual difference).

John Clark
www.JohnDClark.com