Paul C. Buff, Inc. Technical Forum

Hello-
I starting to work with a recently acquired 51" PLM. I already own the previous generation 64" PLM. I am using both with small nikon strobes. I have been extremely pleased with the light quality of my 64", but the light patterns I am seeing on the PLM v2 is not on par with the PLM v1. The first image is one taken with my a sb-800 and the PLM v1, 64". The subsequent photos are of the 51" PLM v2 with various shaft positions, +/- the diffuser dome, and different zoom positions. I have taken others as well, but I am unable to replicate the smooth ring of light I get with the V1.

I have emailed with David in customer service and he seems to suggest that the strobe is what is causing the differences in light patterns. However given the smooth even light of the 64" v1 I am more inclined to believe either 1.) that I perhaps received a subpar PLM v2 or 2) that the design of the V2 is such that I will not be able to get the same smooth light pattern using a strobe that I get with the V1.

I would be interested in the experiences of other forum members here and whether they have had similar or different experiences using small strobes with the V2. If this is the sort of pattern that is expected from a small strobe and the v2's then I am inclined to return it an look elsewhere. If this looks like the pattern from a defective unit, then I would like to look into getting a replacement as I would love to have a smaller, more travellable version of my 64".

Below are images taken with the different PLMs. The first is one taken of the light pattern from PLM 64" V1, at 24mm with no "sto-fen". The other photos show light patterns and strobe positions imaged with the 51" v2.
http://www.flickr.com/photos/sedmands/5882969754/in/photostream/ 64" PLM v1 http://www.flickr.com/photos/sedmands/5882969588/in/photostream/ 51" v2 with strobe position http://www.flickr.com/photos/sedmands/5882408155/in/photostream/ Light pattern with diffuser and v2 http://www.flickr.com/photos/sedmands/5882969008/in/photostream/ Position 2, 24mm http://www.flickr.com/photos/sedmands/5882407939/in/photostream/ plm v2, position 2, 24mm http://www.flickr.com/photos/sedmands/5882407477/in/photostream/ PLM v2, position 3 http://www.flickr.com/photos/sedmands/5882401291/in/photostream/ PLM v2, position 3

I just had a chance to get a speedlite on a 51"PLM. The patterns I am getting are pretty much circular, however, with focusing adjustments to the PLM, I can replicate the dark circles, or make them go away. The effect is very much like focusing a Maglite. The distance I shot at was about 6'. I did find optimum focus from my speedlite to be when teh speedlite was pulled back from the umbrella opening by about 3" or so. I found this focus point by using the "modeling" function and sliding the umbrella along the 7mm shaft until the pattern evened out. I did use a diffuser cap (not a StoFen brand one), and zoom was set to 24mm. The flash was placed close to the axis of the 7mm shaft, similar to teh distances you have shown.

Yes, there are differences in the fabric from v.1 to v.2, and certainly without a diffuser on a speedlite, I would not be surprised to see unevenness. However, with a diffuser and with proper focussing and positioning, you should be able to obtain a fairly even and fairly circular pattern.

Thank you for your reply. I have tried a number of different positions along the umbrella shaft from 2 inches inside to ~2 inches outside the plm, both with and without the diffuser cap. .. I actually have the nikon diffuser cap. However, I haven't been able to attain a round, smooth light pattern. On the v1, I get changes to the pattern, particularly with regards to the center, going from a dead spot to a hot spot in the center as I move the flash along the umbrella shaft, however the overall round shape with nice steep falloff is maintained. With the 51", I am having trouble attaining a smooth round shape with any set of conditions.

I will try your suggestion of using the modelling light to see if there is something I have missed. In the meantime, would it be possible for you to send me what you are getting either via email or a post so I might compare with what I am getting.

I will try to get that together for you, but it may take a little while. I also have sent you an email as well.