Nice modifications Dave. Looks very functional now.
Did you source the nut at the hardware store?
Is both sides of the positioning rod threaded? If it is you could replace the suppled 5/16-24 bolt with a ~ 1 3/4 threaded stud and put a nut on each side of the hub. This way with the threads on each side of the hub you could screw the cage onto the back of the umbrella making it one compact unit to carry.
Might be able to just turn the positioning shaft around even if it's not threaded on each side to do this when storing.
Kacey wrote:
Nice modifications Dave. Looks very functional now.
Did you source the nut at the hardware store?
Found the nuts this morning, Jerry, in a mom-and-pop hole-in-the-wall hardware store in a not so great part of town. Persistence paid off in this case. Now if I could just find a 3/4" 8-32 thumbscrew or wing bolt ...
Tetrode, the suggestion for a wing screw at the back will work, but will defeat the ability to focus the PLM when the the speedring is used. Also, you will not be able to put on the black outer cover without removing the wing screw. If you remove it, the whole umbrella will disassemble and you will have to reassemble the whole thing.
As for the bolt and nut you show at the front end of the center shaft, this is workable, but will require an additional lock washer or the center shaft will unscrew from the bolt as you rotate the PLM™. But I still contend that 99% of users will likely leave the speedring attached or detached permanently, as most users will attach the PLM to the same make of light . . . Buff, Elinchrom or "universal off-center 7mm shaft mount" almost universally.
If you plan to only use the 7mm off center mount, I would recommend a 3/8" 8-32 self locking set screw where you have the wing screw. Then you will be able to lock the center shaft in position more effectively and still be able to attach or remove the black outer cover without any disassembly.
I also believe with time and use-experience most customers will find the PKMV2 as supplied will fulfill it's purpose well.
Paul Buff wrote:
Tetrode, the suggestion for a wing screw at the back will work, but will defeat the ability to focus the PLM when the the speedring is used.
With the positioning shaft secured at the PLM's tip, an Elinchrom light mounted on the cage will sit with its flashtube just inside the umbrella canopy which, I believe, you've stated in the past is the optimal position and the PLM's prime focus. Moving the light further out would result in excessive spill around the sides of the umbrella. Although I can't foresee a need to do so, moving the light further in can still be accomplished with the positioning shaft secured at the PLM's tip.
Also, you will not be able to put on the black outer cover without removing the wing screw. If you remove it, the whole umbrella will disassemble and you will have to reassemble the whole thing.
I will not be using my PLM in shoot-through mode so this is not a consideration although the point is well taken. Once I get the back cover for the 51" PLM, it will be installed and likely never removed.
As for the bolt and nut you show at the front end of the center shaft, this is workable, but will require an additional lock washer or the center shaft will unscrew from the bolt as you rotate the PLM™.
Once mounted, why would I be rotating the PLM? The 5/16" bolt is a tight friction fit in the threaded end of the positioning shaft. Once screwed into place, the shaft and PLM aren't going anywhere. This arrangement is not that different from the removable end section of a Photek Softlighter shaft. That, too, is held in place purely by friction.
But I still contend that 99% of users will likely leave the speedring attached or detached permanently, as most users will attach the PLM to the same make of light . . .
The cage with positioning shaft attached is, FOR ME, an inconveniently sized and shaped assembly. The ability to quickly and easily disassemble it into two more packable pieces shouldn't be dismissed.
If you plan to only use the 7mm off center mount, I would recommend a 3/8" 8-32 self locking set screw where you have the wing screw. Then you will be able to lock the center shaft in position more effectively and still be able to attach or remove the black outer cover without any disassembly.
As I mentioned in a prior post, I was not able to lock the 7mm rod into place using the supplied setscrew. Advancing the setscrew so that it would trap the 7mm rod resulted in it running out of its threads in the casting and coming loose inside the PLM's shaft. If the 3/8" setscrew you suggest is longer than the one supplied, I would strongly recommend that it be made standard, replacing the one currently shipped with the PLM V2s. The 1/2" wing bolt seen in my photo is able to secure the 7mm rod with no problem.
Last point: You can address me as "Dave" rather than Tetrode like everyone else does.
kenyee wrote:
Dum question, but what does that thumbscrew in that photo do?
As seen in the photo, it's doing absolutely nothing as it was almost fully backed out of its threads when the photo was taken. The positioning shaft, remember, was being held in place by the wing bolt at the umbrella's tip.
One nice feature of the PLM V2 is that it actually snaps into the the full open position and does not require that the sliding collar be locked into position to stay open. The thumbscrew, when advanced, will lock the collar. However, that thumbscrew has additional responsibilities: It is also tasked with retaining the positioning shaft (when it's not being retained at the PLM's tip as is the case here) and the 7mm shaft when that is being used.
But the focus point is an important consideration, The optimal focal point for distant shots is with the tube further into the PLM than for close shouts. Also the position you describe will yield maximum output and minimum pattern diameters. For many uses, it's desirable to defocus the PLM to achieve a wider angle of coverage.
For amateurs, the fixed focal point you describe is simple and reliable, but for professionals, adjustable focus is important. It can be tricky, but once learned, quite valuable.
But the focus point is an important consideration, The optimal focal point for distant shots is with the tube further into the PLM than for close shouts. Also the position you describe will yield maximum output and minimum pattern diameters. For many uses, it's desirable to defocus the PLM to achieve a wider angle of coverage.
For amateurs, the fixed focal point you describe is simple and reliable, but for professionals, adjustable focus is important. It can be tricky, but once learned, quite valuable.
Thank you, Paul, for that explanation. It's very helpful. In that case, I will definitely experiment with light placement.
Thank you Dave & Paul, that exact set-up is what i was wondering about and this is very helpful information.
I'm a bit confused by the last bit of information about de-focusing the PLM however...
I think i just need to bite the bullet and try out one myself, though for the shipping charges to canada i was planning on buying more then one and a few other things as well. I will have to wait maybe for some youtube videos so i can see, i am much more visual then reader
Paul Buff wrote:
The optimal focal point for distant shots is with the tube further into the PLM than for close shouts.
Is this to minimize light loss at the edges (so the 1/2 stop outer edge of light is inside the umbrella) so everything is reflected for longer distances vs. close up where you want to fill the entire PLM?
Here's another possible configuration of the 51" white PLM V2. This one is with a long 7mm shaft in place:
I happened to have a 26" section of 7mm stainless steel rod in the basement (doesn't everyone?) and thought I'd try it with the PLM. The PLM ships with a 16" nominally 7mm rod. According to my caliper, the supplied rod is actually 6.75mm in diameter which is a good thing. It fits very well in the Elinchrom umbrella tube. My 7mm stainless rod measured 6.99mm which makes for a snug fit in both the Elinchrom and in the PLM's positioning shaft. It does fit though.
So what you see in the photo is my 26" length of SS rod inserted into the positioning shaft and locked into place using the wing bolt at the tip of the umbrella. By not using the PLM's cage, it is possible to mount a reflector on the Elinchrom light which is something you would want to do if the light is backed down the umbrella shaft such that the flashtube lies beyond the plane of the umbrella canopy edge.
An additional benefit is that, with the longer shaft in place, it is possible to open and close the PLM in the same manner as you would a standard umbrella. When closed, the 7mm umbrella shaft does not extend beyond the sliding collar. In other words, the collapsed umbrella remains the same length it was without the 7mm shaft in place.
I'm not recommending this configuration, just sharing it as a point of interest.
Is that the new plm v2 silver 86 umbrella? i can't see the cage in the shot for the image, just the reflector. Do you have a shot with the umbrella fully illuminated?
c2thew wrote:
Is that the new plm v2 silver 86 umbrella? i can't see the cage in the shot for the image, just the reflector. Do you have a shot with the umbrella fully illuminated?
PLMV2 is designed with extreme care and testing to function as designed using a true bare bulb light source such as all Buff lights, with the flash tube parallel with the umbrella outer perimeter for studio use in the 5' to 15' range. For long distance lighting focus is optimal with the flash tube in 1" to 2" from the fabric perimeter. This provides maximum output, minimum spill light and even light coming from all surfaces of the fabric. This is extremely important with the silver fabrics. From this starting point the PLM can be defocused by moving in or out an inch or two to widen the pattern.
Every use I see here has the PLM extended too far out from the flash tube, or with non-bare bulb sources. This degrades the entire design of the PLM and results in uneven light levels from the silver fabrics, poor catchlights, lower output, anomalies in the projected pattern, more tip-over effect with small light stands, side spill light and bending shafts.
The easiest way to confirm optimal flash tube placement is to stand at the subject position and adjust such that you see even light coming from the inner and outer portions of the fabric. This will give you the full effect of the umbrella's size and best shadow structure.
If you are indoors where you can see the size of the projected pattern, you can observe the pattern change as you move the PLM in and out relative to the flash tube to observe the focusing effect from the modeling lamp. But remember many modeling lamps are an inch or two forward of the flash tube, so you should compensate for this after you observe the focal pattern by then moving the flash unit into the PLM such that the flash tube is in the position that the modeling lamp was in when visual previews were made.
This is not necessary with Einstein because the flash tube and modeling lamp are exactly in line with each other, so modeling and flash patterns are identical.
Tetrode: You will get much better results if you take off the umbrella reflector and move the light unit 6-8" further into the PLM. It won't make much difference on the white PLM, but is very important to get maximum effectiveness fro the silver. Of course, also, given an Elinchrom light and the Elnchrom speedring, I would never compromise everything by using the 7mm off center shaft mount and reflector.
Brent . . . I would move the PLM about 3-4" closer to the light for best results also.
