Microcrystalline Wax Techniques?

[Jim Lafferty]

I'd love to learn more from you guys who are using PCX lenses. I have two 100FL PCX lenses here that I picked up from surplussshed or somewhere on the cheap, and I need to know what (approx) distance from the GG they should be placed, and in what direction. I'm looking at my 3" long aluminum tubing here and I'm worried I haven't enough distance between the rear of the 35mm lense and the GG to properly make use of the PCX lens(es).

[Bill Porter]

Matt, you have a point in terms of overall light loss but others are talking about the light loss through the adapter itself, not through the adapter plus subsequent loss induced by the camcorder's iris due to zooming.

[Glen Hurd]

Jim, for me the dual PCX GG sandwich is dead. It created lots of vignetting, and I didn't like that the PCX on the SLR side was making my SLR lens a wider lens than what I 'd put on -- not to mention it would be expanding my DOF, since it would actually be playing with the FOV (for a constant area). I mean, before these adaptors came along, people were attaching 35mm lenses to video cameras, adding glass to get the full image small enough to fit in a video frame, only to discover that they'd converted the 35mm lens into a standard video lens with video DOF.
So it's the single PCX on the video side for me. And there are two things I look for.
First, there is a sweet spot where the PCX distance from the GG has neither pin-cushioning or barrel distortion at the edge of the frame. This distance is no-where near the maximum magnification point, either, unfortunately. Because the second point is finding a PCX that will magnify the GG image sufficiently that you don't have to do a lot of zooming on the video camera in order to fill frame (and I hate the thought of having to buy another quality piece of glass so my video can macro through excessive zoom settings).
With my adapter, I'm looking at a little less than 100 mm FL, for now. I don't know if the shorter FL PCXs are more prone to distortion, or not. I guess I'll see. Hope this helps give one perspective, anyway.

Matt, do you have an incident meter? If so, can you put a small cylinder around the white dome, take a reading, and then cover the cylinder with your GG and take a second reading? That seems like a fair way to evaluate how much light is lost due to the diffusive nature of the wax. Your 2 to 3 stop loss sounds extreme for wax, unless you are layering it so thick as to avoid some grain issues. Your footage does have a nice contrast to it.

Glen

[Jim Lafferty]

I guess my interest is in getting as close to or matching the G35 experience -- and they comment that they use "faster" lenses than stock Century Optics glass (like the +7 macro I'm using). Without having access to a "faster" macro, my interest is in using a PCX mounted in front of the GG to bring in extra light. My half hour or so of fooling around with my 100FL PCX in front of the GG proved not to make much of a noticable difference, though (no vignetting or pincushioning, either.)

So, I'm just trying to get some guidance here instead of making it pure guesswork -- which, while that can work for some parts of this project, I suspect will be more trouble than good when aligning glass.

[Ben Winter]

what does "fast" mean?

[Wayne Kinney]

i believe the word 'fast' is related to the light transmission of the lens or glass.

Wayne.

[Glen Hurd]

What experience is that? Not having to use PCX lenses? Getting the fastest adapter possible?
Right now, the fastest adapters would be the vibrating/rotating glass GG setups. If a wax gg loses a stop and a glass one loses about a third, no special macro glass in the world is going to make up for that difference.
As for talking about using faster glass, I just did some experiments with a spot meter on sticks, and found that my fastest glass was the $3 PCX I bought at surplushed. It also sucks for chromatic problems. It was losing less than 1/10th stop.
Next was an achromat I'd bought at the same place, losing about 1/10th. With this achromat, I don't need to use a macro.
Next was my +10 macro (ebay special DKE) at 1/4 of a stop loss. With 4 macros stuck together, I lost almost 1/2 a stop.
So, with 4 cheap macros stacked like pancakes, on a moving glass adapter, I could expect the same light loss as just using a wax GG alone.
Considering that most of us are going to lose 3 stops just by putting an f/2.8 lens on the front, their talk of "fast" glass seems much less important than issues such as resolution and chromatic aberration. 1/10th of a stop isn't going to change much of anything. Maybe they list it for distraction -- a fluff-filled red herring, so to speak ;)

Just my thoughts.
Glen

[Oscar Spierenburg]

Jim, I can just tell you what I got. To begin with, I don't even have an 'official' condenser, but that's probably why they are so good. I took two very thin lenses (just big enough for a -35mm frame) from old camera's. One from the inside of a super8 camera, and one from a telephoto lens. I sandwich them together with the GG in between on the flat sides of the glass. It's a bit hard to find such big lenses though.
Glen says: <<expanding my DOF, since it would actually be playing with the FOV >>

But in my opinion, that exactly the effect that we see on the G35 and I like it. Glen, I would reconsider it, because it gives such a bright image. On my site you can see I don't lose any DOF effect, only on the highlights that pass the wax layer.

[Jim Lafferty]

What experience is that? Not having to use PCX lenses? Getting the fastest adapter possible?

They repeatedly show some amazing looking footage. Despite their insistance that it's grainless, you can see it clearly in the highlights of some of the shots -- but at that it's far supressed compared to what I've been able to produce. They also seem to have very little light loss, no color aberrations. So, yes, I would guess it's the fastest *static* adapter out there, with the least amount of grain showing (aside from Frank's footage).

On their forums there's talk of what others are doing here as merely "the work of hobbyists," i.e. nothing of quality build. I wouldn't mind making them eat those words :D But getting it done is another story altogether.

- jim

[Bill Porter]

Out of respect for G35 guys' work it's not true to say they insist their footage is totally grainless. If you look in Jonathan's last posts you'll see where he says there is some grain in some shots in one of their earlier-released vids.

[Frank Ladner]

I've fallen behind a bit on the adapter progress. We got some pretty bad weather down here. Glad to see people are still working on it!

Ben: Regarding Fast lenses - (as I understand it) the closer the ratio is to 1:1, the faster the lens. For example, 1:1.8 is faster than 1:2. You want fast lenses when using these types of adapters to lessen the appearance of grain.
Telephoto lenses are usually 'slow', having bigger numbers like 1:4 (and the numbers change - they are lower on the wide end and higher on the telephoto end)

[Leo Mandy]

To me the biggest problem is finding the right condenser or Achromat - Oscar is lucky he found a great set that worked. As I have asked before, it would be nice to get a list from Surplusshe or anchoroptics of achromats and condensers that work - period. Problem is when people find something that works great, they end up making 'another adapter' and keep the trade secrets.
I was lucky to find a condenser from a SLIDER FILM PROJECTOR (you know the ones from school when they played a tape recorder while the slide was showing). This worked amazingingly at getting rid of vignetting, but it is small - a bigger condenser will get a bigger image. Again, I can't stress this enough - smarter peopple than myself have made discoveries with the proper achromat that doesn't have colour abberhation or barrel distortions and smarter people than myself have found the perfect condenser or PCX lens - the unfortunate part is that they are keeping the info to themself and letting us fumble in the dark (I suppose like they had to). Oscar (and Quyen with his tutorial on the Letus35 adapter) are one of the few that actually comes out and tells how he does stuff - in detail, what they used and where they got it/. I wish more people were like him on this board...

[Dan Diaconu]

This is not new and works as good as you can get:

http://www.bhphotovideo.com/bnh/cont...ughType=search

less than that, you get wyp4. (no magic and no short cuts in optics) I wish I could help more, but when I thought I needed one, I bought the above (and I can't say I do not have any lenses laying around)

[Oscar Spierenburg]

Of course, Dan is right. But like I said about my condensers, originally they are not condensers, but pieces of glass from old camera lenses. I think you have a better chance of finding a quality lens there (old telephotos or even binoculars or something) than get some cheap condenser or achromat from a surplus store.

[Dan Diaconu]

I agree with you Oscar. Pretty much ALL lenses ARE chromatically corrected (even the older ones). Now... some have enough glass on the front elements to cover the "scene" some don't. Some have "air" between elements, some are glued together, etc. By the time you "bastardize" a lens just to use the front elements..... it may not be worth it (even if glass is fine, you will need some sturdy mounts to hold them together (at precise aligned distances and squared to each other and the rest...)
Try your luck in the 4/200mm (4/135 may be on the edge) Better yet, find some older optics books and read a bit, you'll gain a lifetime knowledge (nobody can take from you) and you might find yourself spending less on cheap (glass) and you will know why! Don’t mind me Leo for preaching, I mean well.