Rainbow H6x8 II Zoom Lens on GH2 - Parfocal Test

Rainbow S6x11 Zoom Lens on GH2 - Parfocal Test

Ok, I'm unclear on several things.

1. GH2 EX Tele Crop Factor FOV equivalent to fullframe: is it really only 2.6X FOV compared to full frame, or is it more? by this, a 20mm lens would be 52mm equiv. FOV (as opposed to 40mm equiv. on whole GH2 frame)?

2. Which lenses work in EX Tele mode with full coverage? 1"? 2/3"? 1/2"? 1/3"?

The Fujian 35mm is OK for shallow DOF shots, not wide shots. Closed down it's gets sharper at the edges.

One of the best C-mounts I've seen is the Fujinan 12mm f1.4: Video by Geopaca I'm not sure if vignettes in video mode but It can be modified for full 4:3 coverage.

I know of at least one (because I own it): the Fujian 35mm. Fun, funky lens. No vignetting (but heavily blurred at the edges--which is why you buy it).

Can anyone provide a list of C-mount lenses that work with GH2 , full image, not ETC ?

The holes are for the 3 screws that hold the adapter to the lens housing, otherwise the whole thing would fall out. The original metal ring on the Rainbow H6x8II lens is what's keeping the c mount part on the lens. The H6x8 plastic version has a plastic piece instead of metal. Please watch the vimeo video that details this so you can get an idea. If I have time I'll see about making my own video.

@fosterchen

More and more modifications. This is interesting but what's the purpose of the drilled holes? How does making the adaptor hug the camera snugly help in yr work? I had this canon lens as well, my frustration was that it became a varifocal lens on the GH2, meaning whenever i zoomed in or out, the focus changed. I know of pp who have successfully made such lenses parfocal, but it takes time and money. Given that c mounts are not the easiest glass to use on m4/3, with all the modification which can be a hassle, I think it's more expedient to go for full frame 35mm glass.

One clarification though: c mount glass built for one inch sensors are fantastic on GH2. Check out the Navitar 75mm, or Cosmicar.

So I managed to drill 3 holes into the c mount adapter, but one hole was off so only 2 screws fit in. Still feels pretty tight on. To get the adapter to go on the GH2 completely you need to grind down the metal so the small screw heads don't stick out and get caught. That takes careful grinding. If I had to do this again, I would use a table drill and clamps to get better results...maybe even get better measuring tools so all holes will match up. Pictures to come!

@Ebacherville, can you give details how you modified the Rainbow H6x8II?

I'm trying to think of ways to mod it without using glue.
So far I'm thinking of an attempt to drill 3 holes into the c mount adapter and use that in place of the black metal ring, and screw the adapter directly onto the rear lens after threading the c mount all the way in.
This way if it doesn't work, I'm only out a c mount adapter.

Looking at a Navitar 25mm f0.95, 1" sensor...would this vignette?

Man, wish I found this topic earlier before spending quite a bit on lenses that don't work well! What I have now: - Zolomatics 22.5mm-90mm f1.5 - Canon TV16 25-100mm f1.8 - Pentax 12.5mm f1.4 (needs modding...any takers?) - Rainbow h6x8 II (I actually just took apart the whole lens today...learned alot, but still haven't modded it) - Rainbow S6x11 2/3" just ordered - Rainbow 25mm f1.4 (works fine, though almost fell apart fiddling with it)

I have a canon Jx6 11 11-70 1.4 from a very old toshiba video camera..from what i"ve found around the net it seems to be a c-mount lens for 2/3.. Focus and zoom rings looks ok as well as aperture ring.. Any info of which adapter to buy so i can use it with GH2? What about infinity focus? Here is a photo of the lens.. http://campl.us/g8QZvX9FBm0

Thanks!

I have a number of c mounts, CCTV lenses, my favorite are the 2 rainbow para focal zooms.. 8-48mm f1.0 and the 11-69mm f1.4 they both have focal adjustments on the lens nice and cheap usually.

The 11-69mm is made for 2/3" so it is longer than 69mm 1/2", this lens requires no mods to use.

The "h6x8" 4-48mm is a 1/2" and its a bit soft at f1.0 but at f1.5 it is good.. that lens takes a really easy mod to get to seat properly.. I also picked up a 8-48mm rainbow that was the "h6x8 II" that was easily moded simular to the "h6x8" also, same basic lens as the "h6x8" but more metal construction than the mainly plastic "h6x8"

other than those I love the Tamron 4-12mm f1.2 for super wide almost fisheye shots. easy mod to get it to fit..

I also tried a prime 3.5mm Rainbow f1.6 took a bit of heavy moding but works well, nice sharp wide prime lens but the mods are drastic to get it to work.