4-12mm 1.2 Tamron on GH2 (Seb Farges inspired)

Psynema

Psynema

Well-known member


Saw a long list of lenses in Seb's thread. Wanted something just as fast, a zoom, and wider, so I gambled and got the 4-12mm 1.2 Tamron from BH for $90. Needed the same conversion process, but the lens is plastic so that kind of helped.

Made a video review of the lens since I couldn't find a lick of info on it before buying, so wala. Not too much in terms of video reviews for odd/obscure/vintage glass, MAINLY FOR VIDEO. So I may do a series of videos like these if needed - suggestions welcomed (up next I'd like to do vids on Vivitar 28-105mm, Pentax 35-105mm)
 
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Good job mate, footage looks great and a really nicely done video as well :)

Makes me wish the crop mode was on the GH1 :(
 
Uh, is it me or i cannot find the link? So this is a full-on industrial lens then? I've seen some ridiculousy fast wide zooms like these but never tried them..
 
maranfilms said:
if the adapter is for c-mount to m-42, why does it not fit? Are there different c-mounts?
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To be honest I'm not sure, but from reading Seb Farges and other people who have adapted Pentax and Rainbow C Mounts, as said in the video, Security Camera lenses have a higher tendency not to fit in a C Mount adapters. It will screw in, but won't go in all the way, so hence the filing. I filed the adapter as I originally didn't want to scrap the lens for obvious reasons. But after a while I just couldn't take it anymore and filed the plastic casing with ease to finish the fit. Though if you get this lens or another platic CCTV lens that needs filing, be careful you don't file a hole. The tamron casing is rather thin.
 
Again a toy lens but should've put this in the video compared to the Panny 7-14mm

1.2 at 640 ISO for church shot at 1/25th of a second

The Panny lens, at 4.0, would have to be at ISO 5000 or so (a little over 3 stops slower)

So I'd say, yeah, even though you have to keep the ISO lower due to the crop, the 1.2 aperture will still under cut the grain of 4.0 lenses.
 
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Thanks for sharing your lens and for preparing such a nice video describing what you did... Al
 
Psynema said:
It's embedded, but http://www.youtube.com/watch?v=38Za5JD6vYE&feature=player_embedded
http://www.youtube.com/watch?v=38Za5JD6vYE&feature=player_embedded
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Ah right, I was viewing on the iPad that's why I couldn't see the vid... But yeah great review and great footage! Well impressed by the quality.. My fear though with 1/2" lenses is that it just about fits the GH2's cropped sensor, meaning soft & aberration edges are more pronounced. I have lots of 2/3" lenses and you just about do away with the edges meaning you get more of the sharpest part of the lens.
Keep it up!
 
ed_lee83 said:
Ah right, I was viewing on the iPad that's why I couldn't see the vid... But yeah great review and great footage! Well impressed by the quality.. My fear though with 1/2" lenses is that it just about fits the GH2's cropped sensor, meaning soft & aberration edges are more pronounced. I have lots of 2/3" lenses and you just about do away with the edges meaning you get more of the sharpest part of the lens.
Keep it up!
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I have to find some good 2/3 and 1 inch glass. Still it's hard to find info on C Mounts. I've heard reports about some fast wide zooms at 1.4-2.0 for 1" sensors that will cover the Lumix sensor in widescreen mode only vignetting with 4/3 aspect photos
 
Loved your review. And thank you for having good shots with the lens. Letting us see the lens itself, and narrating about the lens. So many demo videos just have music and you get very little info. Tell us about the skaters at the end? What focal length? not 1:1 crop? That looked VERY usable for skateboard videos. And it's crazy people comparing a very expensive 7-14mm Panasonic lens. Also a major benefit of these type of lenses besides cost and fast F stops, is how SMALL they are. What I believe is a MAJOR benefit of the GH-1/2 over regular DSLRS. A full size Nikon or Canon with a heavy piece of glass feels ridiculous after working in m43.

But please do review more lenses. And don't feel you can't cover lenses already discussed by others. I really like my 35mm Fujian lens. I bought it after seeing Seb's work. If you have this great, inexpensive lens please do a review for us.

Thanks

Max

I just watched it again. Those last two shots are GREAT!!! Those skaters and that tilt down shot. All for $90!
 
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Thanks, the skaters were at the widest 4mm and the lens needs the ETC mode, it's still wide with the ETC mode (about 10mm give or take fisheye, zoom in a bit to get 12mm ish non fisheye I'd estimate)

Yep, most likely will do more lenses, other gear, and probably cognitive film/FCP workflow tutorials. As far as lenses - I'll probably do the 40mm Hex next, possibly another c mount, and hoping to try Vivitar 28-105mm Series 1 and or the Pentax 35-105 zoom. I'd maybe do the Rokinon 85 but everyone knows that's good.
 
Recently got this lens and fiddled with it on family vacation... so here's a mildly dippy, far less polished example of the lens in real-world, uncontrolled, extremely rushed and unfacilitated use. Used nothing but this lens, and didn't grade the footage aside from some color correction for some fiercely YELLOW fluoro lights in a pavilion. Whee!

Also wanted to add that it took me under 5 minutes to modify the lens by taking a Dremel to the base of the plastic collar. Three of those minutes were finding the Dremel and one minute was protecting the lens with gaffer tape.

I also removed the front set screw (plenty to grab onto otherwise for focus), and used a small amount of loctite to cement the other two set screws in the "loose" position... thus, I hopefully won't lose them and have smooth stepless aperture adjustment.

Anyway... the video...

http://vimeo.com/27131652
 
Great to see you both did this test / review. I did put the list of 1/2 C-Mount lenses in Seb Farges thread after some research and I was waiting someone try some of them. This tamron shows great results, I would like to ask if you did a try correcting the barrel distortion using some filter as the photoshop "lens distortion" to get a rectilinear image from this amazing lens. It would be usefull to do some architecture shots at night if it can be converted to rectilinear...
 
I downloaded the vimeo 1920x1080 file and did some tests. I found it is possible to correct the barrel distortion to get a rectilinear wide angle in the shoots showed in the footage. I got sharp edges. I just dont know if the tamron was used at maximum wide angle (4mm) where i did the corrections.
 
I extracted some frame grabs from youtube footage and I did some tests trying to get a rectilinear image from them. It needs two pass in the lens correction filter to became rectilinear so It does not deserves the use for who wants rectilinear images at 4mm wide... It is a fish-eye lens, great for who can use fisheye images.
 
+1 on the great review. Nice how you handled all aspects of discussing this lens.
 
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