Fujinon (or Canon) 7.5-90mm 1.4 on GH1/2 ?
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ed_lee83
Well-known member
Not that particular one, but I've got heaps of broadcast lenses in the similar range.
Is that one c-mount or B4?
They vignette severely so you need to use ETC on the GH2. But first you need to make sure if it can focus to infinity properly or else you can't use it without modifying the mount.
I'm getting rid of my broadcast zooms (modified c-mount) if you're interested PM me for more info.
Is that one c-mount or B4?
They vignette severely so you need to use ETC on the GH2. But first you need to make sure if it can focus to infinity properly or else you can't use it without modifying the mount.
I'm getting rid of my broadcast zooms (modified c-mount) if you're interested PM me for more info.
ekoe
Member
That's an old ENG type B4 mount 1/2" video zoom with servo iris and zoom, but you'd probably want to remove
the servo unit. It will project an image circle to nicely cover the GH2 ETC sensor area.
However... if you're looking to pick up a good, fast, affordable zoom for your m4/3, that particular lens is not the best choice.
First of all, B4 to m4/3 adapters are expensive. That's also a relatively large lens compared to c-mount 1/2" zooms.
But you don't need to limit yourself to shooting ETC if you want a fast, wide zoom. There's several c-mount zooms
in the range of 20-100mm/f1.5-1.9 that provide very good coverage of the m4/3 sensor in 16:9 mode. I've identified
several models that provide much better coverage than the few Canon c-mount zooms with poor coverage that have been
reviewed. There is some vignetting on the wide end of these lenses which is easily scaled out in post. In seconds you can
add motion keyframes to vary the crop scaling for zooms within a shot, requiring no render.
Whatever you get should be properly adjusted after adaptation, in order to maintain parfocal performance (i.e.- so the lens
holds sharp focus through the zoom range). I perform this adjustment. Many of the zoom lenses advertised as "modified for m4/3"
on eBay and elsewhere have not had this parfocal adjustment performed properly, and the result is that the lens does not hold focus
through the zoom.
I'm always willing to offer free advice to those looking for the right lens, in addition to providing lens service and modifications.
Just get in touch through my website www.ekoecamera.com
the servo unit. It will project an image circle to nicely cover the GH2 ETC sensor area.
However... if you're looking to pick up a good, fast, affordable zoom for your m4/3, that particular lens is not the best choice.
First of all, B4 to m4/3 adapters are expensive. That's also a relatively large lens compared to c-mount 1/2" zooms.
But you don't need to limit yourself to shooting ETC if you want a fast, wide zoom. There's several c-mount zooms
in the range of 20-100mm/f1.5-1.9 that provide very good coverage of the m4/3 sensor in 16:9 mode. I've identified
several models that provide much better coverage than the few Canon c-mount zooms with poor coverage that have been
reviewed. There is some vignetting on the wide end of these lenses which is easily scaled out in post. In seconds you can
add motion keyframes to vary the crop scaling for zooms within a shot, requiring no render.
Whatever you get should be properly adjusted after adaptation, in order to maintain parfocal performance (i.e.- so the lens
holds sharp focus through the zoom range). I perform this adjustment. Many of the zoom lenses advertised as "modified for m4/3"
on eBay and elsewhere have not had this parfocal adjustment performed properly, and the result is that the lens does not hold focus
through the zoom.
I'm always willing to offer free advice to those looking for the right lens, in addition to providing lens service and modifications.
Just get in touch through my website www.ekoecamera.com
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ekoe
Member
Not just you, Ed. And I didn't mean to refer to anyone specifically. It's good you attempt to clarify the parfocal performance of the lens.
It's important for legacy lens users to know that a parfocal zoom should hold sharp focus through the zoom, but will not do so without proper set-up.
Most shooters are not currently aware of the need for these adjustments, and they will tend to believe a reputable seller when they say it has been 'modified
with proper tools and a collimator', although it is evidenced by the backfocus drift in the demo video that these adjustments have not been made.
It's not intended as a personal affront, but an appeal to all sellers to have a bit of restraint and not describe a lens as having been collimated when it has not.
It's important for legacy lens users to know that a parfocal zoom should hold sharp focus through the zoom, but will not do so without proper set-up.
Most shooters are not currently aware of the need for these adjustments, and they will tend to believe a reputable seller when they say it has been 'modified
with proper tools and a collimator', although it is evidenced by the backfocus drift in the demo video that these adjustments have not been made.
It's not intended as a personal affront, but an appeal to all sellers to have a bit of restraint and not describe a lens as having been collimated when it has not.
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ed_lee83
Well-known member
And yet you are still talking to me as a 3rd person. Incredible.
In short, not every c-mount zoom I encountered cannot be properly collimated. At the very least, I ensure it focuses to infinity at all ranges which is my primary concern.
The demo videos are there for those to see.
And by the way, the Marketplace is the place to go to advertise your wares. I know, because I got stung a long time ago about it when mentioning in posts. But the game will be all yours soon, I'm retiring after this last batch goes.
In short, not every c-mount zoom I encountered cannot be properly collimated. At the very least, I ensure it focuses to infinity at all ranges which is my primary concern.
The demo videos are there for those to see.
And by the way, the Marketplace is the place to go to advertise your wares. I know, because I got stung a long time ago about it when mentioning in posts. But the game will be all yours soon, I'm retiring after this last batch goes.
ekoe
Member
That link to my website is to get in touch for free advice, not to sell a lens. The only thing vaguely 'advertising' about
my post is that I mention I perform collimation adjustment, and that's because it is very relevant to the discussion
of this type of lens.
Please stop describing your mods as having been collimated when you have not done so. Is that in first person yet?