Highest focal length usable for pro results in practice

J

jdennings

Member
Wondering what's the highest focal length on a BL gimbal that anyone has successfully flown achieving professional quality (say one a first rate advertising agency would accept, after post stabilization).
Static shots hovering and flying at low speed.

I am after the shallowest depth of field I can get, and the highest "compressed" depth look one typically gets with higher focal length lenses, on relatively close shots, 2-30 feet ... Large apertures lenses like f0.95 help for shallow depth of field, but interested in finding out more about experiences in general. Anything above 40mm usable? 85mm?
 

Q

Quinton

Active Member
I have actually JUST ordered a panasonic 35-100 F2.8 lens to experiment a bit with the gentles shutter controller, as it has zoom working on it with the GH4 70-200mm full frame equivalent)
It is quite light only 460g, but it is par focal and the lens does not retract change size when zooming, as its internal.

TBH If you want shallow depth of field the only real way is with a full frame camera, the Sony A7S might be your best bet if you are looking something small.
F0.95 I don't really buy, it lets lots of light in yes, but it wont give you as shallow depth of field with for example a full frame 5D and a F1.2, especially if its on a M4/3 camera.

Its focusing at these distances that is the killer though, an 85MM with a full frame sensor at f1.4 you only have 0.3ft that will be in focus with a subject that is 10ft away, 30ft away you have like 1.5ft to make sure you nail the focus, so you really need a follow focus.
At f2.8 and 30ft distance you have 7ft to play with, so big difference.

I only got the 35-100mm to play with zoom at lower apertures, but it certainly would look great if you got the right sort of shot wide open, however F2.8 on a 2X crop sensor GH4 isn't exactly shallow DOF
And focusing is even harder at 30ft distance as you only have 3.5ft to play with at 85mm (as long as my depth of field calculator is set right).
 


kloner

kloner

Aerial DP
I've flown the 14-140 at about 90-100mm stable and steady enough to use in a professional gig, but it still had the alexmos shake.... postable of course

cool lens, kinda long but it has the speed....
 

Q

Quinton

Active Member
Last edited by a moderator:


kloner

kloner

Aerial DP
the size of that 14-42 with power zoom is nice,, would work mid day but man that's slow

Is the x series something new? We have the 12-35 2.8, use it a lot, not sure if it's the same thing or not,,, couple nd's and away we go

I just got the 12mm rokinon m43.... can't wait to fly it, 1/4 the weight of the 16mm
 

J

jdennings

Member
Quinton said:
...
TBH If you want shallow depth of field the only real way is with a full frame camera, the Sony A7S might be your best bet if you are looking something small.
...
).
Click to expand...

Yep. After "Light, strong and inexpensive, pick any two" for frame materials, there's also "Light, good, and inexpensive", pick only one!" for shallow depth of field/longer lenses. :)
That's actually what is stirring me away from the BMPC .... The A7S sounds like a great candidate, depending on lens weight ...

And focus is definitely an issue ... Need AF for filming ...
 

J

jdennings

Member
baja-king said:
Unfortunately it's just the 14-42mm and the 45-175mm that have the power zoom function.
Click to expand...

Could always go remote follow-focus on the zoom ring ... A simple rigged-up solution with servo and minimalist rail might not yield smooth zooming, but it sure would beat coming down just to change focal length ...
 

Q

Quinton

Active Member
baja-king said:
Unfortunately it's just the 14-42mm and the 45-175mm that have the power zoom function.
Click to expand...

Oh crap, your right, I seen the "power" on the lens, but that is stabilisation.
Oh well I needed a nice 70-200 fast lens anyhow, and I did not fancy hauling my Canon one along with the metabones for that.

Is the 45-175 really only 210g, looks like ill pick that up as its pretty cheap, only thing is its not constant aperture which is a PITA
 

B

baja-king

Here for the ride :)
I bought the 12-35mm and the 35-100mm, nice and compact after being used to the 5D Mk III and 70-200 2.8L IS :)
 

Q

Quinton

Active Member
baja-king said:
I bought the 12-35mm and the 35-100mm, nice and compact after being used to the 5D Mk III and 70-200 2.8L IS :)
Click to expand...

Yes but I would always take the 5D over the GH4 anyday, especially with the 70-200 as it'll hit the mark every time with focus.
The same can't be said with the GH4 so far for me, focus is a bit hit and miss, maybe thatll improve with the 35-100.

Just ordered the 45-175 and it will be here tomorrow, will let you know how it goes with the gentles controller.
Just think with 2x optical zoom on that gives you 700mm zoom lens..
 

Q

Quinton

Active Member
Just wondering how users here would describe parfocal.

I had the 35-100 F2.8 and the 45-175mm x series Panasonic lenses come today.
The 35-100 is suppose to be parfocal, however if I focus at 35mm and zoom to 100 it is out of focus, so it certainly is not true parfocal.
Or does this only apply when you focus at 100 and zoom out to 35mm it is OK

BTW from what I have seen so far for the price the 45-175mm is a great lens, and only 201g.
Now to try out the gentles zoom controller to see if it works remotely.
 

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