ydgmdlu
Veteran
Once upon a time, a nice French dude who called himself "divide" created a field-of-view chart comparing the popular motion picture image formats. You can find it here: http://www.dvxuser.com/V6/showthread.php?t=169831
Hard to get decent lenses for the GH1?
- Thread starter Schmoe
- Start date
Martti Ekstrand
Veteran
According to a article on Four Thirds User the sensor width used for 16:9 on GH-1 is 22.5 mm which would make it nearly identical to the width of widescreen 35mm 1:85: http://fourthirds-user.com/2009/04/the_biggest_four_thirds_sensor_yet.php
Compare with illustration here: http://en.wikipedia.org/wiki/Super_35_film
Anybody have a opinion on this Sigma 30mm/1.4 lens that's available with a standard 4/3s mount? Looks like a good close-up lens to me but I don't know much about Sigma at all. http://www.sigmaphoto.com/lenses/lenses_all_details.asp?id=3300&navigator=6
anthonybsd
Active member
This whole discussion is confusing to no end to me as a photographer. A 1.4 aperture, is a 1.4 aperture, regardless of the FOV. In other words GH1 with a 50mm lens at fully open will give you the same exact dept of field, but at 2x multiplication. In other words, I'm not sure where you are getting the whole 2.8f. Want the same exact depth of field with 50mm 1.4 with GH1 as on MK2? Stand back a bit - that's all there's to it. Two lenses at the same aperture covering the same frame will have the same exact depth of field, whether you have 25 mm lenses, 50 mm lenses, 100mm lenses or 400mm. The 400 mm would have to be standing quite a bit further away from the subject to have the same FOV as opposed to the 25mm, but that's not the point.
In other words, is the problem here the fact that people are used to a certain style of shooting and don't want to move around?
Schmoe
Member
And that's the point, if you are shooting inside, there are WALLS that might prevent backing up
Can't speak for everyone, but for video, I will likely be using this for 90% indoor shots. I honestly can't imagine anyone shooting a short that takes place entirely outside, and I don't think most of us would be looking at the GH1 if we did most of our shooting on actual SETS. Personally, I'll be shooting video in houses, apartments, hallways... places where I can't always simply "stand back a bit".I'm comparing how the lenses will behave on the GH1 compared to a full frame camera at the same distance, field of view, and depth of field.
For example, if I were shooting with a full frame camera with a 50mm f2.8 lens: I'm shooting at a distance of 7 feet from my subject. This gives me roughly a 5 ft wide by 3.5 ft high FOV. I would get a 1ft depth of field.
Now I switch to the GH1 with a 25mm f1.4 lens:
I'm shooting at the SAME distance of 7 feet from my subject. This gives me the SAME 5 ft wide by 3.5 ft high FOV. I would also get the SAME 1ft depth of field.
So for this VERY practical purpose,
25mm f1.4 lens on a GH1 = 50mm f2.8 on a full frame
And the problem is that the 25mm f1.4 lens is gonna be MUCH more expensive than that 50mm f2.8 lens. That's why I think this could be an important price consideration for those choosing between the GH1 and a full frame camera like the 5DMK2.
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anthonybsd
Active member
I see the dilemma(I think). You see my film making knowledge is minus one, i.e. less than zero. In photography I wouldn't have considered this a limitation, just as I never really thought of 1.6x crop on my first APS-C DSLR as a limitation since I could simply move around and achieve the same DOF for portraits (case in point: http://www.film-and-video.com/dofmyth.htm). Except of course when the subject is your entire frame i.e. focus is infinity - in which case I really never concerned myself about how much foreground is blurred.
What you are saying is logistical consideration is of enormous importance?
From my totally amateuristic point of view I'll use all my bright FD lenses on this and get the 1.4 of the low light sitations - and work around different FOV. I mean I'm still getting tons of light on the sensor, right?
What you are saying is logistical consideration is of enormous importance?
From my totally amateuristic point of view I'll use all my bright FD lenses on this and get the 1.4 of the low light sitations - and work around different FOV. I mean I'm still getting tons of light on the sensor, right?
puredrifting
Major Contributor
50mm 2.8? Haven't seen one of those.
You do know that the GH1s crop mode with non 4:3 Micro lenses has nothing to do with lens speed, only field of view, correct?
Dan
You do know that the GH1s crop mode with non 4:3 Micro lenses has nothing to do with lens speed, only field of view, correct?
Dan
we were talking about how the 2x crop factor affects to DOF compared to 35mm full frame.
the results are about two f-stops more, but only related to DOF. To get the same image with the same DOF with a GH1 and a 35mm full frame you need :
GH1----> 25mm f1.8
35mm-> 50mm f3.6
of course, the 25mm f1.8 on the GH1 remains f1.8, allowing low light filming, but the DOF is equivalent to a 50mm stopped down to f3.6
the results are about two f-stops more, but only related to DOF. To get the same image with the same DOF with a GH1 and a 35mm full frame you need :
GH1----> 25mm f1.8
35mm-> 50mm f3.6
of course, the 25mm f1.8 on the GH1 remains f1.8, allowing low light filming, but the DOF is equivalent to a 50mm stopped down to f3.6
puredrifting
Major Contributor
Okay, now I get it. Thanks for clarifying that. Stupid me, jumping on the conversation without reading the whole thread. Carry on!
Dan
Dan
Is this based on actual camera tests you've carried out with both formats?
It's odd to me that the Original Posts in this thread somehow manage to pain the MKii as a cheaper option in ANY way SHAPE or form. No matter if you're going for ultra shallow DOF or not.
Price doesn't matter, you're going to spend more money no matter which way you go if you're trying to do what you're outlining.
MKii body - 2800 after tax w/NO lens. 50/1.4 - 300 for a Contax Zeiss. CF card fast enough to handle data - 60. A Lens adapter to EOS - 10 for one that doesn't even work right.
Rounded DOWN to about 3100.00
GH-1 Body w/Kit Lens - 1500.00. 20/1.8 SIgma (I have this lens) - 500.00. SDHC Card fast enough to handle data - 60. Micro Four Thirds to Four Thirds to Your Choice Adapter - 100.00
Rounded up to about 2200.00
No matter which way you want to slice yoru bread, the MKii is a more expensive purchase then the GH-1. You buy an MKii body and you spend even more money trying to do the same thing that you can with a GH-1 for less.
A 20/1.8 on the GH-1 is pretty damned shallow, especially the SIGMA 20/1.8 which has insane close focus.
oi
Price doesn't matter, you're going to spend more money no matter which way you go if you're trying to do what you're outlining.
MKii body - 2800 after tax w/NO lens. 50/1.4 - 300 for a Contax Zeiss. CF card fast enough to handle data - 60. A Lens adapter to EOS - 10 for one that doesn't even work right.
Rounded DOWN to about 3100.00
GH-1 Body w/Kit Lens - 1500.00. 20/1.8 SIgma (I have this lens) - 500.00. SDHC Card fast enough to handle data - 60. Micro Four Thirds to Four Thirds to Your Choice Adapter - 100.00
Rounded up to about 2200.00
No matter which way you want to slice yoru bread, the MKii is a more expensive purchase then the GH-1. You buy an MKii body and you spend even more money trying to do the same thing that you can with a GH-1 for less.
A 20/1.8 on the GH-1 is pretty damned shallow, especially the SIGMA 20/1.8 which has insane close focus.
oi
Illya Friedman
Well-known member
Hi Martti,
That's actually a 22.5mm hypotenuse (not width) from the 4:3 mode; if you look again you'll see that they don't actually know the size of the width in 16:9, but I'm willing to guess that the methodology they propose is correct.
Pythagorean theorem puts Super 35 hypotenuses at about 28.8mm which is about 22% greater than 4:3 in 4/3. Regardless that point is moot, because you're not shooting in 4:3 with the GH1 in HD (16:9 only) and you get to take advantage of that extra horizontal resolution.
There's a couple ways to solve the hypotenuse question beyond a doubt; and it's likely someone will have need of knowing exactly and solve the distance before I do (next month)- it will save me the effort.
Again- just to repeat myself (paraprasing) it's deliberately misleading to say "2x crop factor" when "compared to 35mm" is a problem when shooting indoors. That's like saying that 16mm and HD can't be shot in a car, becuase it's a confined space. But that happens every day- and it can look very, very good.
Before the advent of HD video, one of the big pushes by DPs was to convince Kodak/Fuji/Agfa to make tighter grained high speed stocks so DPs could work at a higher T-stop to get more DoF, not less. Then after HD comes along, some of those same film purists who wanted more DoF now say that additional DoF is a liability. DoF (or lack there of) is a fad like many of the other tools of the trade. Best case cenario is you can have it when you want it, and take it away when you don't. IMO 4/3 may be the best format for that kind of flexibility and control.
Use the tool that's right for the job, if VistaVision for A camera was the right choice for most productions, a heck of a lot more projects would have shot that way- and they didn't. There's plenty of reasons not too beyond cost.
I.
Illya Friedman
Hot Rod Cameras
Martti Ekstrand
Veteran
Oh yes, now I see, I misread that figure. Calculating from the 18 mm measure in their diagram it seems then like the width is 19.5 mm which still is pretty close to Academy 1:1.85 negative width. And I definitely concur with your conclusion that 4/3 sensor size may be the best option for flexibility. I can understand that coming from still photography on horizontal 35mm format one can worry about '2x crop factor'. However coming like me from vertical 35mm & 16mm film and 2/3 video cameras the DoF on GH-1 is not a concern, quite the contrary; to me the crop factor is roughly 1x.
I don't know how many of you who fear that the DoF on GH-1 wouldn't be enough have actually shoot scenes with actors moving about and tried to follow focus on them. Even at f4.0 is pretty darn hard for a dedicated focus puller, step up aperture to 2.8 and he has to be very good - it's a job position that can take a couple of years to master. Do it as a lone operator without assistance and you'd have to be pretty frakkin ninja to pull it off. Especially without a follow focus rig.
Not only that, in narrative film context a very shallow DoF is not used that much, because it tends to isolate the character from the place and give a claustrophobic/alienated feel. One wants the background to be there but a bit off-focus as not to pull attention to it - a super soft background that looks beautiful on a still often feels 'unreal' in motion throwing the viewer out of the narrative. And it's hard to get a good flow in the edit when having a bunch of such shots following each other, also disrupting the viewer. Look at some features on DVD, freeze-frame here and there and pay attention to the DoF and you'll see that cuts with very shallow DoF are rare. Most features are shoot around f4 with 5.6 for wider shoots and 2.8 for close-ups. 2.0 is used mostly when running out of daylight on location or for that super-dramatic close-up - "Dammit Chloe, should I cut the blue or the pink wire?" - pulling from the hero's eye to the ticking bomb.
As for super wide angles again they are not that useful in a narrative context, make a pan and the whole world bends, have somebody walk across the frame and he/she bends with the world and this also will risk throwing the viewer out of the suspension of disbelief (plus few actors enjoy having their faces and bodies distorted). And if Hype Williams managed to make all his crazy super-wide boot-shaking hip-hop videos on 35mm film cameras I'm pretty certain the GH-1 will suffice as well.
Side note Illya: a friend of mine is sitting on a bunch of old lenses with Arri mounts. Do you have any plans for a GH-1 / Arri adapter? I mean, speaking of getting decent lenses
rogar-BigGrin(DBG)
I don't know how many of you who fear that the DoF on GH-1 wouldn't be enough have actually shoot scenes with actors moving about and tried to follow focus on them. Even at f4.0 is pretty darn hard for a dedicated focus puller, step up aperture to 2.8 and he has to be very good - it's a job position that can take a couple of years to master. Do it as a lone operator without assistance and you'd have to be pretty frakkin ninja to pull it off. Especially without a follow focus rig.
Not only that, in narrative film context a very shallow DoF is not used that much, because it tends to isolate the character from the place and give a claustrophobic/alienated feel. One wants the background to be there but a bit off-focus as not to pull attention to it - a super soft background that looks beautiful on a still often feels 'unreal' in motion throwing the viewer out of the narrative. And it's hard to get a good flow in the edit when having a bunch of such shots following each other, also disrupting the viewer. Look at some features on DVD, freeze-frame here and there and pay attention to the DoF and you'll see that cuts with very shallow DoF are rare. Most features are shoot around f4 with 5.6 for wider shoots and 2.8 for close-ups. 2.0 is used mostly when running out of daylight on location or for that super-dramatic close-up - "Dammit Chloe, should I cut the blue or the pink wire?" - pulling from the hero's eye to the ticking bomb.
As for super wide angles again they are not that useful in a narrative context, make a pan and the whole world bends, have somebody walk across the frame and he/she bends with the world and this also will risk throwing the viewer out of the suspension of disbelief (plus few actors enjoy having their faces and bodies distorted). And if Hype Williams managed to make all his crazy super-wide boot-shaking hip-hop videos on 35mm film cameras I'm pretty certain the GH-1 will suffice as well.
Side note Illya: a friend of mine is sitting on a bunch of old lenses with Arri mounts. Do you have any plans for a GH-1 / Arri adapter? I mean, speaking of getting decent lenses
rogar-BigGrin(DBG)
BrianMurphy
Veteran
On the BH specs page it lists the sensor as "17.3 x 13.0mm".
Martti Ekstrand
Veteran
Yes, but that's the same spec as given for G-1 and according to the Four Thirds User article Panasonic has said that the active area for 16:9 is bigger on GH-1.
Illya Friedman
Well-known member
Side note Illya: a friend of mine is sitting on a bunch of old lenses with Arri mounts. Do you have any plans for a GH-1 / Arri adapter? I mean, speaking of getting decent lenses
Sweet! That's a good friend to have. Some Arri mount lenses can also be converted to PL, then you get more flexibility.
There's a couple different Arri mounts, Arri B and Arri Std. Let me know which on it is, if there's enough demand, I could do a run of these (probably need at least 9-more people to make it worth while.) I hadn't planned on building those initially.
I can also always do a custom '1 of' job Arri to m4/3. If you're interested, contact me by PM.
I.
Illya Friedman
Hot Rod Cameras
Schmoe
Member
I have shot approximately NONE. As in not a single one. If you've shot even as much as a well-produced wedding video, you have more video experience than I do.
I've only shot stills and was coming from the perspective that I'd hate to have such limits there. But I'm buying this camera for video, so it's video performance is really my concern.
This is exactly the kind of advice I'm looking for from you guys with video/film experience. To be specific-
About how many feet(near focus limit to far limit) of DOF will I need for a "film-like" look? Just for average narrative storytelling, nothing fancy/artsy. And what focal length and aperture would you recommend for achieving it on the GH1?
How many feet of DOF for good "film-like" close ups and "attention focussing" shots? And what focal length and aperture would you recommend for achieving it on the GH1?
Would love to hear comments from anyone with some proper video/film experience. Even guesses are welcome :beer:
Oh yes, now I see, I misread that figure. Calculating from the 18 mm measure in their diagram it seems then like the width is 19.5 mm which still is pretty close to Academy 1:1.85 negative width. And I definitely concur with your conclusion that 4/3 sensor size may be the best option for flexibility. I can understand that coming from still photography on horizontal 35mm format one can worry about '2x crop factor'. However coming like me from vertical 35mm & 16mm film and 2/3 video cameras the DoF on GH-1 is not a concern, quite the contrary; to me the crop factor is roughly 1x.
I don't know how many of you who fear that the DoF on GH-1 wouldn't be enough have actually shoot scenes with actors moving about and tried to follow focus on them. Even at f4.0 is pretty darn hard for a dedicated focus puller, step up aperture to 2.8 and he has to be very good - it's a job position that can take a couple of years to master. Do it as a lone operator without assistance and you'd have to be pretty frakkin ninja to pull it off. Especially without a follow focus rig.
Not only that, in narrative film context a very shallow DoF is not used that much, because it tends to isolate the character from the place and give a claustrophobic/alienated feel. One wants the background to be there but a bit off-focus as not to pull attention to it - a super soft background that looks beautiful on a still often feels 'unreal' in motion throwing the viewer out of the narrative. And it's hard to get a good flow in the edit when having a bunch of such shots following each other, also disrupting the viewer. Look at some features on DVD, freeze-frame here and there and pay attention to the DoF and you'll see that cuts with very shallow DoF are rare. Most features are shoot around f4 with 5.6 for wider shoots and 2.8 for close-ups. 2.0 is used mostly when running out of daylight on location or for that super-dramatic close-up - "Dammit Chloe, should I cut the blue or the pink wire?" - pulling from the hero's eye to the ticking bomb.
As for super wide angles again they are not that useful in a narrative context, make a pan and the whole world bends, have somebody walk across the frame and he/she bends with the world and this also will risk throwing the viewer out of the suspension of disbelief (plus few actors enjoy having their faces and bodies distorted). And if Hype Williams managed to make all his crazy super-wide boot-shaking hip-hop videos on 35mm film cameras I'm pretty certain the GH-1 will suffice as well.
Side note Illya: a friend of mine is sitting on a bunch of old lenses with Arri mounts. Do you have any plans for a GH-1 / Arri adapter? I mean, speaking of getting decent lenses
Martti, I agree with everything you say but, as a director, I'd like to have as many tools available in my shot list toolbox. We all know that composition/ framing, camera movement and, yes, DOF can strike an emotional chord with the audience. Having the option to shoot that claustrophobic/alienated feel if it fits the context of the the story is an option I'd like to have at hand. I freely admit with this camera, or any other DSLR format cam, it's going to be a ***** for all the reasons you mention but, hey, no pain no gain. Know your cam, you'll know your shot list.