Can You Get Aperture/Shutter Priority Option in HMC40?

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Denniscasey

Well-known member
Moving from standard def Sony VX2000 to world of high def I recently bought AG-HMC40 as it seemed the best cost/performance option for my “prosumer” level. However, as I read and experiment more with HMC40 it appears it does not offer Aperture Priority or Shutter Priority options? At least I can’t find settings in any one of the three camera menus or mention in PDF manual.

With VX2000 and other video and still cameras I have had I used Aperture Priority or Shutter Priority options to get motion effects, depth of field and other looks I wanted and camera would maintain correct exposure. For example I could select shutter speed for motion look I wanted and camera adjusted iris to get correct exposure.

How do you manage this with HMC40? Do you have to go to full manual, select shutter speed you want, and then manually adjust iris opening and rely on LCD or EVF as only indication of correct exposure? I hope not because I think everyone agrees neither LCD nor EVF on the HMC40 are adequate for that purpose.

At one point I had thought moving auto/manual switch to manual in HMC40 would leave all settings in auto except for what you manually adjusted—i.e. if you manually set just shutter speed the iris would remain in auto and adjust exposure to compensate for shutter speed. But experiments today showed that was not the case—in bright sunny day in full auto camera selected 1/120 shutter and 6.8 aperture (did not check gain). I switched to manual and changed iris opening—shutter speed stayed at 1/120 with different iris settings so of course picture only got darker/lighter as I changed iris.

If I decide to leave camera in full auto what does it prioritize in trying to get best exposure—does it prioritize avoiding diffraction by ensuring lens opening stays more open than f8 (I recall forum note saying diffraction not noticeable as long as iris stays in single digits) and it then adjusts shutter speed to get correct exposure or what? That would mean exposure and picture definition is going to be good, but motion look could be something you don’t want depending on what shutter speed camera selects.
 
Even though the LCD and EVF are weak spots of the HMC40, you could just use your zebras or waveform to help you maintain accurate exposure while shooting with manual controls.
 
When in manual mode, the HMC40/80 do not offer "aperture priority" automatic exposure control. Auto exposure controls the iris (and the linked gain and neutral density filters) only; the shutter speed can only be set manually (or turned off, in which case it defaults to 1/2 the time of each frame, e.g. 1/60 second for a 30fps video mode).

Since the shutter speed can profoundly affect the rendering of motion in video, it is not a control that I would generally want the camera adjusting on its own. Iris adjustments are more visually subtle (although they do affect depth of field and sharpness, of course) and are the less obtrusive way for the camera to change exposure settings automatically. Still, except when shooting in truly wild and fast-moving situations, like most shooters I prefer to stay in full manual mode and adjust the iris using the viewfinder, waveform monitor and zebra bars to achieve correct exposure. This eliminates the problem of the camera over-reacting to small changes in the scene while shooting (like a subject in a light colored shirt moving in or out of the frame), and makes it easier to deal with situations like backlighting that would make a fully automatic camera underexpose a foreground subject.

The "iris" control on these cameras is a bit of a complex subject, and it works unlike any other camera I have ever used. There are actually three inter-linked means of adjusting exposure through the "iris" dial, and you can't really control them individually. Depending on the lighting conditions, moving the iris dial will change the electronic gain of the camera, or introduce a graduated neutral density filter into the image path, as well as changing the physical aperture of the lens in the traditional way. Under some circumstances in daylight, the HMC40/80 will select apertures that are small enough to cause noticeable image degradation through diffraction. For this reason, a lot of us like to add a front-of-lens neutral density or polarizer filter when shooting outdoors.

Hope this helps.

- Greg
 
Since the shutter speed can profoundly affect the rendering of motion in video

Most of this was shot at 1/1000 ( 90% )
http://video.felipehenao.com/San_Marcos.html

Could you please show us a footage ( from the HMC40 ) with the profound affecting of motion in video ?
Please images not words, in practice not theory
 
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Felipe, with caveat that my comments are more book learning than experience: If the waterfalls in your video at times 1:03 and 4:06 are included in the 90% shot at 1/1000 shutter speed then I think they illustrate shutter speed impact on the motion look. At 1/1000 you come close to capturing each water drop in sharp focus rather than motion blurred as would happen at 1/60. Consequently the waterfalls in your video do not have the smooth flowing look you probably would get at 1/60 and that one usually associates with waterfalls. The Panasonic tutorial on shutter speed used a waterfall to illustrate the different looks you get with different shutter speeds which is why I was tuned to look at the waterfalls in your video.

As most of the elements in your lovely video are not moving I am thinking the effect of shutter speed is not noticeable (or more subtle) in most of your video.

I do particularly agree with your comment of seeing images more than theory. By the time the video one shoots goes through additional "processing" by televisions and human eyes the actual "look" that really matters can differ from what theory might predict in some cases.

Regards, Dennis
 
Denniscasey said:
By the way, Felipe, my comments were written before I saw your subsequent videos.
Click to expand...

Yes Dennis that is why I insist in the point that high speeds oftenly can be used to your benefit, and motion blur can be used but is not a rule .
As you can see in my video ( Thank you for the comments ), the ant in the yellow flower looks with a very natural movement .
that was shot at 1/1000
 
Greg, thank you for help and patience with this beginner. I have seen many references to turning shutter "off" , but I can't see how to turn shutter "off" in HMC40. I thought maybe shutter was "off" when camera was in full auto but in my experiments in different lighting conditions I find the camera can change both shutter speed and the iris conditions when in full auto per my original post. I repeated experiment this morning in bright sunny day--shooting at 90 degrees to sun in full auto (scene was neighborhood mostly in full sun, not shaded) camera selected shutter speed of 1/60 and iris of 7.2. From same location I swiveled and shot with sun to my back (and scene again mostly in full sun) and under this condition camera changed shutter speed to 1/120 and iris to 5.8. So does your comment that "the shutter speed can only be set manually (or turned off).... mean the OPERATOR can only set shutter speed manually---the CAMERA still can adjust both shutter speed and iris when in full auto?

The PDF manual is confusing in a number of areas and in this case it says on Page 50 Adjusting the Shutter Speed under point 5 “ With auto iris control , as the shutter speed increases, the aperture widens and the focal length decreases.” To me this means there is a way to maintain auto iris control while adjusting shutter speed. Again, thanks for patience explaining these basics to beginner.
 
I should explain my videos are not in the controlled environment of a studio or interview or similar settings--they are primarily scenery or activities shot while on a business trip with collegues telling me to hurry up or action shots of sports cars on road courses with cars moving from sun to shade to sun. I guess I could put the camera in full auto, look at the shutter speed and iris settings it chooses to get a quick exposure that won't be far off, and then use a table showing which shutter speed/iris openings give the same exposure to then manually adjust shutter speed and iris if I want to get a different look from full auto? If full auto shows f5.6 and 1/60 for "correct" exposure I could also manually set f2 and 1/500 or f8 and 1/30 to get different look if I wanted to. However, as Greg points out the unknowns at this point are neutral density and gain that camera also dialed in when it was in full auto?

A minor gripe I am now having is that camera gives you two ways to manually quickly set iris; the iris wheel and also select the lens ring to adjust iris (or focus) but to set shutter speed you have to go through menu settings. Seems it would have been better to give the option to have lens ring adjust shutter speed (or focus).
 
Right, shutter speed is one of the variables when the camera is in full-auto mode. The first words of my message above were "when in manual mode ..." and that's what I was referring to throughout. I've never shot in full-auto and probably would never encounter a situation where I thought that was the best approach -- so I have little experience with it.

You can certainly put the camera in manual mode overall and still get auto-iris function - just press in on the iris dial near the back of the lens to change modes. The LCD and viewfinder will confirm this. Auto-iris by itself (without all the other automatic stuff that comes in full auto mode) can certainly be useful at times. But the shutter speed does not change automatically in this mode, and will stick to whatever you set it at. That's why I say there is no "aperture priority" mode as with a still camera where you preset the iris and the shutter speed changes automatically to set the exposure. The HMC doesn't do that. The only two modes, in still camera terms, are "full auto" and "shutter priority," for which, badly named perhaps, you have to set the master switch to the "manual" position.

- Greg
 
Greg. thanks again for your patience and very helpful informative comments--its beginning to cut through my fog of too much reading and not enough experience. Once last thing, you mentioned turning shutter "off", but how do you do that in HMC40 (apologies if I somehow skipped over that)? Dennis
 
GrahamH said:
Felipe Henao said:
This is interesting

Interesting? I suppose so, in the sense that is shows why footage shot with high shutter speeds is very unpleasent and unnatural to watch. Or was that not the point you wanted to make?
Click to expand...

I find it pleasant, crispness is something I like in video, blurriness is not pleasant for me. Motion blur for my taste can be used, but for some situations.
I THINK.
Click to expand...
 
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