HMC40 shutter

B

Barry_Green

Moderator
Been playing with the HMC40 stills capability, and I had a question pop up in my head -- since it's a CMOS chip, of course, the video can be affected by the traditional rolling shutter artifacts. But what about stills? A still photo CMOS camera doesn't use a rolling shutter, it has a physical curtain shutter, and by having that physical shutter it allows the camera to do a global exposure instead of a rolling shutter, so still cameras do it the "right" way.

But the HMC40 doesn't have a physical curtain shutter, so -- would it have skewing photos on fast pans? Would it show flash banding if a flash went off during the shot?

Happily, the answer is no -- they did it "right". While it doesn't have a curtain shutter, they still implemented it the same way that still photo cameras do -- when in stills mode, it goes to "global exposure" instead of rolling shutter, and they do have a mechanical physical shutter in the camera -- the iris! When you take a photo, the iris will open up to appropriate exposure, and then when the shutter time has elapsed, the iris will snap shut. If you listen closely you can even hear it doing that; if you look through the lens you can see it happen.

Pretty cool no-cost way to deliver proper stills imaging on a video camera...
 
Robert M Wright said:
To bad they look like crap anyways...
Click to expand...

Oh Robert! Come on. :smile: They aren't that bad. I agree that it isn't what my Nikon DSLR shoots, but for some reasonably decent shots for casual photos, the camera works fine.
I've been able to take some pretty nice shots with the stills feature.

Here are some un-retouched shots I took in San Antonio a few weeks ago (New Year's). They aren't perfect, certainly, but I don't think they look like crap:

http://gallery.me.com/bicparker#100327
 
You sure wouldn't want to make 8"x10" prints with stills from an HMC40 - and heck, 1080p frame grabs from an HMC40 can look just great for web photos displayed on a computer monitor. I seriously doubt I'll ever shoot another (true) still with the cam.
 
I told a friend of mine "The HMC40 takes better stills than any video camera I have seen, but it still sucks at it."

10.8 million wasted pixels is about how I would describe it.

I imagine outdoor shots with lots of light come out pretty good, but anything else...doesn't.

It shoots nice video though.
 
Really, I'm not sure the stills are actually better than frame grabs (in any meaningful sense). I only tried shooting a couple stills though, before I concluded I won't bother with that anymore. The cam may record 10 million dots when you shoot a still, but they sure aren't 10 megapixel images.
 
In my testing I found that they're about 4-megapixel images, maybe 4.5 worth of detail. But the larger sizes do yield a little more detail. So what I mean is, detail-wise, about 4.5 on my 7D matches about 10.6 on my HMC40.

No, it's not a stills camera. It's a video camera that shoots stills, and its stills don't compare well to the stills from dedicated stills cameras. Kind of exactly the same scenario with the DSLRs, they're still cameras that shoot video, and their video doesn't match up to the video from a dedicated video camera.

Point was -- yes, you could extract stills from the video -- but they're going to be rolling-shutter frame grabs. If there's skewing or flash-banding, that'll show up. Whereas if you put it in photo mode, those concerns disappear.

I wouldn't buy an HMC40 to use it as a still camera, no; there are much better still cameras available. But, if you do want to snap stills on an HMC40, you can do so without worrying about rolling shutter because they implemented the shutter comparable to how a professional stills camera would.
 
I honestly think the lack of quality in the stills is being way overstated here. I think the samples I provided demonstrate that, too. I agree that they aren't something that would necessarily work on a 8x10... but they will work on a snapshot size and seem to work quite well for web images, if you need them.

If you really need quality stills, then you should, by all means, use a good DSLR or other quality still camera. That is what they do best.

But if you need a convenient still, and the lighting is good enough, take it with this camera while you can. The shots have a lot of worthwhile utility.

The wooden sign shot in my linked gallery of the Landing on the Riverwalk is a good example. I had to get a shot of that and I had left my Nikon back in the hotel room. So I just took a quick couple of shots with HMC40 and stuck it in the video later.

If I am wrong, then what is really crap about this picture? (and I mean this seriously, I'm not trying to troll an argument, maybe I am just missing something in this discussion. I'd really like some better specifics here)

web.jpg


Thanks,
Bic
 
Just a few more samples. The exposures on all of these, btw, range from around 1/60 to 1/2000:

web.jpg
 
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This was taken from about 1,000 feet away, though a window using full zoom (I was at the top of the Tower of Americas in San Antonio). Probably has the least overall quality:

web.jpg
 
Come on now. That frame grab of the train isn't even close to the quality you can get for a frame grab with an HMC40. Heck, I can get better frame grabs from HV20 footage. If that was as good as it got, shooting 1080p with the HMC40, or even 720p, I'd be highly upset about paying way to much for the camcorder!
 
Regarding the HMC-40 flash banding issue for VIDEO. Did this camera get a similar flash banding compensation firmware update as the 300 did?
 
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