OT: Buying a DSLR to film with

Mark_e wrote on 6/30/2014, 8:35 AM

I guess drifting off topic but FYI when I was testing my GH4 4k footage it was interesting, no moire in the 4k footage at 100% which I guess is to be expected as it's 1:1 from the sensor, re-sampled in vegas to 1080p at all the best settings still almost none but can see some moire, still looks great. Upload to youtube can see moire, looks to me like it gets introduced there as well (either 4k and let youtube re sample or at 1080p re sampled)

One thing that was oblivious when I was testing was the rear monitor clearly showed the potential for moire with the scene with the 4k footage as I was filming which was nice, I left it as I was interested and it didn't really matter but if it was something important I would have had a heads up to re-frame or so something about it manually. At least filming at 4k gives you the option to do something about it in post where as 1080p the sensor crop resize to 1080 has already happened so if you have been caught out it's there already and you are stuck. Another unexpected benefit of 4k source to 1080p

I've found vegas handling it just fine as well so have pretty much left it at 4k now and just work in a 1080p timeline.

VMP wrote on 6/30/2014, 10:01 AM

Mark_e,

That's interesting.

Have you tried viewing the Youtube video at full screen (native resolution)?
The smaller screen size of youtube usually gives the aliasing effect, it's the same with vimeo. Viewing it at full screen usually solves that problem.

VMP

wwjd wrote on 6/30/2014, 10:03 AM

Mark, in a pseudo-related topic tangent, my GH4 filming at 1080 has about 90% less moire than my Canon T3i @"1080" on the same test scene. Panny for the win.

amendegw wrote on 6/30/2014, 2:54 PM

[I]"For video, there are two stages of sampling: first the analog optical signal (light) is digitized at high reolution, and then it is down sampled to video resolution[/I]fwiw, recent Panny Micro Four Thirds cameras have a video mode called ETC (Extended Tele Conversion) which only uses the center 1920x1080 (or 1280x720) of the sensor. No downsampling needed. Of course this results in unreal crop factors.

OT: Extreme Telephoto Test (just some fun)

...Jerry

NCARalph wrote on 6/30/2014, 10:27 PM

My experience with ETC is that the video quality is significantly worse than the downsampled video. I've never seen moire in any video I've shot with the GH2.

PeterDuke wrote on 7/1/2014, 3:07 AM

"My experience with ETC is that the video quality is significantly worse than the downsampled video"

Was the lens sharp enough to have not been a factor? Are you allowing for the zoom-in effect of the ETC? What happens if you zoom in yourself on the full resolution to compare apples with apples?

NCARalph wrote on 7/1/2014, 9:35 AM

"Was the lens sharp enough to have not been a factor? Are you allowing for the zoom-in effect of the ETC? What happens if you zoom in yourself on the full resolution to compare apples with apples?"

Have you personally ever tried filming with ETC and doing a critical comparison to full frame video or is this a theoretical question?

The general problem is that the image color/contrast isn't as smooth as with the full frame image. It has nothing to do with zoom ratio or sharpness.

RalphM wrote on 7/1/2014, 10:23 AM

Last November I bought a Panasonic GX7 mainly as a stills camera to take on a 10 day trip. While it's not nearly as easy to use for video as a dedicated video camera, it does take some very nice video and I didn't have to carry two separate cameras.

The ETC has been fun to play with using a 300mm stabilized m4/3 lens, but one still benefits from something really steady to support the combination.

My main problem with the camera is that it is smarter than I am...

i c e wrote on 7/3/2014, 9:31 AM

So I never thought I'd get so much help here but it sure is great.

In "conclusion" I am thinking about getting two bodies (used) a Panasonic GH2 and NIkon D90. The gh2 would be for more video, once I get it hacked. Then the D90 would be primarily for time lapse as I have seen some really great vids from that camera.

What do you guys think? I can get both cameras and some lenses.. all used for under a grand. I think I can get some lenses that I would use on both cameras if I get the right ones.

Thanks a million everybody.

Joshua

wwjd wrote on 7/3/2014, 9:46 AM

er.... does GH4 has this ETC mode in it? I don't recall seeing that

amendegw wrote on 7/3/2014, 10:42 AM

[I]"er.... does GH4 has this ETC mode in it? I don't recall seeing that"[/I]ETC works by using the 1920x1080 center of the micro four thirds sensor (4592x3056 on a GH2).

Since the 4K image size on a GH4 (4096x2160) is nearly the same size (width) as the full sensor (4608x3456), ETC would not buy much, if anything. OTOH, it might be available when shooting in lower resolutions (e.g. 1920x1080) on the GH4.

...Jerry

K-Decisive wrote on 7/3/2014, 3:05 PM

"How do you guys cope with moire and aliasing that DSLR's cause during video capture?"

+1000 on the mosaic filters!! I have one for my 7D and it works wonders, however you do need to add a touch of sharpening in post.

I'm waiting for the filter to come out for the BMCC like a 5 year old before Christmas.

Do not go for the cap rock filters, they do not work..

Also, the rolling shutter fix in AE6 works very well for those issues.

Cheers

i c e wrote on 7/3/2014, 8:08 PM

In addition to what I asked about (which I would love an answer to)..

Does anyone have any tips on things to check out when your buying a used camera (from craigslist). I am going to be looking at a few and hope to be buying one next week. I don't know anything about DSLR's so I guess I'll just turn it on and see that it all seems to go. What about lenses?

Any tips would be great.

Joshua

GeeBax wrote on 7/3/2014, 11:06 PM

I would be asking you whether you have any lenses already and what type they are. The reason for asking is that every DSLR manufacturer uses different mount lenses just to screw things up for the consumer. If you already have some lenses, then it might be worth looking for a camera that suits those lenses.

However if you budget is limited to a 'few hundred dollars' as you originally said, that seriously limits your choices in the DSLR stakes, particularly if you want to get good video from the camera.

PeterDuke wrote on 7/4/2014, 3:02 AM

In particular, if you want to save money buy either Canon OR Nikon, not both so that you don't have to double up on lenses. Canon is more popular, so you might get better value from that body.

Serena Steuart wrote on 7/4/2014, 7:09 AM

I started to create a check list and then thought that such advice is probably out there already. One is http://petapixel.com/2009/05/22/a-guide-to-buying-used-dslr-gear/check guide[/link], and putting "buying a second hand dslr camera" into Google brings up several more.

One important tip is that you never try to clean the sensor by wiping or brushing it. Use an air blower (very clean air. too). Check for dust and scratches by photographing a uniform surface (throw it out of focus) and enlarge the image.

I like this one: http://photographylife.com/how-to-buy-used-dslr-camerasanother guide[/link]

i c e wrote on 7/4/2014, 12:10 PM

@Serena Steuart

Thanks so much! that's exactly what I was looking for. Believe it or not, I didn't think of googling it. (lol). But those will help a lot.

I don't have any lenses.. this is my first DSLR. but I did see that the GH2 can be adapted to many lenses with the right coupler so I am going to probably go that route.

The reason I am considering two cameras is to get both high quality video and high quality photos.. I have multiple users so it makes sense to me. There are so many out there on Craigslist, It seems I can get one for even less than I though originally.

thanks all.

Laurence wrote on 7/4/2014, 1:00 PM

>"How do you guys cope with moire and aliasing that DSLR's cause during video capture?"

Moire is the worst on the wide shots. What I found when I used a DSLR is that you could get around this by using infinite focus and certain f-stops. Really tiny f-stops lose a bit of sharpness. I had one lens that would do something like an f-32. Moire would disappear and the hit in sharpness wasn't noticable on HD video. I also went the other way. By using infinite focus and larger f-stops, a slight but controllable out of focusness would get rid almost all the moire and the softness again would have been noticable on stills but was not an issue on the much lower res HD video. I did this video with a Nikon DSLR and the kit lens. It starts off showing sharp focus at f-3,5, then infinite focus with f-stops up to f-10 (at which point the moire was gone, but the focus started getting too soft):

http://vimeo.com/36425051

Now with my GH3, moire is there very slightly, but not enough that I worry about it. With the DSLR I was constantly working around the moire issue. With the GH3, I rarely think about it.

Laurence wrote on 7/4/2014, 1:03 PM

As you might have noticed looking at the video, setting the Nikon DSLR to f-16 or bigger infinite focus worked pretty well for the wide shots.

NCARalph wrote on 7/4/2014, 5:12 PM

I've never noticed moire in videos from my GH2 although I've not gone looking for it either.

Aliasing is a different matter. I've seen some really awful examples shooting in 1080i with fast motion though the frame, but in 30p it's not a problem beyond the unavoidable resolution limits which normally aren't a major issue with the kind of video I shoot.

As a comment on handling: I strongly feel that EVF's are almost a complete requirement for a video camera if it's going to be handheld. If the camera has a flip out display like the GH series, shooting from the waist with the camera stabilized against your stomach is OK, but I really prefer pressing the camera against my forehead. Particularly with a heavy zoom lens it makes for far smoother video than attempting to hold the camera out away from the body to see a fixed display.

Laurence wrote on 7/6/2014, 11:10 AM

On an EVF camera like the GH1,2 and 3, the viewfinder is much better for video than a DSLR. The autofocus is contrast based rather than phase based, and there is a tiny amount of delay. These two things can make a big difference if you are shooting stills, especially stills of a moving target like a flying bird or a bride walking towards you down an isle. With the phase based auto-focus when shooting stills through the lens, the focus will track the bride moving towards you whereas the GH3 will do a bunch of "too close, too far, then focus in between the extremes" searches on the same moving target. No better or worse on video, but not nearly as nice on stills.

PeterDuke wrote on 7/6/2014, 7:58 PM

"With the phase based auto-focus when shooting stills through the lens, the focus will track the bride moving towards you "

When I press the button half-down on my DSLR (Nikon D7000), the camera focuses and holds that focus. If I move the point of view to something closer or more distant while holding the button down, the focus doesn't change. Am I overlooking something?

Laurence wrote on 7/6/2014, 9:23 PM

http://www.digitalcameraworld.com/2012/09/04/how-to-use-autofocus-with-moving-subjects/

PeterDuke wrote on 7/7/2014, 12:22 AM

Thanks Laurence.

One of these days when I get time I must read the manual!

My camera has Single, Continuous and Auto modes. It was on Single. I have now put it on Auto (which automatically selects S or C mode depending on subject motion).

That reference has other useful tips as well. Thanks again.