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Camera for Merlin


chris fawcett

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Hi Chris:

 

I have both the Canon HV20 and the XH-A1, and while the HV20 is a really impressive little camera, the A1 has a more "sophisticated" image and a lot more control over it. A1 is close to the top limit of weight you'd want to put on a handheld Merlin while the HV20 without accessories is honestly too light/squirrely (add the Canon wide angle adaptor and their hotshoe mini-shotgun mike and you are getting closer). However it is available at a truly amazing price point, around $800-900 here in the US, while the A1 is more like $3000.

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Hi Charles,

 

I'd want to mount maybe a Sennheiser 416 or a Sanken CS1 at least, and have the possibility to add a radio mic receiver, so I'd probably be pushing it with the XH-A1, but what the hell, it looks great.

 

Thanks for the recommendation,

 

Chris

 

P.S. Has anyone tried mounting a mic where the counterbalance weights are?

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Chris,

 

I have the Canon HV-20 for chasing my kids around, and it works great on the merlin with a Sennheiser wireless reciever attached.

 

I have had a bare-bones Panasonic HVX200 on a merlin and it works well too but it is a good arm workout for anything over 10 minutes or so. The metal gimbal upgrade for the merlin may increase the payload enough to add a mic, but not with the standard gimbal. The HVX is at the 5.5 lb max the way it is.

 

Best,

 

Kevin

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Very interesting Kevin,

 

Thanks for the report. It is so tempting to go heavy, yet your 10-minute limit is not so handy for documentary work. I'm keen to hear more testimony from Merlin users on this point.

 

Charles,

 

I'm very curious about your XH-A1. Canon states this about the 30F, 24F, and 26F frame modes:

 

"These Frame modes have the same look as progressive frame rates, but are not labeled "progressive" because they are created with an interlaced chip. The end result is exactly the same to the editing system (and to our eyes) as 30p and 24p, respectively."

 

My understanding is that this cannot be correct. What am I missing?

 

Thanks agian all,

 

Chris

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Hi Chris:

 

Rather than a "it just does" sort of answer (which is correct but not enough for an inquiring mind such as yours), here are some more in-detail explanations from folks more able to do so from me, quoted from DVInfo.net:

 

Pete Bauer:

 

24F is a term Canon uses for its method of creating 23.976fps video using interlaced CCDs. F-mode processes the image (by means as yet undisclosed) from an interlaced CCD to produce a progessive-frame video file. For HDV, it lays the image to the tape as a true 23.976fps file, not 60i pull-down as is done in most "affordable" 24p cameras. So editing software that handles 24F puts it on a 24fps timeline without having to do pulldown processing, but otherwise exactly like typical 24p-from-60i video. If you use HD-SDI to get full raster 4:2:2 video or use composite-out, the 24F will leave the camera as 60i 3:2 pull-down.

 

So 24F and 24p are just two flavors of 24fps video. One's not a substitute for the other, and neither is inherently "better." They are just two different means of creating a 23.976fps video file. That's all. The resolution, image detail, latitude, color space, color rendition/depth, etc are dependent on the hardware and software used. The 24F from the XL H1 has as good or better image detail as any currently competing camera, but each camera has it's own particular strengths and each shooter has his/her own particular likes, so I think "better" is a rather meaningless word in the endless 24F vs 24p measurebation.

 

 

Nate Weaver:

 

24P in HDV is done differently than in any other video format. Since HDV is more or less a computer file streamed to page (an MPEG file), there's more flexibility in what data is written. Or put another way, MPEG2 had a history of multiple framerates and frame sizes long before somebody had the idea of streaming it to tape.

 

Ok, so a 24p MPEG stream doesn't use pulldown. That's the news. None of the 24p HDV cameras use pulldown ON TAPE. On tape is the qualifier here. The data stream is 24 discrete frames. That's it.

 

But, within that stream, are hints for the MPEG decoder device as to how to display that 24fps info for 29.97 devices. The hints are called repeat flags. So one frame will have an instruction tagging along with it to display for say, 2 fields. Another will have an instruction for displaying over 3 fields. You know the rest...it's instructions for the DECODER device to create the pulldown ON THE FLY. Decoder in this context means hardware decoder in a tape deck, or something of the sort.

 

So anyway, what this means is that some software will read the stream verbatim and tell you the footage is 29.97 interlaced, and it'll display it in this manner. Other software will be smarter and read it all as just 24 discrete frames.

 

The Canon is a problem of semantics. Canon doesn't want to call it 24P, because technically, that is reserved for CCDs that are progressively scanned (and purpose built for that, which is technically more difficult and more expensive). So, they take a 1440x1080 interlaced chip, and do signal processing voodoo between the field scans off the chip, and end up with 24 discrete, full, frames per second.

 

Of course there's no free lunches, so the downside of this is that because they're doing weird things with fields, vertical resolution takes a little bit of hit. In the end, the signal processing outputs 24 full frames per second which is then passed along to the MPEG encoder, yadda yadda yadda.

 

So the Canon is not true progressive, but it does possess the most important part of a true 24p camera, which is 24 separate images per second, captured with an even interval between each image (Something the Sony Z1, with it's "Cineframe24" mode, doesn't manage to do)

 

The amount of vertical resolution compromised is up for grabs. A 1080 line system, with Kell factor accounted for, is only good for about 750-950 lines vertically, depending on who you ask. Worst case scenario for straight-up field blending on the XL-H1 would be 540 lines vertically. Canon's special secret-sauce DSP is somehow doing a bit better than that, but still south of what it could do in interlaced mode.

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And yet somehow still not definitive--but that's the nature of the "secret sauce" that Canon has cooked up!

 

Incidentally, I recently had shot some 1080i 24f material with the Canon that had to cut in with 720p HVX-200 footage. I did the deinterlacing and downconversion to 720p and watched the resolution noticeably drop at the final step. Not to say that the HVX isn't capable of a good looking picture, it's just not a resolution powerhouse.

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Interesting Charles,

 

If the HVX footage was shot in 720 24PN (notice the N for Native) there shouldn't be any need to do any sort of frame rate conversion on the footage. The camera only records 24 descreet, progressive frames per second to the P2 cards.

 

If it was shot in 24p or 24 pA mode, then simple 3-2 pulldown is all that is needed. It still isn't interlaced so deinterlacing is most likely what caused the resolution drop.

 

I do agree, however, the HVX isn't the sharpest of the small form factor cameras, but is 4.2.2 color space and DVCProHD rather than HDV and variable frame rates and all that.

 

Not to change the direction of the thread but the HVX has been a solid perfomer for me, not sure why you had resolution issues.

 

Chris,

 

If you do want to go with a heavier camera on the merlin, check out the new arm and vest you can use to fly the merlin. It also comes with the gimbal upgrade I think.

 

http://www.steadicam.com/merlinarmvest.html

 

It might make you feel strange going from a big rig to this, but you could give your arm a break.

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As I said, I had to convert the 1080i Canon footage to 720p to conform with the HVX footage as the project was being cut in DVCPROHD. So this required deinterlacing and downcoverting. I noticed the resolution drop going from the deinterlaced 1080 footage to 720.

 

I don't think this is all that terrible--I've shot plenty of Varicam stuff and now this project which was largely HVX200. We had some debacles with the P2 cards and losing footage, but other than that I think it's a good camera. Native 4:2:2 and variable frame rates are the strong suit. Resolution however is not where that camera or format shines. But as I said it's not a deal killer. I have a 720p DLP projector for my home theater that looks fantastic as far as I (and everyone who sees it) is concerned. No doubt the newer 1080p version of it would blow it away, but thankfully I haven't tortured myself by checking it out.

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Sorry Charles, I misunderstood your post. I see what you mean.

 

The HVX200 has a ton of features for a 6000.00 camera but the thing that has always bugged me about it is the softness of the image. I used to comfort myself by saying, "well, it is only a $6000.00 camera. You can't have everything." Until I bought the $1000.00 Canon HV20 for home use and side by side produces a sharper image than the HVX200 in 1080 mode.

It doesn't have the sort of Varicam-like magic to the image or control capabilities of the HVX, but it is sharper none the less.

 

Oh well, there is always the next generation of gadgets to spend money on.

 

Kevin

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