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-   Sony TRV950 / PDX10 Companion (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/)
-   -   HC1000 -- various questions (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/30692-hc1000-various-questions.html)

Tom Hardwick June 8th, 2005 05:52 AM

First to Boyd: Thanks for the wake-up call. Oh, and your VX2000 most certainly does have (and can use) apertures smaller than f/11. Using the focused Maglight technique you can see the aperture blades gently closing as they go through f/16, f/22 and f/32. The camera will even film at these tiny apertures, but to do so you have to have the Auto Shutter set to off in the menu and you have to film in bright light and ignore the silent scream for the ND filters to be inserted.

For all those who don't know what the degrading effects of diffraction look like, film at (a genuine) f/11, f/16 or smaller. I say 'a genuine' simply because so many camcorders these days tell you you're filming at f11 (say) and even on replay insist the aperture was f/11, but of course it's somewhere around f/4 with lots of internal (and invisible) ND filtration applied.

tom.

Tom Hardwick June 8th, 2005 06:10 AM

To Stephen. The HC1000 replaced the TRV950 and although I haven't had a good look at one, I know the 950/PDX10 pretty intimately. I suspect the 1000 is a repackaged 950, saving Sony money along the way. And you're right - more expensive cameras don't cripple you in this way.

As such I'd expect the 1000 to use the same lens/chip-block assembly and have the three neutral density filters working in conjunction with the aperture blades. Turning the 'exposure' wheel is simply altering the exposure, and this is a combination of actual aperture (the hole caused by the diaphragm blades) and three ever denser ND filters being raised one after another into the light path. Often you can be filming through 2/3rds of a filter, but the edge of the filter is so out of focus you don't see that effect on film. It's not nice though, but I guess it's cheaper than having a curved, vari-density ND fitted inside the lens.

All camcorders that don't have external ND switches do this. So Canon, Panasonic, Sharp, JVC - all do it, and don't tell you. On replay they interpolate, giving you a readout aperture figure of f/8 (say), even though the shot has been taken at an actual aperture of f/4 + an internal ND4 filter.

This trick is used by manufacturers simply because diffraction (especially at short focal lengths (wide-angle) and tiny chips) robs you of lots of sharpness. Diffraction effects start as soon as the aperture blades start to close BTW.

As Boyd says, the replay readout on the 950 is very suspect and I guess the 1000 is using the same firmware, so take the info with a pinch of salt. Also remember that the readout (of shutter speeds and apertures) is only to the nearest half stop, so is only vaguely right anyway.

tom.

Boyd Ostroff June 8th, 2005 06:23 AM

Tom, based on what Stephen said I think the firmware in the HC-1000 is different, even though the camera behaves the same way. If you read his posts again you'll see that the data code never claimed he was shooting at an iris opening any smaller than f4.8 or f4.0, depending on the situation. Then when he turned the exposure wheel one click further it faded completely to black. As you say, on the 950 the data code makes bogus claims of shooting at f8 or f11.

So it sounds like the HC-1000 is accurately reporting the iris opening, it just isn't admitting that it augments that with ND filters.

Stephen Finton June 8th, 2005 06:38 AM

How many ND filters are in the 950 and PDX10?

Tom Hardwick June 8th, 2005 06:56 AM

Three Stephen. Boyd, I see you're right. That would suggest then that there's a good few aperture wheel clicks beyond f/4 (possibly 6 of them while the NDs are progressively pushed up into place) before the auto fade to black.

Does the 1000 also claim that f/1.6 was used at full telephoto?

I found I could film at smaller (real) apertures in the PDX10. Make sure you've locked down the shutter speed and got all three of the internals on lens-axis by shooting a white wall in sunlight, say. The automation - in an effort to give correct exposure at the expense of sharpness, will indeed film at apertures smaller than the sweet spot.

tom.

Stephen Finton June 8th, 2005 08:44 AM

Quote:

Originally Posted by Tom Hardwick
Does the 1000 also claim that f/1.6 was used at full telephoto?

I have no problem getting it to stay at f1.6, whether in wide or telephoto. It acts the way I would expect it to act manually, to the right of the exposure bar, all the way to 18dB Gain @ f1.6.

I'm going to have to get my Digital8 back from a friend to check it again because I don't think I was ever so critical of its performance, as I am the HC1000. Maybe it has something to do with the fact that I bought it for $350 at a pawn shop? Not too shabby as it is a TRV510, SONY's flagship model the 1st year they were manufactured. It was, at one time $1500!

Does physically closing the iris create distortion of the image after the sweet spot? Is this why ND filters are used in a professional camera? I guess these are the only answers I was looking for...

Boyd Ostroff June 8th, 2005 09:15 AM

Quote:

Originally Posted by Stephen Finton
I have no problem getting it to stay at f1.6, whether in wide or telephoto.

That's one of the points which Tom and I were making. It is physically impossible to shoot at f1.6 while zoomed to full telephoto, so that data code is bogus. At full telephoto the lens is rated at f2.8 IIRC - look at the specs in the back of your manual.

Stephen Finton June 8th, 2005 09:37 AM

Quote:

Originally Posted by Boyd Ostroff
That's one of the points which Tom and I were making. It is physically impossible to shoot at f1.6 while zoomed to full telephoto, so that data code is bogus. At full telephoto the lens is rated at f2.8 IIRC - look at the specs in the back of your manual.

You think that's why they went with an exposure bar instead of true f-stops? I guess I shouldn't gripe about a camera that is too sensitive to light. I just do not want to have to start an ND filter collection. I bought 2 cameras, afterall so everything costs twice as much now.

Tom Hardwick June 8th, 2005 09:46 AM

Boyd's right, the lens loses a good 1.5 stops from its way from wide-angle to telephoto, so if you need f1.6 to give correct eposure, zooming in (even a little bit) will progressively under-expose the footage if you're in manual.

"Does physically closing the iris create distortion of the image after the sweet spot? Is this why ND filters are used in a professional camera?" No Stephen. Stopping down simply increases the depth of field for any given focal length, while at the same time reducing the amount of light that gets through the aperture. So f/5.6 lets in half the light of f/4, but also suffers slightly more diffraction losses.

ND filters are available on more professional kit so thay you can remain in much greater control of the aperture in use, specifying shallow depth of field (blurry backgrounds for instance). Better kit also uses multi-bladed diaphragms - the TRV900 for instance had a proper 6 bladed diaphragm, which meant it had accurate circles at small apertures. The two bladed version in the 950 / 1000 is cheap, but doesn't give anywhere near as nice specular highlights on chrome or water.

tom.

Stephen Finton June 8th, 2005 01:08 PM

Okay. Here's the deal.

When I go into auto exposure it changes from f1.6 to f2.4 as I zoom in. Have you guys been talking about auto exposure all this time?

You're not just pulling my leg because I bought an HC1000, are you? ;)

When I use manual exposure, with the shutter locked on 1/60 and set it to f1.6, it doesn't change from f1.6 as I zoom. This is what I was expecting and you guys are telling me it's wrong?

Boyd Ostroff June 8th, 2005 01:41 PM

See this thread, especially Lamar's explanation. Every prosumer camcorder works like this. The lens is slower at the telephoto end of the zoom. For some unknown reason the data code is correct in auto mode, but it lies in manual...

http://www.dvinfo.net/conf/showthread.php?t=37526

Stephen Finton June 8th, 2005 02:22 PM

Maybe it "knows" the exposure setting I set it to in manual but does not calculate the added f-stop of the lens in full tele? I guess this would be the difference between it and the TRV950. They did miniaturize it even further...

Stephen Finton June 8th, 2005 03:06 PM

I'll be quiet now. I think I have broken my brain to fit into SONY's mold now. I understand. I guess I was just expecting to buy something that would allow me to screw up the video, if I didn't know what I was doing. I don't mind having my hand held with sweet spots.

Stephen Finton June 8th, 2005 10:35 PM

I can see the IR light of the remote!
 
I was plaing with an older remote, pointing it at the HC1000 to see if it would work and I could see the IR LED on the remote light up a very obvious red! I tried seeing it with my naked eye but I couldn't!

Tom Hardwick June 9th, 2005 12:13 AM

Sorry to hear about the brain ache Stephen, but even so you now see clearly. Nobody's pulling your leg and yes - use the 1000 in auto and you won't go far wrong. Having asked the camera what it thinks the settings should be, *then* lock those settings for the shot. It's those that fiddle with the settings that get into the CCD smear and diffraction modes, whereas the camera designers have gone to great lengths to help you avoid these nasties.

tom.


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