Increasing camera low light and range performance

[Joseph George]

If nothing else helps, try light color sets and white makeup -- that should be worth a few lux/dB. Just don't quote me on it. Quote Frank. :)

[Frank Granovski]

http://www.dvfreak.com/lux.htm

[Wayne Morellini]

Thanks guys, but I was looking for a way around having to set up big lights, bounce board, make up and sets all the time. Vladimir advice looks useful.

I tried a TRV22 yesterday and noticed that it was much better at rendering the outside scene in the background then the 953 (shame). There is a cheap DV3000 available (with some re-work it would be all right).

I am actually considering what would happen if I bought a cheap second hand 35 MM lense, and mount that to a camera (probably need intermediatory lense or something as well). I might try to experiment with my old camcorder in the next week or two.

Joseph, thanks, you wouldn't think that the JVC HD could possibly be 35 Lux with gain up, pity because otherwise it would get to nearly 4 lux with gainup (where it should have been). This lux thing is interesting because theorectically, a one lux camera should produce very usuable video, better than the human eye, with just one candle; has this been anybody's experience, at all? But most lux ratings aren't worth the soap there written on. On the other hand I have seen the JVC GY DV5000 at 0.4 lux, even two lux settings down from that it was producing low light vision as good (or better) than what I was seeing and no niose, without pixel combining that low lux modes can use as well as gainup and slow shutter. If anybody wants to work out the lux of their cameras it can be worked out from the db (I have been told about double for every 6db), slow shutter speed and cameras pixel combining scheeme. I looked at some cameras and figured that they were between 30-40 lux unasisted.

Anyway thanks everybody, from what I can tell knowbody makes an attachments to do this, but it should be possible. I know enough to look at doing it myself in future. I have also been offered a second hand VX9000 (pro VX1000) I think there 4 or 5 lux, and the VX2000 might come down to $4000AU eventually and that would be nice to improve. Unless somebody can tell me where I can get lense 35mm adaptors from that should be about all. Thanks for everybodies help, and hopefully there is a way around the crippled camera modle syndorme we have been seeing.

Thanks

Wayne.

[Joseph George]

Wayne, as to the Lux rating, let me give you an example. DVX is rated 3 Lux. In progressive it becomes 24 lux. The chips have the same sensitivity, but there is no gain up in progressive, for reasons unknown, since it would not cost Panasonic anything to include it. The extra video amplifier gain ads sensitivity but also noise. Unless you do some testing, the Lux ratings are meaningless.

[Wayne Morellini]

>> Wayne, as to the Lux rating, let me give you an example. DVX
>> is rated 3 Lux. In progressive it becomes 24 lux. The chips
>> have the same sensitivity, but there is no gain up in
>> progressive, for reasons unknown,

Probably a marketing consideration for the higher Cinema series of cameras. Pity a 24fps shutter speed could be used to halve the lux, and people could tune the gainup to suit their preference.


>> the Lux ratings are meaningless.

They are, we could allways work backwards from the slow shutter speed, gainup and pixel combining functions, but we still need to see the footage to see how bad the niose is.

Somebody has pionted me to an interesting site:

http://www.tiffen.com/contrast_filters.htm

Not exactly what I'm looking for but seems good.

http://www.tiffen.com/digital_lenses.htm #Wide Angle Lenses

the 0.54 WA convertor seems to make the brightness double. They also have some interesting DV filter sets.

Well thanks Jospeh

Wayne.

[Jeff Donald]

Wayne,

it takes a lot of effort to find information, or people, who are interested in the progression of the art rather than restort to the standard. It takes so much time and hassle to get true answers I don't even bother to ask difficult questions, the simple ones I usually can find out myself

It's time to put some facts in this discussion and to paraphrase Indiana Jones, Truth is down the hall in the philosophy class.

There are no attachments that will add light to your camera, short of powered light amplification devices. If there were, every newspaper photographer and photojournalist in the country would be running around with one attached to their lens. Any changes to light levels brought about by attaching a WA convertor is due to the increased angle of view bringing an additional light source into the frame. If anything performance will be decreased because of increased reflection and optical defects brought into the optical system.

There are no adapters to attach 35mm lenses to cameras with fixed (nonremovable) lens systems. The least expensive series of cameras with a removable lens is the Canon XL1 series. Panasonic had some older, 1 chip designs with removable lenses, WV-3260, I believe. By today's standards a poor performer. Why no adapters? There are many reasons, added glass would cause loss of light, AF would perform poorly, and the aperture mechanism would not couple, to name a few. It would also result in extreme telephoto focal lengths.

In answer to your question, there is no magic pill or magic filter or any other magic device to add light where it doesn't exist. Well, except for the obvious one, a light.

Joseph summed it up when he suggested that you buy a camera with better specs. I've read your reply and I understand it. But the facts are the camera manufactures have stacked the deck against you. Better performance (lower lux ratings) come with the higher priced models. In the future the lower end models will get some of those high end feature sets. The trickle down theory. It's the way camera manufactures have always done it. It's unfortunate, but it's the way the manufactures do it.

None of this is meant to "knock or subvert" you in your search for answers. But many before you have been down this same path. What you seek does not exist or the effort to produce it, exceeds the value of your camera.

If anyone has something new to ask feel free to post. There is no need to restate the past.

[Yow Cheong Hoe]

<<<-- Originally posted by Wayne Morellini :
The 953 is a toy non toys virtually start at the PD150, the challenge is to make a 953 (for example), decent enough (fit for purpose/s), to give an edge to everybody that owns a cheaper cam. -->>>

Now you have to be careful, Wayne, because I am using a toy called MX350 and making some money with the toy. I also know of at least 4 other people using toys to make money. For these people, and their clients, your toys are tools of the trade.

I agree that a good camera would start at the VX2000, the PD150, the DVX100 or the even XL-1. But the 'prosumer' label is applied to cameras in the 3CCD range, manual controls, optical stabiliser, zebra (maybe) and audio input control. These qualities are all found on the MX500. So the MX500 may be the lowest of the prosumers in terms of quality. But even the XL-1 is nowhere near broadcast quality video, or film cams, at best, a prosumer cam with interchangeable lens and XLR input.

I use to own the MX8, a consumer 'toy'. I normally call it the highest possible consumer cam, though, as the images are good and the OIS is wonderful. It's not as sharp and not as beautifully coloured as 3CCD cams, but at 1 lux rating, it captured light where most other cams see nothing. And at +18db gain, the grain is so much less prominent than the XL-1 at +9db gain. So you can save $2000 from buying the XL-1 and pay $800 for the MX8, if low light is your only concern.

To tell you the truth, I'll prefer to use both the MX8 and a better cam (my MX350 for now) to shoot. Switching from the nice colours of 3CCD in good lights, to the less-grainy and brighter but greyish footage of the MX8 in very low lights. It's interesting that my clients are not too concern about colours, but whether the events were well covered and the key shots taken.

BTW, I shoot cheap commercials, training videos, church productions, weddings and cheap documentaries. some paid jobs, some free.

[Vladimir Koifman]

Frank, Jeff,

Let me disagree with you that it's impossible to improve low-light sensitivity with lens attachments. The reason is that among other factors, the sensor light level depends on lens aperture. Once an adapter is attached to the lens, the aperture of such a combination is not necessarily same, as naked lens. It can be more or less. In the first case, the light intensity measured at the sensor plane would increase, it we neglect the light loss from additional glass surfaces.

In short, the lens attachment can change the amount of light reaching the sensor. Theoretically, it's not necessarily should be WA convertor. It can be made a convertor that does not change the focal length, but just increase an effective aperture.

Jeff, you are right in your assertion that WA converter collects more light because of increased field of view. Then this light is distributed between available number of pixels, with each pixel getting more light. The angular resolution is sacrificed here, but so it is in any WA lens. This can be compensated if object is placed closer to the camera.

I'm not saying that ANY WA converter would increase light sensitivity. It depends on its optical design, its antireflective coating quality, and on camera lens as well. If some camera naked has aperture 1:0.7, I doubt this can be improved. But if camera maximal aperture is 1:1.8, this opens some possiblities.

Saying all this, I dont think this way to increase light sensitivity is worth the trouble. In my opinion, the possible gain is too small to justify a huge and heavy convertor on the camera. But for the sake of theoretical purity we should agree that it could be done.

[Tom Hardwick]

It's worth repeating that the way to get your camera to perform better in low light is to remove all filters and converter lenses and to film at maximum wide-angle. Remember that all camcorders loose a stop as you zoom towards telephoto and some - like the Canon GL2 loose closer to two stops.

What this means is that if you can correctly expose a grey card using the wide-angle end of the zoom with one lamp on in the room, then you'll need to have four such lamps lit to expose correctly at full telephoto. This is quite a penalty. The losses are directionally proportional to focal length, i.e. the more zoom, the more losses.

My MX300 is even worse as full telephoto has the in-built ND firmly in place, covering a good third of the maximum aperture. No wonder it carries the banner of being crap in low light, yet at max wide it's pretty good.

Remember that every piece of glass you put in front of your lens absorbs some light and reflects some light, however beautifully coated it is or however thin the glass is. Some wide-angle converters use 4 elements and this introduces 8 extra surfaces for the reflections to take place.

Never was the term 'less is more' more apt.

tom.

[Jeff Donald]

Vladimir, please find a link or article that describes such an optical device. I am very curious to read about it.

Remember that all camcorders loose a stop as you zoom towards telephoto and some - like the Canon GL2 loose closer to two stops.

Tom, not all camcorders have variable aperture lenses. An F number is an F number no mater what lens or focal length. In other words F2.0 is F2.0 on any lens at any focal length. F2.0 is not unique to a particular lens, focal length or camera.

[Tom Hardwick]

Very true Jeff, though domestic camcorders exhibiting such lenses are very few and far between, which is why I felt I could say that. My 10x zoom on my Canon 1014E Super8 camera had a maximum aperture of f1.4 throughout the zoom range, so it's perfectly possible for this to be made more widely available today.

It isn't only for cost, size and weight reasons, it's also competition. If Panasonic hasn't seen fit to supply that need then Sony are happy to remain in step.

I also agree with you that f2.0 is f2.0 whatever the lens or format. My real point is that T stops are never quoted and that Panasonic, with their in-built ND, can remain very quiet about the transmission at full telephoto.

tom.

[Vladimir Koifman]

<<<-- Originally posted by Jeff Donald : Vladimir, please find a link or article that describes such an optical device.

Well, I don't have a link. I've seen a clear low-light improvement by my own eyes a few years ago. The best reference I was able to find is Century claiming "no light loss" for their adapters:

http://www.centuryoptics.com/products/dv/4/chart.htm

I think what happens here is that aperture gets bigger, but surface reflections eat most of the gain. The net result is "no light loss".

[Frank Granovski]

With what cam and adaptor did you see "a clear low-light improvement by my own eyes?"

I doubt it was with a MX5/PV-DV953.

[Vladimir Koifman]

<<<-- Originally posted by Frank Granovski :
I doubt it was with a MX5/PV-DV953. -->>>

You are right. It was some 5 years ago. DVcams were in their infancy then.

[Wayne Morellini]

Thanks Vladmir for introducing some sense. Over here , there has been lots of people, in the past, who just want to be negative rather than find a solution. It has been prolific, many people have been sent broke trying to prove, or invent something, that was right. That is one reason America does so much, better there is an interest in sucess, rather than failure. Admitedly, on average, inventors and creative people can reach higher hieghts here because of the opposition, they have to be good, but America reaches a much bigger bulk and heights. I can smell this from a mile off.

An wide angle convertor is actually not what I really want, but it is needed anyway, as the normal angle is to low for tight situations.


<<<-- Originally posted by Vladimir Koifman : Frank, Jeff,

Let me disagree with you that it's impossible to improve low-light sensitivity with lens attachments. The reason is that among other factors, the sensor light level depends on lens aperture. Once an


Jeff, you are right in your assertion that WA converter collects more light because of increased field of view. Then this light is distributed between available number of pixels, with each pixel getting more light. The angular resolution is sacrificed here, but so it is in any WA lens. This can be compensated if object is placed closer to the camera.

justify a huge and heavy convertor on the camera. But for the sake of theoretical purity we should agree that it could be done. -->>>

Jeff thanks for your comments. I don' think it is a magic pill, it will cost a bit of money, not as much as many would think, but still alright.

> Joseph summed it up when he suggested that you buy a
> camera with better specs. I've read your reply and I understand
> it. But the facts are the camera manufactures have stacked the
> deck against you. Better performance (lower lux ratings) come
> with the higher priced models. In the future the lower end
> models will get some of those high end feature sets. The trickle
> down theory. It's the way camera manufactures have always
> done it. It's unfortunate, but it's the way the manufactures do it.

Well that is a good reason to attempt it. The problem is that cartels, or anti trust behavour, in some Asian countries aren't regulated like they are in the States (where there illegal), so they can set the trend for the market. Any accesory manufacturer can produce trouble for themselves if they buck the trend as well.

> None of this is meant to "knock or subvert" you in your search
> for answers. But many before you have been down this same
> path. What you seek does not exist or the effort to produce it,
> exceeds the value of your camera.

I appreciate that, and I also appreciate your much more graciouse reply compared to some. But the fact that a particular answer is being looked into, and is possible, is a reason to explore that rather than getting stuck in avioding it by restating opposing answers that are obviouse but aviode the issue asked, over and over again, like some had. I didn't expect to find an easy answer, it was either going to cost money or time.

Yow Cheong Hoe:

Thanks Yow. I'm sorry for the toy camera remark, it is a quote of professional opinion I have come across. Over here we have moved to HDTV broadcasting and standards have risen for years to high levels. They only want to accept threee chip footage. The definition of braodcast is probably 4:2:2 from a digi beta camera to some. They define broadcast interms of variouse signal level, resolution, colour requirements etc etc. I have got to admit aswell the footage from the JVC GYDV5000, Digital Beta, JVCPRO cameras does look a lot better than what is produced by the XL1 and the VX which probably fails these tests. My guess is that they probably have some filtering mechanism that takes prosumer 3CCD footage and adjusts the levels to suit and quality standards, and prefer not to spend the time on it. I don't particularly need to buy a pro camera, but if I am going have to be cheap, I prefer not to look good at it.

Tom Hardwick:

> It's worth repeating that the way to get your camera to perform
> better in low light is to remove all filters and converter lenses
> and to film at maximum wide-angle. Remember that all
> camcorders loose a stop as you zoom towards telephoto and
> some - like the Canon GL2 loose closer to two stops.

Thanks Tom most appreciated.


Frank:

I have been advised of 33% inprovement, I have shown you a link that looks like a 100% improvement.

http://www.tiffen.com/digital_lenses...e Angle Lenses

It is theorectically, and practically possible. It is only a complicated design issue (for somebody that knows optical engineering) the issues are image distortion not light gain, that is obviouse, the lens collects the amount of light not the CCD and effects the Lux. Bigger lense and focused right = more light. Lenses don't ussually absorb most of their light but only a fraction of it. If the 10 piece (or 8) DV3000 passes 70% of it's light that averages to around 3% light loss. If it has four times the area and collects 400% light 3%-16% (good coating, thick lense) light loss, plus corection lenses, doesn't make much of a difference. Let alone side tracking the issues.

Well thanks everybody, I have to get going, a lot to do lately, I won't be back for a while, so until the future have a good day.

Thanks

Wayne.