Wow, Tom, that's too bad about the LR on the Canon. Todd you're just having a devil of a time getting this sorted out, aren't you?

Tom is right, I have the A1 and it is f3.4 at the end, my advice is learn how to use the camera, know its strong and weaknesses and use that to your advantage, and research before you buy, rolling shutter and lens ramping has been mentioned every since these camcorder came out, why buy it before you do your research and now hated it, if you think you can live with rolling shutter fine, if you think you can overcome lens ramping by using auto gain or stand a little closer or slower shutter then fine, if not don't buy it.

Just so you know where your particular aperture value comes in the scale, have a look at this line-up of numbers. It shows all the half-stop values between f/1.4 and f/11

1.4 1.7 2 2.4 2.8 3.3 4 4.8 5.6 6.7 8 9.5 11

So a 20x zoom that starts at f/1.6 is actually slightly wider than the half-stop value at f/1.7, but it's f/3.4 is a smaller aperture than the half-stop at f/3.3. This means (in theory) that the lens loses nearly 2.5 stops as you zoom. As a comparison the Z7 loses just over half a stop - impressive for a 12x zoom.

I say 'in theory' because design and production tolerances mean that even if it loses 3 whole stops it will still pass inspection. And if it's a 18.7x zoom it will still pass inspection

tom.

Wow, Tom, that's too bad about the LR on the Canon. Todd you're just having a devil of a time getting this sorted out, aren't you?

You got that right!!! This is very frustrating. I am with you on the extrme close ups. They are a must and I don't want to fight the lens ramping.

I use GL2's now and I figured I could get past the low light performance of the XH-A1 but not if the lens ramping is the same. I guess the biggest deal breaker on the Sony is the cmos. I can't afford post production time with that problem. What to do, what to do??

How about a Canon CCD cam with interchangeable lenses? No rolling shutter, and your lens ramping is a non-issue.

Wow, why didn't I think of that earlier?

Yeah, that shouldn't set you back more than $6,000-$7,000. :)

There will be 2 new JVC camcorders available soon:
JVC Press Release - New Final-Cut-Pro™-Ready Solid State Camcorders (http://pro.jvc.com/pro/pr/2009/releases/solid_state_release.html)

Well the one you'd want to look at is the 700 with 1/3" imagers, but that puppy weighs about 9lbs! I for one wouldn't bother with the 100 with its 1/4" imaging chips. Chips that small will never perform as well as 1/3" or 2/3" imagers. The 100 is supposed to come in at around $4,000, so I have no idea what the price of the 700 would be.

I didn't mention them for the same reasons Ken.

Tom, that is priceless info on the Z7. Great stuff. Thanks for breaking it down.

On the subject of rolling Shutter I have just edited a dance concert two camera using a Z1 and FX1000.

The concert had a huge light show with lights flashing everywhere and it was really full on.

Happy to report that I had no issues at all with rolling shutter. The two cameras handled the lights the same.

The editing involved a bit of slow motion and I didn't see anything that made me go "Wow look how bad that is" in relation to rolling shutter.

The FX1000 was a little better in low light.

Just to make things even clearer, hopefully, f stops are mathematically derived from the ratio of the iris opening to the focal length.

So you could have two lenses side by side, both with the same focal length and maximum aperture. One could be made of the finest glass and be beautifully multi-coated. The other could be made from cloudy plastic and have dead insects stuck to one of the glass elements.

Guess what - they're both the same specification, but one lens passes a lot more light than the other. OK, now we have two lenses with the same spec but one is made up of 8 elements, the other has four. The 8 element lens is probably better corrected, but it certainly won't pass as much light even if they both claim (accurately) that they're f/2.8.

So real and proper cameras have lenses marked in T stops. T for transmission, and this sorts the men from the boys. Generally a 20x f1.6 zoom won't pass as much light as a 10x f/1.6 zoom simply because there are far more elements in the long zoom's lineup. But if both lenses are marked T 1.6 then they will indeed both pass the same amount of light. The 20 x zoom will be manufactured with a wider maximum f stop to counteract its greater light losses. Bench testing determines the lens' T stop - it has nothing to do with the f stop.

We're sold f stops because it looks more impressive. Remember your lens is still an f/1.6 even with the lens cap on, and it's transmitting no light at all.

tom.

f stops are mathematically derived from the ratio of the iris opening to the focal length..
This is a critically important point, and I'm glad you made it. It belongs in the lens ramping discussion as well. Most of those who are most hysterical about this issue seem to fail to understand that the f-number is changing as you zoom, merely because the ratio of iris size to focal length is changing, and you aren't losing my nearly as much light as the numbers would indicate. When you go from, say, 1.4 to 2.8 as you zoom, it only means the focal length has doubled -- you are not really losing 75% of the light -- the iris size is relatively unchanged and your only light loss is as the elements shift (so T-value would change).

As you and others have pointed out, to have no ramping, you'd need a lens with the diameter of a dinner plate -- which the pro studio and sports cameras do, even though they still have relatively small 2/3" chips. And the iris would have to open up dramatically as you zoomed to maintain the same "f-stop."

Most of this hysteria over this non-phenomenon is just uninformed nonsense.

We're indeed fortunate to that you see fit to straighten us out Andrew.

Maybe someone will tell us soon that these things are actually benefits, but that since we don't understand them we can't appreciate them. :)

Wow guys!!! what a wonderful site this is with all the info you can get. You know, you can google everything, but it's not the same, because here, you get people who interact with each other and you "hear" other opinions too. I have learned so much in these forums that I would have never learned anywhere else.

Stelios

I agree Stelios. There is LOTS to learn here!

you aren't losing nearly as much light as the numbers would indicate. When you go from, say, 1.4 to 2.8 as you zoom, you are not really losing 75% of the light

Not quite on your side here Adam. If your f/1.4 lens has smoothly changed into an f/2.8 lens you'll need to quadruple the light in the room to get the same exposure on your chips.

Or to put it another way. If you can film at f/1.4 with two 100 watt lamps lit (say) then at f/2.8 you'll need to turn on eight 100 watt lamps to get the same exposure. This shows how dramatic a two stop loss can be, and the Z5 loses two stops, wide to tele.

tom.

This is a critically important point, and I'm glad you made it. It belongs in the lens ramping discussion as well. Most of those who are most hysterical about this issue seem to fail to understand that the f-number is changing as you zoom, merely because the ratio of iris size to focal length is changing, and you aren't losing my nearly as much light as the numbers would indicate. When you go from, say, 1.4 to 2.8 as you zoom, it only means the focal length has doubled -- you are not really losing 75% of the light -- the iris size is relatively unchanged and your only light loss is as the elements shift (so T-value would change).

As you and others have pointed out, to have no ramping, you'd need a lens with the diameter of a dinner plate -- which the pro studio and sports cameras do, even though they still have relatively small 2/3" chips. And the iris would have to open up dramatically as you zoomed to maintain the same "f-stop."

Most of this hysteria over this non-phenomenon is just uninformed nonsense.

"This non-phenomenon is just uninformed nonsense" is your opinion!! At the end of the day when you zoom all the way in you loose to much light too be of any benefit plain and simple!!!

when you zoom all the way in you loose to much light too be of any benefit plain and simple!!!

Calm down Todd. This situation *only* occurs when light levels are so low that even using +18dB of gain you're forced into using apertures wider than f/3.4. For most of a camcorder's life this just doesn't happen - in fact I'd think that for most filmmakers using ND filters is much more common.

tom.

As you know Tom, I feel similarly as Todd. But what you say it absolutely correct, 90% of the time it is a non- issue, maybe 95%!

I think for typical shooting, for most any typical shooter, it really is not a big deal. I agree on that wholeheartedly. We know that is true because so few complain about it.

On the other hand, for the few of us for whom the indoor extreme closeups at about 10 feet are important, the lens ramping goes from being unimportant to "Oh my God!".

I remember how I freaked out when I discovered it. I didn't even know it existed. There I am about 8 feet or less, and I could not fill my LCD with my bride's face...because the exposure changed and it was unusably dark.

I do feel hopeful with your post Tom re: the V7. That, again was really great info, and for the likes of me it seems like the solution.

I've said how god-awful the rolling shutter can look, and I meant it. But I can and will live with it.

Not quite on your side here Adam. If your f/1.4 lens has smoothly changed into an f/2.8 lens you'll need to quadruple the light in the room to get the same exposure on your chips.You could be right, but I don't think it scales that way. Going back to your earlier post, if we were talking t-stops that would undoubtedly be true as those are an actual measure of light. But with f-stops, as you pointed out, these are merely numerical expressions of physical measurements and have nothing to do with light transmission. There really isn't an exact link between f number and, say, lumens.

Here's an experiment: Take a wide shot full open (say 1.6) and then zoom in fully. Go to your NLE and zoom up the wide shot so it matches the tele you took in the cam. Even though there are at least two, maybe three, stops difference between either end of the zoom, is the luma of the CU really only 25% of the wide shot? (Obviously you'd have to shoot on full manual with fixed gain and shutter.) I'm betting it isn't, but will happily be proven wrong if it means we all learn something.

After reading the latest postings, and Adams post from yesterday, in particular, I did a test with my Z7. I have a broadcast (style?) Fujinon lens for my Z7. It will maintain f1.4 from full wide to full telephoto. Since I have doubts that anyone's eye is so finely calibrated to tell very minimal exposure differences, I used the zebras to evaluate the exposure. And what I found was that from full wide to full telephoto a grey object would show virtually negligible change throughout the entire range of the lens. And realistically, I would never need to adjust the exposure to compensate for the zoom. No matter what the zoom was, the 70% zebra indicated that the subject was correctly exposed right at f1.6 to f1.7.

That is awesome Greg. Got to get me one.

Maybe someone will tell us soon that these things are actually benefits, but that since we don't understand them we can't appreciate them. :)

This is obviously an intentional benefit -- if the lens held at f1.6 through the whole zoom, then the depth of field at 20x, focused on a subject 10 feet away, would be so shallow that you couldn't get the entire face in focus! The tip of the nose to the ears would be too far off the focal plane to be sharp! So that F3.4 is a good thing :-)

Yes, I jest.

-Terence

This is obviously an intentional benefit -- if the lens held at f1.6 through the whole zoom, then the depth of field at 20x, focused on a subject 10 feet away, would be so shallow that you couldn't get the entire face in focus! The tip of the nose to the ears would be too far off the focal plane to be sharp! So that F3.4 is a good thing :-)

Yes, I jest.

-Terence

I thought that was why Sony gave us only 1/3" chips, so the DOF wouldn't be too shallow.

[QUOTE=Greg Laves;1017775]I have a broadcast (style?) Fujinon lens for my Z7. It will maintain f1.4 from full wide to full telephoto./QUOTE]

What is this Fujinon lens you have on the Z7 Greg, and how much zoom does it have? The stock 12x Fujinon that comes with the Z7 most certainly doesn't have an f/1.4 maximum aperture - it ramps from a nominal f/1.6 to f/2.0.

tom.

Take a wide shot full open (say 1.6) and then zoom in fully. Go to your NLE and zoom up the wide shot so it matches the tele you took in the cam. Even though there are at least two, maybe three, stops difference between either end of the zoom, is the luma of the CU really only 25% of the wide shot?

I'm afraid the answer is yes Adam. In your example the grey card would be correctly exposed at full wide but be two or three stops under-exposed (depending on the amount of ramping built in to your test lens) at full telephoto. It's what Jeff's so upset about, and why he should buy a Z7.

In fact the test you describe is best done like this. Go full wide, max aperture. Fill your frame with a pretty picture, lots of colours and tones. Now step back, zoom to full tele and frame fill the same picture, again using max aperture. Your NLE will be able to 'rescue' this under-exposure to a degree, and give you a numerical readout of the compensation applied.

tom.

tom.

I found this last night.

"What is ramping and why do lenses ramp?
Ramping is when the diameter of the lens glass is not larger enough for a lens to maintain the minimum F No. and therefore it will increase in a linear function. As a result you will see in a lens specification some thing similar to “1:1.8 (4.5 to 41mm), 1:2.6 (59mm)” which means that this lens will hold the F No. of 1.8 until 41mm and than ramp to F 2.6 when the lens is zoomed to 59mm. When lenses are designed there is a compromise between size and weight and performance. There are lenses which do not ramp, like the Fujinon Cine lens HAe12x9.5 which has a flat F1.6 across the whole range but the weight is 10kg."

Stelios

[QUOTE=Greg Laves;1017775]I have a broadcast (style?) Fujinon lens for my Z7. It will maintain f1.4 from full wide to full telephoto./QUOTE]

What is this Fujinon lens you have on the Z7 Greg, and how much zoom does it have? The stock 12x Fujinon that comes with the Z7 most certainly doesn't have an f/1.4 maximum aperture - it ramps from a nominal f/1.6 to f/2.0.

tom.

Fujinon TH16x5.5BRMU. The standard 12x lens is not a Fujinon. It is made by Zeiss.

Zeiss - of course. Brain-fade this end.

In fact the test you describe is best done like this. Go full wide, max aperture. Fill your frame with a pretty picture, lots of colours and tones. Now step back, zoom to full tele and frame fill the same picture, again using max aperture. Your NLE will be able to 'rescue' this under-exposure to a degree, and give you a numerical readout of the compensation applied.

Yes, that's exactly what I was talking about doing, although I was applying a zoom ("stepping back" or actually forward) in the NLE to make the picture composition the same, although your way makes more sense. Has anyone actually done this and put the results on a scope? That's what I'm curious about -- actual numbers rather than anecdotal personal perception polluted by the placebo effect. Some will see the f-number go from 1.6 to 3.4 and panic and assume they are losing 3/4ths of the light, when it may or may not in fact be so. Numbers, man, I need numbers!

I'm wondering if Chris or another Moderator can split this off and append to the ramping thread, as we're really OT at this point.

Hey folks,

Have been reading with interest comments on rolling shutter. I bought the Z5 in December after months of research where a lot of wedding videographers had said it wasn't a massive issue and thought it was the one to go for. I went out to South Africa for new years and most of the footage I got was fantastic. Low level light filming was exceptional and 80% of the footage looked amazing! However, there was few focus problems (although this could be down more to my camera skills than anything else), but a few shots inside clubs and in general around cape town were ruined due to flash photography. Really annoying....

I've done some experiments with using flash and it is a real pain in the backside. I have to do a few weddings this year and so quite worried. Most of my work is short experimental films and I thought this would be a perfect cam to combine my corporate work with my short films. Although I have enjoyed using the Z5, with the amount of digital cameras about nowadays this issue I forsee will have more probs for me. In the past I have ended up with some of my best freeze frames when a camera has gone off in the background and lit the subject.

So I'm a bit stuck on the subject too, I won't pretend to be a professional cameraman I just went for what i thought was the best in my price range at the time. The downside is that if I sell it I'm stuck back again where I started......

(fantastic forum by the way - much respect to all contributors - Matty)

It's a very good reason to choose from the new CCD cameras put out by JVC, Canon and Panasonic.

is there any one in particular that stands out for you Tom?

Matty, just go in to it knowing your low-light will not be as good as it is with the Z5. I'm not sure if you've used the Compact Flash Recorder with your Z5, but that too won't be as convenient as it is in the Z5 since it won't fit directly on the camera, feeding off of the camera's battery. Also be aware that the smaller JVC (consumer-sized HM-100) uses 1/4" chips and for that reason I'd stay away from it. The next larger JVC, which uses 1/3" chips, does not record 1080i video and is pricier.

I'd prefer the Canons if I were dissatisfied with the Sony (which I most certainly am not). So shop carefully before pushing the panic button.

I agree with Ken - don't let the CMOS chips one and only failing (as far as I can see) blind you to its other attributes. But the Panasonic 150 is receiving good reviews.

On the other hand (just to reassure myself that I'm not overstating the case against CMOS and the electronic flash banding) I've been going back through my films. Many's the time I've held a shot on the flash frame, even using it for the DVD printing. And some of my couples walking back down the aisle have 30 or 40 flashes go off, and as I bring this to a gentle slow-down and stop in the church doorway I'd prefer not to have banding because it looks so unnatural. It's just me - don't worry.

EventDV.net: In the Field: Panasonic AG-HMC150 (http://www.eventdv.net/Articles/ReadArticle.aspx?ArticleID=52607)

tom.

The 150 looks nice, but does record in the AVCHD format which is much tougher to edit. So you'll need a high power computer, and even then, if you do multiple video layers, filters etc., you'll more than likely have a slower editing experience.

The side by side comparisions he did were really interesting, but I always find it odd how some reviewers compare two cameras at similar gain settings as they check for image brightness. This tells you nothing about how the cameras compare in real-world situations. Camera A may look much cleaner at 9db (and brighter) than Camera B which may have looked brighter at 0 gain, so who cares how the cams compare at the SAME gain setting? One of the great things about the new Sonys is that they handle higher gains so well.

So keep in mind this comparison was done with the Z1 and not the Z5. I owned the FX1 (stripped down Z1) and I can attest to the fact that the Z5 is a decidedly better camera on many fronts. The lens is much better and wider than the lens on the Z1, the color is better, the exposure latitude is better, the low light is better and the camera is sharper and more detailed. Another consideration which may or may not be significant depending on your shooting situations, the 150 does not record in SD.

So I guess what I'm saying is that if the comparison was made with the Z5, it would have looked quite different in my opinion. The one thing that I would definitely appreciate and where the comparison would still be valid, is the lighter weight of the 150.

You should check the Panasonic forum. Very few complaints on that camera. For what you are looking for at present it is the best option, IMO.

There are many complaints about the HMC150. Mostly audio related. Either screwed up mic glitches or noisy servos. That sucks, because I was all set to get it over the FX1000.

So THEN, I was starting to drift back to the FX1000, but after looking at some more wedding clips on Vimeo, there's really no way I want to deal with rolling shutter.

I think those that say it's no big deal are simply trying to justify their purchases. Sort of like parents with ugly kids. In their eyes, they're perfect.

So THEN, I was starting to drift back to the FX1000, but after looking at some more wedding clips on Vimeo, there's really no way I want to deal with rolling shutter.

I think those that say it's no big deal are simply trying to justify their purchases. Sort of like parents with ugly kids. In their eyes, they're perfect.

On the other hand, if you do lots of night-shoots, you might want infra-red imaging but if you only shoot in daylight, it's a non-issue.

Same goes for the "rolling shutter issue" - if you never shoot in situations where it might occur, then, likewise, it becomes a non-issue.

I wholeheartedly agree Steve. If I did video work where there wasn't a flash going off beside me all the time, then the Sony is a fine choice.

But since my main source of income is weddings, RS is a big issue for me.

But since my main source of income is weddings, RS is a big issue for me.
Just to throw in a big smile:

Will shooting at funerals be no problem with the RS?

I wholeheartedly agree Steve. If I did video work where there wasn't a flash going off beside me all the time, then the Sony is a fine choice.

But since my main source of income is weddings, RS is a big issue for me.

It's an interesting debate for sure and if most of your work invloves situations where it is most likely to be an issue, it makes sense to avoid it.

I recently shot a stage production where there were quite a few camera flashes going off at various times in the audience but I haven't seen any instances of RS in the footage yet (from capture). However, as I progress through editing, who knows what I might find. More of an issue for me is balancing the sound from the different performances for editing in from different angles (that's the main problem with "live" performances - no multiple takes possible other than from multiple performances. Can be a real PITA when you don't have total control over the sound and lighting as well. Obviously, it's all controlled by the backstage crew, so even when you take a sound feed from their mixer - it can still fluctuate as they tweak it for their purposes (at the end of the day, they are trying to produce the best for their stage performance - not for your recording of the event!).

If I do any more of these, I think I'm going to have to invest in a seperate field recorder for audio (as I recall someone suggesting on here some time back) :-)

The field recored might be a good idea. Of course with plays, they're usually all over the stage, so I wonder how much a single recorder will benefit you. But at the very least, it will be better audio than what your camera can achieve.

I think a 4 channel recorder would cover it reasonably well - with the option that one could also add a mixer into the equation. I think I could have covered the stage reasonably well with 4 mics. One area that's difficult to cover though, is continuity - the actors tend not to give exactly the same performance from one night to the next - or hit the same spots on stage! Still, it makes for an interesting editing experience! ;-)

It would be great to be able to mic up each individual but it's not really practical with a cast of a dozen or so. However, it could still be an option for those actors that I know don't have very powerful voices that need gaining up in post. It could introduce problems of matching ambience though...

I have taken an extra camera, hooked up a wireless receiver to it and placed the mic front and center near the stage and it worked beautifully, at least for a play. No sync issue, which I hate. I have a zoom h2 but don't use it.