Rolling Shutter??

Tom Hardwick · February 25th, 2009, 02:25 AM

Quote:

Originally Posted by Adam Gold

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.

Stelios Christofides · February 25th, 2009, 06:50 AM

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

Greg Laves · February 25th, 2009, 08:26 AM

[QUOTE=Tom Hardwick;1018076]

Quote:

Originally Posted by Greg Laves

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.

Tom Hardwick · February 25th, 2009, 08:35 AM

Zeiss - of course. Brain-fade this end.

Adam Gold · February 25th, 2009, 01:02 PM

Quote:

Originally Posted by Tom Hardwick

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.

Matty Ross · February 26th, 2009, 02:04 PM

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)

Tom Hardwick · February 26th, 2009, 02:20 PM

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

Matty Ross · February 26th, 2009, 03:21 PM

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

Ken Ross · February 26th, 2009, 05:38 PM

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.

Tom Hardwick · February 27th, 2009, 04:22 AM

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

tom.

Ken Ross · February 27th, 2009, 06:25 AM

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.

D.R. Gates · April 10th, 2009, 04:53 AM

Quote:

Originally Posted by Jeff Harper

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.

Steve Renouf · April 10th, 2009, 05:12 AM

Quote:

Originally Posted by D.R. Gates

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.

D.R. Gates · April 10th, 2009, 07:07 AM

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.

Jo Ouwejan · April 10th, 2009, 07:36 AM

Quote:

Originally Posted by D.R. Gates

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?

February 25th, 2009, 06:50 AM	#77
Stelios Christofides Trustee Join Date: Jul 2003 Location: Nicosia, CYPRUS Posts: 1,080	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 __________________ My Blog: http://steliosc.blogspot.com "I hope for nothing, I fear nothing, I am free" Nikos Kazantzakis

February 25th, 2009, 08:35 AM	#79
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Zeiss - of course. Brain-fade this end.

February 26th, 2009, 02:04 PM	#81
Matty Ross New Boot Join Date: Dec 2008 Location: Edinburgh Posts: 8	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)

February 26th, 2009, 02:20 PM	#82
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	It's a very good reason to choose from the new CCD cameras put out by JVC, Canon and Panasonic.

February 26th, 2009, 03:21 PM	#83
Matty Ross New Boot Join Date: Dec 2008 Location: Edinburgh Posts: 8	is there any one in particular that stands out for you Tom?

February 26th, 2009, 05:38 PM	#84
Ken Ross Trustee Join Date: Jan 2005 Location: New York Posts: 1,945	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.

February 27th, 2009, 04:22 AM	#85
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	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 tom.

February 27th, 2009, 06:25 AM	#86
Ken Ross Trustee Join Date: Jan 2005 Location: New York Posts: 1,945	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.

April 10th, 2009, 07:07 AM	#89
D.R. Gates Regular Crew Join Date: Feb 2009 Location: Bakersfield, CA Posts: 111	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.