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de-clicking lenses for video
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PostPosted: Sun Sep 09, 2012 8:29 am    Post subject: Reply with quote

There is a very big difference in lenses with video. Just because "you" can't tell doesn't mean it's not important. The dynamic range of an image shot on an HDSLR is only about 6 stops. You have 4:2:0 color space. You have highly compressed imagery and as such contrast and sharpness means everything. It also means you can't simply change it with software. There needs to be data to change and if your edges aren't sharp or you have CA you can't just fix it. The problem is made worse by compression and degradation of the recorded image. It's absolutely noticeable on the average computer monitor. Sure you might not know what the problem is but people can tell one video is of higher quality than another. Just as people can tell one still picture is of higher quality than another. But where it really becomes important is when you want to edit your video. As I said before if you don't have the data in your image nothing is going to recover it. If you image is not sharp nothing is going to fix it. If your image is lacking color information or has CA in the edges of objects nothing is going to fix that. You can mask it which looks like it was masked but nothing is going to fix a bad image.

When you get into the Red, Phantom Flex, Arri Alexa and even the C300 range of camera's you can see a big difference. If you couldn't then why would those camera's even be made? I can tell the difference between a video shot Uncompressed RAW from the new Black Magic Cinema Camera with 13 stops of Dynamic Range and footage shot from a Red, Phantom Flex with 19 stops of dynamic Range and a 65mm sensor for video. Even compressed down to fit on You Tube I can absolutely see the difference as it's night and day. In fact my 12 year old daughter can see the difference without any special training. If you have a camera capable of capturing the differences in lenses it's completely obvious to anyone. It's more difficult to tell on HDSLR footage but a Super Takumar still looks a lot sharper than a Canon Kit lens or even a lot of EF L series lenses. Then you have the problem of fixed aperture settings which don't work for video.

The need to de-click has nothing to do with constant aperture lenses. The need to de-click is because moving from indoors to outdoors will every time require you roll the aperture smoothly while your moving so nobody notices the exposure change. We have a second person pulling focus while we move normally for the same reason. We move and so does our subject so focus must constantly be changed. Surely you wouldn't say that 1/3 of a centimeter is a good enough setting for focus on a camera. That's basically what your saying about aperture for motion picture. It must change as our exposure changes and it must be done smoothly and without the audience knowing it was altered.

You must match the change of your environment with a change of your aperture. This is why video camera's and all cine lenses have no detents. There is no need for a set increment with a motion picture. You need a set increment to keep your aperture from rolling while taking a still photo. You want your aperture to be fluid and unhindered in motion picture or you will see the clicks in the video. This is why Zeiss made the CP.2 lenses which has identical glass the ZE line. The CP.2 also has 14 blade aperture to make a smoother aperture adjustment. It's very important to be able to adjust your aperture on the move since we are not capturing one frame in time that can then be re-adjusted. We are capturing 1-5,000+ frames per second for minutes to hours at a time.

I am about to proudly forever alter a set of SMC Takumar's, Contax, FD's, and Jena's with EOS mounts and extra blades. They will be put to good use for another 30 years of service instead of collecting dust or just being mistreated by somebody looking for cheaper lenses than a new set of ZE's. I make no apologies about it and I assure you it's necessary to produce the image I want even if you won't be able to tell a difference most people actually do. They may not know what the difference is but they know it's different. That's why Hollywood DP's use vintage glass from the same period as their movie. It gives an aesthetic that can't be achieved with modern CNC made lenses. It gives the image a unique feel which is important to cinematography.


PostPosted: Sun Sep 09, 2012 9:49 am    Post subject: Reply with quote

Thanks for the explanation. You said it so much better than I could.


PostPosted: Sun Sep 09, 2012 5:28 pm    Post subject: Reply with quote

welcome to the forum 4130!

very interesting read, thank you.
you certainly sound like you know what you are talking about and like having much experience doing Video.

that makes me ask you, but also propellor or anybody who can help:
can you point out sites:
- to view fine samples of video taken with ( old ) manual lenses?
- to get info / help making video with manual lenses on - for me personally a NEX, but also on a dSLR, for a beginner?
( I have minor experience with SD video cam only )

thank you,
andreas

edit: just checked out cinema5d.com member Victor Nguyen has suggested in another thread.
sure much talking about manual lenses and their difference of rendering there, great to know that videographers are just as crazy about lenses as photographers Wink
and samples to see too!

a fast fix for recommended settings on a NEX5N for video, resp. what one has to be aware of, maybe has to avoid? still would be very appreciated!


PostPosted: Mon Mar 11, 2013 2:34 am    Post subject: which damping grease Reply with quote

Hi guys,

just arrived here. So funny, if I do the search in google I find this thread, but if I use the forum's search function it states that no topic is found ... strange.

However, just wanted to ask which damping grease you recommend (I know NYE is recommended, but which one exactly...there's a range from light to heavy ...). Furthermore how much should I apply?

Would be great if someone has shot some pics to send me over or post here. At the moment the aperture ring is too loose that I have to fix it with duck tape at the aperture I want.

Thank you for your help!


PostPosted: Thu Jul 04, 2013 3:13 pm    Post subject: Reply with quote

I got this done for a bunch of lenses I have - which was expensive (20 a lens), I did consider doing it by myself, but the longer lenses in particular, taking it apart and reassembling looked quite complex.

It's not so much a case of only being able to adjust exposure more finely - though it helps. I want to have a little bit of leeway when filming documentary stuff to follow subjects into brighter or darker areas, or doing other camera moves where the difference in exposure is just too great between your start frame and end frame, and you don't have an opportunity to light.

I have only ever seen a sudden change in aperture in one film, some later Woody Allen film, perhaps Vicky Christina Barcelona. Following a character from indoors to outside. A bit jarring, but it was a massive change in lighting, and they clearly decided it was better to do suddenly rather than gradually in that case.


PostPosted: Thu Dec 25, 2014 2:09 am    Post subject: Reply with quote

Well, my Canon FD 50mm 1.8 just arrived and I'm waiting for the FD to EOS adapter to use it on my T3i.
Rumors and some youtube videos say that it is possible to control the iris with the adapter, making the adapter itself into a declicked smooth iris ring....
As soon as my adapter and my Tefnon FD 28mm 2.8 arrive I'll test it to make sure....