Why would you need/want to adjust aperture via manual aperture ring while filming?

[frazzywig]

This is a actually a two part question. The real thing I'm after is arming myself with the proper info so that I make the smartest lens purchases. I'm purchasing lenses primarily for video on a Canon 60D.

So... I've been doing research and here's what I've come up with so far:

1. Future-Proof, Buy Nikon mount and adapt since Canon lenses wont fully work on other cameras, at least not without a Birger mount. I'd rather just keep things simple and not rely on that, especially since I've heard it will probably be expensive when it comes out.

2. Manual Aperture Control, I've come across a lot of people saying it is better to buy lenses that have manual aperture rings.

This recommendation to get lenses with the manual aperture ring seems to potentially count out a lot of lenses, the G Series, other third party makers that don't have it. I've noticed that the Fotodiox adapter that I'd like to get can accommodate the lack of an aperture ring for the G Series lenses (not sure if it does the same for other makers where the ring is absent).

What is the reason for the presence of the ring being important? Is it also in the interest of future-proofing? Is it to enable someone to use it to control their aperture while filming instead of using the camera, whereas you can't on a Nikon, and you'd have to use the button/click wheel on a Canon. I keep noticing people emphasizing the importance of being able to control the aperture while filming with a manual aperture ring, a lot of times in the context of warning against G Series lenses. This is sometimes even to the extent that people talk about spending the money to have their lenses de-clicked in order to enable smooth aperture changes while filming.

Anyway, I'm kinda at a loss as to why you would need or even want to do this, mainly because of the existence of variable nd filters that are already smooth rotating. Wouldn't it be preferable to just set your aperture per the dof that you'd like, then adjust your variable nd for proper exposure, start filming and just adjust the vari-nd to compensate for changes in light as needed? If you're adjusting your aperture while filming for aesthetic reasons then you're changing the amount of light coming in as well. If you're doing it for exposure reasons then you're being forced into changing your dof as well. I understand the benefit of being able to manually control aperture via a ring for photography and would definitley prefer it. It just seems like you wouldn't want to do it while filming for the same reason that you wouldn't want to zoom while filming with a lens that doesn't have a constant aperture. It also seems like the desire to do it while filming video would make more sense if we didn't have variable nd's to adjust for exposure. So yea, I feel like there may be something I'm missing.

Applying it to the main point, what lenses to purchase, what do I miss out on when purchasing lenses without it, G Series or otherwise? Also, how can I find out which of the other manufacturers' Nikon mount lenses come with the manual aperture ring. I heard that the Tokina Nikon mount ones do but when I looked at the product image it wasn't there. Can the ones that don't be controlled via the "Aperture Lever for Nikon G Lenses" on the Fotodiox adapter?

Thank you in advance.

 

[mcbob]

Sometimes its nice to have the option to stop down a lens smoothly, and vari-NDs can degrade your image. Lots of ways to make movies, so just get what works for you and use it.

 

[frazzywig]

Yea, I had heard that about the vari-ND's. I just decided that I'd rather take on the image degradation while being careful to try and minimize it instead of having to take the time to keep unscrewing/screwing static ND filters or spending the $ on a matte box. So you're saying that you prefer to avoid the vari-ND, and having to stop down your lens while shooting in daylight or open it up while shooting in darker situations doesn't get in your way too much? Do you use a regular ND to help out with the daytime situations? I'm thinking maybe I'll give that a try instead of using my variable.

 

[mcbob]

Completely depends. Sometimes I use a Vari-ND, sometimes I adjust aperture, sometimes I combine both. My C-mount, OM, and Leica primes have all been de-clicked, so the aperture adjustment is smooth. I rarely shoot so shallow that aperture adjustments are conspicuous.... and if they need to be, they can be (ever do a rack DOF?)

 

[frazzywig]

I rarely shoot so shallow that aperture adjustments are conspicuous

Ok great, I feel like I've learned a little more with that statement alone, if you're not on the extremes of things all the time then you tend to have more options to adjust without making it obvious in the image. My background is computers, networking and web development, but I LOVE filming and I'm learning all the time. I have not done a rack DOF, what is that?

Also, in your opinion, is there a good chance that I'll regret not having the manual aperture ring as an option if I ended up purchasing lenses without it here or there? I'm gonna be pretty limited budget wise and would like to keep my lens purchases to a fair minimum until I'm able to start making a little more money out of my work. One more thing, is there a way to stay futurproof while avoiding the feature dissabling adapters? I'm gonna have to shoot in a lot of shoulder mounted situations and it really bothers me that going this route would disable vibration reduction, but the most important thing to me is to make sure that I don't end up having to start over if I end up buying a camera from a different manufacturer. What about the option, for example, of buying canon mount lenses from third party manufacturers. Would those lenses still be as cross-compatible with future cameras? Thanks for your help.

 

[Searcher]

There are vari-NDs and vari-NDs. The Heliiopan is getting rave reviews with almost non existent image degradation. Personally I have ordered a Heliopan and plan to have it on my FS100 pretty much always... If the quality of it is as good as "they" say then I will be doing just as you described: pick an aperture and then dial in the exposure with the Heliopan. In a way having a Heliopan is better than using on board ND filters because such small changes can be made with it.

 

[deltoidjohn]

Seems like you've been reading a bit of misinformation/old information.

A lot of people used to prefer manual-only lenses for video work because not so long ago, DSLR's had no manual control in video mode. So the only way to adjust your iris, (or just as importantly, to stop the camera from adjusting the iris by itself) was to have an aperture ring on the lens. This is still true of the Nikon D7000 which can't change aperture during live-view or video modes unless you do it manually with an aperture ring.

Secondly, Nikon G lenses (as well as modern Pentax AF lenses) are adaptable to the EOS mount with aperture control as long as you use the correct adaptor. Of course, you won't know what aperture you are actually at so you're working around a rough estimate - so this solution is not quite as simple as if the lenses have an aperture ring. The adaptors with the aperture control tab only work on lenses with a mechanical iris system, so you could not, for example, adapt Canon EOS to Micro 4/3rds using such an adaptor, because the EOS lenses do not have a mechanical aperture tab.

So, for the current Canon HDSLR's, with full manual control, there is no advantage in having an aperture ring on the lens. The information you've got is probably a hangover from bygone days when the bodies could not adjust aperture manually in video mode.

 

[frazzywig]

Actually I knew all of these things and put them in my original post:

no manual control in video mode

still true of the Nikon

Nikon G lenses (as well as modern Pentax AF lenses) are adaptable to the EOS mount with aperture control as long as you use the correct adaptor

I didn't know about the mechanical iris system though and that the lenses that have this are the only ones that work with the aperture control tab adapters. Thank you, that's going to help me out a lot. Kinda curious, what is the alternative to a mechanical iris system then, like the Canon EF's? Something that only functions via internal servos and signals sent from the camera through the leads on the back of the lens?

So, for the current Canon HDSLR's, with full manual control, there is no advantage in having an aperture ring on the lens

I had also mentioned the existing method (for the lower end Canon's like my 60D) of manual aperture control: holding the button and using the click wheel. I was under the impression that this is widely disliked because of how it can induce camera shake and that people still prefer a de-clicked manual aperture ring lens even on the lower end Canon's and (though I can only speak for the lower end ones) probably the 7D and 5DMKII with their dedicated wheel. I would think that turning a smooth ring on the lens would be less prone to camera shake than a wheel on the back of the camera.

 

[frazzywig]

There are vari-NDs and vari-NDs. The Heliiopan is getting rave reviews with almost non existent image degradation. Personally I have ordered a Heliopan and plan to have it on my FS100 pretty much always... If the quality of it is as good as "they" say then I will be doing just as you described: pick an aperture and then dial in the exposure with the Heliopan. In a way having a Heliopan is better than using on board ND filters because such small changes can be made with it.

Nice. I had definitely heard that they greatly vary in quality and have decided to go with Light Craft since it seems like they are the budget option of choice and seem to get some solid endorsement as being "good enough" quality by some very experienced people. Of course Philip Bloom being one of those people just posted a couple of months ago that the Heliopan is the best vari-ND that he's ever used, but you probably already know that. It's just that, with the Light Craft one being $125 and the equivalent Heliopan one being $444, I couldn't really bring myself to make the jump.

Interesting point though. So I suppose it might be safe to say that you are someone who would not want to adjust aperture while filming and would rather utilize a vari-ND (provided it's of a very high quality) to control exposure, thus providing full creative control over DOF.