My lens has a spot on it, is there anything I can do?

[Chris Hurd]

Originally Posted by Ryan Elder

why is it that people say that in order for a lens to be constant aperture, that the lens has to be larger and heavier, when you can just turn a variable aperture lens into a constant aperture by closing the aperture down?

Look, both halves of this are true. First:

people say that in order for a lens to be constant aperture, that the lens has to be larger and heavier

This is correct. If you could take your current 75-300 and hold it in one hand, and hold the Canon EF 70-200 f/2.8L in your other hand, the difference in size and weight (and cost) might astonish you. The 70-200 f/2.8 is much larger and much heavier (and much more expensive) precisely because it is constant aperture (well, also, it has much better glass, plus a much better AF mechanism).

And:

you can just turn a variable aperture lens into a constant aperture by closing the aperture down

This is also true. Except... you wouldn't be shooting f/2.8 at 200mm full telephoto. Get it? Some people want that. And they can afford it. And they don't mind the size and weight.

I've been telling you to "just turn a variable aperture lens into a constant aperture by stopping down" because you don't have much of a choice, my friend. There is no such thing as a constant aperture telephoto zoom to 300mm in a Canon EF or EF-S lens mount. The sole exception to this would be the Canon EF 100-400 f/4-5.6L IS, which would give you a constant f/4 from 100mm to 350mm or so. Beyond that it closes down to f/5.6.

I can't speak for Nikon, Sony or anything else in the APS-C / Super 35 image circle size, but I kinda doubt any of them have a constant aperture telephoto zoom that reaches 300mm. Maybe someone else who knows can chime in on that.

[Brian Drysdale]

There are some 16mm cine zoom lenses, which also display the variable aperture when at maximin aperture, as do ENG zoom lenses and the zooms in video camcorders. The reason is to keep the sizes and weight down..

I saw some constant aperture zooms intended for 2/3" cameras (to be used on dramas) and they were much larger than the usual zooms made by the same manufacturer (with the same focal length) as found on ENG cameras. .

[Ryan Elder]

Originally Posted by Chris Hurd

Look, both halves of this are true. First:



This is correct. If you could take your current 75-300 and hold it in one hand, and hold the Canon EF 70-200 f/2.8L in your other hand, the difference in size and weight (and cost) might astonish you. The 70-200 f/2.8 is much larger and much heavier (and much more expensive) precisely because it is constant aperture (well, also, it has much better glass, plus a much better AF mechanism).

And:



This is also true. Except... you wouldn't be shooting f/2.8 at 200mm full telephoto. Get it? Some people want that. And they can afford it. And they don't mind the size and weight.

I've been telling you to "just turn a variable aperture lens into a constant aperture by stopping down" because you don't have much of a choice, my friend. There is no such thing as a constant aperture telephoto zoom to 300mm in a Canon EF or EF-S lens mount. The sole exception to this would be the Canon EF 100-400 f/4-5.6L IS, which would give you a constant f/4 from 100mm to 350mm or so. Beyond that it closes down to f/5.6.

I can't speak for Nikon, Sony or anything else in the APS-C / Super 35 image circle size, but I kinda doubt any of them have a constant aperture telephoto zoom that reaches 300mm. Maybe someone else who knows can chime in on that.

Oh okay that's what I thought. But since being zoomed at 300 mm around has such a shallow deph of field, I didn't think it was possible to shoot an f 2.8 and still have the footage be usable because the depth of field would be way too shallow to fit more than one actor in focus.

so I didn't think I would be using f2.8 anyway therefore, or a wide f-stop at all.

I thought if i shoot under low light I would just get a camera there was good for it like the Sony a7s II or the Panasonic gh5 and then shoot at a deeper depth of field, unless there would be any reason not to?

Well the store was able to replace my lens since it was under warranty and they gave me a new one under store policy. But as far as getting a lens with an aperture ring goes, since I was going to get a new camera anyway, why not just get a camera where I can switch off the servo controls to the lens, rather than by a new lens with an aperture ring?

[Brian Drysdale]

High end f2.8 300mm lenses have been available since the 1970s and used by sports photographers and film makers ever since.

As for the aperture ring, it really depends on your future plans and if you wish to buy a digital cinema camera, which commonly have an ISO of 800 when shooting RAW and log. If you don't know what these are (and their advantages), please look it up online, since I don't think a thread would be long enough to explain it to you.

If you plan just to shoot with a DSLR and are happy to get a camera that can set the aperture using manual mode (you'll need to check that you can do this with a particular camera) that fine. I don't think this involves switching off the servos controlling the aperture like you can the focus, it involves using the camera menus.

Personally, because it's intended for video rather than stills, I'd buy a f4 Canon 300 with an aperture ring and a range extender, but you seem to make a simple decision complicated.

[Ryan Elder]

Oh okay, I've tried shooting at a wide aperture on my lens but feel I need to close it down to around f11 to get a couple of people at least in focus.

What I mean is a camera where you can shut off the auto exposure system, since it was that that was causing the lens to change aperture when zooming, through the servo controls, unless I have that wrong...

I would want a camera where you can have full manual control during the zooming. Or I could get a video camera instead of a DSLR, but I do have projects I want to to do shooting on streets at night, where I can't light the streets, so I would want a good ISO, like the one the Sony A7s II has or something like that, probably.

[Brian Drysdale]

The aperture setting should be on manual for drama, regardless of if you're zooming. You need to check that the camera can allow you to set that and that also lock the shutter, so that it also won't change.

My argument for the aperture ring is that it's quick to set and you're not fiddling with the camera trying to set the aperture. I lit a video that used a lens with no aperture ring on a GH5 and it involved some playing around and I'm still not sure if everything was under manual control. I wasn't operating the camera, bit there seemed be some compromise going on.

[Ryan Elder]

Oh okay, for sure.

On my camera I have full manual controls and have total control on the shutter, aperture, and ISO and it's all locked and won't change. The only thing I don't have manual control over, is the aperture changing while zooming, so I will want a camera where I can lock it while zooming as well.

I've used lenses with the rings while doing projects in a film school course I took. The one dis-advantage of the rings is that the ring was very sensitive to moving and if the lens was bumped or anything, the aperture would move, where as by setting the aperture in camera, it locks, unlike a ring.

But the ring I could probably get more use to. I just figure that since so many zoom lenses out there don't have rings, maybe I should just get the best one, and get a camera where I have manual control of the aperture during zooming, since I was going to get a new camera anyway. If I get a camera that has full manual control during zooming, then I do really need an aperture ring on the lens?

[Paul R Johnson]

The ring can get know knocked? Well yes, if you are careless, but you just train yourself to do it. I don't think I have ever knocked the iris ring as it's close to the camera - I've done the focus ring lots, because it's at the other end and easier to move when you hold the lens up?

Why are you asking questions, then ignoring the multitude of comments?

You have a lens that is performing poorly from your posts optically, and physically. So when you buy a new one FOR VIDEO - buy one that:
1. Stays in focus when you zoom
2. Stays on exactly the stop you set it to
3. Has sharp focus
4. Is cost effective.

All 4, or nothing - but until you do, don't keep reinventing the problems you currently have.

If you plain just don't wish to hire the right tool, for goodness sake, buy one that will do what you say you need.

You NEED a lens that will allow YOU, or the camera to adjust the iris. It needs to be selectable - give control to the camera or keep it for yourself. Very straightforward.

Loads of lenses have servo control (I just won't use the 'fly by wire' term) and clearly for you these are bad, because it shows they are designed for photography not video. If you want to shoot video, buy video kit. How many photos do you take on your camera? As I have said, nothing would make me shoot video on my DSLR - it's simply awfully designed for moving pictures. Some, I admit can be optimised for this, but so many do video as an 'amateur' add on, and do it pretty poorly - other than maybe picture quality.

[Ryan Elder]

Okay thanks. Yes I will get a new lens, just still deciding. As for a new camera, which I also want, since I am not digging the T2i for other reasons anymore, I want a camera like the Sony A 7sII, which is good for shooting on the streets at night, when you can't light a whole street, since it has a high ISO, but I want a camera that a smaller sensor than full frame, like an APS-C sized sensor, cause then the shallow DOF won't be so sensitive, when shooting under low light.

Are there any video cameras, that would have those two features, plus no servo control limitations? :)

[Paul R Johnson]

Ryan - I know little of the A7, but my colleagues in the Guild of Television Professionals here in the UK have been looking for users with their own recommended setups to solve the camera's noise problem in low light - dealing down to 400 equivalent, and they complain about the screen which is difficult to see in sunlight? No idea if this impacts on you, but thought I'd mention it.

[Ryan Elder]

Yeah when I used the Sony A7 s II before, the screen was difficult to see, especially since it has zero contrast in the image. I thought maybe I would use a monitor that I can add a higher contrast lut to, so the screen would be more viewable if that would make sense.

As for noise problems, I thought it did pretty good when I used it before. Here is some test footage I found on youtube, is there a lot of noise at night as long as there is light around?

Now I See: Sony A7S Low Light - YouTube

Here is also a short film project we shot with the A7s II:

Trioxin Commercial second copy - YouTube

The noise is a lot less in the lit street, but once you get to the cemetery, even though we lit the cemetery, there is still plenty of noise. So it seems that a lit cemetery will still have noise, but on the street, with streetlights, it's much better, but what do you think?

[Paul R Johnson]

For me that is a LOT of noise and it's that unpleasant 'moving' type of noise. If that's what my friends are complaining about I can see their point.

[Ryan Elder]

Well I could use a program like Denoiser II to try to reduce it if that is best. I have a project I want to shoot which is undercover cops, surveying suspects, and it would be on streets at night. It's fiction of course.

I was watching a documentary on the making of The French Connection and they too, had to shoot on streets at night that the couldn't light all that much, so they said they shot at a high ASA and embraced it the grain that came with it, but should I do shoot in a French Connection style, and embrace a certain degree of noise then?

[Paul R Johnson]

Buying a repair app to cure a problem with a camera - which to be fair wouldn't be an issue if you never wanted low light performance, is daft.

if you have a forthcoming project that needs low light capability, hire something or buy something with a good rep for being noise free. I can't believe you want to buy a new product and software to try to fix its issues?

[Ryan Elder]

Oh okay well it was suggested to me by others and everyone I know uses denoiser plug ins, so I thought it was fine...

But is there a camera with better quality high ISO than the Sony A7s II then?