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

Okay thanks. I asked how to switch this off before to people familar with the T2i. They say switch to full manual controls, but it already is on that, unless maybe it's impossible to turn off.

However, if I do buy a new camera where you can turn it off, is it necessary to still get a telephoto lens with an aperture ring then? What's the point of an aperture ring, if you have a camera, where the servo controls can be disengaged?

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

I dont know that cam at all. I would look through the menus one by one for auto anything, turn off, look in manual index for auto to see what those settings might be, google search, youtube tutorials for setting up t2i (or whichever cam it is) for filmmaking and also videos about those auto settings.

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

In video the advantage of an aperture ring is that you can adjust the stop during the shot, to the exposure you want, rather than where the auto exposure system wants.

The 1st AC or DP can easily reach an aperture ring, compared to trying to do the adjustment on the back screen of the camera while filming.. This can be really handy during complex shots that involves going from dark areas into light ones etc and when the sun keeps going in and out behind the clouds, you can ride the stop.

Please do the test with a blank surface (gray would be ideal) with flat lighting, It's the method you'd use when testing an exposure meter,

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

Okay thanks, I already read through the instructions for my camera, as well as googled it but it doesn't say anything about their being additional servo controls to switch off though.

As for having a ring handy to change when lighting changes, I didn't think it would be any more easy than turning the dial on the camera to change the aperture. Plus on the camera you can see what the aperture is on the screen all the time, where as with the ring, you have to look over on the lens to see.

So I thought that a dial on the camera was just as easy to operate than the ring.

But yes, when I did this test at f22 just now, I did it on a blank wall, and it's the same thing, darker, brighter, then repeat.

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

There are 3 possibilities:
1. You haven't set the camera into full Manual. I glanced at the T2i manual and it looks like you need to change this in the menu and turn off auto iso.

2. The camera could be changing the exposure based to compensate for a darkening at the edges (vignetting) which might be located in a zoom range. Modern cameras commonly communicate with the lens and can modify the image to correct for aberrations in the lens. It also could be increasing the exposure to compensate for the variable lens aperture. Note these cameras and lenses were designed for still photography not video, so they often don't operate in a way that film makers would like.

3. Either the lens or camera is malfunctioning. Although I find this highly unlikely.

#2 is the most likely and if it's the case you just live with it. It's a very minor issue and you shouldn't be zooming while filming on a flyby wire lens. You said you're getting a new camera and lens.

Lesson to be learned consumer equipment doesn't operate like professional gear, the value of constant aperture lens and finally always understand and test your equipment.

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

Okay thanks, but I never have the auto ISO on. The ISO was at 800 the whole time during that zoom in the video, and during all my tests, I always set the ISO manually first.

The full manual is on.

I think it's most likely #2 as well. Why is there aberrations going on though, if they need to be corrected? What is causing the aberrations? Is it because less light is traveling into the lens, the longer it gets when you zoom in? Is that what's causing it?

This part I don't understand cause it was said before that the lens could become an constant aperture lens, if I stop down enough. But if there are aberrations, can it become a constant aperture lens, or not then?

I just want to know these things, cause when I get a new camera and lens, I don't want to replace all my lenses, such as my 24-35 lens for example. My other lenses, do not have aperture rings. So when I get a new camera, I want a camera where #2 will not be an issue, since my other lenses don't have rings. Are their cameras out there where it will not compensate for aberrations when zooming?

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

Ryan, why do you never do what people suggest, but just bits of it? It's so frustrating to waste time on your questions and then you answer questions with questions.

What do you really want? It feels like you are looking for solutions to avoid changing the lens, avoid changing the camera and for some reason, avoid the lenses that have a manual, conventional iris setting. Why are you fixated on having servo controlled aperture?

Yesterday I was on an airfield shooting parachutist. The most frequent lens adjustment was the iris ring. A real mechanical one, that I do NOT need to look at because I'm interested in the viewfinder, which shows me where it is. They kept moving across white fluffy clouds, at some points the over level zebra was the entire image but he parachute was the constant. Then it would traverse into clear blue sky, then white again. Everything is on manual. Everything stays static, unless I decide to change things.

Unless your system can do this, it is flawed. Find out now if it is the lens or the camera. This is pretty vital. You do have other lenses I think you said. Pretty much the train of thought points to the lens doing its own thing but you must be certain.

What did your film school teach you about zoom's? It seems to be very little. A curious omission. Did your training do everything with prime lenses? Did you have your zoom at that time? I assume you decided to not follow their training and do your own thing. They also seem to have missed things like modules on image stability, grip equipment and movement? I find it difficult to believe they're teaching film with so many critical elements missed or glossed over. What kind of film making are they concentrating on, because it's obvious they totally missed cinema production no. 1 - as in how it was done for the great movies over the past 100 years.

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

What make and model is this zoom lens?

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

It's this one - Canon EF 75-300.

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

This issue may be possibly vignetting at f8, the image seems to darken at that stop as you go to longer focal lengths in this test video on the lens


There doesn't seem to be any aperture ramping after f5.6.

The answer is to sell the lens, the test video confirms what has been said here; it's a poor performer at 300mm. The zoom action is poor, so anything less than a fast zoom won;t work, although its near parfocal, so the focus holds pretty well as you zoom.The video also gives a possible reason why dirt could get into the lens.

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

“Worst Canon Lens Ever” LOL
They were meant for each other.

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

I pointed this out long ago and I repeated it several times... in this thread plus a couple of other Ryan discussions.

That particular telephoto zoom is without question the single worst lens he could possibly be using. It's cheap junk.

He could stay in the Canon line and choose any one of several other Canon telephoto zooms in that same focal length range. *Any* change would be an improvement.

I have pointed this out more than a few times before and I've just said it again now.

It is definitely a vignetting issue with that lens as Brian points out. It has nothing to do with camera settings or anything else... it's just that particular lens. It's showing off just how bad it is for video -- an application for which it was *never* intended or designed.

Even if he stayed in the Canon consumer range, the very next step up -- the Canon EF-S 55-250mm f/4-5.6 IS STM -- would be a huge improvement for only $100 more. The next one up from that, the Canon EF 70-300mm f/4-5.6 IS II USM -- would be even better, and it's less than $500.

But he's rejected these suggestions because they're "fly by wire" and somehow for him that's a deal breaker. Well, the deal's already broken by that bottom-of-the-barrel junk he's using right now. Either one of these two lenses would put him in a newer and much better world. But, I feel like I'm talking to a brick wall here.

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

Well I was told before, that it's not possible to use a follow focus with a fly-by-wire lens, so if you cannot use a follow focus with one, isn't that a deal breaker?

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

I don't quite understand what he really wants - at one point, we're talking camera tape and markings for somebody to do focus while somebody else does aperture, then we switch to night time shooting, then wildlife - my head spins. It's even more difficult when information is dotted around in the other posts.

What is 100% certain is that this lens is the worst for virtually all his projects - it doesn't seem to do any properly - although in all the video clips we see, the killer for me is wobble and shake. Real cinema and real video doesn't do this, yet Ryan hasn't;t spent any of his money on keeping images stable.

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

Well I want a lens that I can do telephoto shots with for projects that can zoom up to 300mm. And as a bonus if possible, one where you can zoom during the video without any type of exposure changes or vignette issues that are noticeable. Even if I can only do fast zooms with it, that's fine, as slow zooms look a lot more cheesy anyway, in my opinion. Even if it's not parfocal, I can pull focus myself, during the zoom or so I was told to, if it's not parfocal. And I want one where I can use a follow focus with it, which means no fly-by-wire and mechanical then. That's what I want.

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

The answer is to get another lens and sell this one, Going over this again and again with the same questions on the forum is wasting other people/s time.

Look at the more expansive lenses. You'll be unlikely to be do more than a simple focus pull for the end to be in focus (but with the zoom itself out of focus) if you;re talking about the shot in a different thread, I don't think we want to go over that, since it was well covered

You should do the research on all the zoom lenses in this range, there are online reviews on many of these lenses, so you can check these reviews out and make a decision yourself.

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

What you have right now is a deal breaker.

Plus, you're wanting to shoot video with a still-photography telephoto zoom. Considering that your budget is too limited for a proper cine zoom or a traditional broadcast video lens (and a camcorder to match), I think something as elaborate as a follow-focus mechanism is pretty much out of the question here.


That would be almost any telephoto zoom lens other than what you have right now.

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

Oh ok but why is a follow focus out of the budget though?

As for my lens being wobbly like in the video, i thought that that is because in the video, the guy is handholding it. It wouldn't be wobbly on a tripod.

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

because the legitimate non-janky ones are expensive. Youre gonna google search and find all kinds of stuff for $150 and probably less. Those are crap. The good stuff is around $600 and up.

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

Okay then, thanks, I'll keep that in mind. I know I am going to get a new lens, but if I search for one that does not have vignetting, I want to know how to spot it. I can't spot the vignetting in my footage. I know when I zoom, it goes from darker to brigher, then repeats that, but I can't see any vignetting, when zoomed all the way to 300mm.

Here's a shot zoomed all the way. Is there vignetting in it, than I am not seeing?

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

Some of the best wildlife video work by an amateur that I have seen is by Tara Tanaka. You would do well to read/study her notes for her videos. Lots of valuable info there on gear and technique.

https://vimeo.com/h2otara

Also, on the low cost equipment end of things is the amazing work done by Bob.

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

Ryan - no I cannot see any vignetting at that iris setting. The lens has it listed as a common issue so if you can shoot your long shots at that aperture you have it covered.

It's been a while but I bought a cheap matte box from India with a follow focus unit. The eluminium was ridiculously poor and soft. Screws pulled out, hinges twisted off when they got stiff, and the plastic lens gears lost their teeth. I replaced the matte box with a proper brand but never replaced the focus unit because frankly, I didn't need one!

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

In the review video the vignetting test was shot against at plain blue card (so there's no distracting detail) and was poor at f8 and better at the other stops and changed with the focal lengths, It may also vary with the distance your lens is focused at, but I assume the test was done with the lens focused at its closest distance.

For example, the Zeiss 10mm to 100mm T2 16mm zoom lens vignetted at the shorter focal lengths when focused closer than 5ft. It didn't have any focus markings below 5ft (it can focus down to a metre) , so it was left to your discretion if you focused closer than that.

So it would depend on which stop your bird video was shot at if the vignetting was noticeable and the longer distance involved may mean that the vignetting doesn't occur..

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

Oh okay, I think that bird shot was done at f18. However, I did tests on that lens while zooming at f22. It get's darker than brighter, then darker, then brighter, during the zoom. So if that is vignetting, then it is only occuring during the zoom, but then disappearing after the zoom. Why would the vignetting disappear, if there is no zooming going on, if that seems to be what's happening? I just want to know so I know what I am looking for when getting a new lens :).

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

Since people here don't have access to your lens or camera, I suspect you'll have to go to a local technician or similar person to get them checked out.

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

Can I check something? Vignetting is a gradual darkening at the extremes, with centre as origin - so the corners darken, NOT the whole picture. Are we sure we are talking about the same thing? The still lens on my old DSLR would gradually creep the corners in as I approach maximum focal length. If your problem is an overall brightening or dimming of the image as you progress through the zoom range, that suggests a totally different problem with it - not vignetting at all.

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

I think it's the whole image that darkens when zooming in. I only thought it was a vignette cause it was said on here that it was.

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

A vignette at the long focal lengths with be softer than one at short focal lengths. it'll won't be in the centre, but around it.. The review video had significant darkening at t8, which appeared be more than just the corner's. It also varied with the focal length. Your lens may vary from their test lens.

Again, we can't see your camera and lens or make adjustments to them, we can only speculate on the causes. You'll have to take the action required by going to someone local, who has the experience and can physically check out your equipment, that''s the only way you'll get a solid answer.

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

Since this is a new lens, perhaps this issue should be addressed by your local dealer.

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

Not to muddy the waters here, but I think this is a "feature" of his particular lens, and not a bug.

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

But the camera does this to my other zoom lenses too, darker to brighter, darker to brigher, during the zoom. It is the camera that is causing it.

I don't think it going darker is a vignette though, cause you would see the vignette when I stop zooming wouldn't you? Or is there any reason a lens would only have a vignette during the zoom only?

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

We keep describing vignetting and you keep describing brightness fluctuations? If you get the same effect on other lenses then it's your camera. It could even be faulty, but I suspect it's just doing what stills cameras do, constantly tweaking exposure, and because you are recording video, you record the result. Neil you buy a new camera and a new lens, it's not something we can fix for you. Maybe we need to stop here, we're making no progress at all because your equipment is preventing it.

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

Is the T2i supposed to do that though? I know it's "obsolete" now (there are still people using 5DM3s out there for video) but in its day I think it was a pretty popular low cost alternative to the 5Ds even for paid work. Can't imagine people would have gotten away with using it if it was constantly screwing up exposure. Maybe I'm wrong.

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

As Paul says, if the common factor is the camera, that's what you need to address. Given its age and that you want to shoot more than YouTube cat videos with the camera, it's probably long overdue being replaced. This issue could either be a fault with the camera or operator error, However, that's something that we can't tell from a distance.

The logical thing is to test the lenses on another camera to see if it occurs there. Although, I'm assuming that these zooms are different models. rather than just the old zoom lens with the spot and its replacement from the dealer and the zooms are not being used with the aperture wide open.

A vignette will stay, it's nothing to do with the zooming, it's the focal lengths at which this issue occurs in a lens, not the zoom action.

There is nothing more that can be served by continuing this, the solution lies in your own hands.

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

I still have my old T4i, which replaced a T2i, and Josh is correct, a lot of folks used the T2i (and T4i) for video back in its day. I never got around to putting mine on Ebay, although it's all boxed up and ready to go. I would dig it out, but this is a very busy time for DVi right now (last week was camera week -- did you see all of the big announcements at https://www.dvinfo.net/news -- and there's more happening today).

Brian is right of course, this has been a case of operator error or equipment failure, and it's too difficult to remotely diagnose What we do know to be true is that the OP has an obsolete (that is, pre-DPAF) DSLR and the single worst lens one could possibly buy.

I agree that this discussion has pretty much run its course. I'm tempted to lock it down.

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

Sorry, I didn't mean to extend the discussion too much, I was just trying to figure out the best lens possible to buy, for me, and my budget.

If I put my lens on a different camera with an adapter though, it only changes exposure while zooming, if I am using an adapter with servo controls. If I use an adapter without servo controls, the aperture stays the same when zooming.

So since I want a new camera and new lens for future projects anyway, I would have to get one that allows more options on the servo controls, specifically which servo controls it can control. I don't want to replace all my lenses, with aperture ring lenses, cause I would still like to keep the other ones.

So are there cameras out there, newer ones, that allow the servo controls to control the aperture, but then once the aperture is locked, the camera will not to change it when zooming specifically?

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

From what you say, the answer is to buy a new lens and camera.

If you buy a camera with a manual mode you can set the aperture and other exposure settings and these won't change unless you change them.

We can do no more for you on this matter.

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

Confused even more - you decided early on that you wanted to be able to set the iris manually, and were talking about people working the lens, and now you want another servo lens? Why not invest in a parfocal that will allow zooming, constant focus, and on most a ring with a distance readout? Doesn't;t even need to be new as old glass is usually good glass flooded after?

I n' work you out at all - your requirements change like the seasons and vary like a tide ebbing and flowing. A statement in one topic contradicts one in another.

Ok - here we go.

how much money are we spending for you on a lens, and as you don't seem to take photos, could we suggest maybe one of the Blackmagic style cameras could actually be better for what you seem to do?

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

No i dont want another servo lens, i just want a camera that will work with my other lenses that don't have rings. I will replace the telephoto lens bur I don't want to replace all the lenses.

But getting a camera with manual mode is not enough cause as you can see, my camera is on manual mode and it still changes the aperture when zooming. Will the blackmagic cameras not do that while in manual mode?

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

Your camera may have a fault, so it needs to be checked.