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

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?


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


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?

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

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.

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

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?

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

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?

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

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?

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

Having shot thousands of hours using lenses with aperture rings, knocking it from the correct stop has never occurred. Also, sometimes you may wish to pull the stop during a shot and the aperture ring is the precise method of doing so,

Don;t use de noisier unless you really have to. Shooting with a high ISO should only be done if there's a really good reason to do so, For example, Professor Brian Cox on the BBC talking about the universe under a sky full of stars - the subject matter links in with the shots.

In most dramas the noise will be excessive and DPs want the best dynamic range and one limitation to this is having acceptable noise in the blacks.

"they shot at a high ASA" What be regarded as high ASA during the time of the French Connection would be the 100ASA film stock forced two stops at the most, That would give you 400 ASA, Film grain is aesthetically accepted more than video noise

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

How many times do you place all your faith in people who have proven time after time to offer very dubious advice. Denoisers, and I have used one myself just once - to repair something vitally important - are repair tools. They cannot make the picture better, they just remove artefacts but like all processing, throw away data.

I cannot recommend a different camera as I don't use DSLRs - but I respect my colleagues opinion and they like the camera apart from low light performance. Would you buy a car with known hard suspension if you have a bad back and buy a cushion to make it tolerable?

Ryan - this time, it's really for you to draw up the list of things you need a new camera to do, in some kind of priority and then use your skills to make the choice. I just find it very strange to pick a camera to do low light shots and because it does them poorly, spend a lot of money trying to fix something? That night time clip on a big screen is pretty horrid - did you really think that is acceptable, considering the tiny issues you are finding with otherwise good footage? I'd suggest you try to get somebody with the software to clean up that clip and see if it works - I have my doubts.

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

Well is there a camera that has good night vision that you can shoot streets without lighting them then?

For example, in the movie Skyfall, how did they shoot this scene, without lighting the city, and they just used the natural light, and not have any noticeable noise:


As to whether or not I think the footage is acceptable, I am not sure. I need to see more indie films shot at night that got distribution I guess, to know what is acceptable then.

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

They shot the film with an Arri Alexa, using RAW, which usually rated at 800 ISO. I gather the aerial shots were shot on a RED Epic, which has a pretty similar ISO. Certainly there's no extreme ISO involved and digital tends to be very good in the blacks, while film is good at the highlights. so nothing surprising.

I've shot on the city streets with very similar rating and a small lighting rig, so you don't need an ISO of 12,000 to shoot at night.

It's a balance, otherwise your highlights start to blowout

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

Oh okay, so when it comes to shooting city scenes like that with no extra lighting, and just using the street and building lights, what kinds of cameras would be good for that, that would be around a similar price to the Sony A7s II, if any?

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

If being serious about dramas I'd look at the new Blackmagic Pocket Cinema Cameras. https://www.blackmagicdesign.com/uk/...etcinemacamera https://www.provideocoalition.com/re...gic-pocket-6k/

It seems you need Infra Red corrected ND filters on the new camera, but that's not unusual these days with digital cameras and high density ND filters, (although the situation is improving).

I saw a student film shot on the very first camera Blackmagic made, which was shot last year and it looked really good, with a nice sense of style. Made by an 18 year old student, it certainly didn't look televisual and it wasn't in scope either. The new cameras are a lot better,

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

Oh okay, but even with that camera, if I want to shoot on downtown streets at night, I will probably have to find some way of lighting the streets, even without permission then, no matter on the camera, is that right?

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

Absolutely not! have you seen how much lighting is required to light large spaces - Inverse square law applies big time! Some cameras perform well in low light - some, er, less so.

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

Oh okay, so what would be the best approach, budget wise, if the story calls from some night street scenes, but cannot be lit at the expense that a big budget production would go?

I thought about getting creative and maybe a camera like the Sony A7 s II, or something with that high of ISO might do it, but if not, what would be the best approach then?

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

So we’re moved on to cameras that can film in the dark? That’s easy the Sony A7 series of course it records in compressed 8bit. The black magic pocket cameras are not intended for low light and use a smaller sensor but record in 10 bit raw/Prores allowing for a proper color grading.

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

Oh okay, but would low light be more important than the bit size though, in low light shooting cases?

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

Night scenes really depend on how bright the street lighting and other lighting (eg shops). I've rarely gone beyond 1500 ISO with these and I've done with less using high speed lenses.

You should be thinking of using small portable lights - battery powered LEDs would help for the closer shots. Small generators are useful and can be rented. Some of these are pretty quiet, but not for shooting dialogue beside them. Locations where you can access power are useful. BTW All this is possible on an extremely low budget film, you just need to be organised. Depending on local regulations, you may need a permit, but you may get away with just chatting to the local police.

The new Blackmagic 6k has two 2 native ISO settings: 3200 is the highest. You can see a test in the link to Provideocoalition above.

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

I feel that small lights will be good for close ups, it's just the wide shots that establish geography that might be a problem to light.

I have a scene at night where the police are surveying suspects, and it builds to a stand off and shoot out. But that kind of a scene would need a lot of establishment of geography, and don't think I could have the viewer make sense of it, if it was entirely in closer up shots, because of the lights not being able to light whole large sections at night, if that makes sense?

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

It depends where your street nights as to how large an area they'll light. You should pick your location carefully. Modern street lighting is surprisingly bright.

Be aware that if you go too high an ISO the lights on the police cars will blow out causing highlight issues and flares, it's a balancing act.

I would go for the largest lights you can get, 2k lights will do a pretty large area at 1500 ISO when combined with location lighting. Small lights involve a lot more rigging and moving around.

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

Okay thanks. I noticed that the traffic lights are also blown out too, but not sure how much the audience will care about something in the background more so being blown out.

But on topic of the lens though, if I closed down the aperture so I can have a constant aperture while zooming, wouldn't it get darker as I zoom because the longer you make the lens, the slower the light travels into it?

I thought this is the reason why my camera is turning up the aperture when I zoom, because it gets darker the more you zoom, so the camera turns it up more as a result. Wouldn't the lens exposure get darker, the longer you extend it?

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

The speed of light is a constant.

You should go through the explanations earlier in the thread again and think about the mathematics of how f stops are calculated. Bear in mind that for longer focal lengths you need a bigger diameter than short focal length lenses, so if your iris diameter is correct at the short end when wide open, the front of the lens is not going to be large enough for the long focal length in a compact lens, so the latter going to be effectively stopped down because the diameter of the lens is acting like an aperture for setting stops.

BTW Don't use zoom lenses on your night exteriors, you lose too much light with large sensor stills camera zooms because they're slow lenses. F1.4 to f2 primes is what you should be using.

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

Okay thanks, I only have two night sequences in the script and can restrict the zoom lenses to the day scenes then if that's better. It's just that is why I thought a camera with good low light vision, would be good, cause then the ISO can be high enough to shoot at say, f8 or something like that, where you can fit more actors into focus, with a deeper DOF.

As for a constant aperture, it's just that when you zoom, the lens becomes longer, so I thought it would take light longer to travel through the lens then.

As long as the aperture remains constant, if I buy a lens with a ring. If I buy a lens with a ring, will their be any hidden surprises that will make it less usable, or any hidden catches with it at all? Or will it perform perfectly with no hidden catches, as long as I am stopped down enough?

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

Well - if the lens is longer, it does taken light longer to travel down it. If the lens extends 100mm, then it takes an extra .3335 nanoseconds longer to get to the other end - but why does that matter?

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

I thought that it matters because the longer the lens gets, the slower it will take for light to travel through and hit the sensor. Isn't that why the camera is using the auto exposure as I zoom, cause it is trying to make up for the light slowing down, as I zoom in closer?

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

No it just gets dimmer, and that is why the camera tries to compensate.

Did you read Brian's excellent explanation up the topic? Explaining why the iris functions oddly when the focal length gets longer. Worth going back and trying to understand it. you can actually see this in action of you hold a proper lens up to your eye and close and open the iris. Because your eye is only looking through the centre rather than the full field like a sensor, you can see the change in brightness as you zoom. This is what the camera tries to compensate for. google lens ramping for more info, but Brian's post explains it quite simply.

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

Oh okay, I went back and read it, but this is also what I was not understanding before either. If zooming in causes the image to become dimmer, how does stopping down help be a constant aperture then? Wouldn't it still get dimmer as you zoom?

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

no - the best I can explain is that of the the overall light that gets to the sensor, through the lens has a pretty strange distribution. As you close the iris, you reduce the light getting through at the edges, working to the middle. The trouble is that at the longer focal lengths, there is very little light at the widest part, so if the lens is stopped down from say f22 to it's specified largest aperture f2, it can be that once you get to f3.5 closing further has little effect, because there isn't any light at the edges to iris out! It suddenly becomes ineffective. If the lens is zoomed out, then the level can be reduced between f3.5 and f2. The practical upshot of all this is that when you have the iris closed so you are only using the centre of the glass, you can zoom through the entire range and there is no drop in light level, but when you use the iris wide open, at some point the light starts to drop off as the focal length increases. and there is no light path that the iris can uncover to recover the brightness.

You'll notice that lenses that have a larger diameter are usually 'faster' - the larger diameters of the glass lenses let more light through. They can manage to function properly in a linear fashion. My Sigma lens is a good example of compromise. It looks quite large in diameter but as you zoom in, the front extends and you can see the diameter of that section is quite small - so at full extension the light has gone down quite a bit, and the camera can compensate in stills by adjusting the shutter opening time to recover the light. Doesn't matter in stills but in video the ramping is obvious. I don't think I've done a great job explaining this to be honest but without spending much longer, it's the best I can do for the moment keeping the language and the physics simple. For the people who know lens physics, I apologise for simplifying some of the actual physics, but it's all about tube diameter, and the clusters of lenses inside the package.

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

Okay thanks. I understand parts of what you are saying, and just trying to process it.

So would a lens that is not constant aperture though, but has the ring and no servo controls, be able to remain constant aperture, or no, if longer focal lengths, means less light is getting in, at the edges?

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

The long lens needs a larger diameter hole to let the same quantity of light through than the short focal length lens, but if the lens is too small a diameter the amount light coming through is reduced at the long end of a zoom lens compared to the short focal because of this, This is because the front of the lens itself is also acting as a stop aperture, restricting the quantity of light at the long end of the zoom.

As you stop down using the stop aperture a point is reached where the light passing though all the focal lengths becomes the same because the long focal length is no longer being affected by the restriction of the lens' because of its small diameter.

It's just the mathematics of how f stops work (which involves diameters), if you can't follow it, just accept that when you stop down to the smaller stop in the wide open aperture range, the aperture is then constant at all focal lengths. You don't need to know the reason to use the lens.

How the exposure system works doesn't come into it, so ignore that. It can't bring in more light than the lens allows by the nature of its design.

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

Oh okay, that seems to make sense, thanks.

This is what I thought, but how come if I stop down to f8, like in the video I posted before, the aperture still goes down as I zoom in though? This part I wasn't understanding before.

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

In your example, the image content was not even, so maybe the small highlights passing through exposure measuring zones triggered it? Try it again on a plain grey background and see what happens.

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

As Paul says, your exposure system was probably not totally on manual, so it was still making adjustments. If you had set the aperture, it was probably making adjustments to the shutter speed.

These are two separate items, the lens and the camera. Remember DSLRs are primarily designed for stills photographers, so they may not be as convenient for operation as video cameras, especially older ones. Unless you really know the exposure systems you may end up switching from aperture priority to shutter priority (or the reverse) instead of going totally manual. That doesn't include Auto ISO, which is another setting you want off.

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

Oh okay, but I thought it was the aperture that is changing because if put the lens on a camera that requires an adapter, then it won't get brighter as you zoom in. So therefore, wouldn't it be the aperture that is compensating, and not the shutter speed and ISO?

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

We don't know how your camera is set up and given the variables you need to ensure that you're following the correct procedures.

DSLR Basics: 8 Easy Steps to Learn Manual Mode for Canon DSLR Cameras - Nature Photography Simplified

The exposure changes that your video displayed wasn't characteristic of a lens issue because the exposure was intermittently changing during the shot. This was either due the lighting changing during the shot or the exposure being adjusted by the camera or the camera operator.

A lens exposure issues would be linear, not intermittent, unless you got some flickering flare from a light hitting the lens and that cause is external to the lens.

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

Oh okay, well the lens goes from darker to brighter, to darker to brighter every time I've tried it though, which is a lot of times as I've used in my shoots so far.

So if it was the lighting, would lighting in locations do this, this commonly, that happens every time?

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

You're not giving the the circumstances when this variation from bright to dark etc is occurring, so no one can give a response.

I know some of these schools are not good, but from the questions you're asking you should be requesting your money back from your film school, as well as getting the lens replaced.

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

Okay how am I suppose to figure out the circumstances though, like what can I do to figure it out? Do you mean the lighting circumstances?

As for the film school, they taught us on cine lenses, but I guess I should have asked what do you do if you don't have a cine lens in the end, and want to adapt a non-cine lens, and try to want to zoom anyway and what can I do therefore. But I didn't think to ask that, at the time of school, since I was use to learning on their cine lenses.

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

The lighting circumstances would be if there were flickering lights or a transient sweep of a light that would cause a change of lighting levels in parts of the image that could be mistaken for an exposure change during the shot.

It was the lighting question that left me wondering about film schools, not the lens stuff.

You still haven't given the circumstances when this "darker to brighter, to darker to brighter every time I've tried it" is occurring. If it's at f8 and doing the same thing as in your video, you should possibly get the camera checked together with the lens, especially if it's happening against a gray card or a plain wall with even lighting

If it's when the zoom lens is wide open, you'd expect it to get darker when you zoom in and lighter when you zoom out, it's doing what's expected.

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

Yes I mean when it goes darker to brighter, darker to brighter, every time I zoom, it happens exactly as you see in the video. I haven't done it under flickering lights. I've done tests in different places, and in the video you see, there were no man-made lights, and that test was done under sunlight shining in the windows, but no indoor lights were on.

I just did another test at f22 in under different lights, and even at f22 it still goes darker to brighter, darker to brighter again, just like in the video.

I took the lens off the camera, and looked through it with my eye as I zoom on it. When I do this, the brightness remains the same through the zoom as far as I can tell, looking through it. Same when I put an adapter, in between the the lens and a different camera. Then the exposure is consistent. If I hook it up to my specific camera, without an adapter in between, then it goes from brighter to darker, and repeat, like in the video.

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

Thennnnnnnnnn it sounds like you have an auto something engaged on your particular cam somewhere deep in a menu. Godspeed.