Is it possible to pull focus on a lens while crash zooming?

Brian Drysdale · February 19th, 2019, 05:54 PM

If you've got a car mount you may get jello effect from the vibration because of the rolling shutter on the CMOS sensor in the camera. You need to test to if if this might be an issue.

If you need to use IS on your tripod, it shows that your tripod is not the best quality,

https://www.bhphotovideo.com/explora...2855/KBID/3801

If the lenses don't have IS, you can't use it.

Ryan Elder · February 19th, 2019, 06:10 PM

Okay thanks. What about if I am panning with a telephoto lens on a tripod, and the movement is much more exaggerated when zoomed into 300mm? Wouldn't I need IS if I am zoomed in that far, while panning?

Brian Drysdale · February 20th, 2019, 02:13 AM

No, you don't need IS, invest in a good tripod.

Ryan Elder · February 20th, 2019, 02:18 AM

Okay thanks, will do! I have been looking around for telephoto lenses with mechanical focus rings to replace my fly-by-wire one.

Now it would be nice to have the zoom as a bonus like the DSLR lens in the film riot was able to do, but when these lenses are on sale, they never list whether or not it can pull off a zoom and maintain focus through the zoom as one of features. Is there a way to tell, since it's not listed? Or I could just pull focus during a crash zoom if that would help.

Brian Drysdale · February 20th, 2019, 02:52 AM

As mentioned earlier in the thread, you need to test the lenses, but the Sigma still zooms might be a good starting point. https://www.newsshooter.com/2016/12/...al-evaluation/

Ryan Elder · February 20th, 2019, 03:23 AM

Okay thanks, sorry, it's just a lot of the lenses have to be ordered, but I can see if I can find a source that will let me return them for a refund, until I have found the best one for me.

Now since I am using the telephoto lens for a chase scene, I was going to use a focal length around 300mm, to pan for the side shots, of the chase, and then a 24mm around on a gimbal for other shots in the case, closer up.

But would mixing a 300mm focal length with a 24mm look strange at all, for a chase scene, or is that perfectly fine?

Brian Drysdale · February 20th, 2019, 03:40 AM

It's all in how you do it.

Ryan Elder · February 20th, 2019, 03:33 PM

Okay thanks, I will keep that in mind.

Someone also said that it was worth keeping the telephoto lens even though it is fly-by-wire as long as I shoot the action and chase scenes with really deep focus, but do you think that doing it that way, can cause any other problems?

Some viewers say they don't like deep focus, but is it possible to make it look good, like older black and white movies with deep focus use to have?

Brian Drysdale · February 20th, 2019, 04:02 PM

Films with deep focus don't use telephoto lenses.

Fly by wire will work if you focus by eye through the viewfinder, it won't work with marks.

Ryan Elder · February 20th, 2019, 04:15 PM

Okay thanks. Well I meant just stopping down enough on the telephoto lens so the focus is deep enough you won't have to pull focus, provided there is enough light and good quality ISO.

Pete Cofrancesco · February 20th, 2019, 07:58 PM

The most important thing at your stage is learning the best approach and technique. All the defects in your last movie clip you posted could have been fixed without spending any money.

You really are fixated on long lenses. Do you know you can zoom with any lens, even a wide angle prime? You have two things called feet.

Before you said you used 35mm lens on the gimbal, but if you're filming with a Micro 4/3 camera, the crop factor is 2x, meaning it's really a 70mm. That's not wide at all in fact that's a telephoto. Also many people prefer IS on a gimbal. Btw there was a lot of vertical motion in your movie clip, that can be reduced with practice.

If I were you I'd hold on to your FBW lenses. They're great for shooting on a budget, people use them all the time for run n gun type stuff like weddings. If you want to pull focus and have the money then cine lenses are a must. (but we've been over this for the millionth time)

Ryan Elder · February 20th, 2019, 09:25 PM

Well there are different reasons why I wanted a long lens. For one thing, I can track running actors for a long time in a chase scene, which is what I wanted it for, to do really pans.

As with zooming with feet, I wanted to do some crash zooms in the scene, if possible, but a crash zoom is the lens zooming really fast, and I cannot run that fast with my feet. I would have to run about 75 feet, in a fraction of a second. A zoom lens can zoom that fast, but a person's feet, cannot go that fast of course.

I tried the speed ramp thing, but the footage looks obviously sped up and it doesn't look right in my opinion, compared to just finding a way to crash zoom it. I can forget about the crash zoom and just hold onto the FBW lens if that's best, I am just not sure if I can shoot a whole chase scene, and pull focus without hitting marks. But I can practice.

Pete Cofrancesco · February 20th, 2019, 10:08 PM

For two months you’ve been insisting on shooting a scene that requires a lens you neither have or can’t afford/acquire. Either rewrite the scene or buy the lens.

I’m not suggesting you use feet for a crash zoom rather that even a wide angle lens can become a telephoto by simply moving closer to achieve a close up.

Ryan Elder · February 20th, 2019, 10:36 PM

Sorry, I am just trying to explore all possible options to shoot the scene the best way possible.

The problem I have with shooting on a wide, during a chase scene, is that a wide angle lens, cannot pan with an actor very long at all, before the actor goes further away. Here's a shot I did of a friend, with the 300mm.

As you can see, the lens can track along with a person for a much longer amount of time, compared to a 70mm. This is why I wanted a telephoto around 300mm. Moving in closer with a 70mm will not give me near as wide of a pan.

But I also wanted a telephoto cause it makes people and objects look closer together with high compression.

For example I want to do a shot, where an actor points a gun towards the camera, and the gun looks really close to the face. You can do that on a 300mm, but not on a 70mm. Also when doing over the shoulder shots, you can make actors look really close on a 300m but not a 70mm.

What if I tried to fake the compression, and make them look closer? Would the viewer be able to tell? Here are some comparisons I did with the 300mm with real compression, to an 85 mm, trying to fake the compression but having the objects actually be closer:

Does faking compression work with an 85mm lens, or can the audience tell that the compression is being faked? Cause if I can do these types of shots, on a non-telephoto, by simply moving a wider lens closer, than I'll do it, but I think these kind of shots I want, have to be done on a telephoto, unless I am wrong?

Brian Drysdale · February 21st, 2019, 02:55 AM

This thread seems to be going run in circles.

The crash zoom is separate from the telephoto. You either rent a parfocal cine zoom or buy one of the few varifocal still zooms which have "near" parfocal characteristics. The stills version of Sigma zoom mentioned above is worth checking out.

You don't need a zoom lens for a long lens look.

You can't use markings for focus on fly by wire lens..

If you want IS you'll probably;need a fly by wire lens for the gimbal shots, So either borrow or rent a suitable lens if you can't afford to buy both a manual focus and an IS lens, You could test adding a weight to the camera (as mentioned earlier) to dampen it on the gimbal if a manual focus lens is the only option because you really need manual focus with markings and only obtain/afford one of these two lens options,

Google is your friend (other search engines exist) you can check out from sites that have run tests on zoom lenses.

I don't think you need to repeat your thought processes,when they've already been mentioned earlier in thread.

I suspect everything has been exhausted on this chase scene apart from you going out and shooting it.

February 19th, 2019, 05:54 PM	#211
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? If you've got a car mount you may get jello effect from the vibration because of the rolling shutter on the CMOS sensor in the camera. You need to test to if if this might be an issue. If you need to use IS on your tripod, it shows that your tripod is not the best quality, https://www.bhphotovideo.com/explora...2855/KBID/3801 If the lenses don't have IS, you can't use it.

February 19th, 2019, 06:10 PM	#212
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Okay thanks. What about if I am panning with a telephoto lens on a tripod, and the movement is much more exaggerated when zoomed into 300mm? Wouldn't I need IS if I am zoomed in that far, while panning? Last edited by Ryan Elder; February 19th, 2019 at 06:47 PM.

February 20th, 2019, 02:13 AM	#213
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? No, you don't need IS, invest in a good tripod.

February 20th, 2019, 02:18 AM	#214
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Okay thanks, will do! I have been looking around for telephoto lenses with mechanical focus rings to replace my fly-by-wire one. Now it would be nice to have the zoom as a bonus like the DSLR lens in the film riot was able to do, but when these lenses are on sale, they never list whether or not it can pull off a zoom and maintain focus through the zoom as one of features. Is there a way to tell, since it's not listed? Or I could just pull focus during a crash zoom if that would help.

February 20th, 2019, 02:52 AM	#215
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? As mentioned earlier in the thread, you need to test the lenses, but the Sigma still zooms might be a good starting point. https://www.newsshooter.com/2016/12/...al-evaluation/

February 20th, 2019, 03:23 AM	#216
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Okay thanks, sorry, it's just a lot of the lenses have to be ordered, but I can see if I can find a source that will let me return them for a refund, until I have found the best one for me. Now since I am using the telephoto lens for a chase scene, I was going to use a focal length around 300mm, to pan for the side shots, of the chase, and then a 24mm around on a gimbal for other shots in the case, closer up. But would mixing a 300mm focal length with a 24mm look strange at all, for a chase scene, or is that perfectly fine?

February 20th, 2019, 03:40 AM	#217
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? It's all in how you do it.

February 20th, 2019, 03:33 PM	#218
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Okay thanks, I will keep that in mind. Someone also said that it was worth keeping the telephoto lens even though it is fly-by-wire as long as I shoot the action and chase scenes with really deep focus, but do you think that doing it that way, can cause any other problems? Some viewers say they don't like deep focus, but is it possible to make it look good, like older black and white movies with deep focus use to have?

February 20th, 2019, 04:02 PM	#219
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? Films with deep focus don't use telephoto lenses. Fly by wire will work if you focus by eye through the viewfinder, it won't work with marks.

February 20th, 2019, 04:15 PM	#220
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Okay thanks. Well I meant just stopping down enough on the telephoto lens so the focus is deep enough you won't have to pull focus, provided there is enough light and good quality ISO.

February 20th, 2019, 07:58 PM	#221
Pete Cofrancesco Inner Circle Join Date: May 2004 Location: USA Posts: 3,005	Re: Is it possible to pull focus on a lens while crash zooming? The most important thing at your stage is learning the best approach and technique. All the defects in your last movie clip you posted could have been fixed without spending any money. You really are fixated on long lenses. Do you know you can zoom with any lens, even a wide angle prime? You have two things called feet. Before you said you used 35mm lens on the gimbal, but if you're filming with a Micro 4/3 camera, the crop factor is 2x, meaning it's really a 70mm. That's not wide at all in fact that's a telephoto. Also many people prefer IS on a gimbal. Btw there was a lot of vertical motion in your movie clip, that can be reduced with practice. If I were you I'd hold on to your FBW lenses. They're great for shooting on a budget, people use them all the time for run n gun type stuff like weddings. If you want to pull focus and have the money then cine lenses are a must. (but we've been over this for the millionth time) Last edited by Pete Cofrancesco; February 20th, 2019 at 08:53 PM.

February 20th, 2019, 09:25 PM	#222
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Well there are different reasons why I wanted a long lens. For one thing, I can track running actors for a long time in a chase scene, which is what I wanted it for, to do really pans. As with zooming with feet, I wanted to do some crash zooms in the scene, if possible, but a crash zoom is the lens zooming really fast, and I cannot run that fast with my feet. I would have to run about 75 feet, in a fraction of a second. A zoom lens can zoom that fast, but a person's feet, cannot go that fast of course. I tried the speed ramp thing, but the footage looks obviously sped up and it doesn't look right in my opinion, compared to just finding a way to crash zoom it. I can forget about the crash zoom and just hold onto the FBW lens if that's best, I am just not sure if I can shoot a whole chase scene, and pull focus without hitting marks. But I can practice.

February 20th, 2019, 10:08 PM	#223
Pete Cofrancesco Inner Circle Join Date: May 2004 Location: USA Posts: 3,005	Re: Is it possible to pull focus on a lens while crash zooming? For two months you’ve been insisting on shooting a scene that requires a lens you neither have or can’t afford/acquire. Either rewrite the scene or buy the lens. I’m not suggesting you use feet for a crash zoom rather that even a wide angle lens can become a telephoto by simply moving closer to achieve a close up.

February 20th, 2019, 10:36 PM	#224
Ryan Elder also known as Ryan Wray Join Date: Nov 2017 Location: Saskatoon, Canada Posts: 2,888	Re: Is it possible to pull focus on a lens while crash zooming? Sorry, I am just trying to explore all possible options to shoot the scene the best way possible. The problem I have with shooting on a wide, during a chase scene, is that a wide angle lens, cannot pan with an actor very long at all, before the actor goes further away. Here's a shot I did of a friend, with the 300mm. lens running test 2 - YouTube As you can see, the lens can track along with a person for a much longer amount of time, compared to a 70mm. This is why I wanted a telephoto around 300mm. Moving in closer with a 70mm will not give me near as wide of a pan. But I also wanted a telephoto cause it makes people and objects look closer together with high compression. For example I want to do a shot, where an actor points a gun towards the camera, and the gun looks really close to the face. You can do that on a 300mm, but not on a 70mm. Also when doing over the shoulder shots, you can make actors look really close on a 300m but not a 70mm. What if I tried to fake the compression, and make them look closer? Would the viewer be able to tell? Here are some comparisons I did with the 300mm with real compression, to an 85 mm, trying to fake the compression but having the objects actually be closer: compression tests - YouTube Does faking compression work with an 85mm lens, or can the audience tell that the compression is being faked? Cause if I can do these types of shots, on a non-telephoto, by simply moving a wider lens closer, than I'll do it, but I think these kind of shots I want, have to be done on a telephoto, unless I am wrong?

February 21st, 2019, 02:55 AM	#225
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Is it possible to pull focus on a lens while crash zooming? This thread seems to be going run in circles. The crash zoom is separate from the telephoto. You either rent a parfocal cine zoom or buy one of the few varifocal still zooms which have "near" parfocal characteristics. The stills version of Sigma zoom mentioned above is worth checking out. You don't need a zoom lens for a long lens look. You can't use markings for focus on fly by wire lens.. If you want IS you'll probably;need a fly by wire lens for the gimbal shots, So either borrow or rent a suitable lens if you can't afford to buy both a manual focus and an IS lens, You could test adding a weight to the camera (as mentioned earlier) to dampen it on the gimbal if a manual focus lens is the only option because you really need manual focus with markings and only obtain/afford one of these two lens options, Google is your friend (other search engines exist) you can check out from sites that have run tests on zoom lenses. I don't think you need to repeat your thought processes,when they've already been mentioned earlier in thread. I suspect everything has been exhausted on this chase scene apart from you going out and shooting it.