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Interceptor121

What is the right focal length for video?

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years ago when I started video people even professionals had camcorders. Looking back at those books you see things like a lens with 29mm equivalent is considered wide and then you would want the ability to zoom. Camcorders would have lenses that would go easily 8x. You would then by special lenses like fathom when you needed a wider viewBack in the days you would work with 60 degree lights to cover for 35mm equivalent more or less stretching to 28mm. Now you have 90 to 120 degrees lights and wider lenses like the Nauticam WWL-1 and some people even shoot fisheye.

When I started off with compact camera videos I would shoot reef scenes with a 24mm equivalent and would get a 100 degree wet lens only in special circumstances. Would have never shot 130 degrees video as I did not like the barrel distortion.

Then DSLR and mirrorless came into the mix and it looks like everything is getting wider including of course the coverage of video lights but lenses obviously are not so versatile like camcorders.

I have seen first the 7-14mm being used on the GH4 then the WWL-1 has become more prevalent both lenses have around 104 degrees field of view horizontal versus the 74 of a 24mm equivalent lens. Clearly as there are issues with dome ports at very wide angles the trend has been for wet adapters like the WWL-1 or the WACP however I am not totally convinced all this field of view is needed at all times.

I shoot a Leica 12-60mm for video reef scenes and talking to a fellow wetpixel dreifish we discussed briefly that he had tried the 12-35mm and left it as the zoom was not enough which is a fair comment. But the 12-60mm works well and there are other users here that adopt this lens for video.

At 1 meter the WWL-1 can show a 2.5 meters frame horizontally, now that is pretty big unless you have big animals a 24mm equivalent will cover 1.5 meters that for me is not little for most circumstances, turtles, reefs and any fish that does not come close like sharks. The same 12-60 lens can cover a 9x5 cm frame at one foot when fully zoom this is not macro but good enough for portraits. Obviously as distance increases effectiveness of lights decreases too so this has to be take into account.

The other benefit that I have experienced with the 12-60 f/2.8 lens is that the angle of view is not that wide and you can shoot at wide apertures without excessive blur effectively gaining almost a stop from the WWL-1 situation and finally the WWL-1 is a pain for snorkelling unless you manage to seal the port with water flushing in and out.

I wonder if there are other people out there shooting 24-100 equivalent either on full frame cropped or other formats and how many times do you really need the extra field of view if you don't have large animals

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I have used various 3/4 format cameras with wide angle lenses (7-18, 9-18) Focal length was just okay. However, my major issues was video quality. I finally switched to a dedicated video camera [ Sony AX100 with Gates housing, wide angle port] .

The difference was very pleasing. Even shooting in 1080p was superb. The focal length is f = 9.3–111.6 mm. I would not go back to a standard photo camera 4/3 or full frame after getting this. A tad on the $$$ side, but if you want good video, you are going to have to pay for the equipment. 

Hope this helps.

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Interesting topic, will be following along. I dont know the Leica 12-60mm. Its M43 I take it? (will go look it up now) f2.8 is a nice fast aperture - not sure many zooms go above this??

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3 minutes ago, bill1946 said:

I have used various 3/4 format cameras with wide angle lenses (7-18, 9-18) Focal length was just okay. However, my major issues was video quality.

Bill, wht 3/4 format cameras did you use?

You like the AX100 - would you consider the BM P4K ? If not why not? To me 12 bit RAW is very enticing and the 60P is icing on the cake.

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I think what I sad re: 12-35 was that it wasn't wide enough at the 12mm end :D. I didn't feel much need to shoot beyond 35mm -- just get physically closer. 

For my purposes, the 14-42 behind the WWL-1 actually offers a pretty good range. I often end up shooting at the wider end of that spectrum (inherent preference for wide sweeping vistas or reef-level action I guess), but find the barrel distortion to be very mild and totally acceptable. (unlike with a fisheye). I think anything wider would be too much, however. 

The biggest advantage to wider optics of course is that you can get closer, if the subject cooperates, and still fill a significant portion of the screen with that subject. Even at the 42mm end with the WWL-1 (equivalent to ~30mm full frame FoV, since the WWL-1 is a .36X wide angle converter), I start to find that image quality is lost because of all the water between you and your subject. 

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Interesting topic, will be following along. I dont know the Leica 12-60mm. Its M43 I take it? (will go look it up now) f2.8 is a nice fast aperture - not sure many zooms go above this??
The panasonic Leica 12-60 is an mft the f/2.8 drops pretty soon and at tele end is f/4 however the f/2.8 is not useful at full zoom
I had a 12-35 Panasonic great constant aperture but I found the zoom to be lacking on land so I sold it and got the 12-60 that I like much more is my favourite land lens and I use it underwater too in a 7" acrylic dome. The only annoyance is that the dome floats a lot but the quality is terrific
I only have a skin diving clip but gives an idea

I really like this lens and if I sell the 7 dome in the classified section I will invest in a 180mm glass port

Sent from my SM-A505FN using Tapatalk

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I think what I sad re: 12-35 was that it wasn't wide enough at the 12mm end . I didn't feel much need to shoot beyond 35mm -- just get physically closer. 
For my purposes, the 14-42 behind the WWL-1 actually offers a pretty good range. I often end up shooting at the wider end of that spectrum (inherent preference for wide sweeping vistas or reef-level action I guess), but find the barrel distortion to be very mild and totally acceptable. (unlike with a fisheye). I think anything wider would be too much, however. 
The biggest advantage to wider optics of course is that you can get closer, if the subject cooperates, and still fill a significant portion of the screen with that subject. Even at the 42mm end with the WWL-1 (equivalent to ~30mm full frame FoV, since the WWL-1 is a .36X wide angle converter), I start to find that image quality is lost because of all the water between you and your subject. 
The wwl-1 is not 0.36x but more a 0 5x fisheye converter the horizontal field of view is the same as the 7-14mm
At full zoom the quality drops but is mostly to do with the relative drop of depth of field not so much the water so you need to push the lens to f/11
In theory would be better to take the lens off but frankly despite the bayonet I dont remember doing it a single time

Sent from my SM-A505FN using Tapatalk

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3 minutes ago, Interceptor121 said:


I really like this lens and if I sell the 7 dome in the classified section I will invest in a 180mm glass port

Sent from my SM-A505FN using Tapatalk
 

This is all on the GH5 I take it ? What about the P4K - what do you like there ?

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22 minutes ago, John Doe II said:

This is all on the GH5 I take it ? What about the P4K - what do you like there ?

You mean the BMPCC 4K? I am not interested in this camera personally as I believe is not adequate to underwater shooting due to ergonomics and lack of IBIS amongst others. The Leica 12-60 should work well in that camera actually as the BMPCC4K has a longer sensor giving something like 22 - 110 equivalent. 

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7 minutes ago, Interceptor121 said:

You mean the BMPCC 4K? I am not interested in this camera personally as I believe is not adequate to underwater shooting due to ergonomics and lack of IBIS amongst others. The Leica 12-60 should work well in that camera actually as the BMPCC4K has a longer sensor giving something like 22 - 110 equivalent. 

yes thats right - the BMPCC 4K. I would be interested to hear why you think its not adequate. The Leica 12-60mm has OIS. Is the OIS in the lens or in the body of the M43? I thought the OIS was in the lens itself, and if so, then the P4K gets some stabilisation. I suppose this is a topic for a different thread. 

TBH, I was hot and bothered for an old Sony F23...talk about ergonomics.....but 3 CCD through that special prism that gives colour purity like no other before or since....using Digiprimes......alas, the housing cost and handling issues.

There are interesting Digizooms too.....

But I wonder how much difference there really is to that old F23 compared to a modern sensor like the P4K? I am not a fan of the GH5 at all.

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The 12-60 has OIS on it yes.

I am not saying the BMPCC 4K is inadequate in fact probably to shoot some film stuff on land with tripods, gimbals etc does wonders. What I am saying is that I do not see the additional color correction and dynamic range be worth it underwater where the colours are not there in the first place and dynamic range rarely gets to 10 stops.

I have been taking some shots with the GH5 shooting the surface and it did not clip exposed properly

I try to get the colours right in cameras using filter, light and other tools and then minimise the grading so far I have not found a situation where the camera was the problem it was more poor choices I made at the time of shooting

I also shoot stills and I want a camera that can do both decently and the GH5 does. In fact based on my stills experience I can tell you raw is overrated. I rarely make correction on my stills and when I do they are small. If i get the lighting wrong there is nothing I can correct after. Due to the mixed use I do the BMPCC 4K is not an option as it does not take pictures.

With regards to other features like stabilisation and white balance the lack of custom white balance on an underwater camera is simply not acceptable just this for me makes me wonder about the BMPCC 4K.

I would say the things that make me not consider it in order

1. lack of custom white balance

2. lack of IBIS

3. Does not take pictures 

What I really like about the nauticam housing is the solution with the drive and the batteries which is fantastic

I do not know much about professional grade video equipment but if video was all I was doing I would get a proper piece of equipment and not a still camera like widget 

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This is a good discussion of underwater optics trade offs.  Interchangeable lenses or built-in?  Wet optics or dry?  Zoom range? Lots to consider.  

As bill1946 points out, optical versatility is one of many reasons small camcorders / housings are a popular choice for underwater video.  The Sony AX700, for example.  The internal lens 35mm equivalent is 29mm to 348mm (just optical zoom).  29mm is not really wide, so a Wide Angle Port opens that up and retains nearly the entire zoom range.   

And it gets better.  Add a SAGA flips diopter kit to the Wide Angle Port, and you add macro / super macro to the range.  

No ILC system comes close.  

One more comment about camcorders:  they are designed and optimized as proper video platforms.  Not a photo camera that also acquires video.   The UI is different:  how you hold it, shoot it, what buttons are accessible, etc.  Internally the camera has video-centric features like optical image stabilization, 4 hour battery life, multiple SD card slots, one-touch WB, and subject tracking focus (watching the camera track an octopus across a reef is surreal).  And whatever magic Sony has put into the camera, the AX700 requires no white card to perform an AWB.  Amazing.  

If you're serious about shooting underwater video, consider carefully the tradeoffs.  

J-

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40 minutes ago, JohnE said:

This is a good discussion of underwater optics trade offs.  Interchangeable lenses or built-in?  Wet optics or dry?  Zoom range? Lots to consider.  

As bill1946 points out, optical versatility is one of many reasons small camcorders / housings are a popular choice for underwater video.  The Sony AX700, for example.  The internal lens 35mm equivalent is 29mm to 348mm (just optical zoom).  29mm is not really wide, so a Wide Angle Port opens that up and retains nearly the entire zoom range.   

And it gets better.  Add a SAGA flips diopter kit to the Wide Angle Port, and you add macro / super macro to the range.  

No ILC system comes close.  

One more comment about camcorders:  they are designed and optimized as proper video platforms.  Not a photo camera that also acquires video.   The UI is different:  how you hold it, shoot it, what buttons are accessible, etc.  Internally the camera has video-centric features like optical image stabilization, 4 hour battery life, multiple SD card slots, one-touch WB, and subject tracking focus (watching the camera track an octopus across a reef is surreal).  And whatever magic Sony has put into the camera, the AX700 requires no white card to perform an AWB.  Amazing.  

If you're serious about shooting underwater video, consider carefully the tradeoffs.  

J-

That was my point @JohnE but going back to the discussion I find that the 24-120 mm equivalent is sufficient for the large majority of scenarios 29 maybe not. And I do agree if video is all you do then a video device is what you need really. Fact is I like to take pictures so the GH5 works and there are no other mirrorless that have the same capability but this is another story

My point really is that even on a photo camera a 24-120 works and likewise you can put a wet lens with zoom through if you need to.

In terms of ergonomics the feature you mention do come in the BMPCC 4K nauticam housing so I can see some pure video guys may want that

 

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the  panasonic Leica 12-60 is my dominant lens. I really like everything about it. I used to shoot mostly 16mm FF equivalent due to bad vis in out country and my interest in shooting reef/week structure. But shooting small to medium fish portraits and behaviors with the 16mm is quite challenging cause you need to get very close to the subject which usually scares them away. My dive buddy always shoots around 24mm and he would have the best story to tell about the sea creatures than I. I was wondering why but then I discovered the secret: 24mm FF eq.

The Leica 12-60 is a very good lens in all aspects. And one more thing: once zoomed all the way you can get very good closeups (magnification of 0.3x)

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17 hours ago, thani said:

the  panasonic Leica 12-60 is my dominant lens. I really like everything about it. I used to shoot mostly 16mm FF equivalent due to bad vis in out country and my interest in shooting reef/week structure. But shooting small to medium fish portraits and behaviors with the 16mm is quite challenging cause you need to get very close to the subject which usually scares them away. My dive buddy always shoots around 24mm and he would have the best story to tell about the sea creatures than I. I was wondering why but then I discovered the secret: 24mm FF eq.

The Leica 12-60 is a very good lens in all aspects. And one more thing: once zoomed all the way you can get very good closeups (magnification of 0.3x)

I agree, I use it with the 7 Acrylic dome. Do you have the glass dome with the 55mm adapter and 10mm screw extension?

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On 10/6/2019 at 9:07 AM, John Doe II said:

Bill, wht 3/4 format cameras did you use?

You like the AX100 - would you consider the BM P4K ? If not why not? To me 12 bit RAW is very enticing and the 60P is icing on the cake.

Actually I did not know about the Black Magic until after I bought the AX100 kit (including housing). With that outly $$ I cannot afford another rig. I found that cameras cannot match the quality of a camcorder in video. The Sony sensor is a killer and hard to beat. If I shoot 4k (and I do) the difference is amazing. With the Gates housing, I have access to all the controls. The killer is the AX100 sells for more than the Black Magic! Oh, well, I'm much happier with this rig than a high end 4/3 camera. Now my wife is getting shots in raw photos, that put me to shame. She has an eye for composure!!

 

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What I know about Sony Sensors is they do not W.B well. Cant beat canon for that. My Pick would be the C200 if the price was the same as the P4K/P6K. Housing costs seem to be the biggest costs in this field.

It seems a true cine lens in PL mount holds no real advantage underwater. That damm filter called water that we all have to deal with dulls everything down....no matter the lens used.I like a fast lens so that I can stop down at least 2 stops so that the lens gets into its sweet spot.

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1 hour ago, John Doe II said:

What I know about Sony Sensors is they do not W.B well. Cant beat canon for that. My Pick would be the C200 if the price was the same as the P4K/P6K. Housing costs seem to be the biggest costs in this field.

It seems a true cine lens in PL mount holds no real advantage underwater. That damm filter called water that we all have to deal with dulls everything down....no matter the lens used.I like a fast lens so that I can stop down at least 2 stops so that the lens gets into its sweet spot.

 

1 hour ago, bill1946 said:

Actually I did not know about the Black Magic until after I bought the AX100 kit (including housing). With that outly $$ I cannot afford another rig. I found that cameras cannot match the quality of a camcorder in video. The Sony sensor is a killer and hard to beat. If I shoot 4k (and I do) the difference is amazing. With the Gates housing, I have access to all the controls. The killer is the AX100 sells for more than the Black Magic! Oh, well, I'm much happier with this rig than a high end 4/3 camera. Now my wife is getting shots in raw photos, that put me to shame. She has an eye for composure!!

 

I think Sony looks really blue I would add an URPRO filter they work very well together

Regarding white balance it works to 10 meters more or less after the color temperature is too cold and it goes off too so you need a filter really

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