Using 4K/2K switch as a lense doubler

[deadfred]

Hi All,

Could you advise on the following..

If the end product only needs to be 2K. Then does the following work.

1. Use your 35mm glass (say Red 18-50).

2. Shoot 4K when you want the wider end of the lens(18-50)

3. Switch to 2k and in effect double the lens to a 36-100.

If this works then it is similar to using a doubler on a video lens. If it does work then..

4. How long does it take to switch between 4 and 2K.

5. Can you switch without any problems in regard to the storage you are recording onto.

6. Would the quality be better if you used S16mm glass in 2K as apposed to cropped 35mm glass

7. Or would it be simpler to shoot 35mm 4K and then just crop in to increase the lens size.

Thanks in advance.

Fred

 

[Gunleik Groven]

You DO want to work iin 4k, especially if you deliver 1080/2k.

You can do it, but it is the same as pan/scan/crop in post... No real gain in any way.

Gunleik

 

[deadfred]

Thanks Gunleik.

If I shoot 2K though with 35mm lenses will that not make them double their focal length - ie red 18-50 becomes 36-100?

Maybe I am being stupid but does shooting 2k mean that I need to use s16mm glass especially if I want to shoot wide angle.

Fred

 

[deadfred]

Sorry i misread your post Gunleik - thought you were saying not to shoot in 4K!Doh!

Ok. So are you saying I should just crop the 4K image to get a tighter shot if I don't want to change lens. Do you know what % I can blow it up before i loose image quality if my final output is 1080.

Thanks!

 

[Cüneyt Kaya]

Sorry i misread your post Gunleik - thought you were saying not to shoot in 4K!Doh!

Ok. So are you saying I should just crop the 4K image to get a tighter shot if I don't want to change lens. Do you know what % I can blow it up before i loose image quality if my final output is 1080.

Thanks!

you will have a better quality (technically seen its better to scale down a 3,2 k rgb image to 2k, then blowing it up to 4k, but stuart said there is little difference visually to be seen on screen comparing a 4k rgb image and a 3,2k up scaled to 4k image) if you scale down to 2k....and yes your lens would become a 36-100 mm...because its like using a 16 mm cam...

i would go for 2k only for slow motion...rest is like gunleik said