Magic Lantern Forum

Using Magic Lantern => Raw Video => Topic started by: N.Mendes on July 19, 2013, 12:54:46 PM

Title: 3x Crop mode vs Lens
Post by: N.Mendes on July 19, 2013, 12:54:46 PM
Hello all, everything is said in the title..

Let's say, for someone who got a 35mm 1.4, is it judicious for him to buy a 100mm macro (2.0) or the 3x crop mode will do the same job ?

I'm talking about zeiss lenses, with the 3x crop mode, the 35mm 1.4 will become a 105mm 1.4, vs the real 100mm 2.0 macro, what do you think guys?

Does the 3x crop mode can replace a lens or never at all?
Title: Re: 3x Crop mode vs Lens
Post by: Andy600 on July 19, 2013, 01:04:06 PM
A 100mm lens will become 300mm at 3x would it not? On APS-C it would be 480mm. It depends if you want line skipped video or 1:1.

It's only relevant to video so you'll still need that 100mm for photos.

It's nice that my f1.4 and f1.8 glass can be used as fast tele lenses :)
Title: Re: 3x Crop mode vs Lens
Post by: N.Mendes on July 19, 2013, 01:27:17 PM
I agree dude ;)

But what i'm asking is, does the crop mode have the same quality than a normal lens or does the image feels like it was shot in crop mode?

And yes, we'll still need it in photo, but i make videos more than photos ;)
Title: Re: 3x Crop mode vs Lens
Post by: mageye on July 19, 2013, 01:36:24 PM
It's only as good as the lens it's shot with. If your lens is 'soft' then the softness will be accentuated. Same with anything else such as chromatic aberration.

So if you had the highest quality glass then the 1:1 crop will look fantastic. Generally the crop record is better than I imagined it to be. If you use a prime lens then the quality should certainly be acceptable.

So good optics are the key here. Good optics are always important in any situation.
Title: Re: 3x Crop mode vs Lens
Post by: PJSOFT on July 19, 2013, 02:04:36 PM
Quote from: mageye on July 19, 2013, 01:36:24 PM
So if you had the highest quality glass then the 1:1 crop will look fantastic.

Right!! I believe with less moire artifacts also, since there were no line skipping involved.
Title: Re: 3x Crop mode vs Lens
Post by: N.Mendes on July 19, 2013, 02:22:15 PM
Good optics are always the key bro' ;)

So (like i said in the first post), a zeiss 35mm 1.4 in crop mode can match a zeiss 100mm f2?

I guess so, but there'll always be something that the crop mode doesn't have compared to a real lens..

Correct me if i'm wrong..
Title: Re: 3x Crop mode vs Lens
Post by: Andy600 on July 19, 2013, 02:51:14 PM
Quote from: N.Mendes on July 19, 2013, 02:22:15 PM
Good optics are always the key bro' ;)

...I guess so, but there'll always be something that the crop mode doesn't have compared to a real lens..


Yes, it's called the focal plane. A 50mm lens is still a 50mm lens even if it's working effectively as a 240mm lens.
Title: Re: 3x Crop mode vs Lens
Post by: bnvm on July 19, 2013, 08:23:57 PM
Quote from: N.Mendes on July 19, 2013, 02:22:15 PM
Good optics are always the key bro' ;)

So (like i said in the first post), a zeiss 35mm 1.4 in crop mode can match a zeiss 100mm f2?

I guess so, but there'll always be something that the crop mode doesn't have compared to a real lens..

Correct me if i'm wrong..

The lens is still a 35mm lens, so some aspects of the image are never going to be the same as a 105mm lens. Depth of field for example, the 3x cropped 35mm will not have as shallow a depth of field as a true 105mm would have. Check the link if you want to see for your self.

In the example I tested, focused 10 feet away a f1.4 at 35mm cropped had a similar depth of field as a true 105mm at f13.5.

http://www.dofmaster.com/dofjs.html
Title: Re: 3x Crop mode vs Lens
Post by: Mr. Propaganda Guy on July 19, 2013, 11:48:51 PM
Correct me if I'm wrong, been wondering since I heard of RAW crop mode - Full frame at 3x Crop is approximately equivalent to a 16mm sensor or film negative in size, Right?
Therefore, a 5DMKIII equipped with a 16mm sensor/film lens (aligned correctly in crop mode) should be akin to a BMPC on steroids - Same FOV, DOF + Higher Resolution Options, Low light Sensitivity, 14Bit RAW and 60fps.   

What would be max resolution to keep it 16mm? (11.9mm x 6.7mm) 1920x1080?
If the higher resolutions, 2K+ (5DIII Crop mode 1:1) use a larger area of the sensor compared to 1920x1080, what res would emulate micro 4/3rd sensors?
Title: Re: 3x Crop mode vs Lens
Post by: reddeercity on July 29, 2013, 01:12:59 AM
Hey all :)
here is a 3x crop mode test i did last week with my 200mm = 2x extender = 400mm
then in crop mode = 1200 mm  ;D @ 2048x930 23.976p continuous record on Lexar 1000x 64 GB card
Super telephoto lenes  ;) with the equipment i have !



edit: for the 2K video, link to YouTube
www.youtube.com/embed/k5utCP7mRQ4
Title: Re: 3x Crop mode vs Lens
Post by: Audionut on July 29, 2013, 04:52:13 AM
3x crop mode is a direct sample of the sensor.  No line skipping or pixel binning like occurs with 1:1 view.

Lens quality does not change.