Sunday, March 8, 2020

Near-Far, Zero-Noise Bracketing

It’s a rather windy and wet Sunday, so an ideal opportunity to carry out some indoors photography experiments: this time ‘perfecting’ what I call the Near-Far, Zero-Noise Bracketing technique.

I’ve evolved this technique mainly for use with my manual lenses, to ensure I capture the ‘optimum’ 4-image, focus and exposure bracket set.

In this post I’m using my OM-D M5II, with my manual, Laowa 15mm f/4 Wide Angle Macro, which means I can focus ‘anywhere’, ie (really) near to (far) infinity.

The technique, on my OM-D M5II, using an infinity blur criterion of 15 microns, is rather simple, but I constantly find it works. It goes like this: 

  • In manual mode, put the lens at the widest aperture, ie F/4 in this case, and focus on the nearest object you wish to see in focus, typically for this technique to work this object will typically be greater than, say, 0.5m away. If it's closer than this, you may need to inject intermediate focus-exposure brackets;
  • Set the lens aperture to F/7.1 to F/8, but on my MFT camera, no more, as diffraction will begin to get the better of you;  
  • Using the OM-D LV, with exposure blinkies on and the LV histogram to guide you, set the exposure for the highlights and take your first image;  
  • Take note of the exposure compensation and adjust the exposure by 4 stops, and take your second image;  
  • Reset focus for the background, eg I have set my lens infinity at the lens hard stop, using the fotodiox dlx stretch adapter, so all I need to do is set the focus to the hard stop point on the lens, where I know I will have optimum infinity focus;  
  • Take the third image at the current exposure;  
  • Finally, change the exposure by -4Ev and take the fourth and last image.
Ingest the four images into Lightroom, and use LR’s HDR capability to process the two exposure brackets. Then, in my case, I do a round trip with these two processed images to Helicon Focus. Once I’m back in LR, I process for a look.

As an example, here are the four captured zero-noise images, just taken in my kitchen. Note the focus difference between the tap and the chairs:

Here are the two LR HDR merged images, ie covering near and far, merged exposure brackets:

Here is the final ‘Near-Far, Zero-Noise’ image. BTW it was a windy day outside, so some tree movement can be seen:

I hope some found this post of value/interest; and, as usual, I welcome feedback on this or any previous post.

No comments:

Post a Comment