Getting 100 Megapixels in Focus

Originally Published on www.megapixelsdigital.com

Shooting With 100 Megapixels

IQ3 100MP, 120mm f/4 Macro Blue Ring @ f/4, 1/1000s, ISO 50, Capture One Screenshot

100 Megapixels is a lot of resolution. More than a lot. I mean, 100 million pixels is like, an absurd, obscene, very large amount of pixels.

And that’s great! We love resolution. Resolution allows you to do things like create multiple compositions from a single image by cropping after the fact, or print to extraordinary sizes without having to sacrifice quality. There wouldn’t be 100 of them in Phase One’s flagship digital back if megapixels weren’t important. And to tell the truth- the kinds of images 100 million pixels can produce are, in a word, moving. However, with great resolution comes great responsibility.

Using a 100 megapixel beast: a practical tutorial

Some that have used 100 megapixel cameras have found that achieving sharp images can be difficult in certain situations. And they’re not wrong.

Its easy to take a photo with a 100 megapixel camera. Click the shutter button and suddenly you’ve got 16 bits of color, 15 stops of dynamic range, and 130mb of the sexiest data a medium format camera can squirt out.

 

But the 100 million pixel question is: does it look good? 

 

 

IQ3 100MP, 120mm f/4 Macro Blue Ring @ f/4, 1/640s, ISO200. Capture One Screenshot

As we increase resolution we decrease acceptable sharpness. Depth of field is, of course, the area of an image we perceive as in focus. In focus areas do not suddenly become “tack sharp” and then just as suddenly become out of focus. Depth of field occurs gradually from out of focus, somewhat in focus, in focus, somewhat out of focus again, and finally out of focus once more.

As we increase our resolution and view at 100% we can see this difference in focus with much more detail. As a result we perceive more of the image as out of focus than we would have at lower resolutions simply because we couldn’t detect the difference in focus with as great an accuracy. This behavior is no fault of the camera system, but merely a side effect of the level of detail we’re able to achieve when using the highest end equipment.

Understanding this concept is especially important when photographing a subject in situations with a naturally shallow depth of field. For example, if we’re shooting a portrait with the subject 3 feet away with the SK 120mm Macro Blue Ring with the XF100MP, the depth of field at any aperture is going to be very small- even just a few inches at f/11.

 

When shooting with shallow depth of field, several things become extremely important:

 

Focus Trim

Nailing focus with such a shallow depth of field can be difficult. Since we’re dealing with 100 megapixels of resolution, even things like the tolerances between two interlocking pieces of metal become a factor in achieving perfect focus. This is why Phase One introduced a quick, intuitive method of dialing in focus with a particular body and lens with the Focus Trim tool on the XF body. This tool allows users to dial in the perfect focus area for a body/lens combo. For blue ring lenses, the XF body will save that focus trim for that lens’s serial number so every time that lens is attached the XF and the lens will be in sync.

 

The trick to the focus trim tool is that it requires testing! The ideal (and highly recommended) scenario is shooting a test target while tethered to a computer and viewing at 100%. The nice thing is that this only needs to be done once per lens. The XF body remembers the values set for that blue ring lens’s serial number and now you’re done. Click to learn how to use the Focus Trim tool. 

I cannot overstate the importance of the Focus Trim tool. Trimming focus is arguably the most important step in achieving perfect focus regularly and consistently. Take advantage of this tool! 

Camera Shake

In ambient light, shutter speed plays a huge factor, particularly when hand holding. As described above, due to the increased resolution, the margin of error for optimum image quality is extremely small, especially when the subject is close to the photographer. The slightest motion blur will be apparent at 100%. To counteract this, the use of a tripod or a very fast shutter speed is extremely important to get the best possible image quality.

A decent guideline for medium format is to take your lens’s focal length and multiply it by four. Set your shutter speed to a value close to that number and you’ll generally be in a good situation for hand holding. Take this with a grain of salt because it won’t be correct for every shooter or scenario.

Spot vs. Average Focus

When trying to focus on a very specific area like a pupil, switching the XF camera’s autofocus mode from Average to Spot is advisable. This will reduce the area the camera uses to find focus to a small area in the very center of the viewfinder.

 

Movement

If you’re alive, you’re going to breathe at some point. If your subject is alive, they will also eventually take a breath (we hope). However small, this action creates movement. Depending on your depth of field, the few millimeters of movement caused by a living body’s natural twitches and effort to stay upright will effect where your plane of focus falls on your subject. This could mean the difference between the near eye being in focus or completely out. Being aware of this is half the battle. When hand holding the camera and photographing a live subject with shallow depth of field its important to check focus often. And don’t forget to make use of the focus assist beam and the focus mask!

IQ3 100MP, 120mm f/4 Macro BR @ f/4, 1/1000s, ISO 100. Focus Mask turned ON- Capture One Screenshot

 

Aperture

Unless you’re fighting ambient light or going for the most shallow depth of field possible, it may be advisable to use a smaller aperture. On most blue ring lenses diffraction isn’t prohibitive at f/16. If you’re shooting strobes or have the ambient light available, stopping down to f/16 or f/11 may be the best way to achieve the highest degree of sharpness over the greatest distance.

Distance

Some photographers force themselves to get the composition perfect in-camera, which could potentially mean filling the frame with a person’s face and decreasing depth of field. However, shooting 100 megapixels allows you to crop in a great deal on an image to achieve a new composition. This is a technique that should not be overlooked if you’re struggling to focus in a certain scenario. Often, backing up from a subject will aid autofocus by putting more information in front of the focus point. That, combined with the expanded depth of field from increased subject distance makes for a much easier focusing experience.

IQ3 100MP, 110mmLS f/2.8 @ f/2.8, 1/400s, ISO 200. Capture One Screenshot

 

Conclusion

100 megapixels is an enormous amount of information. Focusing an image with that kind of resolution isn’t always easy, but if you know your equipment before going into a shoot and are familiar with the tools Phase One puts at your fingertips, shooting 100 megapixels with a shallow depth of field is a breeze and can result in mind blowing images. And now is the perfect time to get started with the release of the 150mm LS f/2.8 IF. Shallow depth of field never looked so good…

 

 

 

— Zac Henderson