Ask Jason
Will Jason be able to provide the answers to all of your crazy camera quibbles? Well, probably…
Our resident Nikon expert Jason Parnell-brookes answers your questions and solves your problems. If you’d like Jason to come to the rescue regarding your Nikon-related question, email it to mail@nphotomag.com. Please note that we reserve the right to edit queries for clarity or brevity.
After reading your recent macro lens reviews, I bought the latest Tamron 90mm Macro to use with my D810. No matter what aperture I use at the closest focus distance, I only seem to get a tiny depth of field. Why is this? Ian Carter
Jason says... At its shortest focus distance, any ‘full macro’ lens will give you a 1.0x or 1:1 magnification ratio, reproducing objects at full life-size on
the image sensor. This enables extreme magnification when viewing the resulting images on screen or in print. However, even with a narrow aperture of around f/16, the depth of field will only be a few millimetres. To render three-dimensional objects like bugs sharply from front to back, you’ll need to use a technique called ‘focus stacking’. This requires taking a series of shots with an incrementally changing focus distance. You can then merge the shots into a single image, using a program like Adobe Photoshop, Helicon Focus or Zerene Stacker.
A friend told me that he likes using his camera’s ‘back button focus’. What is this and how does it work? Dave Johnson
Jason says… Many photographers, especially those specializing in action, sports and wildlife photography, like to initiate and control autofocus with a dedicated button on the camera – they do this instead of pressing lightly on the shutter-release button.
High-end Nikon cameras, like the D500 and D850, therefore have a separate ‘Af-on’ button at the rear of the camera, which can be operated with the right thumb. This button is lacking on cameras up to and including the D750 and D7500. As a workaround, you can usually configure the AE-L/AF-L button to work as an Af-on button, via the Custom Settings menu. In entry-level DSLRS, the option is usually available in the Setup menu.
Back-button focusing is useful because it enables you to effectively switch between continuous and single-shot autofocus by holding or releasing the button.
I mainly shoot landscape photography in Namibia. Is there any way of setting a Tv-friendly 16:9 aspect ratio for image capture on my D750, apart from using Movie Live View mode? Johann van Schalkwyk
Jason says... Sadly, no. You need to use Movie Live View and assign the shutter button to ‘Take Photos’ in custom setting ‘g4’.
You don’t have to be recording a movie when taking a shot but, if you are, the movie will be stopped before the still shot is taken. You can use FX or DX image area options with small, medium or large sizes, up to 6016x3376 pixels, all in the 16:9 aspect ratio.
In most instances, I’d be more inclined to shoot full-sized images in regular shooting mode, and then apply a 16:9 crop afterwards, either to individual images for best creative effect, or as a batch process in an image-editing package to save time.
Nikon’s new Z6 and Z7 mirrorless full-frame cameras both support regular stills shooting in 16:9 aspect ratio.
I rarely respond to comments in magazines but feel that your dismissal in N-photo 91 of the AF-S 28-300mm VR lens, in favour of the AF-S 24120 VR, is slightly unfair. Keith Pointon
Jason says... The AF-S 28-300mm VR is certainly a good ‘superzoom’ option for use as a travel lens. But it was launched back in 2010, when most Nikon full-frame DSLRS only had 12Mp image sensors. It’s sufficiently ‘sharp’ for these cameras but, to get the best out of newer cameras that have a larger megapixel count, it’s better to use lenses with greater resolving power. As usual for a ‘superzoom’, the 28-300mm does make compromises in terms of quality. In our lab tests and ‘real-world’ tests, the 24-120mm lens is sharper and we find that the 24mm, rather than 28mm, minimum focal length gives greater wide-angle potential, although it naturally loses out for telephoto reach. As
I said in N-photo 91, the heavily discounted price of the 24-120mm lens when you buy it as part of a D750 ‘kit’ makes it a great buy.