President's Blog August 2021

Last Updated: 12-8-2021 17:04

The Last Post

This is my last President’s Blog. I’ve been a member of the Marlborough Camera Club for the last eight years, and a member of the committee for seven of them. I’ve served as president for two years through the unprecedented situation of a global pandemic.

I won’t repeat everything I’ve written in my President’s Report for the AGM, but will instead focus on what the club is about; photography.

Before I do, I’d like to remind people that the club runs based on volunteers. I’ve done seven years on the committee, and will likely continue to help with the club website and IT issues in a non-committee member role, as those are my areas of expertise, and I encourage all members to look for ways you can help the club, whether it be as a committee member or some other role.

Lets talk about noise

There’s been quite a flood of new products on the market recently using AI aimed at noise reduction. Topaz, On1, Corel, DxO all have new or recent offerings.

Noise is the digital equivalent of grain from the film era, and gets worse the higher you push ISO or increase exposure in post processing.

For the record, there’s a thing called ISO invariance that applies to quite a few modern sensors that means whether you increase ISO in camera by one stop, or increase exposure in post processing by one stop, the results will be the same. This only works if you shoot RAW, as jpg files strip out a lot of information, so that if an image is badly underexposed, there’s not much you can do to rescue it.

ISO invariance can often rescue a RAW image that would otherwise be a reject, so long as you’ve captured it at a fairly low ISO to begin with, eg if you capture at ISO 100, then increase exposure in Lightroom or ACR by four stops, you’ll get the same result in terms of noise as if you’d captured the image at ISO 1600, which with most modern camera sensors and some good noise reduction software is usually perfectly usable. For this reason, I normally shoot in RAW and if in doubt, slightly underexpose, as it’s usually possible to recover shadow detail, but blown highlights are blown highlights, and there’s not much you can do to recover from overexposure.

It’s important to assess your scene, as you ideally want to underexpose as little as possible to avoid blown highlights. In highly contrasty scenes, you’ll probably need to underexpose more to get a usable image, but in even lighting you may not need to underexpose at all.

It’s a really good habit to get into to check the histogram in your camera after you capture an image, and if it’s got peaks on the right hand end, use negative exposure compensation and reshoot.

All noise reduction software causes some loss of detail, but the better it is, the more detail is preserved while reducing noise.

In terms of noise reduction software, DxO PhotoLab is the gold standard to beat in terms of quality of noise reduction, however it is also the slowest software, and comes with a bit of a price tag unless you get it on sale. Adobe Lightroom/ACR is probably the weakest offering, but if you already have an Adobe CC Photography subscription, you already have it, and it’s often good enough when you don’t need a lot of noise reduction.

Software isn’t the only way to beat noise, and the other (expensive) way to beat noise is to upgrade to a camera with a larger sensor and/or larger pixels. A full frame camera has a bigger sensor than an APS-C sensor, and as a result will typically be more expensive and require bigger, heavier lenses that are also often more expensive, but at any given image viewing size, images from a larger sensor, all things being equal, will appear less noisy than from a smaller sensor. This is simply due to physics. A bigger surface area collects more light and can average out inconsistencies better at a given enlargement factor. The noise is still there, however it’s less obvious. If you pixel peep an image from a large sensor and a small sensor with the same size pixels, the noise in individual pixels will be the same at the same settings, but that’s not how most people view images.

Smartphones are an extreme case of small sensors, and this becomes really apparent when you try to enlarge a phone image taken in poor lighting conditions. At a computer screen sized enlargement, a smartphone image taken in good lighting can look just as good as one taken with a DSLR or mirrorless camera, but start increasing the ISO or enlargement a lot, and the limitations of smartphones become more apparent.

The photography equipment that many people underinvest in

As many of you know, I work in IT. I’ve helped a few members out with the software and computer issues, and one of the things I’ve observed is that many people invest in really good camera equipment but severely underinvest in computers or software to manage their images. In the world of digital photography, your computer is just as important a piece of equipment as any lens or camera body, and you need to invest accordingly. Unfortunately many salespeople have no idea of the computing requirements for photography, so I’m going to list some here, hopefully to avoid people making disappointing choices. If in doubt, I’m available for a chat. I don’t sell computers, but I can help make sure you purchase something appropriate.

Computer Minimum Specifications for Photography

RAM – 16GB minimum. If you want to run Lightroom or Photoshop, especially both together this is a must. Often it’s hard and expensive to find laptops with more than this, but don’t settle for less or you’ll be setting yourself up for performance issues.

Screen – Full HD (1920x1080). If you’re buying an external monitor, you could go higher than this – 4K would be nice, but this is a minimum for a decent workspace. Many cheap laptops have lower resolution screens, and this will be frustrating. Another thing to take into account with screens is colour gamut. This means how many colours they can display. High quality screens that can display a larger colour gamut tend to cost more, but they’re especially important if you intend to print frequently, and need accurate colour.

Storage – 1 TB. Photos can take up a lot of space, especially if you shoot RAW, or work extensively with Photoshop. Ideally a dual drive system with a fast SSD and a cheaper, but higher capacity hard drive with give you both storage and capacity at an affordable price. Most laptops only come with one drive, typically a modest capacity SSD, but many have capacity for an additional drive to be added internally. Desktop systems are are more likely to come with both an SSD and a hard drive.

Macs or Windows? - Both Macs and Windows PCs can make good photo editing computers. Macs have been popular with creative professionals for many years, but they can come with quite a steep price tag. An iMac in particular will give you an excellent platform that will met all the specifications for photo editing. Windows PCs can work just as well and more people use Windows, but the huge variety of different brands and models means you need to check you’re getting something with suitable specs before you buy.

Chris Cookson