ISO is not ISO when it comes to digital photography

When you first learn about photography, you’re taught about the exposure triangle – shutter speed, aperture, and the ISO sensitivity of the film. Back in the day, you’d choose your film sensitivity to suit the light levels under which you’d expect to shoot. You then play aperture against shutter speed to balance the exposure of the image. You might then opt for smaller apertures (bigger f number) for longer depth of field means you need a longer shutter speed. Choosing a short shutter speed to freeze action would conversely mean you needed a bigger aperture to capture sufficient light.

In digital photography, the concept of ISO has changed. With a digital camera, you can have a different ISO for every frame you shoot if you like and so you have more options about balancing aperture and shutter speed for artistic purposes. However, it is important to note that while a different ISO value really meant a different light sensitivity of the film, you cannot change the sensitivity of a digital camera’s sensor. So, changing ISO is not changing anything physically as it would be with film.

Rather, changing ISO in a digital camera affects how the signal from the sensor is processed by the camera’s software. When you increase the ISO in a digital camera, the sensor’s raw signal is amplified. This means the image becomes brighter. The change in ISO is more akin to turning up the volume control on your stereo or headphones. And, as with a stereo turned up too loud you get distortion. For a digital image that distortion is, ironically, known as noise (random specks of colour in the image). Noise is more noticeable at higher ISO settings and in the darker areas of an image, which is why many photographers try to keep their ISO as low as possible.

The high-ISO noise effect is worse the smaller the sensor, so full-frame digital cameras tend not to be as “noisy” as cropped sensors and cameras with even smaller sensors, such as superzooms.

Of course, there are tools such as DxO’s PureRaw, Lightroom, Topaz Denoise, etc that allow you to remove the noise to some degree without distorting the image. Some work better than others, for me, PureRaw 4 seems to give me the best results.

 

Striving for something more than the half-decent record shot

Photography, as with any other visual art form, hinges on a blend of technical skill and creative vision. While perfection can be elusive and subjective, achieving a “half-decent” photo that captures attention and tells a story is almost always an attainable goal whatever your skill level and with whatever equipment you have. Remember, if you want a photo, any camera is better than no camera (we’ve all been there and done that!). Meanwhile, here are a few thoughts on how to lift the passable snapshot to the inspiring image.

You can take a look at some of my photographic work and decide whether I live up to my own standards here.

Understanding light – Light is the fundamental of photography. Whether you’re working with natural or artificial light, how you harness it can define your photo. For instance, the magical Golden Hour: Early morning just before sunrise and late afternoon just before sunset offer soft, warm light that flatters most subjects. Shadows are gentle, and the light’s directionality adds depth.

Contrast that with the serenity of Blue Hour: The moments before sunrise and those after sunset provide cool, moody tones ideal for atmospheric shots. It’s also worth adding that darkness and shadows are not the enemy of the photographer, indeed they help you create drama, texture, and contrast. Timing the shadows in a landscape or even a portrait lets you leap from flat to dynamic.

Correct exposure – A well-exposed photograph is the foundation of visual appeal. Proper exposure ensures that details in both highlights and shadows are visible without appearing bleached out or overly dark. While modern editing tools allow some latitude for correcting exposure, it’s always best to get it right in-camera. Understanding your camera’s metering modes and how they interact with the scene’s light levels is the key. Also, shoot in RAW every time if that’s an option it then gives you the chance to retrieve detail from seemingly over-exposed or under-exposed areas in your photo and balance once against the other.

Sharp focus – A blurry subject can ruin an otherwise excellent composition. Ensuring your subject is in sharp focus is non-negotiable, unless the blur is the artistic choice. Autofocus systems have become highly advanced, but their capabilities must be matched with a keen eye for detail. For portraits, focus on the eyes. For landscapes, ensure the desired depth of field is achieved. The sharpness guides the viewer’s attention to what you want them to see. Of course, depth-of-field is like any commodity. You may want a short depth of field for a portrait so that the background is blurred, but for a macro shot you may want the whole frame to be sharp. This comes at the cost of how much light reaches your sensor or film. Smaller aperture means less light getting in, but a bigger depth of field.

De-noising grainy images – Noise, especially in low-light conditions or at high ISO settings, can detract from a photo’s quality. While some genres, such as street photography or film emulation, embrace a certain level of grain for artistic purposes, overly noisy images in genres like wildlife or portraiture can feel distracting. Post-processing can sometimes help you clawback the clarity, working best with RAW files.

Artistic cropping – Cropping is a powerful tool that allows photographers to refine their composition post-capture. A thoughtful crop can eliminate distractions, emphasize the subject, and create visual harmony. Whether filling the frame with an intimate close-up or leaving negative space or background for context, the crop should complement the story you’re telling. Remember the rule of thirds but don’t be afraid to break it if the composition feels stronger with different angles and different space.

Animal photography: The leading eye – When photographing animals, the leading eye must be pin-sharp. This draws the viewer’s attention and conveys emotion and personality. The leading eye acts as a visual anchor, guiding the viewer through the frame. Shots where the animal is looking away don’t often work, unless the context justifies it. For example, a distant gaze that matches a dramatic landscape or tells a broader story about the animal’s environment.

Catchlights: Breathing life into eyes – Catchlights, the reflections of light in a subject’s eyes, add depth and vitality, particularly in animal or human portraits. Without catchlights, eyes can appear flat and lifeless. Photographers often use natural light or controlled artificial light to introduce this subtle yet critical element. Catchlights don’t just reveal the light source; they transform the image by infusing character and emotion.

Photography, like any art, is about emotion. You need patience to get that perfect light, expression, or moment, but that patience can be rewarded with the shot you’re really after rather than the record shot you’d quickly snap just to make do.

Learn the rules so you can use them to best effect when they’re needed, but also so you can break those same rules when it means a better photo. You can ditch the rule of thirds, the golden ratio, you can try unusual angles or play with unconventional perspectives. Focus on that unusual aspect of the subject, not the obvious. Observe and try to see things from a different angle to help you tell a unique story with your photos.

My older photos online

Before my current penchant for avian and Lepidoptera photography, I took a lot of photos of bands at festivals, masses of landscape shots, and a stack of architecture. If you fancy digging deep into roughly a quarter of a century of photography, check out my 500px, GuruShots, and Flickr galleries. I used sciencebase as its own link shortener to get you there quickly:

GuruShots

500px

Flickr

Paxton Pits Nature Reserve

It’s quite some time since we last visited Paxton Pits Nature Reserve in Cambridgeshire, well before the covid pandemic, March 2019, in fact, if my photo archive dates are to be believed and before that January 2018. Tempus fugit, as they say. And, speaking of things that fly and sound a bit Latin, there were plenty of Regulus regulus among the fir trees not far from the site’s visitor centre.

Goldcrest at Paxton Pits Nature Reserve
Grumpy Goldcrest at Paxton Pits Nature Reserve

The nature reserve is, like so many of our local sites gravel pits that have been turned over in whole or in part to nature. It saves the aggregate companies having to back-fill once they have excavated all the millions of tons of sand and gravel they need and gives nature a chance to thrive in areas that would otherwise be turned back into unused flatland. The Paxton reserve was, until World War II, largely farmland on the edge of the village of Little Paxton. The gravel excavations were started during the war. There is still activity, but a large area is now lakes for wildlife, trails, and some lakes for fishing and boating activities.

Goldcrest taking flight at Paxton Pits Nature Reserve
Goldcrest taking flight

Not far from the visitor centre was the site of the former farmhouse. The historical sign there tells visitors about the farmhouse that once stood on this spot and about the provenance of the row of quite tall fir trees that stand in front of where the farmhouse once was. Apparently, they were Christmas trees! They have now grown so tall that you’d need the longest of long ladders to put the fairy on the top and hang your baubles.

Anyway, it was among these fir trees that numerous R. regulus were darting about. Readers that are regulus as clockwork will know that this species is the UK’s joint smallest bird, the Goldcrest, as I’ve mentioned it before. Its equally diminutive partner is the slightly less common but equally tiny Firecrest.

A fellow photographer, who turned out to be on the reserve’s bird-ringing team, pointed out that the Goldcrests we were photographing were probably winter visitors from Scandinavia enjoying the slightly warmer climate of East Anglia and the rich pickings to be had on a sunny January day among the fir trees. She wasn’t entirely certain, but seemed to imply that there aren’t usually any in this location during the summer months although she had witnessed nesting in one of the Xmas trees previously.

Goldcrest are so small, so fast moving, and often spend their time in the depths of the needles of fir trees, that it is commonly rather difficult to get a good snap in sunlight. If you’re hearing isn’t shot, you can usually pick up their very high-pitched hissy tweets. However, the Scandinavians were rather obliging today and at least I got a couple of nice shots of these delightful creatures with their golden crests.

A Kestrel for a Knave

A Kestrel for a Knave was a book by Barry Hines published in 1968. It was adapted for the Ken Loach film Kes.

Kestrel perched on a solitary, vertical branch

The protagonist, Billy Casper, was played by actor David Bradley who later had to adopt the stage name Dai Bradley, because there was already an EQUITY member, the RSC actor David Bradley. You may know the latter from many a TV drama, as unintelligible Arthur Webley in Hot Fuzz, as Filch in the Harry Potter films, as the first Doctor in Doctor Who and as William Hartnell in An Adventure in Space and Time, and Walder Frey from Game of Thrones, etc…I met him once, I mentioned it before.

As for Dai Bradley, he was also in the film Zulu Dawn, a couple of other films and various TV parts.

When the book was reprinted after Kes the film, they used the infamous scene of Billy sticking two fingers up for the cover…I grew up with this book…I was infamous by proxy as a child.

SWT Lackford Lakes

First trip of the year to the Suffolk Wildlife Trust nature reserve known as Lackford Lakes. 2nd January 2025, glorious sunny day, first such of the year and the first for quite some time.

Nuthatch, Sitta europaea on *the* log at Lackford Lakes
Nuthatch, Sitta europaea on *the* log at Lackford Lakes
One of several Marsh Tit picking at titbits on the Lackford Log
One of several Marsh Tit, Poecile palustris, that were picking at titbits on the Lackford Log, bird seeds and bird fat placed deliberately by birders and toggers.
Blue Tit on thorny branch
Blue Tit on thorny branch
Great Tit, Parus major
Great Tit, Parus major. Should be known as the Black-masked Gold Tit, I reckon

Having seen four raptors on the journey there – Buzzard, Kestrel, Sparrowhawk, Red Kite – a trek through the reserve to see what we could see then gave us:

      1. Blackbird
      2. Black-headed Gull
      3. Blue Tit
      4. Buzzard
      5. Canada Goose
      6. Chaffinch
      7. Cormorant
      8. Coal Tit
      9. Coot
      10. Dunnock
      11. Egyptian Goose
      12. Gadwall
      13. Great Tit
      14. Great White Egret
      15. Greenfinch
      16. Greylag Goose
      17. Grey Heron
      18. Kestrel
      19. Lapwing
      20. Little Egret
      21. Long-tailed Tit
      22. Mallard
      23. Marsh Tit
      24. Moorhen
      25. Mute Swan
      26. Nuthatch
      27. Pheasant
      28. Pochard
      29. Red Kite
      30. Robin
      31. Siskin
      32. Snipe
      33. Song Thrush
      34. Sparrowhawk
      35. Teal
      36. Treecreeper
      37. Tufted Duck
      38. Wigeon
      39. Wood Pigeon

There was also a very odd looking bird being harried by a Blackbird in a tree. It was probably a juvenile Blackbird, but it seemed to have a rufous bib and a very pale, speckled breast for a brief second I imagined it might be an Asian vagrant in the form of a Red-throated Thrush. But, very, very doubtful.

2nd January 2025 was also our first outdoor picnic of the year! Is an indoor picnic an oxymoron?

North Norfolk New Year’s Eve 2024

Once again, we headed for the North Norfolk coast for the end of the year. Decent weather on arrival so a trek along the beach from Old Hunstanton in search of Glaucous Gull and Shorelarks although we saw neither.

Old Hunstanton, Sunny Hunny
Old Hunstanton, Sunny Hunny

The Glaucous Gull had been reported as feeding on a dead seal, we saw at least a couple of seal carcasses above the tideline, but perhaps too many people and dogs even for a brute like a Glaucous Gull to sit tight for a meal. It was reported on the 2nd January, so it was still around. Funnily enough, there are two Glaucous on the dump near our village at the moment, although no seals.

Black-winged Stilt, with copper ring on left shank. Fish supper in bill. RSPB Titchwell
A rather rare Black-winged Stilt, with copper ring on left shank. Fish supper in bill. RSPB Titchwell

From Sunny Hunny, we drove on towards Holkham and stopped briefly on Lady Anne’s Drive where a Long-billed Dowitcher had been spotted in previous days. I took photos of the much larger Black-tailed Godwits and other birds on the flood to the east of the Drive. The LBD is 11 inches bill to tail whereas the BTG is 17″). Once back home, I could zoom in on the long shots and could see I had got a snap of the LBD. So obviously smaller than the BTG but somewhat similar in appearance otherwise. It’s an American bird that presumably got lost and headed south down the wrong line of Latitude some time ago. They have been reported in North Norfolk previously and elsewhere in the UK.

Long-billed Dowitcher, Limnodromus scolopaceus, Lady Anne’s Drive, Holkham

Once in Wells-next-the-Sea, we checked in at the Arch House Rooms in Wells (run by the Globe Inn) before a sunset walk through the town and out along the East Fleet and then on towards the lifeboat station. Amazing sunset.

Sunset, Wells-next-the-Sea
Sunset, Wells-next-the-Sea, 30th January 2024

We were back in time for a half-decent supper at the Globe Inn, although the pub was not quite as nice as we remembered it from a previous meal there a couple of years ago. But, at least we got fed, one couple didn’t get their choice of drinks, none of the food options they chose were available, and they walked out hangry.

Brent (Brant) Geese, Branta bernicla, East Fleet, Wells-next-the-Sea
Brent (Brant) Geese, Branta bernicla, East Fleet, Wells-next-the-Sea. The flock of ~200 took flight seconds after I took this photograph and headed for the fields on the far side of the sea wall.
Curlew wading in the East Fleet at Wells-next-the-Sea
Curlew wading in the East Fleet at Wells-next-the-Sea

We had planned to walk to Holkham from Wells on New Year’s Eve and perhaps hop on the bus back, but given the windy, wet weather forecast for New Year’s Day, we changed our minds about that and drove to RSPB Titchwell instead. Titchwell is often our NYD haunt, but while it was windy at least it was dry.

The same BWS with another fish
The same Black-winged Stilt with another fish
Hawthorn Shield Bug that landed on Mrs Sciencebase rucksack while we were having a snack in between birding sessions.
Hawthorn Shield Bug that landed on Mrs Sciencebase rucksack while we were having a snack in between birding sessions.
Wren snacking on millipede while we were having a snack
Wren snacking on millipede while we were having a snack
The Eurasian Jay, Garrulus glandarius, one of the corvids. The blue on its wings is second only to the green on the nape of the Eider's neck
The Eurasian Jay, Garrulus glandarius, one of the corvids. The blue on its wings is second only to the green on the nape of the Common Eider’s neck
Ruff, Calidris pugnax
Ruff, Calidris pugnax, RSPB Titchwell
Black-winged Stilt standing out of the water showing off its magnificent legs
Black-winged Stilt standing out of the water showing off its magnificently long legs

I realise it’s not all about lists, but we recorded 60+ bird species on this trip. One of them new to us, that Long-billed Dowitcher. Titchwell was also the closest we’ve ever been to the rare Black-winged Stilt (a ringed specimen that had dropped in a couple of days before). Interesting to see that the reserve still has a Tawny Owl hiding in the same ivy-covered tree that we’d peered at on our previous visit to Titchwell earlier in 2024. We also noted a couple of species of fungi we’d not noted before – Scarlet Elf Cup and Candlesnuff.

Scarlet Elf Cup, Sarcoscypha coccinea
Scarlet Elf Cup, Sarcoscypha coccinea
Candlesnuff fungus, Xylaria hypoxylon a bioluminescent fungus, also known as carbon antlers or the stag's horn fungus.
Candlesnuff fungus, Xylaria hypoxylon, a bioluminescent fungus, also known as carbon antlers or the stag’s horn fungus.
  1. Avocet
  2. Black-headed Gull
  3. Black-tailed Godwit
  4. Blackbird
  5. Black-winged Stilt
  6. Blue Tit
  7. Brent Goose
  8. Buzzard
  9. Chaffinch
  10. Cetti’s Warbler
  11. Collared Dove
  12. Cormorant
  13. Curlew
  14. Dunnock
  15. Dunlin
  16. Gadwall
  17. Goldfinch
  18. Golden Plover
  19. Great Black-backed Gull
  20. Great Tit
  21. Greenfinch
  22. Grey Heron
  23. Greylag Goose
  24. Herring Gull
  25. Jackdaw
  26. Jay
  27. Kestrel
  28. Lapwing
  29. Lesser Black-backed Gull
  30. Linnet
  31. Little Egret
  32. Little Grebe
  33. Long-billed Dowitcher (New to me, 2024)
  34. Long-tailed Tit
  35. Magpie
  36. Mallard
  37. Marsh Harrier
  38. Moorhen
  39. Oystercatcher
  40. Pheasant
  41. Pink-footed Goose
  42. Pintail
  43. Red Kite
  44. Redshank
  45. Robin
  46. Rock Dove
  47. Ruff
  48. Sanderling
  49. Shelduck
  50. Shoveller
  51. Skylark
  52. Snipe
  53. Starling
  54. Stock Dove
  55. Stonechat
  56. Tawny Owl
  57. Teal
  58. Tufted Duck
  59. Turnstone
  60. Water Pipit
  61. Wigeon
  62. Wood Pigeon
  63. Wren

The Merlin app claims to have picked up Hawfinch, Firecrest, and Long-eared Owl at Titchwell. Fairly unlikely, but who knows?

Photographing birds from the comfort of the settee

Busy day, no chance to get out birding or togging, even. Moreover, it was dull and grey, so not great for capturing avian beauty. That said, I was setting up the new lens on my Canon R7 adjusting the customised settings buttons, a Canon RF 100-500mm F4.5-7.1L IS USM. Once I’d done that I snapped a cheeky Robin that landed on the bushes in the front garden after it was chased in by a male Blackbird. It sat on its usual perch and the Blackbird didn’t bother it again.

Anyway, photographed in low light from the comfort of the settee through the double glazing, the bird largely in shadow. Camera settings: shutter speed: 1/500s, aperture: f/7.1, ISO 4000, lens pulled to full extent 500mm.

Denoising with DxO PureRaw 4. Original and the left, denoised on the right
Denoising with DxO PureRaw 4. Original and the left, denoised on the right of the split image

I processed the image with DxO PureRaw4 as I generally do, see above. The reason I mention it so often is that it does an incredible job denoising job. I reckon it effectively pulls your image down 3-4 stops of ISO; my ISO 4000 is thus being cleaned to the noise levels one might expect at much better ISO of between 250 and 500. There’s no way I’d get a properly exposed shot with these light levels and that shutters peed at such a low ISO.

 

I then did a quick levels edit and crop in PSP to show a fellow togger:

Quick PSP edit of the DNG output from DxO
Quick PSP edit of the DNG output from DxO

Finally, I did a more detailed edit of the kind I would do before uploading to my socials:

Through-windows Robin processed in DxO PureRaw and then PaintshopPro
Through-windows Robin processed in DxO PureRaw and then PaintshopPro

Another mineral moon

Some time ago, I discussed the concept of a mineral moon shot. Basically, you take a photo of the moon, or a stack of photos, and then process them to bring out the colouration of different areas of the surface. Different areas, the seas, the mountains, the plains, have different minerals on the surface that scatter light of different wavelengths in different ways so that reds, blues, purples, and even yellows, can be brought out in a photo of the moon that will most likely have appeared as nothing more than fifty shades of grey to the naked eye.

Waning gibbous moon, Canon R7 with Canon 100-500 at 500mm. Handheld, shutter 1/640s, F/7.1, ISO 800. Denoised in DxO PureRaw4, levels adjustments in PSP.

Well, you may recall I had a Sigma 150-600mm lens that I originally bought to take photos of the moon but that became my mainstay through various cameras for bird photography. I have now traded-in that lens for one more suited to my Canon R7 mirrorless camera, the Canon RF 100-500mm L series F4.5-7.1L USM. The above moonshot was taken using that kit and denoised in DxO PureRaw 4 and levels adjusted to taste in PaintShopPro. PSP was then used to incrementally raise the saturation to reveal the minerals in the image below.

Mineral moon
Mineral moon – Additional saturation adjustments done incrementally in PSP

The quality of the photos with the R7 and this new lens are far better than the ones I was getting with this camera and my 8-year old Sigma lens despite, the additional reach of the Sigma at 600mm as opposed to 500mm. The photos are even better than those I’ve got with a smartphone camera clamped to the objective lens of a 5-inch reflector telescope! I’ve not successfully used a dSLR with my telescope, unfortunately.