Will someone please explain camera sensors/resolution/pixels

looking for a bridge camera with big zoominess but as I understand it, most cameras with a big zoom have smaller sensors & vice versa, which mean less resolution? What about pixels? I always thought more megapixels = better pictures?
We have a budget of up to £250 & don’t even expect to produce award winning/fantastic quality photos, (mainly half decent shots of birds of the ornithological sort)
Probably won’t be taking many shots in low light either.
Some cameras for under £200 have 60X zoom, equivalent to around a 1200mm lens!

Can someone explain in simple terms & reccommend a camera please??

lots of little teeny pixels mean noise on the image (which looks like grain/spots). Less pixels mean larger pixels which means less noise – so a smoother picture.

Larger sensors allow bigger pixels and hence lower noise for the same resolution (MP).

In a very simplified way.

I suspect you will struggle to photograph birds with anything in that price range… but I would probably go with something from Lumix or Canon if pushed.

Not much to add other than long zoom lenses on cheap bridge cameras have narrow apertures.

This means poor low light performance and or slower shutter speeds even in reasonable light.

Again not desirable for birding. You may get the odd decent shot of a static bird in good light but will struggle beyond that.

If you want to get into bird photography I’d personally look at one of the somewhat older but quality dslr’s-Nikon D80, Canon 50D or the like then spend a chunk on the lens.

Or up your budget considerably!

A Lumix TZ72 has a 20x optical zoom which can take pretty good zoom photos, and some of the megazoom bridge cameras made by the likes of Panasonic and Sony have pretty respectable optics, but I have a suspicion that your confusing optical and digital zoom; with optical zoom the number of pixels in the sensor are irrelevant, although with a smaller sensor increasing the pixel count will usually increase digital ‘noise’, but with camera phones, the greater majority have fixed lenses, so any zoom involves enlarging the pixels digitally, increasing any noise already inherent in the tiny sensor in the phone’s camera.
One disadvantage with long zoom lenses is that the angle of view gets narrower and narrower as you increase the zoom, making it increasingly difficult to find and follow a moving object, and camera shake becomes increasingly difficult to control.

Cheers Capt, I’ve seen plenty of good shots taken on DSLR’s with mahoosive lenses but A) waay above budget & B) theyr’e huge!
Looking for something cheaper & lighter, I’m already carrying a spotting scope & have tried digiscoping using my existing Lumix G1 but the results were crapper than some stuff I’ve taken with my compact!

I have a suspicion that your confusing optical and digital zoom;

Naa, that’s the bit I do understand! I’ve got a 20X Canon compact & on 20X optical zoom the quality stays decent. Stick it on it’s 72 digital zoom & it’s….shoite!

I shot this with my Lumix TZ-72 near the Ridgeway, I’m amazed I got anything at all!

Don’t worry about pixels too much. Almost all cameras surpassed the number of pixels the average person needs many years ago.

The main advantage of having a huge pixel count is the ability to print images at huge sizes without losing any quality.

looking for a bridge camera with big zoominess but as I understand it, most cameras with a big zoom have smaller sensors & vice versa, which mean less resolution? What about pixels? I always thought more megapixels = better pictures?

Not just big zoom cameras, but most cheaper cameras have smaller sensors.
This doesn’t necessarily mean lower resolution, but it generally means more noise in the image which degrades quality.
Think of pixels as tiles in a mosaic. The more tiles you hav in a mosaic of a given size, the closer the image will look to the reality of a continuous gradient of colour and definition. So, this is where the thinking arises that more megapixels = better quality images.

A camera sensor is made up of tiny sensors – each pixel is a sensor site.
If you have a 20 megapixel sensor of a given size, each pixel will have to be smaller than those on the same size sensor with only 10mp.
Each pixel is recording it’s own data for the image falling on it. As I understand it, background electrical noise and cross talk between the pixels results in error in the recorded image. This is known as noise. There are various types of image noise, but basically it means you lose detail and colours start to look speckley.
Larger sensors are generally less noisy, as each sensor site is larger and there is less cross talk.

Someone will probably be along to tell me that’s all bollocks, but that’s my basic understanding of it.

The trouble with catching birds (particularly in flight) with a cheap camera is not just the small sensor but often the focus system will struggle to recognise the subject and/or stay latched onto it.
There’s also the issue that as soon as you start zooming in, the aperture will get smaller and so less light hits the sensor and the shutter speed goes up.

That’s not to say it’s impossible as the above pics show, but it can be tricky….
Would you be taking pics of birds in flight or static birds…

I did a bird photography day at a sanctuary with Wild Arena and even in a controlled environment it was very difficult to get good results. I was using my Nikon D80 with 70-300mm VR (stabilised) lens.

Pixel count = showroom appeal. Anything over 10M pixels (arguably less) is just willy waving.

Ignoring form factor, for what you’re describing I’d be looking at an older DSLR plus long zoom lens. The lens will be most of the budget. And the whole thing will be pretty large and heavy.

OR (and this is the more sensible option) I’d suggest buying the best of what you’re willing to carry around with you, ideally with a <10M pixel count and as large (i.e. numerically small) aperture at max zoom as possible, and getting the best you can out of it. I don’t know what’s great for that, but the STW hive mind probably do…

You’re going to struggle with a cheap bridge camera for wildlife photography.

As a minimum, I’d say you’re going to need a TTL viewfinder. Electronic viewfinders on cheap cameras have latency which make it almost impossible to capture moving subjects. You’re also going to need the fastest lens you can afford, which will probably be a telephoto zoom with f5.6 at the long end.

I think your best bet for bird photography for £250 would be an SLR from eBay (Canon EOS 400D for £100ish) plus Sigma/Tamron 70-300mm f5.6 lens (£120ish). I think that’s the best you’ll get for your budget.

Pixel count = showroom appeal. Anything over 10M pixels (arguably less) is just willy waving.

Low resolution sensors are generally* just old. Old technology is crap compared to new technology, not because of pixel count, just because it’s old.

No idea what would fit the bill at that price point though.

*with some specialist exceptions

Pretty much as others have said, but I’d add that you can get more from the images by shooting in .raw and developing them with software (lightroom or acdsee for example).

Take those bird images, if there’s a raw file there’s probably more detail to be found in the dark areas of feathers, sky could be bluer, and blurred out, ground could be de hazed etc. Jpg’s from the camera are fine, but it’s a small processor compared to your PC and it’s making its best guess at what you saw, you can always do better yourself.

Larger sensors are generally less noisy, as each sensor site is larger and there is less cross talk.

That’s how I understand it also; larger wells generally mean higher ISO capability. The Sony A7s and A7sII for example has a pixel count of 12mp and pops up to something like ISO 250,000.

Larger wells also have the benefit of being easier to focus the light into them; the range of angles over which the light can enter and be in focus is greater so the light well is more forgiving. The smaller the well the less forgiving it is of inacurate focus, which is why you need extremely good and expensive optics for very high megapixel sensors.

However, high pixel count has a lot more to offer than just fine detail and pixel peeping.

Pixel count = showroom appeal. Anything over 10M pixels (arguably less) is just willy waving.

This isn’t quite true since while it may be the case that 6mp is enough to print A3 or even larger without noticing pixelation, the dynamic range and noise performance of high pixel count cameras also tends to improves when you descale a high MP count image to the equivalent size image of a lower MP count image.

That’s how I understand it also; larger wells generally mean higher ISO capability. The Sony A7s and A7sII for example has a pixel count of 12mp and pops up to something like ISO 250,000.

Not quite true. When you downsample the 42mp a7r2 to 12mp you get better noise performance right up to iso 6400ish. The a7 then holds on better than the r2 but you may well be beyond an acceptable level quickly anyway.

The A7s is 12mp because it’s primarily a video camera and when cropped 16:9 gives you HD output without line skipping.

So arguably it might be better at willy waiving iso, but in practice it’s much the same. Just better at full frame video.

The only reliable rule of thumb is newer = better (and newer = more pixels).

The trouble with catching birds (particularly in flight) with a cheap camera is not just the small sensor but often the focus system will struggle to recognise the subject and/or stay latched onto it.
There’s also the issue that as soon as you start zooming in, the aperture will get smaller and so less light hits the sensor and the shutter speed goes up.

That’s not to say it’s impossible as the above pics show, but it can be tricky….
Would you be taking pics of birds in flight or static birds…
Oh, so very, very right! It’s a good thing that kite was flying very slowly, and wasn’t much more than about two-three metres away at its closest, but it is very difficult.
My TZ has an electronic viewfinder, as well as the screen but it’s still really difficult to actually find, let alone track and focus on a moving bird, then trying to focus as well…
As I said, I’m astonished I actually got those photos, I’ve been trying to photograph a red kite for some years.

So arguably it might be better at willy waiving iso, but in practice it’s much the same. Just better at full frame video.

I never used my 7s for video but I didn’t see much difference in image quality between it and the 7rII.

Ignore pixel count, it’s a Marketing stunt.

Mate of mine is an amateur photographer, way better than I’ll ever be. He shoots Nikon and has all the gear.

He’s got a 2′ by 3′ landscape canvas over his fireplace which he’s shot, it’s truly stunning. I asked him about lens choice etc to take that. It’s a blown up iPhone snap. I was stunned.

It’s not about the gear, it’s about learning to use the gear you’ve got. Spunking money on equipment won’t magically take better pictures.

If you don’t care and want a specific recommendation, there’s a few recent threads, search the forum. But to my mind, what you need there isn’t a camera, it’s a book.

The larger sensor of a dslr allows more cropping, which is pretty much essential in bird photography. Some of my pictures below are cropped to less than 20% of the original. My dad has an expensive superzoom bridge camera with more reach than my 400mm but the image quality simply isn’t the same.

https://500px.com/timrusson

If you are at all serious about taking bird photos you really should consider a dslr. I’d have thought that £700 would get you a 400mm f5.6 and a crop sensor body. I know that’s rather more than your budget but better to spend more and get satisfying images than spend half the amount and not be happy?

Birds in flight really need the focussing speed of a dslr too as Stumpy said.

There is a learning curve with dslr, and it’s possible to take some very poor shots early on which would have been better on a bridge camera!

And get Lightroom – the saviour of many a photo!

It’s not about the gear, it’s about learning to use the gear you’ve got. Spunking money on equipment won’t magically take better pictures.

Generally I’d agree, I’ve blown up iPhone pictures to print and they can look great, but they need good light and don’t really stand up to any kind of cropping.

I think that wildlife photography is one area where equipment (and cash) still play a big part.

I’d have thought that £700

…

We have a budget of up to £250

I’ve another mate who’s a twitcher. He’s taken some potentially award-winning shots, but he’s spent far more than £700 on a single lens, let alone a £250 total budget.

I think that wildlife photography is one area where equipment (and cash) still play a big part.

Totally agree. But at a £250 price point you’re looking at the sort of superzoom CZ posted, a monopod and a vast amount of good fortune. IMHO, etc.

“I’m amazed I got anything at all!” – cracking shots, sir.

bird photography is very difficult to produce decent results I used to do a bit , used a canon 400L lens,
a second hand hand 300mm zoom and a used dslr body may be a good starting point ,I still use a canon 40d which is a decent camera and can be had quite cheap now used

I started with a canon 70-300 zoom and added a kenko 1.4 teleconverter and had some half decent results, birdforum many be a good place to look for advice and used gear as well

He’s got a 2′ by 3′ landscape canvas over his fireplace which he’s shot, it’s truly stunning. I asked him about lens choice etc to take that. It’s a blown up iPhone snap. I was stunned.

This is a classic error; someone sees one great picture taken with an iPhone or equivalent and assumes that that therefore makes all everything else redundant. Given lots of light and a landscape scene sure you can make great pictures with the iPhone. But ask it to replicate the capabilities of far more sophisticated and capable equipment in much more diverse situations and you’ll soon realise the limitations of the ergonimics, the sensor, the lens etc.

I completely agree that the camera itself is the last thing in the long chain of variables like composition, lighting, subject matter, colour, perspective etc that mark out a great image, but there is still a reason that most of the great pictures in history have been taken with great cameras.

Thanks for everyone’s input on this! FWIW I’m looking through a Swarovski ATS 65 scope & half expecting to get photo’s to match, which admittedly now ain’t happening!
However any photo’s would really be for ID purposes as I didn’t expect to get ‘quality’ shots from a bridge camera, which boils down to the fact that after good input from you guys……I’ll just stick to spotting & not photos! 🙂

It’s not about the gear, it’s about learning to use the gear you’ve got. Spunking money on equipment won’t magically take better pictures.

Pretty much the same as “the best camera is the one you have with you”; but with very strict limitations, as others have said.
It’s quite possible to take stunning photos with an iPhone, but wildlife really isn’t possible, and certainly not birds.

“I’m amazed I got anything at all!” – cracking shots, sir.

It’s very kind of you to say so, but I know they’re really pretty average, but having said that, as far capturing a moment goes, I’m very pleased, because they are a record of an afternoon when I stood watching a beautiful bird of prey cruise past me barely nine or ten feet away, and I managed to capture that.
When it comes to capturing something in flight, when all you have with you is an iPhone, then this is about the right sort of size:

😀

Check out this one

http://m.ebay.co.uk/itm/Nikon-D-D3100-14-2MP-Digital-SLR-Camera-Black-Kit-w-18-55mm-and-55-200mm-/172351997628?nav=SEARCH

Will probably sell for under your budget
It is a small dslr, quite small and light.
Decent zoom
Because it is an SLR can take shots in focus, even when subject is flying.
Decent number of pixels
Comes with all the bits and pieces you need like carry case.

Twisty has it right. A bottom of the range Nikon (or Canon) DSLR with APS size sensor and a reasonable zoom lens. My daughter has a Nikon D3300 and its an amazing camera for the money. Add on a top lens and it takes pics nearly as good as my D610. DSLR has the shutter speed and with more pixels you have the ability to crop the image (I guess that’s like post shooting digital zoom!).

I’m still using a 6MP Nikon SLR from yonks ago and it still produces way better pictures than compact cameras and phones I have that have twice or more the pixel count.

Why?… optics.

Resolution/pixels define how big the picture will be, not the quality. Most people are using photos on the web and sharing on phones these days so even a low resolution camera will provide plenty enough. The main advantage more pixels will give you is the ability to crop while still retaining a useable size that doesn’t have to be scaled (losing quality).

Zooming – two kinds, optical and digital. Optical literally uses the optics to zoom and is the best kind of zoom. Digital zoom is basically cropping the image to a smaller size. Used to be awful but now with high resolution cameras it still produces a useable size photo, although the end resolution will be lower. With optical zoom the end resolution will always be maximum, so you can then crop further if you want.

Digital zooming/cropping an image may highlight the quality of the sensor however.

Sensor size has a physical optical effect. Smaller size sensor only needs small size optics to achieve the same “zoom” as a bigger sensor and big lenses. The smaller sensor will produce greater noise though, which will be noticeable in lower light or when cropping.

Zoom multipliers aren’t generally comparable as it depends on the sensor size and normal focal length, which varies per camera. Actual focal length with the zoom is more useful but to compare you want “35mm equivalent” figures to have a consistent comparison between cameras.

A pile of other things to consider, such as how many shots a second it can take which might be relevant if doing action shots, the sensitivity levels it offers and quality of low light sensitivity if you’re bothered about low light. Bridge and compact cameras (phones even) are often focused now on social media and offer wifi and ability to share photos instantly, have touch screens where you can fiddle with the photo or focus by touch, etc. They can offer in camera post processing that would typically be done on a computer in older cameras. Plus may have video options also.

https://www.dpreview.com/ is very comprehensive in their reviews. Make sure you go to the ‘full review’ section for each camera. They have a side by side compare option also.

(sorry, all got a bit long there)

Let me guess, D40. Cracking little camera.
When i switched from d80 to d600 i found i had to overclock my computer, as all the extra pixels were creating sooo much lag during selecrion and editing

Larger pixels collect more light, so their signal is stronger. This means it doesn’t need amplifying as much. Weaker signals from smaller pixels needs more amplification, and this also amlifies the inherent thermal noise in the sensor material. Hence noise.

Also why you get more noise at low light, because the signal needs amplification.

So a larger sensor with the same number of pixels gathers more light than a smaller one and hence has less noise. More megapixels does give a higher resolution image, but will be noisier unless the pixels themselves are bigger.

Cameras with smaller sensors combat noise by using noise reduction smoothing on the image, which makes it look a bit funny blown up.

Anyway – taking pictures of birds is bloody difficult. One of the few situations where shitloads of money really does buy you much better results. To get decent pictures they need to be pretty damn close, where they don’t tend to be for very long so you have to be ready!

twisty – Member 
Let me guess, D40. Cracking little camera.

Even older, D70 😀

Still not bothered upgrading, though main reason I would is because the frame rate is a pathetic 3 frames a second and slows down due to the slow speed in writing to the CF card. Makes action shots a bit tricky.

Also, it’s got a spot on the sensor screen which I can’t shift despite my usual sensor cleaning techniques. I can usually deal with it post process and not noticeable in a lot of shots.

These were taken on a Panasonic FZ5. An ancient 5mp superzoom

The quality was OK for A4ish prints

My sugestions is that you check out reviews on Cameralabs. One of the few place to test Superzooms at full zoom

Off the top of my head I’d look at a FZ200. Don’t assume more optical zoom would be better. New is £249 from Park cameras. Under budget used. The main down side of used is the potential for dust on the sensor

If I could put in my thoughts.
DeadKenny has it right. A camera is a machine to hold a lens. Its the lens that does the work and the sensor records the image.
Thats why often the most expensive cameras are often quite simple. Hasselblad’s, Phase One and Leica use relatively simple (though expensive) to hold the ultimate glass.
I suggest on your limited budget, if you are keen on an SLR, then buy a decent second hand camera with the largest sensor (not largest MP) you can afford and then put as much as you can into a decent lens.
Have a look on some of the specialist camera sites. You can find a very decent used Canon or Nikon that others are moving on because the latest model MK II, III or IV has come along.

Some great info guys, much appreciated! Can someone show me a ‘noisy’ photo & a ‘quiet’ one? That’s one thing I don’t understand. To me a photo is either of good quality or it isn’t!

Here is one (of a work colleague and friend of mine) taken by accident at something like ISO125,000! This is an example of a very ‘niosy’ picture.

And here is one taken at ISO 3200:

Ethan by Greg Turner[/url], on Flickr

And finally one at ISO 150

Old Blue Eyes by Greg Turner[/url], on Flickr

If you go to dpreview (e.g. https://www.dpreview.com/reviews/canon-eos-1d-x-mark-ii/6) then you can get side-by-side comparisons of cameras that you maybe interested in.

Try comparing that Canon at ISO100 with a Coolpix at ISO1600 for an extreme example.

Some great info guys, much appreciated! Can someone show me a ‘noisy’ photo & a ‘quiet’ one? That’s one thing I don’t understand. To me a photo is either of good quality or it isn’t!

This is another area where ‘quality’ is kind of subjective. A photo with a fair amount of ‘noise’ or ‘grain’ if talking about film, can be an exceptional photo, and one with no perceptible noise or grain barely average.
Photographers have ‘pushed’ the ISO rating of film for years, to increase sensitivity in awkward lighting situations, going from ISO400 to 800 or even 1600, mostly in mono, which produces ‘grain like golfballs’, but adds a lot of atmosphere to a situation, especially in rock photography, whereas the same in a landscape might not work, although it can do so in bleak snowscapes with rocks and trees,
Reportage photography often produces some of the most iconic photos in grainy mono, the same scenario in grain-free colour would lose a fair bit of emotional impact.
A grain-free sunset landscape, awash in subtle shadings and tints would work better than any grainy, noisy photo.
It’s about emotion and impact, not necessarily quality, and that is largely subjective, as I said; beauty being in the eye of the beholder, and all that stuff!
How well would this photo work shot in colour on a fine-grained film like Kodachrome?

Photo by the great Don McCullin

He now only takes landscapes, but he sticks mostly with Mono, and the grain/noise is very apparent in this one, but it adds, not subtracts to the atmosphere…

This gentleman, on the other hand, shot landscapes on 8″x10″ Polaroid Land film that produced a negative, so multiple copies could be made. This film has no grain/noise whatsoever, so big enlargements show staggering detail.
His name is Ansel Adams, one of the finest landscape photographers who’s ever lived:

Even older, D70
Still not bothered upgrading,
frame rate is a pathetic 3 frames a second
slow speed in writing to the CF card[/small buffer]
Makes action shots a bit tricky.
it’s got a spot on the sensor

Bro, I sold my D80 body for £50 and that is better at everything. Aside from all the electronics the viewfinder is bigger/brighter too. You must be addicted to compact flash or something.
Then again I’ve heard that the D500 with XQD card is king of action shooting.