I never print out bigger than 6" x 4"

On standard printers photos print out at 300 dpi. So

6 x 300 x 4 x 300 = 2160000 or 2.16 mega pixels.

My 24" iMac has a screen 1920 x 1200 = 2304000 or 2.3 mega pixels


My camera is 4 mega pixel. So I am wasting about 50% with every shot. At the moment I have reduced the image size to 2 Meg so as not to have the waste. Does anyone know if there is a good reason not to do this?

CC

Shooting at maximum resolution enables you to crop close in to zoom interesting features. It also keeps the maximum image quality until the last minute, which may help to reduce grain and improve dynamic range. For the same reason, I never use the rather pointless digital zoom option. It's better just to crop later when you have all the time in the world to frame the image, and you may spot something interesting you'd otherwise miss.

My snapomatic has a 2GB card, and the 11 Megapixel JPEGs are less than 3MB in size. That's almost 1000 images on each card, which is several months worth for me. Even if I was touring for weeks, I doubt I'd fill the card.

So my question is, why would I reduce the setting and potentially lose detail I may be interested in later?

^^^Agreed. You are losing out on info you might want.

For several generations of camera, Fuji kept with 6MP because of their superccd sensor which far superior results to other cameras at the time that were 8 or 10MP cameras. People tend to get lost in the chase for MP, bit like the CPU thing. There are people who thought a celeron 2.4GHz bare spec PC was better than an athlon xp 2Ghz well-specced PC.

All those MPs are useless without a decent lens and electronics.

You can't always take a 2nd try at a shot, so if you manage to get that once-in-a-lifetime capture and you've chosen to limit the maximum size for reasons of economy, you may well kick yourself!

None, I always cook just the right amount and make sure I eat them all. Wait, what?

I always shoot at maximum settings for the reasons given.

I have a 300mm lens, which equates to a 480mm lens on a 35mm camera. I can get small or distant objects pretty large in the picture and by the time that the photograph is expanded to its full size, something quite small can take up one heck of a lot of screen space.

Cropping? Who does that?

Well a slight trim maybe but major cropping? I have a camera with a viewfinder so I can see the image before I take it. I have never had reason to crop hard.

Kodak and others happily print out 8" x 10" images from a 2Mp image. So there is no problem there. I would much sooner have a low Mpix camera with each cell on the sensor more sensitive than have a camera that takes images that can be zoomed. Maybe if you are a private eye more pixels would help but for day to day use I just can't see the point.

Large images take longer to load, can't be Emailed in large groups, take up storage on your main drive and your backup drive, are slower to stream over your Wi Fi LAN. They have to be compressed to fit on your screen, have to be compressed to print out. They don't look any sharper, they are prone to noise and artefacts if they have been taken with a small area sensor (or at least AFAIK they do they certainly did till recently on small cameras).

All you seem to get in return is the ability to crop a pic really hard. Not a good trade off in my book.



What I wanted to know though is if you cut the Mpix size directly on the camera is there any theoretical/actual loss of quality? The point is prints normally are at 300 dpi so higher pixel densities seem pointless to me.

I waste none. All pixels are needed. All pixels are used.

Well that is impressive.

I thought about getting a long lens for my SLR but as I never actually found a use for anything over 100mm I did decided not to bother.

I used to shoot at 5MP, when I started using the photos as backgrounds on my 19" monitor which has a resolution of 1280x1024, I noticed they were a little pixelated, and didn't look too sharp, I upped the camera to it's max (8MP) and the images look a lot better. Even on my 13.3" screen (1024 x 800) they look a lot better

Each image is around 4MB, but with the 500GB backup drive it really doesn't matter, my 80GB hard drive on the Mac still has 20GB to chomp through, and I don't take that many photos...
If I want to email them I'll usually zip them up and put them online somewhere for my recipient to download, or downsize the images using something like The Gimp.
The Wi-Fi thing is exactly why I don't use WiFi, when I take my Mac off the gigabit network connection, everything feels just too slow, yes that does mean I have leads almost everywhere linked up the the gigabit switch.

Pictures taken at the higher resolution appear a lot sharper on my screen, and almost seem brighter too...

Obviously I try to frame the picture nicely when I take it, but sometimes you make a snap decision and think later on that a different part of the image should take centre place. Also, I only have a fixed lens so I have no other way of getting in close unless I can physically get close to the subject. Obviously, this is not always practical. Additionally, I may use the image for more than one purpose and need to crop it differently to suit each job.



So would I, but I can't change the CCD so I have to make the best of what I have. Unfortunately, Megapixels are the selling point which is pushed more than the quality - at least in my price bracket. My very first digital camera was only 640x480 but had a lovely sensitive sensor. I miss it sometimes.



I don't find any of these things to be a problem. I keep the raw images as originals, but I always process the pictures worth sharing. Resizing is single keyboard short-cut which is trivial compared to any other messing around I might do. Also, my hard drive and backup facilities are more than adequate for a few gigs of pictures, and my LAN is quick enough. I'd never email my mum a picture that was over 100KB so that would always need resizing anyway.

Even if I didn't want to adjust the pictures and simply wanted to print them, I can just stick the card in the printer and it does it for me.



They do appear sharper to me. As said above, a faster sensor with a lower resolution would have less noise but I can't change the sensor so that's completely irrelevant! Lowering the resolution doesn't make the sensor any different; it simply throws away information.



It depends on the logic in the camera. If it simply discards every other pixel, then yes you loose a lot of quality. If it uses a high-quality resizing algorithm equal to that which I'd use in Paintshop, and the pictures don't need any further adjustment, then there's little loss of quality. The only way to tell is to try it. Why don't you try it?

If you print the images directly without any processing, and you're absolutely certain that you'll never ever want a large print then you're probably right. However, to simply save 50% on storage space I personally think you're a crazy cat.

Interesting discussion.

I shoot in RAW and therefore need a bit of sharpening before I can print out the results. I print A4 at home but sneak a few A2 or even A1's from the office plotter. This is where you see a difference because the plotter is only 600dpi The human eye however is geared at around 300dpi so anything above that is pretty much wasted.

Of course it depends on a multitude of factors but if you set your camera to zero defaults, there will still be a degradation of quality when you save as a jpeg (camera dependent). Also, cropping/resizing for the internet and printing requires different post processing techniques.

The main difference for me is that I have learned that if you switch down the resolution at which you save your images, you can't then return to those images and print off great quality reproductions. In this day and age there is no reason to not use the full scope of the camera sensor as storage is so cheap - you never know when you might need a high-res huge copy of that pic?

Al

Agreed. I would always use the maximum available resolution of the sensor. When storge comes so cheap (I bought a Lexar 8GB 60x SD from MyMemory for 15.99 who are now doing a Kingston 16GB for 20.99!!) its easier to take the pictures full size and resize, crop, etc later. That way you still have the full size/resolution version.

I also agree with whoever mentioned the Fuji 6mp CCD. My dad had a Fuji bridge camera (cant remember the model, the RRP was around £600) back in 2001/02 with the SuperCCD 6MP. In 2006 I bought a £300 Nikon compact 8mp and I still preferred Dads 'old' camera.

Hmm, well you have a point about storage being cheaper these days. Maybe I will switch up to 4Mb for photos. It still seem like real waste to me though. I mean to say I have never in my whole life printed larger than 10 x 8 (and I am an old old cat)

I suppose I could downsize them later if they turn out to be too unwieldy.

I don't waste any. I've set my camera to take them at 1600 x 1200 and my TFT for looking at them is 1600 x 1200.