I have a Canon G7. I know its not a DSLR, but it is a fantastic P&S with full manual capabilties and is built like a brick s***house. I love the camera but I do have a question and I can't find a definitive answer. Thought I'd throw it out for the experts here.

The G7 is 10 megapixel. I know about the small sensor, and the resulting noise at higher ISO settings, and I understand that part. My question concerns shooting at lower resolutions. I don't print out a lot of pictures, viewing most on my computer monitor. Even on my larger screen lcd pics at 3648X2736 are way bigger than the screen, and frankly don't look that good at full size although I think they would print just fine. Scaled down to the screen size they look great. If I back off and shoot at M1-2816X2112 or M2-2272X1704 or lower, I will not be able to print larger posters (I don't do this anyway) but what else am I losing in that process? What actually happens when you switch to smaller size? Does the camera just use a portion of the sensor, does it use the whole sensor but interpolate a smaller output? Does any of this make sense?

OK, that's more than one question but you get my drift. What goes on?

 

I don't know the answer, but my guess would be using the whole sensor and interpolate down to less pixels. But if you are looking at them on your computer, doesn't the software have option to resize them to the screen size anyway? So why not keep the image at max resolution and just left the PC do the temporary resizing unless you are running short of memory in your memory card?

 

Think of it like an LCD monitor. It will have a native resolution, but it can display several different screen sizes. The best image will always be what is native. Unless you are concerned about memory, go with the default size and resize when viewing or printing.

 

Thanks for the replies. Need - you're right, software automatically scales the pics to my screen so that's not a problem. Thing is, I took a series of pics at all different resolutions and on the screen at least can not see any difference in them other than the smaller obviously don't fill the screen and wouldn't be pretty blown up to fit. Memory isn't really a problem, I've 3, 2 gig cards which will hold well over 400 pics in the highest setting. Going to Ireland next month however, and may want to take some movies clips also which tend to fill a card fairly quickly. If I could downsize without loss I thought I would.

Scottinbend - your example makes sense, yet, if the native resolution is always best do you then compromise each time you downsize to print? If so, I gather it would still be better to compromise from a position of more info rather than less.

 

For times, I thought about setting the camera to a lower setting when I am taking pictures I don't intent to keep (for ebay or posting on the web etc..). The only reason I didn't do it is that I am afraid that I will forget to set it back to the highest setting next time when I caught that Kodak moment!

 

That's a good point. I normally get around it by using one of the custom program modes with saved settings. That way the camera always returns to my favorite settings each time I turn it on. I have to check the ISO dial though, it has a tendency to move if I'm not careful when I pack the camera away.

 

Keep in mind that your monitor displays ~70 to 100 pixels per inch, but to get a good print you typically want ~300 pixels per inch (unless you have a good interpolater). Won't make much of a difference if you're printing 4"x6", but step up to a 12"x18" or 20"x30" print size and you'll notice a huge difference.

And yes, the camera's DSP is automatically resizing the full sensor capture down to a smaller pixel size when you use the smaller photo size settings.

Have a great time in Ireland!

 

I don't have any answers, but I bought the same G7 camera for my dear wife for her birthday. I agree that it is incredibly well built and takes incredible photos in almost any situation. It has a great solid feel to it with its metal case that feels like an old solid 35mm slr

I know the photo guru's will probably disagree with me, but I feel that this camera matches DSLR performance 95-99% of the time for an amateur shutterbug like myself. In every situation I've put it against, it has produced excellent results. I was going to get a DSLR for myself but now can't imagine why I would want to carry a big heavy DSLR.

In short, the G7 is like a MINI Cooper. It's not the biggest or fastest thing out there, but it performs well all day every day no matter what I ask it to do.

 

IMO opinion it's always best to shoot at the highest resolution possible. You can always downsize if you need to to, but if you find you have something you do want print & print big you will be SOL.

Cards are becoming very cheap. Why not pick up a 4 GB card for video use.

The G7 is a great camera. Reminds me of a classic rangefinder. I like the size & maybe it's not quite up to DSLR quality, it is darned good & will take much better pictures than the DSLR you left home because it's too big & heavy.

 

Thanks speednut. We're looking forward to the trip.

OK, your last sentence still confuses me. The sensor has 10 million whatevers that grab the light, so when I downsize the pic are you saying the camera throws the input of some of those whatevers away to make the picture smaller. Or, are pixels themselves reduced in size to match a smaller space?


Yucca - I agree with you totally. I'm also an amateur (although I've been taking pictures for a long time and do own an SLR I haven't used in years) but the G7 takes such good shots and is so easy to use I find I'm snapping away and changing settings etc. etc. all the time. Its just a joy to use, and makes me want to learn more about photography which none of my others cameras did. I love it.

My only complaint was a lack of gripping surface and lack of room on the back for your thumb. I solved this by putting carefully cut stair tred material on the front and a small piece on the back. This stuff is self-sticking, black and with a texture like 80 grit sandpaper. It looks good on the camera and makes it real easy to grip.


Crashton - The only thing that stops me from getting bigger memory cards (I guess I could go to 8 gigs) is I fear putting too much on a card - say a whole vacation worth, and then have the card crap out and leave me with nothing. Don't know if its logical but my plan was to take several cards and spread out the risk. In hindsight it would have been smarter to buy larger capacity SD cards in the first place.

 

The camera always shoots at 10MP - it uses the whole sensor area regardless of the image quality or size settings.

It is what happens after that.

If you tell the camera to store the images at (say) 640x480 resolution, the software in the camera converts the image from the raw 10MP image all the way down to 640x480.

If you tell the camera to shoot at Low quality (rather than high/fine) it will use varying degrees of compression to fit the image into as small a apace as possible.


If you choose to store in High/Fine Quality and full resolution, the images will be less 'messed with' when you upload to your computer, you can then choose whatever manipulation you want to to resize etc.

Some cameras have really good compression algorithms, the Canon EOS 20D that I use has a very good one, there slight differences bewteen a raw and a JPEG (compressed) image when you shoot at full resolutions, but nothing that would worry the vast majority of the population.

For 'paying' work I shoot in RAW, then edit and save in lossless formats only, but for my casual / fun use it is Full quality and size - even then a 10MP image is compressed to about 5MB (ie half the size).

 

here's my 2 cents...i'd shoot with fewer pixels. with my first two digital cameras i was solidly in the "always shoot with max res" camp. my first two cameras were a 1.3 Mp and a 5 Mp. my current camera is a 8 Mp and i shoot in the M1 (one step down from max). i have never printed larger than 8.5x11 but the ability to do larger would be driven by the complexity of the image. (simple image would print very nicely very large, a class picture with 100 faces would be limited on how big it would go and still look crisp) the problem with shooting max-always is you have to move and store those huge images. external drives are getting pretty cheap so maybe it isn't a concern, but for me i just didn't want to deal with all the extra pixels i would never use.

on a personal rant...i'm not sure why camera makers just keep upping the Mp's, at some point its sort of ridiculous to keep giving consumers more and more pixels. i'd be very skeptical of anyone (non-pro) who told me they needed more than 5Mp. (for the curious, why then do i have a 8Mp? try to find one with more than 3x optical zoom and manual controls less than 7 or 8Mp!)

hope that helps someone, somewhere

 

Thanks Max, and to all.

I think I've got it now. In summary, there would be no advantage to shooting at a lower resolution setting, other than less storage space used. As said, best to shoot at fine and full resolution and deal with sizing later.

To explain, I somehow got it in my head that cramming 10 megapixels into a ever smaller space would (could) yield a better picture, at least up to a point. Clearly that isn't the case but I couldn't find out why without help.

Speednut - thanks for that monitor info also, I was wondering why the pics didn't look so hot at full size.

Learn something everyday.

 

I can dig it. Luckily I have fast harddrives and I did spring for the Ultra II SD cards - not the fastest but it only takes maybe 30 seconds or so to upload 100 10 meg images. From what I've learned, it would be nice to have a larger (physical size) sensor with less megapixels, but that would mean a dslr at the moment and I can't fit one of those in my pants pocket. The G7 is a squeeze but it will go.

 

Why more and more megapixels ?

Simply because 'bigger' is conceived as 'better'.

My EOS 20D's shoot at a mere 8.2MP the sensor is an APS size one which means that I get a 1.6 crop compared to a full frame sensor. My 5D shoots at 12.8MP and uses a full-frame sensor. Pixel density is very similar between the cameras and image quality (at any given crop) is near-enough identical.

My wife has an XTi - 10.1MP - the pixel density on the sensor is approx 20% higher than the EOS's. Any given crop is, however virtually identical. At these levels it really, truely comes down to lens quality and as I can use the same lens on each of the bodies, the quality is near-enough identical.

In the point-and-shoot market, it is easier to add more pixel density, becuase that old 5MP camera is obviously inferior to the latest 10MP version.

For a Point-and-Shoot camera I really want something like my beloved M6 classic, only armed with a full-frame 8-10MP sensor please something like the M8 only without the crop and the exposure issues :( that works with my classic lenses that do not carry the 6-digit codes :( and I am not so sure about the $5K price tag either, but.......

For casual use I have a Casio Exilim, it is easy to pocket and the 5MP and decent compression allows for 'hundreds' of images to be squeezed onto a 1GB SD card - generally the battery dies before I run out of space on the card. The best thing about this camera is the abscence of shutter lag.

Image quality is 'fairly good' and I have printed a couple of pics up to decent sizes.

 

I defer you to MaxN's much better explanation in post #11.
Have a pint of Guinness for us while you're in Ireland.

Regarding # of MP, my Nikon 4MP DSLR produces beautiful 12"x18" prints and look much better than the same print size from my 8MP point & shoot camera. MP size isn't everything.

 

Sure and I'll be having a bit more than a pint.

I've driven Scotland, England and Wales before so I know what's in store for me on the wrong side of the road. I won't be drinking any Guiness until I'm done driving for the day.

 

Ran ...

Max is correct in everything he has said

You always want to shoot in the maximum file size you can. Anything else looses data. That's bad. You can always post process the picture, especially if your crop it and then resize the picture. We do that all the time, especially to save space when posting on the web since a monitor simply doesn't need big files ... you can't see the resolution.

I suggest you just keep the file size the biggest possible and buy a bunch of cards.

Remember, you might not want to print something today but the moment you loose data, and EVERYTIME you save a file in .jpg data, you loose more data, you can never get it back. In fact, you really just want to copy all the originals into archival storage so you can always go back and get the original, and just mess around with a copy.

As to more megapixels, well the new canon pro camera is what 18 Megapixel and still a crop camera? It's all the in the glass. The investment is not the camera because new models come out every 18 months or so. The money is in the glass.

 

I shoot at the highest resolution the camera will allow and carry one of these Epson Photo Fine P-2000 storage viewers for offloading when my cards fill up. It has a 40GB hard drive and reads CF and SD cards. This way, my photos are always available at max resolution for whatever I may want to do with them. It sucks when I want to make a 13 x 19 print and the resolution of the master is way too small. You may not see yourself doing that now, but what about the future?

To me, this makes way more sense than carrying around a ton of cards. In my experience, if I'm carrying a bunch of cards, I'm usually storing them all in the same place. If something happens to one of the cards outside the camera, it's likely gonna happen to all of the cards seeing as how they are all in the same place.

So now I own three 4GB Lexar Pro cards that rotate between my D2X, my D200 and the Epson viewer. Works like a charm and you can even pick up a used P-2000 for about $150, making it as cost-effective (almost) as buying a bunch of smaller cards.

 

Good info Chows, thanks. I'm going to follow this advice. I don't know if I'll get to Ireland again so I want to take the best pics I can short of hauling a dslr, and I think the G7 will do that for me.

Cooper, that P-2000 looks pretty good. I do have a 20 gig Iriver mp3 player I'm taking along for music and if I can get to a PC I could archive my photos on that for backup, which I might do. It's a nice unit, especially for music but its about 4 years old so it won't display the pics. Damn, now you got me thinking about that P-2000.

 

I off-load files to my laptop and my iPod (Belkin sell an adapter) and also keep the cards too ! until I am absolutely sure I have the images safe and sound on my home server (RAID)

I have (ahem) at least 40 cards, but then I tend to use SanDisk Ultra (II) 1GB cards rather than the 4GB+ ones because I am scared of trashing a card or a whole card failing - losing 100 images (RAW) is bad enough - and it has happened to me (non Sandisk) - imagine losing 400 (RAW) or over 1000 (8.3MP compressed JPG) on a 4GB card ?

 

You know, the P-2000 is also a fine MP3 player as well. One caveat - it is a bit slow when transferring full-rez RAW images off a CF card, but not bad if you're tranferring JPEGs or otherwise lower-rez shots. The newer versions are quite a bit faster, but not so much that I feel a need to upgrade seeing as I have 3 CF cards in rotation anyway - 2 active in cameras and one being offloaded in the P2000.

I work in Europe 3 or 4 times a year and the Epson always makes the trip. I've never come close to filling it up, either!

 

I shoot at varying sizes depending on intended use.

More pixels wont give you better small/medium prints, they just get thrown away & bog down your equipment.

 

That is an incorrect assumption.

By capturing the image in any format other than RAW, you are at the mercy of the JPG compression algorithms built into your camera.

All of these algorithms are 'lossy' they discard information from the photo.

None of the inbuilt algorithms are as good as (say) Adobe Photoshop.

The algorithms generally (there are one or two exceptions) do at best an 'OK' job when shooting at full res/quality, and almost all of them do a worse job the more them compress the image -JPG compression artifacts abound in the more heavily compressed images.

Even if you are shooting for the web - where I publish at 640/800/1024/1200/1600 sizes, it is much, much better to get Adobe to render them down to web sizes as the algorithms are much more sypathetic towards faithfull image reproduction.

Of course the other arguement is that you can easily lower the quality and make it smaller, but once the information is lost, it is almost impossible to rebuild it - that 'killer' photo you took at 2MP is next to useless, but the 8MP image that existed transiently in the camer may have made the front page.

 

¿que?

It's OK to capture smaller files if your camera can do it without over jpegging the image—increasing the amount of compression is never good.

Obviously RAW or TIFF files are preferred over any other file format.