Shooting resolution

[LeeO]

I have been a photographer years but just today switched to digital and got a 10D. My question is, what resolution should I shoot at. I obviously want quality and RAW will give me that. However, the reality is that I will RARELY be printing anything larger than a 5X7 and occasionally an 8X10. My understanding of digital is that you should shoot as close to the size you will be using in the final print as possible. Reason - reducing or enlarging too much with digital will really screw up the image. I don't have a clue and need some advise from everyone. Thanks in advance.

[daveh]

I've never seen a case of "too much resolution".

[LeeO]

Yeah, that's what I thought, too. Maybe the person was wrong. But they told me when using Photoshop and you have to reduce an image it does just as much harm as enlarging. Then again, being new at this, I may have misunderstood.

[daveh]

Reducing an image surely does harm - more so than enlarging it - because it leaves you with a lower resolution image. But I can't see where that's worse than starting with a lower resolution image. After all, the camera has a fixed sized sensor and is also throwing out data to produce the lower resolution options.

[PaulB]

Start with your output resolution.
You need 300ppi (pixels per inch) for best printing quality. so most of the experts agree.
Therefore a 7"x5" will need (7 x 300) x (5 x 300) pixels
= 2100 x 1500 pixels.
Disregard your printer resolution in this 'rule of thumb', that's a different ballgame altogether.

But.
Ah. there's always a but......

The advice you have been given is therefore right (ish) because resizing does have an effect on image quality.
It is worse when resizing up than down though, Photoshop or whatever has to guess when resizing up but just gets rid of excess pixels when resizing down.

I agree with Daveh that it is rare that you can have too much resolution.

My advice would be to shoot at the maximum quality settings you can and keep the original images on your H/D for when you get the order for that poster print.

Seriously though, large JPEG will print to A3+ without problems and I've never printed smaller and had the image get worse - and I know that A3+ resolution at 300dpi is bigger than the 10D can give you.........Shows how rules are meant to be broken.
As for the argument about JPEG vs RAW files - that is another story!

[Highland]

What is A3+?

Don

[Morden]

What is A3+?
A3+ is a 'common' size of paper that several of the larger printers available can handle. It is not much larger than standard A3 (it is 19" by 13"), and usually costs substantially more than A3 paper because it is not a 'standard' size, so less of it is produced. It is useful when the largest possible home-produced print is desired, but on some printer models the gain is not necessarily worth it. For example, my Canon S9000 can print borderless (right to the edges) on A3 paper, but must leave a margin of around 0.3" around photos printed on A3+ paper. This 'border' means that the image printed on A3+ paper is not actually that much larger than a borderless A3 print. I still occasionally use A3+ media, despite the border and that Canon's A3+ Photo Paper Pro is ludicrously expensive in my opinion.

(What a very long answer to such a short question!)

[rdenney]

LeeO wrote:
I have been a photographer years but just today switched to digital and got a 10D. My question is, what resolution should I shoot at. I obviously want quality and RAW will give me that. However, the reality is that I will RARELY be printing anything larger than a 5X7 and occasionally an 8X10. My understanding of digital is that you should shoot as close to the size you will be using in the final print as possible. Reason - reducing or enlarging too much with digital will really screw up the image. I don't have a clue and need some advise from everyone. Thanks in advance.

You can always reduce the image. Photoshop uses "bicubic interpolation" which does a very clean job of downsampling an image. Always shoot at the highest resolution for 8x10 prints in any case. 2056 vertical pixels divided by 240 pixels per inch (optimal on my Epson printer) equals a little over 8.5 inches. If you crop at all, you need the full resolution for no-compromise 8x10's.

Larger prints can be printed at lower printer pixel densities. At 180 pixels/inch at the printer, you can make slightly cropped 11x18 prints. These look really good in practice, because the pixels are so accurate. But if you want to upsample the image to make bigger prints, you can use something like Genuine Fractals, which does a reasonable job for prints that will be viewed properly (i.e., not by other photographers:)).

For smaller prints, you can downsample using your software or even just send a 420 ppi print to the printer for your slightly cropped 5x7.

The real question is whether to use RAW or JPEG large, fine. If you anticipate stretching the tonal values much at all, then use RAW, because it gives you the full 12 bits of color depth provided by the sensor. JPEG only gives you 8 bits, and if you do anything extreme in Photoshop with the tonal scale, you'll get posterization. Otherwise, at your prints sizes, I doubt you'll see the difference. If you use JPEG, convert it to a non-compressed format at first opportunity in the computer. Each time a JPEG is saved it recompresses and you'll get generational losses. I upload the JPEG, and immediately save it as a Photoshop PSD file. I edit that file, and if I need a JPEG for web display later, I save it as a JPEG only then.

Rick "who would cry if the once-in-a-lifetime image was stored at low resolution by accident" Denney

[LeeO]

Thanks everyone.

[Longwatcher]

One added note from my experience.
Two of my favorite images were shot in large-fine jpeg instead of RAW. Arghhhh!!!

Large-fine jpeg does not resize up very well above 13x19 without noticeable (at least to me) jpeg artifacts.
10D RAW will go to at least 16x24" with no artifacts I can see.

[PaulB]

Better any image than none though.
Did you worry this way over film - after all it could have been shot on 400ISO rather than 100, or on negative rather than transparency, oh dear that once in a lifetime shot is on Ektachrome, it would have been a worldbeater on Velvia!

[hmhm]

The sensor has 6 MP. If, for some reason, you want fewer than that, then _somebody_ has to down-sample it. You can either assign that task to Photoshop, or ask the camera to do it (by choosing a lower-res mode). I'd trust Photoshop to do a better job.
-harry

[LeeO]

In an effort to understand all this (which is not coming easy for some reason) let me ask you guys this.

As most of you know, one of the 10D's resolutions is 2048X1360. If I'm really only going to print 5X7's 90%of the time, wouldn't a good camera resolution be the 2048 even though it's one step down from the highest resolution?

I ask as I would save CF space. I got a 512 card but I'm sure in RAW mode ((3000 something resolution) I'd fill that card pretty quickly. So, assuming I would not see the difference in a 5X7 photograph why shoot as the higher rez? Right? Am I making sense and is my logic valid?

And, the biggie, is setting the camera rez. at 2048 almost a one to one in photoshop at 300dpi rez?

Thanks again. Sorry for my seeming inability to understand this quickly.

[rdenney]

leeo wrote:
In an effort to understand all this (which is not coming easy for some reason) let me ask you guys this.

As most of you know, one of the 10D's resolutions is 2048X1360. If I'm really only going to print 5X7's 90%of the time, wouldn't a good camera resolution be the 2048 even though it's one step down from the highest resolution?

I ask as I would save CF space. I got a 512 card but I'm sure in RAW mode ((3000 something resolution) I'd fill that card pretty quickly. So, assuming I would not see the difference in a 5X7 photograph why shoot as the higher rez? Right? Am I making sense and is my logic valid?

And, the biggie, is setting the camera rez. at 2048 almost a one to one in photoshop at 300dpi rez?

Thanks again. Sorry for my seeming inability to understand this quickly.

I would still use the maximum resolution, in case someone likes the image (perhaps you) and wants an 8x10. Don't box yourself in. I am quite confident that you would not be able to tell the difference between a 420 ppi file sent to the printer to make a 5x7 and a 300-ppi file sent to the printer for a 5x7.

Your 512 MB CF card will hold about 160 JPEG images in large, fine mode. It seems to me that should be enough for most applications, and if it isn't, I'd rather use a 1-gig card or get more 512's than compromise the resolution of the camera. Memory is still cheap considering it doesn't wear out. I would much rather have full-resolution, minimally compressed JPEGS than lower-resolution RAW images (which I'm not sure is even possible); plus, you'll still get more images on the CF card. JPEG artifacts may well appear on larger than 13x19 prints, but that seems further outside your stated application than having the option of doing no-compromise 8x10's.

Remember that if Photoshop has to interpolate to downsample the image, so does the software in the camera, unless you cut the linear resolution in half (to 1536x1028, or thereabouts), in which case it will just read every other pixel. You can either downsample in the camera, Photoshop, or the printer. If you do it in the camera, you don't have any downstream choices. If you do it in the software or the printer, you haven't limited yourself. And, again, I can't tell the difference in quality between the latter two (they both give perfect results).

Rick "who downsamples at the last possible moment" Denney