Camera Labs

You want to have fun?
See a David vs. Goliath shoot-out?

Well, I thought about doing this since I ordered a Canon IXUS 870IS / PowerShot SD 880IS a few days ago after raving reviews from Gordon here and Ken Rockwell. The small Canon has not yet arrived, but I wanted to lay out my plans about the shootout and get some feedback on what you'd like me to compare/do. I'll see what I can do apart from the moisture and drop test

This review will show how much a modern p&s can stand up against a "prosumer" DSLR IQ-wise. So my tests will certainly include
- Sharpness ("Oh no, not the dreaded Siemens-stars!"). Yes including scientific comparisons using those.
- Color fringing on contrasty edges
- contrast under different lighting conditions, also some nasty contra-light
- color-rendition (any suggestions as to the type of preferred targets?)
- High-light rendition
- Shadow-detail
- Noise in shadows and mid-tones
- White-Balance outdoors/indoors
- and then I'd like to test the differences in dof and bokeh. I know that the p&s will have lot's of dof and little bokeh so in the end this comparison might just state how much of a difference you can expect betwenn any DLSR and any p&s. But to me both parameters are important in the composition of images.

What do you think? Will I touch all the interesting issues? Something forgotten? Want to flame me about doing unfair comparisons? Go ahead...

And as with all my reviews, this one will develop over time. So be patient with me and come back regularely to see what I've found out. I assume that the Canon will arive middle of next week...

For any other posts related to the Canon 870/880 but not to this shootout use the official thread over there.

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

LOL

I did that myself comparing my 40D and my Sony DSC W130...
After seeing the very first image I though to myself "Ok... it's over"

_________________
Canon 40D and lots of lenses.
my Flickr

Well, Alex. Let's do some calculation to extrapolate how many rounds this fight might go:
D300-sensor = 12MPix, 1.5x crop factor
870IS-sensor = 10MPix, 28/5=5.6x crop factor
From that we can calculate the relative pixel-density as follows:
The D300 sensor would have 12x1.5x1.5=27MPix on FF/FX
The 870-Sensor would have 10x5.6x5.6=314MPix on FF/FX
So the 870IS has a 314/27=11.6x higer Pixel-density than the D300. So each pixel of the D300 can collect 11.6x more light than a single pixel on the 870IS which translates into a 3.5 stops higher sensitivity.

You see what happened when you read this little calculation? You were absolutely stunned when you read that the 870IS has a pixel-density that is equivalent of 314MPix on a full-frame sensor. And then you thought: "Sh*t, the Canon has no chance against the D300!" But looking further into the effects and taking into account that light-sensitivity is measured on a logarithmic scale you end up with a theoretical 3-4 stops difference in sensitivity between both cameras.

Now looking into the catalog the 870IS has a base-ISO of 80 and the D300 of ISO 200 which is a difference of only 1-2 stops. So perhaps all is not lost for the tiny p&s.
And if you take into account that you need to stop your lens on the D300 much further down to achieve the same dof as on the 870IS there might be no difference at all or even an advantage for the Canon if you try to come up with images that look the same

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

WOW!!!
That looks a bit rocket science for me

_________________
Canon 40D and lots of lenses.
my Flickr

Hope you're having fun!
Well, it's just a little math But the proof lies in the pudding of really shooting comparable images, which I hope I can do in a few days.

Btw: If you think of another category of small-sensor devices (no: I'm not talking about camera-phones) the calculation looks quite interesting too! The brand-spanking new Canon HF11 AVCHD camcorder* has a 3.31MPix sensor (of which 2.07 MP are effectively used for video recording) and a crop factor of 42.9/4.8=8.9x. Using the same calculation as above that is an equivalent pixel-density of 164MPix on a FF/FX-sensor. This is only half the density of the 870IS
Thus the calculated sensitivity of that camcorder is only 2.6 stops worse than the D300!

----
*Think I'm converting to Canon now? It's only that Nikon does not produce camcorders...

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Hi Thomas,
I cant get my head around the calculations, though would be quite interested to learn about it. Can you expand the relative pixel density and the calculations abit more for me



.. Yehh!! be Cool be canon .. lol

_________________
Camera's: Canon 450D - Canon 40D
Lenses: Canon 70-200mm F/4 L, Sigma 10-20mm, Tokina 28-70, Sigma 300mm 2.8, Canon 50mm 1.4, EFS 60mm 2.8 macro
Flashes: 430EXII, 580EX and ST-E2

Well, first you need the crop factor of the sensor:
FX/FF=1.0x, Nikon APS-C=1.5x, Canon APS-C=1.6x. To calculate it for a p&s or a camcorder just divide the 35mm film-equivalent of the focal length by the real focal length. E.g. the Canon 870IS has a real focal length of 5mm which is equivalent to a 28mm focal length on a 35mm film body (=FF/FX). Thus the crop-factor is 28/5=5.6

Now you can calculate the number of pixels that a full-frame sensor with the same pixel density has as an intermediate step:
Multiply the number of pixels of the sensor (= 10MP on the Canon 870IS) by the square of the crop factor: 10MPx5.6x5.6=314MP.
Do this with each camera that you like to compare (like the D300 with an equivalent pixel density of 27MP on a FF sensor).

The ratio if these pixel densities then tells you how many pixels of one sensor fit into one pixel of the other sensor. In this case 314/27=11.6x.

So far, so clear?

Now comes the hard part: You need to calculate how many stops a 11.6x higher/lower capability to capture photons is.
Let's turn it this way: 1 stop=2x, 2 stops=4x, 3 stops=8x, 4 stops=16x. So you can see that 11.6x is somewhere between 3 and 4 stops.
If you want to know exactly, just take log2(11.6) or if your calculator doesn't have log2 you can do log10(11.6)/log10(2) or ln(11.6)/ln(2). All calculations lead to the same result: 3.5 stops.

Cool, eh?

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Oh btw. the Windows calculator has Log10 (simply called "log") and LN (or "ln") but no Log2.

On to some other comparisons between both contenders:

Lens:
Before starting some of the comparisons we have to decide which lens to put on the D300. The Canon has a 5-20mm lens which is equivalent to 28-112mm on a film/FF-body plus it has stabilization. That lens would be equivalent to a 19-75mm on the D300. For size, wheight and price-comparisons let's take the Nikkor AF-S VR DX 18-55mm 3.5-5.6G If you consider that the D300 has 10% more linear resolution than the Canon you get the field of view of a 60mm lens, when you crop a shot taken at 55mm focal length down to 10MPix.
So feature-wise the Canon has the benefit of being 20-30% longer than the standard kit-lens for the Nikon.
The Canon also has a max aperture of f/2.8 – f/5.8. So it's a little brighter on it's widest setting.
But the major limitation here is that you cannot change lenses with the Canon. But this is the general benfit of DSLRs vs p&s cameras.
In summary I'd say 1.5 points for the Canon 870IS, 1 point for the Nikon D300.

Weight:
From the catalog: 155g for the Canon vs. 825g for the Nikon, both without batteries. But wait: the Nikon is body-only so we have to add 265g for the 18-55 VR lens. Now adding the batteries we end up with 185g for the Canon vs. 1170g for the Nikon, a difference by the factor of 6.
But I will not award Canon 6 pts. for this but only 1 (Nikon-fanboy that I am )

Size:
Uh oh, another category where my beloved D300 will lose another point
Canon: 94x57x24mm
Nikon: 147x114x(74+80)mm
Guess, which camera fits easily in your pocket!
Another point for the Canon 870IS

Prices:
Canon: 230€
Nikon: 1400€
All incl. 19% VAT from a reputable dealer. So you need to invest 6x as much in the Nikon DSLR as in the Canon p&s. Funny though, that this is the same factor as with the weight. So you get 1g of the Nikon system for the same price as 1g of the Canon, namely 1.20€
So practically this is a draw
Ok, just joking: 1 point for Canon

Summary:
So after the first round it is 4.5 pts for the Canon vs. 1 pt for the Nikon.

Let's see whether the Nikon can recover from those blows.
Next up is screen-size and resolution, weather-sealing and frame-rates.

To be continued...

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

I know you won't need reminding, Thomas, but for those of us who are a long way from our schooldays...

If you need Log2 then the formula

Log2(x) = Log(x) / Log(2)

works well, although there's always the possibility of rounding errors. The base of the two "Log" terms on the right-hand side of the equation can be anything you like as long as both are the same.

Example: We probably know that Log2(16) = 4 as, when written in binary, 16 is represented by 10000. So, using the Windows Calculator

ln(16) = 2.7725887222397812376689284858327

ln(2) = 0.69314718055994530941723212145818

2.7725887222397812376689284858327 / 0.69314718055994530941723212145818 = 4

Phew! Time for a late breakfast.

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Unfair? Not at all!

Jokes and Canon/Nikon rivalry aside, this should help people who are debating between a compact and DSLR.

_________________
Graham
Flickr

About a compact's capabilities, you may remember that A640 article I wrote: http://www.cameralabs.com/forum/viewtopic.php?t=2682

I'm looking forward to your Ixus comparison..the thing is that the Ixus range has a smaller sensor than the G/high end A series (typically 1/2.5" or 1/2.3" vs. 1/1.7"). I've found compacts to be sharper for architecture (deep DOF, comparatively small apertures), and that the good ones have great jpeg engines (Lumix, Canon) which deliver natural, colourful and sharp photos.

Yes this was a very interesting post of you, Shonen84.
Let's see what a direct head to head comparison can tell us about the state of the afairs between p&s and DSLRs.

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

really looking forward to the picture results

_________________
Canon EOS 5D Mark II | Canon EF 35mm f/1.4L USM | Canon EF 85mm f/1.8 USM | Canon EF 135mm f/2L USM
...and a lot of lighting stuff. -> complete list of equipment

Website
Blog

Well, no pictures yet as the little 870IS has still not arrived (Sinta Claas must have taken a wrong turn, maybe a glitch in his GPS ).
But as promised we'll look deeper into screen-size and resolution, weather-sealing and frame-rates.

Screen:
Ha, both are 3" lcd screens, although the screen on the Nikon D300 looks smaller due to the fact that there is so much camera around it. While on the Canon the screen fills what? 80% of the back. From a first inspection the Canon screen looks as bright and contrasty as the Nikon but You should not trust your eye/brain comparing this without having both screens side-by-side. So you'll have to wait for the final verdict on colors and contrast.
As to resolution, the winner is already clear: The Nikon got 920k dots, the Canon is 230k dots. So this is a clear point for Nikon. Why are we talking about dots here and not pixels? Well, a pixel is supposed to display all colors thus it is composed of three dots: R+G+B. So even the massive 920k dots of the Nikon screen are only equivalent to 307k pixels. Compare his to the WUXGA-LCD monitor on my table which displays a massive 2.3MPix you understand why you have to zoom in 6 steps (on the D300) to get a good feeling for the sharpness of the image.

Weather-sealing:
Well, there's nothing mentioned in the Canon sales literature about weather sealing, so you better keep this little camera from the elements. The buttons are perceptible to moisture and the extending lens-tube is especially vulnerable to moisture and dust. I will certainly not test this, but time will tell whether the dust that creeps in through the tube finds its way on the sensor With my Sony P200 I had to send it in at least once a year to get it cleaned from dust on the sensor and only two years (within the warranty) this was done for free. Sadly NO p&s has any anti-dust measure* and there is also no way to clean it for yourself. So a big plus here for the Nikon D300:
- as a DSLR you can take off the lens and clean the sensor all by yourself
- it has wheather/dust-sealing
- it has a anti-dust device trying to shake off any particles that landed on the sensor.
1 point for the Nikon D300.

Btw.: As those small p&s cameras are easily put in your pocket think about putting some protective plastic bag around it to prevent all the dust and grime in your pocket being rubbed into the crevices of the little camera

Frame rates:
Another point for the D300 which easily does 3-4x the fps than the Canon's meagre 1.4 shots/sec. But not everybody needs more fps.

Summary:
After the second round the scores are 4.5 pts for the Canon vs. 4 pts for the Nikon.

So stay tuned for the next round in this fight!
We'll be back after the break.

-------------
*but some are less susceptible than others: e.g. p&s with non-expanding lenses (like Sony T700) are quite well sealed at the lens.

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Thank you Thomas for sharing such information. It has been great reading it..

_________________
Camera's: Canon 450D - Canon 40D
Lenses: Canon 70-200mm F/4 L, Sigma 10-20mm, Tokina 28-70, Sigma 300mm 2.8, Canon 50mm 1.4, EFS 60mm 2.8 macro
Flashes: 430EXII, 580EX and ST-E2