Crop Sensor = Better Reach?

[gingerweasel]

I'm with you, but out of interest, is the physical size of the full images similar? or is the full frame size larger?

Meaning one could crop in on the full to match the zoom...

Not if the MP count is the same...

So a 12.3 MP crop sensor, gives the same image size as a FF 12.3 MP sensor.

Only difference is that the light sensors are less tightly packed on the FF.

 

[CT]

LOL. How many threads have we had on this subject - and still confusion reigns.

The FOV difference between sensors only really matters if you don't crop your image. If you need to crop your images heavily (a small bird being the obvious example) then with a FF or 1.3X crop sesnosr you'd lose an enormous number of pixels just cropping the FF or 1.3X image down to the same FOV as the 1.6X crop sensor. ( the 1.6X crop sensor has lost no pixels at all at this stage)

Now though, we go on to crop even further for a frame filling shot of that bird- say 50% or even 25% of the remaining image, losing further massive amounts of pixels fromm the FF and 1.3X crop images. You quickly reach a situation where there simply aren't enough pixels left under the bird in your image and IQ is degraded to the point that the image is either unusable or if you're lucky, just about good enough for web size use.

Where the 1.6X crop sensor camera starts off with the same or even more pixels than the other two formats anyway, it has an enormous advantage over the other two in the effective reach of your lenses as you can crop much tighter retaining more pixels and a larger physical file size so retaining more IQ.

It's important to appreciate that the bird will be recorded on the sensor at the same size regardless of which sensor format you use. The two important factors now are the size of the full 1:1 image file, and pixel density. The 1:1 file will dictate the largest size you can reproduce that bird (without interpolation) The pixel density will dictate how tightly you can crop while still retaining decent image quality and detail in your bird.

The advantages of the 1.6X sensor coupled with a high pixel count are only advantageous to those who need to crop their images, which in the main will be wildlife photographers and some sports photographers who are the people Canon have aimed cameras like the 50D and 7D at. If you don't fall into these categories then you'd be just as well (or sometimes better) served by a larger sensor format.

 

[Davie]

Imagine a bird sitting on the fence in that shot. Look at the differing field's of view. Does the size of the bird change? No. As I said, you just get more scenery around the bird with the ff sensor than with the crop sensor

And yet, look at all that extra money you have to spend just for some extra scenery

 

[Forbiddenbiker]

I thought the full frame might print out larger, thanks guys just checking.

Not if the MP count is the same...

So a 12.3 MP crop sensor, gives the same image size as a FF 12.3 MP sensor.

Only difference is that the light sensors are less tightly packed on the FF.

yeah, thats why I thought the image might be larger in the case of the matching pix count.

as I say just checking.

 

[Nick T]

However... say you start off with a 25MP 5DMKII and a certain lens, say 200mm. Right next to you you have a chap with a 15MP 500D with the same 200mm lens. You both take the same shot of the same bird.

Chap with the 500D already has it ready-cropped (because he's running a 1.6x crop factor).
You decide you want exactly the same scene/framing as 500D chap so crop your image to match. So you effectively reduce your pixel count by 1.6 - which gives you the same amount of pixels (near as damnit) to the 500D guy.

Wouldn't your image be better because you've started off with a better quality of photosites on the sensor compared to the crop sensor guy?

 

[markjayne]

However... say you start off with a 25MP 5DMKII and a certain lens, say 200mm. Right next to you you have a chap with a 15MP 500D with the same 200mm lens. You both take the same shot of the same bird.

Chap with the 500D already has it ready-cropped (because he's running a 1.6x crop factor).
You decide you want exactly the same scene/framing as 500D chap so crop your image to match. So you effectively reduce your pixel count by 1.6 - which gives you the same amount of pixels (near as damnit) to the 500D guy.

Wouldn't your image be better because you've started off with a better quality of photosites on the sensor compared to the crop sensor guy?

In some respect this is true although I would rather have the full version of a cropped sensor than a cropped version of a FF sensor.

Mark

 

[CT]

However... say you start off with a 25MP 5DMKII and a certain lens, say 200mm. Right next to you you have a chap with a 15MP 500D with the same 200mm lens. You both take the same shot of the same bird.

Chap with the 500D already has it ready-cropped (because he's running a 1.6x crop factor).
You decide you want exactly the same scene/framing as 500D chap so crop your image to match. So you effectively reduce your pixel count by 1.6 - which gives you the same amount of pixels (near as damnit) to the 500D guy.

Wouldn't your image be better because you've started off with a better quality of photosites on the sensor compared to the crop sensor guy?

If pixel count was the same or very similar (after cropping) - then yes - the 5D2 would yield a better image although you might have to print very very large before you appreciated the difference.

The reality though is that bird photography almost always involves cropping - even with a 1.6X sensor and the longest super tele lenses available to us, unless we can get very close indeed, which is the exception rather than the rule. The closest I can get (min focus distance) with the 500mm f4L is around 16 feet and that almost always needs some moderate cropping, assuming I can get that close, which isn't easy.

A far bigger proportion of shots is taken at a much greater range and involves much heavier cropping. The more the range increases, the more the advantage of the 1.6X sensor, particularly where it has a high pixel density sensor, iincreases -and the more likelihood there is of ending up with a usable shot.

 

[Rocket58]

I had this conversation recently

The Red is full frame the Blue is 1.6 crop.

The Red section (Full frame) on a 5d MKII is 21 Megapixels the Blue is 1.6X crop eg Canon 7D (18 Megapixels). With the crop sensor I keep all 18 Megapixels and with the full frame I would crop off about 8 Megapixels to get the same image, resulting in a 13 Megapixel image from the 5D MKII. I realise pixel density comes into play as well but, the 7D would have a larger image to work with after cropping the full frame. Presuming I just wanted the centre portion in Blue. It could be the Mountain it could be a Bird.

Thats how I see it working anyway.

Just my 2 cents

Cheers

Ron

 

[fracster]

Zzzzzzzzzzzzzzzz,zzzzzzzzzzzzzz.........thud!

 

[Splog]

Surely the pixel(photosite) count and size come into the equation
If you have the same number of pixels from a ff crop image as with a 1.6 full size image then pixel size and density would be the same? as such image resolution would be the same (assuming all things equal) What gets confusing is the light gathering ability of each photosite which can be considered to be 'bigger is better" OK, not quite right but if a PS can only hold a limited number of photons? then as soon as its full all kinds of things happen .. i.e. it overflows thus poor image quality esp signal bleed... noise generally happens due to the density of pixels? and therefore high pixel (PS) count is not always a good thing

To put it another way unless the technology for the light gathering and recording of light per PS is improved then smaller pixels will always produce lower image resolution than larger pixels :shrug: Then of course you should also be considering how close PS are to each other and if the technology is sufficiently good enough to prevent bleed from one PS to its neighbours i.e. overflow of light (signal) from one pixel to another?

Ever wondered why you get the blinkies with an over exposed image? ... Simple the bucket is full ... So get a larger bucket ... or larger Photosite / Pixel

 

[CT]

It really comes down entirely to what sort of subjects you shoot. The vast majority of reviewers, whilst mostly bemoaning the fact that the 7D isn't yet another full frame camera, concede that Canon have done a fantastic job in maintaining IQ and keeping noise down with the 7D. The technology which enables these advances is only going to keep on improving.

Note that the 1DMK4 at 16 million pixels, now gets a pixel increase on a scale similar to the one from the 40D to the 50D and those who use it will see an enormous difference in cropping abilty over the 1DMK3, so it isn't just 1.6X sensor users who benefit from this technology.

 

[Rovers_Andy]

yawwwwwwwwwwwwwwwwwn is this another thread where we go round and round in circles :shrug:

 

[sooyeshun]

but do you think it is same as a FF zoom 1.6x , quality wise

 

[Dave450]

With the second image by FITP - when you take the photo the 1.6x photo would "fill" the FF size, giving the impression that it is zoomed\closer but in reality it is the same. Have to agree with FITP and Grendel on this one.