60d or 7d

[hollis_f]

Are these cropped at all ? the reason I ask that several people say that when cropping an high ISO image that is when noise becomes apparrant, if that is the case I think although the 7D is regarded as a good nature camera, if birding then cropping sometimes a lot could cause a problem

But it will be no worse, and would probably be a lot better, than the same bird, cropped to the same size, on most other cameras.

 

[Lbm]

No extermination Rob

Are these cropped at all ? the reason I ask that several people say that when cropping an high ISO image that is when noise becomes apparrant, if that is the case I think although the 7D is regarded as a good nature camera, if birding then cropping sometimes a lot could cause a problem :shrug:

it is probably my turn for extermination

No they're not cropped

 

[arad85]

No they're not cropped

So you're taking an 18Mpixel image, downsampling it to a 1/4 megapixel image and saying it's OK for use?

It also isn't clear what you have done. You say in your original post: "I under exposed iso 100 by 4 stops in camera " so your ISO 100 shot should have been 1/4 @ f5.6 instead of 1/60 @ F5.6. If that is the case, the ISO 12800 shot is a further 7 stops underexposed meaning you are 11 stops underexposed in total.

I don't believe you would get that much information out of an 11 stop underexpose....

 

[Lbm]

So you're taking an 18Mpixel image, downsampling it to a 1/4 megapixel image and saying it's OK for use?

It also isn't clear what you have done. You say in your original post: "I under exposed iso 100 by 4 stops in camera " so your ISO 100 shot should have been 1/4 @ f5.6 instead of 1/60 @ F5.6. If that is the case, the ISO 12800 shot is a further 7 stops underexposed meaning you are 11 stops underexposed in total.

I don't believe you would get that much information out of an 11 stop underexpose....

Yes I resized them to put them up here.

I was responding to the chap who said he found the 7D @ ISO 800 (+) to be unusable. Now he didn't say whether he meant unusable from a commercial point of view, or merely from a web viewing pov, which is very satisfactory for many, and indeed we know when printing, noise tends to go away. See below:

Mine is simply unusable at anything over 800 iso. I feel I've wasted so much time with it & missed tons of opportunities because of it.
Loads of friends own it too & feel pretty much the same about it so I know I'm not alone.
Currently deciding which body to get next. Probably 1D 1v.

I can upload a larger set of files if you like, but I believe I'm restricted to 1024pixels along the long edge on here anyway.


My method was for all ISO shots to be taken at f5.6 & 1/60th secs and so my thinking being that 1SO 100 would be 4 stops underexposed and as I increased the ISO it would start to bring the exposure back into line, and in a sense I didn't see using ISO 12,800 as underexpoing by 11 stops.


Here's Tim's original thread, and my original post is # 28

http://www.talkphotography.co.uk/forums/showthread.php?t=401641&highlight=Tim


Anyway, in general, are you saying the 7D @ ISO 800 and above is unusable? And if so, what do you mean by unusable?

 

[Tom Tom]

Also having the same dilemma - is the 60d much lighter than the 7d? They is an important factor for me as I travel a lot.

Also what body would be more suited to the 24-105mm f4?

 

[arad85]

My method was for all ISO shots to be taken at f5.6 & 1/60th secs and so my thinking being that 1SO 100 would be 4 stops underexposed and as I increased the ISO it would start to bring the exposure back into line, and in a sense I didn't see using ISO 12,800 as underexpoing by 11 stops.

It's not, they are 3 stops over exposed at that point (my maths was wrong I did -4-7=-11 when I should have done -4+7=+3).

Anyway, in general, are you saying the 7D @ ISO 800 and above is unusable? And if so, what do you mean by unusable?

No, not at all... I'm just surprised you can pull back that much in post and still have detail.

Shrinking the files to 640 (which is what they're displayed here I think) just means you obliterate the noise so almost anything will be acceptable.

 

[Lbm]

It's not, they are 3 stops over exposed at that point (my maths was wrong I did -4-7=-11 when I should have done -4+7=+3).

Yes, sorry I'm not clear myself

I wanted to start 4 stops under exposed @ ISO 100, and then by 1600 I would have a 'correct' exposure, and then 3200, 6400 and 12,800 were over exposed (ETTR) so I could then pull it back down again in LR3.

No, not at all... I'm just surprised you can pull back that much in post and still have detail.

Shrinking the files to 640 (which is what they're displayed here I think) just means you obliterate the noise so almost anything will be acceptable.

Ok, I'll bung up a larger 12,800 file.

 

[Lbm]

ISO 12800

 

[arad85]

The only thing is that if you are at ISO 12800, you aren't going to be ETTR.... The only time you will use that is because you are fighting for light, so it's going to be underexposed.

 

[hollis_f]

Ok, I'll bung up a larger 12,800 file.

Unfortunately it's still too small. Your 1024 x 683 image has had 96% of its pixels thrown away. So you've thrown away most of the noise. The only real way to compare noise is to look at it at the pixel level. So one needs to show 100% crops and pixel-peep (although do make sure you wash your hands afterwards).

Here's an ISO6400 image with no noise visible...

But zoom in to one part of the image and the noise is definitely there.

 

[Lbm]

To Hollis, yes I agree, but if it's for web use then these images are useful...I'm just going back to what drexyl means by unusable


Here's a crop of 12,800





@ Drexyl, what do you mean by 'unusable' exactly?

 

[arad85]

But zoom in to one part of the image and the noise is definitely there.

The dynamic range is also gone here....

To Hollis, yes I agree, but if it's for web use then these images are useful...I'm just going back to what drexyl means by unusable
...
Here's a crop of 12,800

Yes, but this is pulled back from 3x overexposed. The question should be if the exposure meter says it's 1/60th at f5.6 at ISO 1600, would you choose ISO 1600 or ISO 12800 to shoot the picture?

 

[hollis_f]

The dynamic range is also gone here....

Really? Perhaps you would be kind enough to elucidate -

What are the symptoms of this loss of dynamic range?
What may have caused this loss of dynamic range?

 

[drexyl]

Sorry ages in reply. Unusable to me means it looks crap so I won't use it.
At the weekend I was fortunate to come across a young cuckoo . Having both my cameras with me I filled both cards ... The ones I took on my 7D were crap compared to the ones I took on my other body. Same lens same conditions same snapper. Just my findings with my cameras. I really would like to like my 7D but the simple fact is I don't.

 

[Lbm]

Sorry ages in reply. Unusable to me means it looks crap so I won't use it.

Ok, fair comment

 

[DizMatt]

interesting
I got this camera because of the upgrade to my 40D in ISO handling
I did some basic noise tests but will upload some samples too and see what I can come up with
mainly I wanted the improved focusing system and my 40D is pushing it now, on 76k+clicks

 

[arad85]

Really? Perhaps you would be kind enough to elucidate -

What are the symptoms of this loss of dynamic range?
What may have caused this loss of dynamic range?

Look at the 100% crop. It looks very cartoon like and has no smooth changes between the lettering and the colours on the background. Also the cellophane doesn't look natural. The sensor is unable to pull the gradual changes in colour out from that, descending into noise. It looks fine downsampled, but at 100% it's not brilliant.

What causes it - using a camera at high ISO generally.... Have a look at the chart here: http://www.photozone.de/dslr_reviews/478_canon_eos_7d?start=4 and you can see as ISO goes up, dynamic range falls significantly (an Ev on that chart is equivalent to a "stop").

 

[hollis_f]

What causes it - using a camera at high ISO generally.... Have a look at the chart here:

Here's an analysis by our partner, the (DxO Lab):

So, it's almost certainly a complete and utter invention. I'm afraid that DxO Labs have zero credibility when it comes to their 'Labs' results.

 

[arad85]

Here's an analysis by our partner, the (DxO Lab):

So, it's almost certainly a complete and utter invention. I'm afraid that DxO Labs have zero credibility when it comes to their 'Labs' results.

You may want to dismiss the numbers, but the 100% crop is still poor quality and has limited dynamic range in the colours :shrug:

 

[Blythman]

Sorry ages in reply. Unusable to me means it looks crap so I won't use it.
At the weekend I was fortunate to come across a young cuckoo . Having both my cameras with me I filled both cards ... The ones I took on my 7D were crap compared to the ones I took on my other body. Same lens same conditions same snapper. Just my findings with my cameras. I really would like to like my 7D but the simple fact is I don't.

Just seen this. Interesting Paul. I have been toying with the idea of getting a 7D. While mine is great at high ISO, I've been thinking about something that has better AF

 

[DW58]

I own both 60D and 7D - both gripped - and like/would highly recommend both. I prefer the handling of the 7D because it's closer to the 40D which I had prior to the 60D/7D, but that's a minor detail.

I don't really have a favourite, love them both.

 

[StephyB]

Which is very strange because, where it matters - the grip, the 60D is slightly bigger than the 7D.

But overall the 7D is bigger and heavier, I can't hold it one handed, can't hold it vertically at all, I've found it to be very clunky and difficult to use, but I have tiny hands.