Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Dec 17, 2011, 1:05 PM   #1
BDD
Senior Member
 
Join Date: Feb 2010
Location: Toronto, Canada
Posts: 204
Default Low light shooting.

Recently, I came across a thread in another forum, where a few members believe that having more MP is better for more dynamic range/low light shooting than having a DSLR with "high useable ISO". This group also claims that the reason why Canon & Nikon keep putting out and marketing hi-end DSLRs with "high useable ISO"...is for profit.

They pointed out a few articles supporting this view. If I find the link I'll post it later.

I find it hard to believe Canon & Nikon continue to put out DSLR's with "high useable ISO" just for business reasons. Spending the money they do on R&D to boost useable ISO if all they had to do was up the MP count again (yes a simplification...of course there's more to it).

Though, if there is some truth to this, that would explain why the rumoured specs for the Nikon D800 include 36MP but only a max useable ISO of 6400.

Will be interesting to see the test reports for the D800 regarding low-light shooting and high MP count. And the Canon 1D-X with a max useable ISO of 51,200 and 18 MP. As well as the test reports for the D4. Will they change their tune and conclude higher MP count is more beneficial? Will they be brave enough if true?

Interesting the rumoured specs for the D4 include a useable ISO max of 100,xxx and a MP count increase to 18.

Last edited by BDD; Dec 17, 2011 at 1:08 PM.
BDD is offline   Reply With Quote
Sponsored Links
Old Dec 17, 2011, 1:49 PM   #2
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

I think you may be confusing a few things:
1) more megapixels cannot make up for slow shutter speeds - MP count has no affect on exposure. If you need ISO 12800 to get a shot given the aperture and shutter restrictions of the situation, no increase in MP will take the place of that ISO capability.

2) Having more mp does not allow you to end up with cleaner high ISO images. For example if shooting with 2 cameras at ISO 3200: One with 12mp and one with 24mp - the 24mp sensor doesn't produce cleaner images just because it has more pixels.

3) The truth is - every time you increase number of pixels on same size sensor, noise is more problematic. But, realize there are other technical parts to noise performance - and manufacturers are improving those things in each generation as well.

The above is why the Nikon d3s was so successful: first because it was low number of pixels on large sensor but also there was an improvement from the d3 even though it's the same sensor. It was the "other stuff" nikon changed between d3 and d3s that improved the noise performance.

Realize though that ISO has become the "it" number - like MP used to be. It's a marketing hype having a high ISO number. That high number doesn't always mean you get quality - just as was the case with MP count. But it's a number the masses concentrate on - so there is alwas pressure from sales/marketing for a company to release a camera with a high "max iso" number.

What you see with Canon and the 1dX is them responding to the wildly successful nikon d3s and d700. While some in nikon camp complained 12mp was too small, Canon is banking on majority of pros thinking 18mp is "good enough". But the point is - the Nikon was infinitely more successful with a camera that had best-in-industry focusing and best-in-industry high iso performance even at a lower pixel count. What is interesting is if the rumors about the d800 are true - which means Nikon is going the route canon had been going and canon is going the nikon route
JohnG is offline   Reply With Quote
Old Dec 17, 2011, 2:56 PM   #3
Senior Member
 
Join Date: Jan 2011
Location: Australia, New South Wales central coast
Posts: 2,891
Default

G'day BDD

May I respond to several of your points ~ not by way of arguement, more observations

My first digi camera was only 3mpx - and when I go back to those images in my files and examine them closely, I cannot see the noise and pixel discolouration that I see today with my 14mpx camera using the same sized sensor. Equally, my original camera went to ISO-400, today's goes to ISO-3200 > though above 800 it becomes pretty useless due to image discolouration

I also read the dSLR specs of the 'up-&-coming' cameras and see stuff like ISO-9999 [pick any number to insert for the 9999] and think that it's all a lot of spin and twaddle

If I were to put it into a motorcar analogy ... it's a bit like having 240km/h on the speedo dial knowing that no-one will ever be able to make any use of it ... but it looks good esp to the advertising gurus

Regards, Phil
__________________
Has Fuji & Lumix superzoom cameras and loves their amazing capabilities
Spends 8-9 months each year travelling Australia
Recent images at http://www.flickr.com/photos/ozzie_traveller/sets/
Ozzie_Traveller is offline   Reply With Quote
Old Dec 17, 2011, 3:47 PM   #4
Senior Member
 
Join Date: Sep 2011
Location: Bangor,North Wales
Posts: 3,734
Default

From my own personal experience- mp count has very little to do with anything- other than resolution and image size.. and is only significant if you need to produce giant sized images..!
All else being equal,a similar sized sensor with a higher megapixel count will have smaller pixels(with less individual light capturing ability)- not to mention putting the processor under higher stress- hence higher megapixel cameras tend to have slower shot to shot times- only counter-acted by an improvement in processors from each subsequent model or by moving up the more expensive end of a given line.
Noise levels at higher iso's and dynamic range are more down to the processors as much as anything these days- and most manufacturers have made HUGE strides in the noise/noise reduction area(thank goodness)- AND processing speeds also.
Whilst genuinely usable higher iso settings vastly improve image capturing capabilities(especially for sports shooters)- the figures now being quoted/rumoured are INSANE... and are highly unlikely to be used by the vast majority of users,much like the fact that most users probably don't need more than anywhere between 6-12 mp....
That said,I can't wait to see a high iso test on one of these new crazy cameras...

http://www.clarkvision.com/articles/...l.size.matter/
SIMON40 is offline   Reply With Quote
Old Dec 17, 2011, 10:21 PM   #5
BDD
Senior Member
 
Join Date: Feb 2010
Location: Toronto, Canada
Posts: 204
Default

G'day mates!!

I'm not sure where I gave JohnG the impression I am confused or believed either way...I was just wondering "could it" really come down to more MP over having more useable ISO? I never thought so.

I was just mentioning that I came across a thread where a group in another forum has been claiming that it IS about the MP count for low light photography. They even provided a link to an article supporting this view. Which I haven't yet read.

If I find the link I'll post it.

If it WERE about the MP count why did Nikon bother R&D and putting out the highly successful and proven D3s?? Canon the 51,200 ISO 1D-X next March. And Nikon with a 102,000 ISO D4 probably in the Fall of 2012. Cost money to R&D...

Last edited by BDD; Dec 17, 2011 at 10:24 PM.
BDD is offline   Reply With Quote
Old Dec 17, 2011, 10:41 PM   #6
BDD
Senior Member
 
Join Date: Feb 2010
Location: Toronto, Canada
Posts: 204
Default

Found it. Start reading Bernie's post on Mon, Oct 3rd here...

http://www.cameralabs.com/forum/view...r=asc&start=90

You'll see him post a link for a DXO article a little further down the page...
BDD is offline   Reply With Quote
Old Dec 18, 2011, 5:29 AM   #7
Senior Member
 
Join Date: Sep 2011
Location: Bangor,North Wales
Posts: 3,734
Default

BDD- whilst interesting,the cups/rainfall analogy is somewhat flawed- you cannot "guesstimate" the amount of rainfall the larger cups will catch by using the data off the smaller ones. Besides- there is a MUCH greater chance that the smaller cups(pixels) will actually catch too much rain(burned highlight) or none at all(black shadows)- not so in the case of the bigger cup(pixel)...!
Despite all of this data/articles etc- the processors seem to me to be the most significant factor in the whole noise/dynamic range/IQ debate- gathering data is one thing- processing it is another...
All else being equal though,I would still prefer a lower resolution sensor- simple logic would suggest that the less data you have to process,the less chance of "interfering signals" degrading the final image.
SIMON40 is offline   Reply With Quote
Old Dec 18, 2011, 11:12 AM   #8
BDD
Senior Member
 
Join Date: Feb 2010
Location: Toronto, Canada
Posts: 204
Default

Quote:
Originally Posted by SIMON40 View Post
BDD- whilst interesting,the cups/rainfall analogy is somewhat flawed- you cannot "guesstimate" the amount of rainfall the larger cups will catch by using the data off the smaller ones. Besides- there is a MUCH greater chance that the smaller cups(pixels) will actually catch too much rain(burned highlight) or none at all(black shadows)- not so in the case of the bigger cup(pixel)...!
Despite all of this data/articles etc- the processors seem to me to be the most significant factor in the whole noise/dynamic range/IQ debate- gathering data is one thing- processing it is another...
All else being equal though,I would still prefer a lower resolution sensor- simple logic would suggest that the less data you have to process,the less chance of "interfering signals" degrading the final image.
I've always had the same thinking. When I came across that thread it stood out. Found it interesting there is (in that forum) people actually believing in "more MP is better...and that needing more useable ISO is a myth". Having fewer MP but with larger pixels makes a lot more sense for better image quality.

I think the D3s is one of the best designs on the market (till the Canon 1D-X and Nikon D4 hit the market next year). I would have bought one but I want it in the body size of the D700. I don't need the portrait grip. I just want a FX body with great useable ISO range. Which is why I was so hoping the D800 would be based on the D3s...low MP great ISO range. Good FPS.

As it is, I guess I'll have to consider the D4 or wait and see what Canon does with it's upcoming 5D Mark III. Will it share similar specs to the D800? Or will it offer more useable ISO? The Canon 1D-X is a bit costly at 7k (not that spending 5k on a D4 isn't...still a little more than I would like to spend but doable).
BDD is offline   Reply With Quote
Old Dec 18, 2011, 11:27 AM   #9
Senior Member
 
VTphotog's Avatar
 
Join Date: Mar 2005
Location: Extreme Northeastern Vermont, USA
Posts: 4,214
Default

While the processor plays a role, the largest factor is the base noise level of the sensor. This noise floor is where everything starts form. The flaw in the rainfall/cups analogy made in the article was mostly the failure to account for the additional area occupied by the spaces between the cups. The more cups you have, the less actual area will be left for the interior of the cups. To compensate, one would have to increase the overall size of the 'field' containing the cups- iow a larger sensor. The article also mentions normalizing to a standard print size equivalent to 8MP. This tends to average out some noise, to the benefit of the higher resolution sensors.
"Interfering signals" are only going to be a factor before the analog to digital conversion. Once the information is in digital form, it is going to remain intact. Corrupted data seldom results in degraded images, or at least not slightly degraded, but usually significantly distorted.

brian
VTphotog is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:28 AM.