Why such High ISO?

[Dikkie]

I would have to say high ISO is useless for me, i do a few 1 minute or more long exposures at 100 with no problems, but anything even as fast as 1/125th at an ISO over 800 looks like crap...(that's on a 7D), the 40 was rubbish over 400...

Same here, I have the Nikon D50, quite old right now... but over iso 400, it's so much noise.
I always use it's lowest 200 iso at long shttrtimes.

 

[Garbz]

Well I'm back so forgive me for answering really early posts.

The trade off in sensitivity vs shutter speed ALWAYS favours shutterspeed. If you CAN shoot 10 seconds at ISO100 then do. You're taking a worse picture for 5seconds at ISO200, or 2.5 at ISO400 etc.

Even with very long exposures? If there is a choice between, say, 30 minutes at ISO 6400 and 28 seconds at ISO 100 (radical example, I know) is the difference worth the extra exposure time? I would think that there would be a point at which ISO begins to take preference over shutter speed, but I don't really know where that point would be.

ALWAYS favours shutterspeed. In terms of average noise distribution in the frame anyway. The problem is noise is multiplicative. It's not a case of adding the high ISO noise with the thermal noise from the sensor, it's a case of the jump from 30seconds to 2min being far worse at ISO800 than the same jump at ISO100.

Now the caveat here is the weird thermal induced bleeding at the sensor edges of cameras from yesteryear. These were mostly thermal induced on the sensor and didn't have anything to do with noise in the normal sense (hence it was always pink and always in the same spots on the sensor). If you're suffering from problems with pink frames over long periods then upping the ISO will eliminate the pink at the cost of much worse overall noise. That end result may actually be aesthetically more pleasing but rank worse when statistical analysis is done on the frame.

The way around that is to reset the frame mid exposure. Take 2 or 3 or many more exposures and stack them together into a 32bit file. Then stretch the shadows. Statistically you're wasting your time going with more than 150 frames but that is exactly how we take long exposures of deep sky objects at night. Even my D200 which would produce a pink bleeding after only 10minute exposures still managed to crank out 2+ hour long exposures using this technique. My longest exposure is just under 6 hours of this faint bastard here: NGC 7293 - Helix Nebula | Flickr - Photo Sharing!

That's understandable, but doesn't the sensor stay exposed for long periods while using the video feature?

Nope you can't keep the sensor on for longer than your framerate. Yes your sensor gets warm, but the sensor is read out and reset ever 1/30th or so of a second.

Why not? One day we will have ISO 25600 that looks as good as ISO 800 today.

If that happens then you wouldn't need ISO 25600 because ISO 800 would also look that much better. If it that dark out that you need that high of a ISO then focusing with todays focus screens wouldn't be easy right.
Well at least with my camera focusing is very hard in low light.

Remember how I said the trade off in sensitivity vs shutter speed ALWAYS favours shutterspeed? Similar principles apply to recording something and pushing it in post. Except in this case quality always favours correctly recording something to begin with. I.e. Shooting at ISO25600 would produce a far better result than shooting at ISO 800 and pushing the image 5 stops.

 

[weepete]

At the top end of the market guys a lot more knowledgeable than me have answered more than adequately.

Personally I think it has another side, primarily cost. How many posts are seen on here after someone has just bought a new dslr (quite often their first) and asks "I want to shoot xxx" to which most of the replies are "buy fast glass", and then the recommendations come to buy a 1.5k lens thats way above their budget and just after them spending what they thought was a lot of money on a great camera. If we could buy a dslr body that cold handle shooting at small apertures with little or no drop in image quality, that body will have more mass market appeal.

Of course it could just be a simple case of costing less to produce better images at high ISO's than it does to produce better optics

 

[Mike_E]

You folks are forgetting the mantra of the corporate world, "Constant Improvement!".

It is simply not in them to stand their ground because good enough isn't any more.

 

[tyranniux42]

My longest exposure is just under 6 hours of this faint bastard here: NGC 7293 - Helix Nebula | Flickr - Photo Sharing!

Wow, 180 exposures stacked from a d800, were you shooting raw?... 18 gig of hdd just for 1 image ( well for the build up at least and that's only counting light frames!

Would love to know how many lights, darks and bias frames you used for this...

Fantastic image by the way!

 

[tyranniux42]

Garbz your flikr gallery is utterly jaw dropping

 

[skieur]

Why are companies pushing for such high ISO numbers? At what point would someone really use ISO 25,600? It seem so pointless to go so high as IQ will drop because of it. Is it just bragging rights at who can produce the better sensor? It seems the same as shutter speed, I can't think of when someone would use a shutter speed of 1/8000th. If you taking pictures at night why not just use a tripod and slow the shutter to let in more light? Heck you could use ISO 100 if you leave the shutter open long enough right?

In my opinion they should focus that R&D funds to developing better optics(which can always get better) or focusing better in low light. How about making a hybrid split screen for better manual focusing and fast auto focusing. Those things are really good at manual focusing. I'm sure it could be done if they stop worrying about such ISO numbers and focus that energy else where.


I'm not saying that it's useless because I'm sure some people use it. Can someone explain this to me because I can't think of a good reason so far? Or could some show me a picture at which they had to push the ISO that high?

-Hunt

The answer is simple. What they are working toward is the premise that if you can see it, no matter how poor the lighting, then you can take a photo or video of it and without noise or blurring and without the need for flash, strobes or auxiliary lighting.

I see nothing wrong with that objective.

skieur

 

[Patriot]

Sometimes I shoot at 50,000 ISO.
Low light and action.

OMG how is the quality of your pictures? Can you post a example? I don't believe the d7000 will do so well so high.

 

[greybeard]

ISO and mega pixel numbers were the thing that you paid for back in the day. My 1st digital (sony) was 64K pixel and recorded on floppy disks. My 1st descent digital (Sony 828 (8 mega pixel)) was descent at ISO 100-200 but that was about it. So, it has been a upward push for ISO and pixel numbers ever since digital photography was born. How high will these numbers go? Who knows? I can say that ISO was a real issue with me with my 828. Not so much now with my D7000. I think the push now will be for full frame sensors in dSLRs.

 

[MK3Brent]

I think the push now will be for full frame sensors in dSLRs.

Clarify?
There are full frame sensors, and even medium format sensors in DSLR's.

You mean as standard?

 

[thunderkyss]

Why are companies pushing for such high ISO numbers? At what point would someone really use ISO 25,600? It seem so pointless to go so high as IQ will drop because of it. Is it just bragging rights at who can produce the better sensor? It seems the same as shutter speed, I can't think of when someone would use a shutter speed of 1/8000th. If you taking pictures at night why not just use a tripod and slow the shutter to let in more light? Heck you could use ISO 100 if you leave the shutter open long enough right?

In my opinion they should focus that R&D funds to developing better optics(which can always get better) or focusing better in low light. How about making a hybrid split screen for better manual focusing and fast auto focusing. Those things are really good at manual focusing. I'm sure it could be done if they stop worrying about such ISO numbers and focus that energy else where.


I'm not saying that it's useless because I'm sure some people use it. Can someone explain this to me because I can't think of a good reason so far? Or could some show me a picture at which they had to push the ISO that high?

-Hunt

The answer is simple. What they are working toward is the premise that if you can see it, no matter how poor the lighting, then you can take a photo or video of it and without noise or blurring and without the need for flash, strobes or auxiliary lighting.

I see nothing wrong with that objective.

skieur

I agree with this. I'm just learning but so far I'm pretty happy with my camera's ability to take low light pictures without a flash. However, I'm also happy they are still pushing the envelope.

 

[Village Idiot]

Plus high ISO is way better than what it used to be. My OM-D is close to being on par with my 5D MKII. That's a sensor that's half the size still performing well at 3200 ISO.

It makes live concert photography that much more easier when you can shoot with narrower aptures while still maintaning a good enough shutter speed so that your subjects aren't completely blurry from movement and only mostly in focus from the wider DOF. My Canon 30D was perfectly capable of shooting concert photography, but I was always shooting wide open; my 5D MKII let me get better quality images because of the higher usable ISOs.

High ISO also lets your flashes do less work. I'll shooting at 400-800 ISO at events where I need flash so that I'm not draining the batteries as quick as I normally would. Also, flashes that are shooting at lower power generally have a shorter flash duration and recycle faster.

Here's a great example of something that wasn't possible during the ealier days of digital photography. I don't know if it's hand held or not, but it's a shot at night and looks like it was dawn or dusk. Read the comments for full details.

http://www.flickr.com/photos/millios/3980904144/in/photostream

 

[chuckdee]

Why are companies pushing for such high ISO numbers? At what point would someone really use ISO 25,600? It seem so pointless to go so high as IQ will drop because of it. Is it just bragging rights at who can produce the better sensor? It seems the same as shutter speed, I can't think of when someone would use a shutter speed of 1/8000th. If you taking pictures at night why not just use a tripod and slow the shutter to let in more light? Heck you could use ISO 100 if you leave the shutter open long enough right?

In my opinion they should focus that R&D funds to developing better optics(which can always get better) or focusing better in low light. How about making a hybrid split screen for better manual focusing and fast auto focusing. Those things are really good at manual focusing. I'm sure it could be done if they stop worrying about such ISO numbers and focus that energy else where.


I'm not saying that it's useless because I'm sure some people use it. Can someone explain this to me because I can't think of a good reason so far? Or could some show me a picture at which they had to push the ISO that high?

-Hunt

Ever shoot a wedding in a dark church with no flash allowed? I hope they (Canon/Nikon) keep pushing the technology so that 25000 is crystal clear.


____________________
Chuck Dee - AKA Chris
"My job as a portrait photographer is to seduce, amuse and entertain." - Helmut Newton
dallas wedding photographer
Real Estate Lawyer

 

[Joves]

ISO and mega pixel numbers were the thing that you paid for back in the day. My 1st digital (sony) was 64K pixel and recorded on floppy disks. My 1st descent digital (Sony 828 (8 mega pixel)) was descent at ISO 100-200 but that was about it. So, it has been a upward push for ISO and pixel numbers ever since digital photography was born. How high will these numbers go? Who knows? I can say that ISO was a real issue with me with my 828. Not so much now with my D7000. I think the push now will be for full frame sensors in dSLRs.

My first foray into digital cameras was the mavica as well though they were not a true digital, and were nothing more than a toy. But the very first CCD camera was one for astronomy that I went in on with a friend to build a Cookbook Camera. That chip was a whole 40K if I remember right, and it cost us a lot of money which is why we partnered in it. He did all the work on it though, I have zero patience for electronic work. By the time we were done with it I think it cost a grand, this included the nitrogen cooling system that you had to use to shoot with it. My how times have changed.

Why are companies pushing for such high ISO numbers? At what point would someone really use ISO 25,600? It seem so pointless to go so high as IQ will drop because of it. Is it just bragging rights at who can produce the better sensor? It seems the same as shutter speed, I can't think of when someone would use a shutter speed of 1/8000th. If you taking pictures at night why not just use a tripod and slow the shutter to let in more light? Heck you could use ISO 100 if you leave the shutter open long enough right?

In my opinion they should focus that R&D funds to developing better optics(which can always get better) or focusing better in low light. How about making a hybrid split screen for better manual focusing and fast auto focusing. Those things are really good at manual focusing. I'm sure it could be done if they stop worrying about such ISO numbers and focus that energy else where.


I'm not saying that it's useless because I'm sure some people use it. Can someone explain this to me because I can't think of a good reason so far? Or could some show me a picture at which they had to push the ISO that high?

-Hunt

Ever shoot a wedding in a dark church with no flash allowed? I hope they (Canon/Nikon) keep pushing the technology so that 25000 is crystal clear.



____________________
Chuck Dee - AKA Chris
"My job as a portrait photographer is to seduce, amuse and entertain." - Helmut Newton
dallas wedding photographer

Exactly!
Even though I do not shoot weddings or indoors a whole lot, I like the idea it will be there if I need it. When they are improving the High speed end of the sensors they are improving the technology which is always a good thing. And as far as dynamic range, that is also improving, one improvement leads to another which is never a bad thing. Some of the responses about this bad amaze the hell out of me, because here is what will eventually happen. We will eventually have chips in the camera that will have such a wide ISO range from low to high, that you will not be hampered by it any longer due to poor lighting conditions. So the low end might not go as far down as you want, but it may very well become that the native ISO of chips will start at ISO 50, or 25, and go up to the 100K range, then there would be the push/pull ISO. While yes that is not yet reality it will be. Embrace the future.

 

[Garbz]

Wow, 180 exposures stacked from a d800, were you shooting raw?... 18 gig of hdd just for 1 image ( well for the build up at least and that's only counting light frames!

Would love to know how many lights, darks and bias frames you used for this...

Fantastic image by the way!

Garbz your flikr gallery is utterly jaw dropping

I should post more often. Thanks for the kind words. I'm disappointed with the Helix nebula. The D800 has very aggressive IR blocking and Ha emissions don't come through very well. Then there's light pollution too and all in all I need to get out of town more.

I always shoot 10 bias and 10 dark frames. Usually one or two flat frames is all that is needed. DSLRs with RAW actually don't benefit much from bias frames as despite the name RAW suggests there's still active pre-processing performed on RAW images. Dark frames are about only good for hot pixel removal, and even then it doesn't work well. 178 light frames in total (good estimation with the 180 ).

Actually the file size is closer to 6GB. A combination of using an f/6.3 reducer to fit the helix in and computer issues means I always shoot with DX crop enabled on the D800. I get horrendous vignetting on my scope with a full frame camera when using the focal reducer. Also Deep Sky Stacker is only a 32bit program and hits the 3.2GB RAM limit when trying to process the ludicrously large D800 pictures.