topic Re: High ISO vs Underexposing in General Discussion

High ISO vs Underexposing

mitchbooth — Mon, 06 Mar 2017 18:51:00 GMT

Hello everyone,

Just returned from the Indoor State Track meet where I took about 1500 photos. As with most indoor venues the lighting was sub par. I met several photographers from MileSplit Ohio who ranged from shooting in sports mode to underexposing every photo by 3 or 4 stops in Raw only to bring up in post production. I was typically at 640 shutter speed and around 3.2-4 on aperature and my iso was set on auto ranging from 2000-10,000. I also used all large Raw files with no JPEG at all.

I'm new in photography and have the Canon 70d, Tamron 24-70 F2.8 and Tamron 70-200 F2.8. I've finally gotten out of auto modes and relatively comfortable with the camera and operating in manual mode. I use Adobe Lightroom for organizing and editing my photos.

I've been trying some night photography and typically leave Long Exposure Noise Reduction off. I have been leaving High ISO Noise Reduction on but have heard by doing so you sacrifice some definition in the photos.

My question to you more experienced photographers is this. Should I shoot indoor events underexposed by 3 or 4 stops and then bring them up in Lightroom or should I use higher ISO for the Canon 70D and let it properly expose them in camera. Which way gets the better result? Is it poor practice to leave the High ISO Noise Reduction off in camera?

Mitch

Re: High ISO vs Underexposing

Waddizzle — Mon, 06 Mar 2017 19:55:01 GMT

"My question to you more experienced photographers is this. Should I shoot indoor events underexposed by 3 or 4 stops and then bring them up in Lightroom or should I use higher ISO for the Canon 70D and let it properly expose them in camera. Which way gets the better result? Is it poor practice to leave the High ISO Noise Reduction off in camera?"

Experiment, and see what works best. What works for one lens, may not be best for the other. Don't lock yourself into doing stuff only one way. Always be ready to think outside the box.

Do you know why the other photographers were underexposing by a 3 stops? When I have done that in the past, it was to maintain a higher shutter speed. It works fairly well for shots that show more context than detail, in other words, not a closeup.

Re: High ISO vs Underexposing

mitchbooth — Mon, 06 Mar 2017 20:13:36 GMT

They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

Mitch

Re: High ISO vs Underexposing

diverhank — Mon, 06 Mar 2017 21:50:52 GMT

@mitchbooth wrote:
They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

While I’m nowhere near the expert level required to talk about this…in my experience, what your friend is doing makes no sense to me. Perhaps you might want to ask him the rational and some objective evidence that it is better. I’ve long learned that there is always something new one can learn so I’m not saying he’s wrong, it just seems against conventional wisdom to me.

I shoot a lot of Birds In Flight (BIF) which in many ways are similar to your shooting sports. Due to the extreme shutter speeds required (e.g. 1/2000), the ISO required are normally high. It is very hard to brighten the dark areas without excessive noise. Most Canon cameras (barring the 80D, 5D4 and 1DX II) can only handle about 3 stops of brightening before the images are unusable. You should do an experiment, set your ISO to 100 and underexpose the shot 4 stops then brighten it in post and see how you like it. Even at ISO 100, the image will be hard to stomach. On the other hand, with proper post process noise reduction, ISO 1600 (4 stops above 100) should be very usable. As a matter of fact, my ISO 12800 images are totally usable (out of the 5DIII).

Re: High ISO vs Underexposing

Waddizzle — Tue, 07 Mar 2017 00:10:50 GMT

@diverhank wrote:
@mitchbooth wrote:
They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

While I’m nowhere near the expert level required to talk about this…in my experience, what your friend is doing makes no sense to me. Perhaps you might want to ask him the rational and some objective evidence that it is better. I’ve long learned that there is always something new one can learn so I’m not saying he’s wrong, it just seems against conventional wisdom to me.

I shoot a lot of Birds In Flight (BIF) which in many ways are similar to your shooting sports. Due to the extreme shutter speeds required (e.g. 1/2000), the ISO required are normally high. It is very hard to brighten the dark areas without excessive noise. Most Canon cameras (barring the 80D, 5D4 and 1DX II) can only handle about 3 stops of brightening before the images are unusable. You should do an experiment, set your ISO to 100 and underexpose the shot 4 stops then brighten it in post and see how you like it. Even at ISO 100, the image will be hard to stomach. On the other hand, with proper post process noise reduction, my ISO 12800 images are totally usable (out of the 5DIII).

I agree with your opinion of going beyond 3 stops adds too much distortion. Sometimes those indoor high school sports venues can be fairly dim, even compared to a basketball court. I think most cameras can produce decent images with high ISO values [ISO 6400], provided you have high shutter speeds. The longer the shutter is open, the more noise it seems able to detect, and the less details you can resolve. It's a trade off.

Re: High ISO vs Underexposing

RobertTheFat — Mon, 06 Mar 2017 21:59:44 GMT

@mitchbooth wrote:
They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

Mitch

There's something not quite right about all this. There's a legitimate reason why photographers sometimes underexpose, but it's in bright light, not dim. The idea is that you can compensate for a one or two stop underexposure, but a blown highlight is unrecoverable. Yes, it's true that if the ambient light is actually insufficient, you can often dig a reasonable semblance of the image out in post-processing. But it's not preferable to getting the exposure right in the first place, as long as the ISO setting is within the camera's capability. And the 5D3 is a very good low-light camera.

Re: High ISO vs Underexposing

Waddizzle — Mon, 06 Mar 2017 22:06:03 GMT

@RobertTheFat wrote:
@mitchbooth wrote:
They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

Mitch
There's something not quite right about all this. There's a legitimate reason why photographers sometimes underexpose, but it's in bright light, not dim. The idea is that you can compensate for a one or two stop underexposure, but a blown highlight is unrecoverable. Yes, it's true that if the ambient light is actually insufficient, you can often dig a reasonable semblance of the image out in post-processing. But it's not preferable to getting the exposure right in the first place, as long as the ISO setting is within the camera's capability. And the 5D3 is a very good low-light camera.

Makes sense to me. So, how would you maintain a high shutter speed in dim light? i think the OP is using a 70D, BTW.

Re: High ISO vs Underexposing

RobertTheFat — Mon, 06 Mar 2017 22:23:59 GMT

@Waddizzle wrote:
@RobertTheFat wrote:
@mitchbooth wrote:
They where under exposing the pictures in order to avoid higher ISO. He was shooting with a Canon 5d Mark III. He claims the pictures are much better bringing the exposure up in post production and keeping a lower ISO as opposed to shooting higher ISO's in camera in order to get an appropriate exposure. The lighting was dim and we needed a minimum shutter speed of 640/800 to keep the athletes from blurring. He and I both were shooting in manual.

I will try to underexpose next time and add the 3 or 4 stops of exposure in post production. Logically to me it makes sense but I'm sure there must be some drawbacks to increasing exposure in post production.

Mitch
There's something not quite right about all this. There's a legitimate reason why photographers sometimes underexpose, but it's in bright light, not dim. The idea is that you can compensate for a one or two stop underexposure, but a blown highlight is unrecoverable. Yes, it's true that if the ambient light is actually insufficient, you can often dig a reasonable semblance of the image out in post-processing. But it's not preferable to getting the exposure right in the first place, as long as the ISO setting is within the camera's capability. And the 5D3 is a very good low-light camera.
Makes sense to me. So, how would you maintain a high shutter speed in dim light? i think the OP is using a 70D, BTW.

Well, you do what you have to do. But if you don't have to do it, you don't.

My reference to the 5D3 was because the photographer who laid that yarn on the OP was reportedly using one.

Re: High ISO vs Underexposing

ScottyP — Tue, 07 Mar 2017 00:57:23 GMT

I have read some photographers saying they will do just that; shoot fast action a couple of stops underexposed in bad lighting. Their belief is that they can lose less image quality bumping the exposure a couple of stops in post than they would have lost shooting properly exposed but at 2 stops higher ISO.

Both shooting at high ISO and boosting underexposure in post degrade the image, and thus it is kind of a tradeoff either way you do it.

The premise of the underexposers is (I think) shooting at high enough ISO in the first place (above a certain threshold, where it really gets noticeable) you fail to capture adequate detail; fewer lines of resolution are recorded. You can erase noise in post, at a price of softening the image, but you can never create detail that wasn't captured in the first place.

I dont personally know if i if I agree or not. It may be total BS or it may be that it depends. I would certainly not underexpose to avoid shooting at ISO 400 or 800 or anything, but depending on the camera (FF? Crop?) at some point I might think boosting an underexposure in post is better than some eye-wateringly high ISO over 12,800. Primarily from the perspective of resolution.

Re: High ISO vs Underexposing

jrhoffman75 — Tue, 07 Mar 2017 01:49:29 GMT

It appaerntly depends a lot on the particular camera (or rather sensor). See this posting:

http://www.fredmiranda.com/forum/topic/1478377

Maybe those photogrpahers have done the experimenting and reached a conclusion that works for them.

If shooting RAW, which one should be doing unless there is a very special need for in camera JPEGs, High ISO Noise Reduction doesn't do anything. It is only applied when in-camera JPEGs are produced. It is a file tag that is read by DPP but not Lightroom or any other non-Canon software.

Re: High ISO vs Underexposing

ebiggs1 — Tue, 07 Mar 2017 10:05:20 GMT

mitchbooth,

This is a situation where you must try both or any and all ways to accomplish your goal. There may be times where LR does a better job with the noise that will be rendered in either case then the camera. But, shooting RAW is largely a method where nothing but the 'raw' data the sensor saw at the time is recorded and saved. I would not use High ISO Noise Reduction in the camera. I would never use auto ISO. Set it where you want it. I almost never use manual mode preferring Tv or Av for most situations. I don't use the top ISO either.

Personally for me, I find post processing is usually best. I shoot RAW 99.9% of the time. Actually, I just want the camera to capture an image and let me edit it the way I want. Skills in LR and PS are invaluable. Far more is possible in post than in the camera!

Re: High ISO vs Underexposing

ebiggs1 — Tue, 07 Mar 2017 16:09:45 GMT

mitchbooth,

You have the "Tamron 24-70 F2.8 and Tamron 70-200 F2.8" pair. Wonderful glass! Off the topic but these are two of the few third world lenses I love. As a general rule I don't buy third party lenses if there is a real deal Canon. Canon's lens line is so vast it leaves little for wants. You will have to pry from my cold dead hands my ef 24-70mm f2.8II and ef 70-200mm f2.8L II, I like them so much but if they were not made the Tamron pair would do nicely.

If you are interested there is another off brand lens I totally recommend. The Tokina AT-X 16-28mm f/2.8 Pro FX Lens. It is fantastic. I consider it equal to, might I say better than the EF 16-35mm f/2.8L II entry in this focal length. Of course the build is no where near a Canon L lens but the IQ is top notch. It is a third the cost !

Re: High ISO vs Underexposing

mitchbooth — Tue, 07 Mar 2017 17:18:57 GMT

@ebiggs1 wrote:
mitchbooth,
You have the "Tamron 24-70 F2.8 and Tamron 70-200 F2.8" pair. Wonderful glass! Off the topic but these are two of the few third world lenses I love. As a general rule I don't buy third party lenses if there is a real deal Canon. Canon's lens line is so vast it leaves little for wants. You will have to pry from my cold dead hands my ef 24-70mm f2.8II and ef 70-200mm f2.8L II, I like them so much but if they were not made the Tamron pair would do nicely.

If you are interested there is another off brand lens I totally recommend. The Tokina AT-X 16-28mm f/2.8 Pro FX Lens. It is fantastic. I consider it equal to, might I say better than the EF 16-35mm f/2.8L II entry in this focal length. Of course the build is no where near a Canon L lens but the IQ is top notch. It is a third the cost !

Ebiggs,

I was looking at the Tokina 300 2.8 with possible a 1.4 telecoverter for photographing birds in flight. The Canon equivalent of 400 f4 would be almost 10 times the cost. Any thoughts on Tokina's other lens for flying bird photography?

Re: High ISO vs Underexposing

ebiggs1 — Tue, 07 Mar 2017 21:52:24 GMT

mitchbooth,

As a general rule I tell people to avoid Tokina completely. Their CS is nonexistent. Their build is average. Even the Tok I suggested above is probably a, you are on your own situation. Keep that in mind when considering Tokina's. The price point and the absolutely fantastic IQ of the Tokina AT-X 16-28mm f/2.8 Pro FX Lens makes it a no brainer. Everybody needs that lens, they just don't know it !

If my feeble memory serves me the Tok 300mm f2.8 has been discontinued so it will be a used only proposition for you. I was a user of one but not an owner. I remember it is very slow to AF and has considerable problems with flare. Not a good candidate for BIF. Converter will make AF even worse. At a good price you may want to give one a try but a used Sigma 120-300mm f/2.8 DG OS HSM Lens is the lens of choice. It will be considerably more expensive but it is fantastic. There is an older version and one without OS (Siggy's name for IS) that can be had pretty reasonably used. It is tough as nails and Sigma is light years better with CS than Tokina. Plus it will be way more useful besides just BIF. It works well with the Siggy 1.4x converter, BTW. I have owned two of them over the years. The Sigma 120-300mm f/2.8 DG OS HSM Lens is a lens that Canon should have made. It is in the same class as any of the Canon "L" series lenses. Even the build.

But if you want MHO of what is the best buy in a tele, it is the EF 400mm f/5.6L USM Lens. This lens gives up nothing in IQ to any super tele. It is light and a joy to use for BIF. Although it can use a converter (depending on camera), you probably won't need one with 400mm. It is also available on the used market reasonably priced because of so many of them. Everybody needs this lens, too. I have two of them also.

Re: High ISO vs Underexposing

Peter — Fri, 10 Mar 2017 11:13:27 GMT

@mitchbooth wrote:
Hello everyone,

Just returned from the Indoor State Track meet where I took about 1500 photos. As with most indoor venues the lighting was sub par. I met several photographers from MileSplit Ohio who ranged from shooting in sports mode to underexposing every photo by 3 or 4 stops in Raw only to bring up in post production. I was typically at 640 shutter speed and around 3.2-4 on aperature and my iso was set on auto ranging from 2000-10,000. I also used all large Raw files with no JPEG at all.

I'm new in photography and have the Canon 70d, Tamron 24-70 F2.8 and Tamron 70-200 F2.8. I've finally gotten out of auto modes and relatively comfortable with the camera and operating in manual mode. I use Adobe Lightroom for organizing and editing my photos.

I've been trying some night photography and typically leave Long Exposure Noise Reduction off. I have been leaving High ISO Noise Reduction on but have heard by doing so you sacrifice some definition in the photos.

My question to you more experienced photographers is this. Should I shoot indoor events underexposed by 3 or 4 stops and then bring them up in Lightroom or should I use higher ISO for the Canon 70D and let it properly expose them in camera. Which way gets the better result? Is it poor practice to leave the High ISO Noise Reduction off in camera?

Mitch
From a developer at Magic Lantern:

"So ISO 100 for example may be able to capture up to 80,000 photons of light, but since it is rather noisy on Canon cameras, once the photon count drops below 40, there isn't enough light to outweigh the noise produced by the camera. Whereas ISO 1600 for example may only be able to capture up to 5,000 photons, however, it can capture photon counts as low as 4 before the noise produced by the camera is greater then the number of photons captured. These are example numbers, but I'm sure you get the point.

So one thing that should becoming clear is that higher ISOs do not increase noise. In fact, higher ISOs are less noisy. Higher ISOs can capture a smaller number of photons, before that number of photons is less then the noise produced by the camera. Higher ISOs cannot capture the same amount of photons (light) as lower ISOs, but a photographer should only be using higher ISOs when the number of photons (the amount of light) is lower then the maximum for that ISO.

Where the lines get blurred is due to the shot noise. So we have a dark scene, we crank the ISO up, but the image appears to have more noise then an image taken at ISO 100, with the same rendered brightness. That's simply because the light itself that has been captured, contains more noise. Darker scene = less light = less photons = more (shot) noise.

It is very easy to see that higher ISOs have less noise then lower ISOs. Using ETTR principles, take a shot with the camera set to ISO 1600, then without changing any other settings, take another shot at ISO 100. In post processing increase the ISO 100 shot by 4EV and observe the results."

And due to Clarkvision, higher ISO will be less noisy until you hit the camera sensor limited high ISO region:

"However, ETTR is irrelevant in the sensor limited high ISO region in Figure 2. In that high ISO region, one is "light limited" and ETTR is irrelevant. If you need to record a faint signal, once at ISO 1600 to 3200 (as above, but different on each camera), forget the expose to the right idea. Simply set your shutter speed and f/ratio and expose the image, then adjust to the desired level later in post processing. if your camera has auto ISO, one could set shutter speed and f/ratio and set an upper limit to auto ISO of just in the sensor limited region (e.g. ISO 3200 in the Figure 2, 5D Mark II camera), and when the upper limit is reached, fix the image intensity in post processing with no quality loss (assuming 16-bits/channel processing or better).
So too with night and star photography. There is no need to expose to the right in the sensor limited high ISO region. Simply set your exposure time, f/ratio, and the ISO at the optimum for sensor noise limited region with maximum dynamic range. Adjust scene intensity in post processing."

If you shoot ISO between 2000-10,000 I suppose the sensor limited high ISO region of your camera (70D) should be ISO 3200 and that it doesn't really matter if you shoot ISO 6400 under exposed or ISO 10,000. It didn't matter with my 7D (between ISO 3200 and ISO 6400) which I believe has a sensor limited high ISO region above ISO 1600.

Nothing to do with your question, but maybe you also would like to know more about the difference between ISO 640, 800 and 1000. Google: "The riddle of the intermediate ISO setting"

@jrhoffman75 wrote:
It appaerntly depends a lot on the particular camera (or rather sensor). See this posting:

http://www.fredmiranda.com/forum/topic/1478377

Maybe those photogrpahers have done the experimenting and reached a conclusion that works for them.

With the new sensor design (M5, 80D, 5DIV and 1Dx II) Canon took a big step forward. But it is still true that ISO 1600 is less noisy than ISO 100 with a M5 with the same shutter speed and the same f-stop in low light. Big difference in real life like the picture in your link? Maybe not.

Two pictures attached from my 7D. The file size from the one with higher ISO has a file size of 3,6 MB. The under exposed one pushed 3 steps has a file size of 3,9 MB due to more noise. Also check the two holes in the cardboard box and compare the noise in them.

Re: High ISO vs Underexposing

Peter — Fri, 10 Mar 2017 10:51:56 GMT

Canon M5 with the new sensor design. ISO 1600 vs ISO 100, same f-stop and shutter speed. The one with ISO 1600 has a file size of 3,6 MB, the other one has 4 MB due to more noise.

Re: High ISO vs Underexposing

Peter — Fri, 10 Mar 2017 11:45:08 GMT

@Waddizzle wrote:

When I have done that in the past, it was to maintain a higher shutter speed. It works fairly well for shots that show more context than detail, in other words, not a closeup.

More context than detail. I took the picture 2009 with a 7D at ISO 12,800 (ISO H). I had to convert it to black and white because of all the colour noise. Eight years later I still think I would use the same settings because of the context.

Re: High ISO vs Underexposing

ebiggs1 — Fri, 10 Mar 2017 14:57:24 GMT

Good job at explaining noise. Most people do not understand how this works and you did a nice job educating them. I try to do this in class and folks eyes gloss over! We must chip away at old theory.