High ISO to make fast lenses obsolete?

Perhaps this topic has been discussed on this forum previously, but I'll state my question anyway: Will high ISO/low noise camera capabilities eliminate the need for fast, expensive lenses in wildlife photography? Can I use a Nikon D300 with a Nikkor 300mm f4 and get the same results as I would using the same camera with a Nikkor 300 mm f2.8 lens? Both are super sharp. The only advantage to the 2.8, it seems, is a greater DOF for isolating wildlife subjects.

The 2.8 not only will give you better DOF options, but you can shoot at lower ISOs, and have better functionality when you pair it with a teleconverter. The 2.8 can be paired with a 2X and still have autofocus, but the f/4 will be at f/8 and won't have autofocus. Also, I believe the 2.8 is a higher build quality and a sharper lens, and the more light that's let in the faster and better the autofocus will be. I understand what you are saying, and in this day and age with noise becoming less and less of an issue, an f/4 becomes a much more viable option, especially since it's actually lighter/smaller than the 2.8. But overall, I don't think the 2.8 is being rendered obsolete by high ISO capabilities....

Another advantage: A larger aperture lets in more light, giving a brighter image in the viewfinder. Also, I believe it will allow faster auto-focusing in a low light situation.

Looking further into the future, I'm guessing we'll have outstanding high ISO capability and EVFs such that you'll pick your aperture based on the DOF you want, and let the ISO float to get the shutter speed you want/need. At least, that's what I'd like to see. But for shallow DOF, many people will always want fast glass.

Roger,

I agree with many of Luke's and Buck's points, but I tend to look at it another way: You'll ALWAYS be able to shoot in lower light with the faster lenses, and every bump in high ISO performance means we can capture images that we couldn't even dream of before (and do even MORE dreaming with the faster lenses). As a real-world example - I shoot a lot in the low-light world of the rainforest on the northern Pacific Coast and it's tremendously exciting what we can do now in terms of capturing bear images (compared to even 4 years ago) - but the guys with the fastest lenses still get the best stuff - and I can't see this changing any time soon. If one wants simply to capture the same type of images that even film users could capture with high ISO cameras, then the argument of high ISO making fast lenses obsolete may be valid. But when you start thinking "outside the box" and start venturing into lower and lower light and capture image types that have never been captured before you'll still want the fast glass...(and it's tremendously exciting when you think about it)...

David - no offence intended, but you realize that what you're describing about floating ISO is exactly what the Auto ISO function does on the Nikon D700 and D3 (and, over a far narrower usable ISO range, the D300 and D300s) when it's used in Aperture Priority mode? You specify the slowest shutter speed you'll accept, then set the aperture, and the camera floats (but minimizes) the ISO (over the range you've specified) to give you the correct exposure. And you're right - it's very liberating...

Cheers...

Brad

Never. They're too useful for shallow DOF.

I don't think it will make them obsolete, but it is having a impact. It is this exact reason why I went with the Nikon 200-400 f4 instead of the 400 f2.8. I much prefer the option to zoom instead of the shallow DOF, but that's my opinion. I think 2-3 years ago I would have went with the f2.8 lens.

David - no offence intended, but you realize that what you're describing about floating ISO is exactly what the Auto ISO function does on the Nikon D700 and D3 (and, over a far narrower usable ISO range, the D300 and D300s) when it's used in Aperture Priority mode?

I realize that Brad. But I'm talking about truly not caring about ISO. To the point where you could take the exact same shot from 100 - 102,000. Then you could pick just about any aperture and still get fast enough shutter speed. I'm envisioning total freedom to get the exposure you want with just about any aperture or shutter speed you may want.

I use a 2x converter regularly with my 300 f/2.8
I have used my 2x + the 1.4x with the lens under sunny conditions and still get AF as well.
The brightness of the lens made the difference..
I used that combo a few days @ ISO 1000, 1/500th, F/7.1 with a 1D M3
Here's one of the shots. Busy setting, but you get the picture

I look forward to the day when much lighter big lenses are available, like a Canon or Nikon 600 f.5.6, or 300 to 700 zoom, and where 1.4 and 2x converters can be paired for auto-focus capability. The size and weight do make a big difference, and I think having lighter lenses in the that can perform to today's standards because of better quality digital files will be agreat boon to nature photography. Ever try packing a 600 f.4? Id love to have them in 5.6 variety with the same capabilities, yet lighter and cheaper. Big, light zooms (Canon or Nikon) wouldn't hurt either :)
MM
MM

Howard,
Your bird shot is a great illustration of the difference a a lens with bigger aperature can make. You and others have answered my somewhat devils-advocate question regarding use of higher ISOs and relevance of big lenses. It seems the big expensive glass will be with us for a long time.

I don't see how the brightness of the lens made a difference? I suspect a Canon 300 F4 with the same set up (assuming auto-focus worked with the 2x) could have been of equal quality. Nice shot btw. MM

Mark - The "brightness" of the lens makes a difference in two ways (and I suspect you realize this already but I'll go through it for anyone who doesn't) :

1) A wider aperture helps the autofocus speed of the camera. The camera will do it's focusing and metering at the widest available aperture, then closes the aperture down to actually take the photo. In general, the more light that comes in, the faster the autofocus speed and accuracy (up to a point, where the system can only run so fast).

Now adding teleconverters effectively slows down the lens - an f/2.8 lens with a 2X teleconverter actually is an f/5.6 lens. It loses 2 stops. So it's dimmer and potentially slower focusing. If you had started with an f/5.6 lens, and added a 2X teleconverter, you'd wind up with f/11 as your fastest aperture! So on "slower" lenses, teleconverters aren't nearly as useful. In fact, Canon disables autofocus on its lower end models when the lens aperture is slower than f/5.6, and on it's pro models when it's slower than f/8.

2) A wider aperture helps you frame in the viewfinder. Once again, with teleconverters, in lower light, the viewfinder can get pretty dark. It helps to have a faster lens to let in more light simply to help you see through the viewfinder better.

So certainly the 300 f/4 could have taken just as good a shot (although with the 2X TC, it would be a 300 f/8, which will only autofocus on the "pro" cameras (1D and 5D series). But you would have potentially had some limits that a faster lens can help.

As far as I know, only Canon actually has the autofocus disabling. Other camera brands' autofocus will just function worse and worse (or not at all) as the maximum aperture goes up (higher numbered f-stops).

Thanks for the specifics. There's two ways to look at speed now, one f stop speed and two, autofocus speed. The light gathering viewability will always factor in and I don't know how tech advances will improve the viewing brightness. But there will probably be a way.

I'm just looking to the future when Canon makes lenses that will readily autofocus at the higher (numbered) f stops like f8 or f 11, and a time when pixel quality is even more phenomenal at higher ISOs. So maybe, shooting at ISO 1600 will be like ISO 100 quality now, an f5.6 lens with a 2X converter witll autofocus very quickly, and somehow the viewing brightness will be enhanced.

Let me fess up- I want a big lens, like a 600 f5.6 that has no limitations for autofocus speed and output quality, even with a 1.4 or 2X, that is much lighter and thus far more maneuverable than the 600 f4, and of course, gobs cheaper, like $2500, Maybe a big zoom with those features too in our lifetimes. Dream on, I guess!

...I don't know how tech advances will improve the viewing brightness.

I do! It's a switch to an EVF (Electronic View-finder) that you would be able to set to auto-brighten if need be. That's probably one of the main reasons I think SLRs will all switch to high-quality EVFs. (Thereby becoming EVILs - Electronic Viewfinder Interchangable Lens cameras.)

As far as auto-focus capability/speed, it's always going to be harder to focus in low contrast scenes with any current method - dedicated sensor like an SLR or imaging sensor based like EVILs and P&Ss. Maybe more sensitive methods will come along. Sure would be nice to auto-focus quickly in low light with small aperture lenses!

Maybe 30 years from now we will have a small and light 800mm f1.2 lens using some new optical construction technology like Canon's DO lenses but better. Also cameras will use a new type of sensor which is better than CMOS sensors and when combined with better processors and noise reduction algorithms and ISO 819,200 will produce images like our ISO 100 today allowing us to acheive a shutter speed of 1/250 lit only by starlight to capture nocturnal wildlife without artificial lighting.

Ok, I don't really believe that to be the case. I think just like film has its limit digital sensors will eventually hit the limit of how well they can perform at high ISOs without introducing too much noise. Noise usually occurs when a pixel on the sensor has not gathered enough light during the exposure to have any data on how bright it should be and what spectrum of light it was. We can design sensors which are more efficient at light gathering and modern sensors implement tiny micro lenses to do just that but there is only so much we can do to improve that before the laws of physics kick in and there is absolutely no more room for improvement. Digital sensors are definitely more efficient at reading light than film was but they have their limits too. I think pretty soon we are going to see a slow down in advancements in high ISO performance as we get closer to the limits of digital imaging sensors. I wouldn't be surprised if we are already getting close to that point.

I would say no, better high ISO performance will not eliminate the need for fast glass as that extra stop can always make or break a shot which is pushing the limits of available light. High ISO will allow more creative shooting that was not possible before but there will always be shots that push the limits and a wider aperture will make or break it. Another big advantage is with an f/2.8 lens you can auto-focus with a 2x tele-converter on any DSLR and not just a pro camera and besides that it will also auto-focus quicker. The advantages of fast glass are numerous and not just limited to being able to use a faster shutter speed (although that is a biggie).

Austin,
Before I finished reading the first sentence of your post, I knew you were kidding. Based on what I'm reading here, I agree that we're probably getting close to the limits of high ISO performance. Photography is all about capturing light. Unless you can bend the laws of physics, it's likely that large apertures with large price tags will remain standard for serious wildlife shooters.

I tend to think we are getting towards the limit as advancements in high ISO performance have seemed to have slowed in the last few years in new DSLRs where there were huge advancements in the original DSLRs and those just a few years later. Only time will tell and maybe more of that light energy is getting wasted than we think and future advances in sensor technology will be able to capture significantly more of it.

I put another spin on this away from wildlife. I shoot wedding photography and a fast 85mm 1.4 lens lets me keep the ISO down as far as possible, while maintaining a good shutter speed. I dont want to shoot high ISO images as I start to lose contrast the higher I go. I can imagine the same would be the case in wildlife. I would prefer to shoot ISO 100-400 than 400-3200.

I would prefer to shoot ISO 100-400 than 400-3200

Keith - I think the point of the question was that if high ISO image quality reaches the same level as lower ISO, then would you need fast glass. You prefer lower ISO now, because it's obviously better. But what if ISO 3200 got so good that you couldn't tell whether it was 200 or 3200? That's the question. Would you still need f/1.4 lenses then? I think the answer (as already stated above by various folks) is that you still likely would because of wanting shallow DOF, viewfinder brightness, and autofocus speed. I think the last two may become non-issues in the future with new focusing techniques and EVFs. The need for a large aperture for shallow DOF is more likely to hang on. However, even that could be mitigated if the right sensors/cameras get into production. (Here's a link to the start of that kind of thing.) But that's probably at least 10 years away.

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I tend to think we are getting towards the limit as advancements in high ISO performance have seemed to have slowed in the last few years in new DSLRs
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ISO's were pretty stable at the 3200-6400 range for several years until this last year. Just within the last few months Nikon and Canon have up'ed the ISO range to 102,400. Saying that they might have hit a limit on advancements is one thing (which I don't agree) but to say it's slowed over the last few years, I'd have to say the opposite.