End in sight for Big Glass ?

[citrinella]

We all take it as read that "you can never have too much reach" and "money is better spent on the lens than the camera". I agree with these whole-heartedly - at the moment.

Looking at some folks tests of extenders versus digitally cropping images, I wonder if we are going to see a big change in the next few years.

If the resolution of sensors continues to improve, might the situation be reached where an excellent medium length lens will give equivalent results to a much more expensive long telephoto ? Will the stage be reached where the original resolution will be so good that cropping and enlarging by quite a large amount will not show any visible, practical, deterioration in quality ?

I can hear the answers already saying that, using equivalent quality glass, greater length is _always_ technically superior. I disagree in some respects. It is true for resolution. However it is always more difficult to eliminate shake, always slower (smaller maximum aperture) and always more sensitive to poor air quality. In practice weight and price are also more burdensome ! It is also a b-nuisance changing lenses specifically for that bird shot - you always miss many opportunities, even if you have two bodies.

I forecast sales slipping, and with reduced sales, prices will have to rise, technical development will slow (probably has already) and a positive feedback loop will establish, hastening sales decline. Who will keep manufacturing ?

Just thinking :-)
Mike.

[JSI]

I disagree in some respects. It is true for resolution. However it is always more difficult to eliminate shake, always slower (smaller maximum aperture) and always more sensitive to poor air quality.



I totally agree with you, higher resolution will eventually overcome the need for large focal length lenses.

[level seven]

I disagree in some respects. It is true for resolution. However it is always more difficult to eliminate shake, always slower (smaller maximum aperture) and always more sensitive to poor air quality.

Not being a bird or nature photographer myself, I hesitate to comment, but I'm not totally convinced by two of those disadvantages quoted for longer focal length lenses.

Is not the effect of air quality on a photograph a function not only of the prevailing conditions (which are the same on any given occasion whatever lens is selected) but also of the distance between subject and image and therefore independent of focal length? It might not be as noticeable with a shorter focal lens using the whole image taken, but enlarge the subject enough so it's the same size as one taken through a longer lens and it might well be.

Will not the same apply to the effect of camera shake? It's going to be present to some degree even using a shorter lens and, again, it could be as obvious when the subject is enlarged to the equivalent size as that taken using a longer lens. Even using a shorter lens, I would imagine shake as well as resolution are limiting factors, it's just that they aren't immediately obvious at normal enlargements.

My experience of photography is limited to general subjects, mostly landscapes, so I'm probably talking through my hat, but I just wondered if it was so simple as described.

[Isurus]

Is not the effect of air quality on a photograph a function not only of the prevailing conditions (which are the same on any given occasion whatever lens is selected) but also of the distance between subject and image and therefore independent of focal length? It might not be as noticeable with a shorter focal lens using the whole image taken, but enlarge the subject enough so it's the same size as one taken through a longer lens and it might well be.

.

this is correct - getting closer with a short lens will of course reduce air quality issues but at the same distance from the subject the problem should not be reduced. Off topic this is a real issue for underwater photographers such as myself who tend to rely on wide angle to let us get closer still to the subject to reduce the artefacts in the water between subject and lens but still fit large subjects in.

[Keith Reeder]

Hi guys,

I think the point Mike's making is that some day, there's going to be so much detail and resolution available from the sensor that you will be able to get away with taking a "small" shot with a low focal length - significantly reducing issues like shake and air quality - and still be able to digitally enlarge it to the desired level of magnification without any perceptible loss of image quality.

I hope so!

;)

[level seven]

Of course, no point in increasing levels of resolution by sensors if this eventually outstrips the resolving capabilities of the lens itself.....

[IanF]

Personally I think the technology is already there as regards these super sensors, it just hasn't trickled down to the consumer market yet!

[Andy Bright]

Personally I think the technology is already there as regards these super sensors, it just hasn't trickled down to the consumer market yet!You only have to look at the world a video for what can be achieved with very small sensors. I met a pro bird video cameraman a few days ago and he's getting a crop factor of 5 with his pro video camera+slr lens... o.k. video is far lower res than what a still photographer needs but with HD video cameras now available, that pushes it a lot closer.

[Yelvertoft]

Of course, no point in increasing levels of resolution by sensors if this eventually outstrips the resolving capabilities of the lens itself.....

Graham's hit the nail on the head here. It doesn't matter how many MPixels you have to be able to crop and enlarge, if the lens can't resolve the detail it'll still be a duff shot. This is one reason why I think big glass will still be around for a long time. Digital sensor technology is still evolving very quickly, the resolving power of glass is changing at a far slower pace. Secondary to this, there's no such thing as "too much reach" when it comes to bird photography, people will want big glass AND digital cropping. Thirdly (I'm beginning to ramble here, aren't I?), people will spend whatever they can afford/justify on their chosen hobby. If big glass is affordable, they will still buy it.

Duncan.