Arguments for Canon replacing another supertelephoto prime with a zoom:
* Technological advancements: Lens technology has improved dramatically. Modern zoom lenses can achieve image quality, sharpness, and fast apertures that were previously only attainable with prime lenses.
* Versatility: Zoom lenses offer greater flexibility in framing and composition. This is a major advantage for wildlife, sports, and action photography where subjects are often unpredictable in their movement.
* Weight and Size: High-quality zooms are now sometimes more compact and lighter than some supertelephoto primes, which is attractive to photographers who travel or need to be mobile.
* Cost: While high-end zooms are still expensive, they can sometimes be more affordable than a top-of-the-line supertelephoto prime, making them more accessible to a wider range of photographers.
* RF Mount Advantages: The RF mount has enabled Canon to design lenses with superior optical performance and features compared to their EF counterparts. This makes it more likely that a zoom lens could match or exceed the performance of a prime.
* Existing Example: Canon already replaced the EF 200-400mm f/4L IS USM Extender 1.4x with the RF 100-500mm f/4.5-7.1L IS USM, demonstrating their willingness to transition from prime-like flexibility to zoom versatility in this category.
Arguments against Canon replacing another supertelephoto prime with a zoom:
* Image Quality (Slight Edge): While zoom lens image quality is improving, many still believe that prime lenses, particularly at very long focal lengths, can offer a slight edge in sharpness, contrast, and overall image quality. This can be crucial for professionals and serious enthusiasts.
* Maximum Aperture (Possible Drawback): Supertelephoto primes often have wider maximum apertures (e.g., f/2.8, f/4) than zoom lenses. This is important for low-light performance and creating shallow depth of field. While zooms are getting faster, they still typically don't match the aperture of comparable primes.
* Autofocus Speed and Accuracy: Primes tend to have a slight advantage in autofocus speed and accuracy. While Canon's latest zooms have excellent autofocus, primes can still be faster and more reliable in challenging conditions.
* Market Demand: There is still strong demand for supertelephoto prime lenses. Many professional photographers prefer the specific characteristics and advantages that primes offer.
* Niche Market: Supertelephoto lenses are a niche market. Canon may focus their resources on developing lenses for more popular focal lengths and zoom ranges.
* Price Point: While zooms can sometimes be cheaper than primes, replacing a high-end prime with a zoom might necessitate a similar (or higher) price to maintain image quality and features, limiting the accessibility advantage.
Which prime lenses are most likely to be considered for replacement?
* EF 600mm f/4L IS III USM and EF 400mm f/2.8L IS III USM: These are strong contenders. A high-quality RF zoom lens covering a similar focal length range (perhaps with a built-in extender) could be a compelling alternative. However, these are still considered to be among the best lenses available, making replacement a very difficult task.
Likelihood:
It's plausible that Canon will eventually replace at least one more supertelephoto prime lens with a zoom, but it's not a certainty. The decision will depend on technological advancements, market demand, and Canon's overall product strategy. It is very likely that Canon will release more RF mount prime supertelephoto lenses first before considering replacement.
Conclusion:
While zoom lenses are becoming increasingly capable, there are still advantages to supertelephoto primes, particularly in terms of maximum aperture, and, potentially, autofocus performance and image quality. Canon will need to carefully weigh the pros and cons before replacing any of its existing prime lenses. The potential for better zoom lens design brought about by the RF mount increases the chances, but replacing a very successful and extremely high-performing lens is a major challenge.