Canon 5D Full Frame -who's thinking to shift camps

Some lenses have the motor in the lens (called USM for Canon and AF-S for Nikon) and some don't.  The lenses that don't have a motor in them are driven by a motor in the camera body.

 

Not all Canon lenses have a motor in them, only some of them.  The same is true for Nikon lenses.

<{POST_SNAPBACK}>

Canon has introduced the EOS system and its EF lenses (dead for the old FD mount) in 1987. Since then, all Canon EF lenses have the AF motor built into the lens (not just USM lenses). There is no EOS body featuring an AF motor in the camera body. Communication between Canon lenses and cameras is purely electrical since 19 years.

Canon has been criticized in the past for switching the mount from FD to EF and Nikon users praised their never changing mount. On the other side, EF has offered the better AF drive system. Each Canon lens has an AF motor specifically designed for one lens which is located next to the element the motor has to drive. Big motors for big tele lenses and smaller ones for smaller lenses and without long mechanical transmissions. Nikon’s AF motor in the camera body has always been the same, no matter if it has to drive a huge tele lens or a small and light lens. It’s obvious which system performed faster by basic design. In addition, Canon offers ultrasonic motors (USM) which are silent and fast. In some cheaper lenses there is a simple version of USM (an ultrasonic micro motor). The “true†USM features a ring type motor and is even faster and allows full time manual override anytime (no switching to MF required), like for example the 100mm macro USM, all those white tele lenses and black L lenses.

Julian

Mea culpa, thanks for the clarification Julian.,

Speaking as someone who 'jumped' to the Canon 1DS, and who used Nikon for ~20 years beforehand (underwater and above) I'll add my own personal observations and opinions here.

The 60 micro Nikkor is a superb lens: put it on a 1.5x sensor camera and then behind a flat port and it produces a result similar to a 60 x 1.5 x 1.5 = 135mm lens on 35mm film.

The Canon 100mm macro lens put behind a flat port produces an effect equivalent to 100 x 1.5 = 150mm on FF.

The Canon focusses very fast - due to both internal motor and internal focussing (it has a lightweight optical system which is moved by the motor - the lens does not change its external dimensions as it is focussed), but can be a bit picky and will sometimes hunt - there's been discussion about this before on wetpixel, and I wouldn't be surprised if it is simply too fast for its own good under the low contrast conditions often prevalent underwater. It is optically superb!!!

So is the 60mm, and having used one on an S2Pro I know that the focus on this and similar cameras is a lot slower and even pickier than the 100 on the Canon, I found the 60 on the S2 would hunt a fair bit. But I would expect the D2X and D200 to be much better on AF speed than the S2, BUT the lens is limited by its physical, mechanical, focus system which shifts significantly and, due to its optical/mechanical moving section's weight, must be fundamentally limited regardless of the camera its fitted to.

My personal opinion is that of the two the 100mm Canon is the lens I would actually use by preference (but I also love its bokeh and use it above water too). I really wish Canon had made their new 60 macro for FF cameras!

As regards wide-angles, well I've used the 12~24 on the S2Pro and the 17~40 on the 1DS. I don't particularly like either - both work adequately but remain a compromise and I've reverted to fixed focals. Whatever anyone says, at the moment there are simply more wide-angle lenses available for the Canon FFs as you can use film lenses. I expect this to change, BUT, I've said it before and I'll repeat it, I think that the 10+MPixel digital cameras used with dome ports are limited by the optical characteristics of the dome set-up when using lenses with a field of view of 90 degrees or more. Which bring me to:

The exception - fisheyes, and here Nikon have the upper hand as they offer both 10.5 DX format and 16mm FF format both of which are fully usable on their digital cameras and both of which by all accounts work very well. As does the 15 Canon on FF cameras.

Debates rage on web fora as to the relative merits of both systems however, although there are differences, in skilled hand either system will produce stunningly good results. At the end of the day the choice depends on your style of photography, what you like using and is finally a matter of personal choice. With the demise of Konica-Minolta, Canon and Nikon now share ~90% of the SLR market and both produce very high qualty products. Shifting camps is an expensive process (believe me I know) and its worth weighing up future possibilities as well as what's on offer now. Canon will almost certainly produce better wide-angle lenses and Nikon may well produce IF internal motor macro lenses.

Hi Paul,

While I accept your calculations regarding equivalent focal lengths behind ports, I think it is not really relevant to include the port magnification factor as we are all underwater photographers here! I know you shoot great photos on land. But my land photos are rubbish!

Alex

p.s. I did a couple of serious shooting dives with the Nikon 12-24mm earlier in the month and for the first time I was very pleased with it (for the first time). Using a dioptre I was getting good corner sharpness and detail. Once I get a few moments I'll post some examples and crops.

Ahh yes, but Alex, I'd love a 60mm equivalent internal and fast focus lens for full frame. Trouble is, as always, such a beast doesn't exist - which is , in a roundabout sort of a way, what I was getting at!!!

Alex,

would be interesting to know what dioptre strength you use?

Julian

The Canon focusses very fast - due to both internal motor and internal focussing (it has a lightweight optical system which is moved by the motor - the lens does not change its external dimensions as it is focussed), but can be a bit picky and will sometimes hunt - there's been discussion about this before on wetpixel, and I wouldn't be surprised if it is simply too fast for its own good under the low contrast conditions often prevalent underwater. It is optically superb!!!

 

<{POST_SNAPBACK}>

I had this problem with the 100mm on my D60, but it was reduced on the 20D, and since moving to the 5D I haven't noticed the problem of the 100mm "hunting" like it did on the cropped sensor cameras.

and the 5D is a fantastic camera - I'll try and post some high ISO filter shots I took if I get some time, but it's definitly a great tool for this.

I did just try a 20D with a 50mm Sigma lens and a D70 with a 50mm nikkor lense and saw no appreciable difference in autofocus speed.

I also tried a 105mm in the D70 vs a 105 sigma in the 20D and I think I got a closer focusing distance, hence able to fill frame better with a small object - the top of my house key.

Also, the 50 on the nikon seemed to give me a bigger object than the sigma 105, but of course I had to get a lot closer with the 50.

Sorry, I guess we are off topic here, but maybe we need a beginers forum for lenses.

- Beth