"USM" or "EF" Lens?

I have been contemplating getting either the Canon Rebel or the Nikon D70. Currently the Canon is less expensive. However at B&H Photo they offer the Rebel with 2 different lens one is with a USM lens, the other EF lens and at different prices. So being a newbie with lenses if I understand it correctly the USM lens is smaller and focal length changes on the inside without changing the length of the lens whereas the EF changes length? If that is the case would the USM be the better choice when housed.

Thanks alot.

Wendy

All Canon Autofocus lenses are EF Lenses, USM stands for Ultrasonic Motor, the difference between a USM Lens and non USM is the motor design used to drive the focus mechanism. Typically a USM Lens will be quieter and faster than a non USM Lens. The two "Kit" lenses for the Digital Rebels (300 & 350) are the 18-55 and the 17-85, if the budget allows the 17-85 USM IS (Image Stabilizer) Lens is the better choice. But you will certainly get good results with the 18-55 as well.

When the length of the lens does not change during focusing, that's called an "internal focusing" lens. It varies from lens to lens and not all USM lenses are internal focus.

Cheers

James

Also, keep in mind that the the zoom factor will alter the length of the lens as well. Nothing in Canon's info on the 18-55mm USM lens indicates that it is internal focusing. The non-USM kit lens I received is not internal focusing either. Neither version of this lens is very expensive, although I'm sure the USM version is quieter and should autofocus a bit faster. The 18-55 is substantially smaller and lighter than the 17-85mm, if that's a consideration.

The Nikon kit lens is AF-S, which is about the same functionality as USM (I think), and that's an advantage to Nikon. I have this lens; it's a good about-town lens. It is quick to focus in most (moderately well lighted) situations.

Chris

Thanks for the clarification, told ya I was a newbie!!! I am in such a quandry about upgrading my camera. My Oly 4040 still takes great pictures but it is starting to show its age, I have cracked the LCD diagonally on a chair lift, the readout on top of the camera (especially number of images left) doesn't show all of the pixels and some of the other functions that I have turned on show partial pixels...(Ok I could turn the info on in the lcd but I don't. So my next step is to consider an upgrade. Reading everything about the DSLR's vs the pro-consumer digital cameras the DSLR seem to be alittle more intimidating to get started with and costly. I am eyeing (somewhat) the new Oly 7070 (familarity) but for a few bucks more I can get a better camera. Oh well....I'll let my tax return continue to burn a hole in my pocket until I can decide...[i know the latest rave is the fuji 810-but honestly-looking a pictures of the camera it does look ugly! okay I'm being vain now.

Thanks everyone.

Hi Wendy,

I feel for you right now, I've just gone through the whole indecision thing of not just deciding whether to upgrade, but then deciding what to go for, so many opinions out there, so many choices!

Last week I received my new baby, a Canon 350D (Digital Rebel XT) with the kit 18-55mm, Canon EF-S 10-22mm USM and a 1 Gig Lexar card.

I've moved up from a Nikon Coolpix 5000 which I had for a couple of years.

Some wide natural light shots that lacked the detailed I wanted, pushed me towards dSLR.

I decided I wanted that quality over the two big strength's of the Prosumers, the all-in-one lens flexibility and the ability to use the LCD screen for composition (do you know that on a dSLR the LCD is only for review, you use the viewfinder for composition?).

You can imagine then why I was so happy when I tried my new 10-22 and it focused down to 10cm from the tip of the lens, 12 cm for the 18-55

I believe I have completed my internship with a Prosumer camera and now, upgrading to a dSLR, I reckon I'll be a better photographer for that internship.

It sounds like your in a similar position.

The 350D appealed over the 20D because of two primary reason's, dollar's and size, I need the saved dollars for lens etc and, I hate big camera's. And by all accounts, there isn't a significant image quality difference between these two camera's if any at all.

The Canon appealed over the D70 because of size again, but also because of reported better performance on higher ISO (natural light at depth), and because of 8mp, ie better crop options.

Already I'm thinking I should have got at least a 2GB or bigger card as this camera produces 6MB to 8MB Raw files so only ~120 Raw shots on a 1GB card.

Only thing that may annoy me underwater is the aperture changing which is a "hold button and turn dial", fortunately for shutter, its just the dial. That said, I rarely changed aperture on the CP5000.

I'm blown away with the near instant auto focus and shutter and know I'll be using the continuous shooting on moving subjects.

I presently do a lot of cropping , I think this camera will help me reduce that because I need to look through the viewfinder and will pay better attention to composition.

Yes, delighted I've gone dSLR and Ike can't make his housing for it quick enough for me!!

Looking forward to getting a hands-on look at the new Canon 60mm Macro and if that works out then my u/w lens suite will be complete.

Go for it Wendy!!!!!!!

Cheers,

Aengus

PS,

A dive buddy of mine just upgraded to a Coolpix 8400 from a CP5000. He is very proud of the fact he uses a Prosumer camera and gets such good shots (and so he should be), but I'm going to give him 3 months......before he dumps it and goes dSLR!

ooooh, my inbox is filling with abusive emails from him already......

The photos your buddy took with the new Coolpix 8400 are awesome, and I don't believe he has gotten to the optional dome port and wide angle lens yet. His results:

http://www.daveharasti.com/Queensland/coralsea/index.html

Touché Ike,

Now I'm definitely in big trouble

Just to emphasis for newbie’s, Wendy I think you should go the dSLR rather than the 7070 because you appear to have the experience with the Oly 4040.

For me, starting on a compact (S40) then going to a Prosumer (CP5000), and now a 350D, I feel I'll get a greater return on the dSLR.

At this stage (very limited u/w dSLR experience), I would be very slow to recommend a dSLR to a new U/w shooter. IMHO, despite a couple of flaws, for a new starter I would be inclined towards the CP8400.

Aengus

Hi Clownfish,

I was in a similar situation to you as I had the Oly. C-3030 in a Light and Motion housing with wide angle lens and felt that I was definitely taking a liking to U/W photo and was ready to upgrade, but to what? After much deliberation, I decided on the 20D in an Ike housing with the Canon 10-22 lens. Everything has arrived but I have yet to get it underwater. I am quite certain that the DSLR system is going to be something I will grow into as my skills increase. Already, the abilities of the DSLR have exceeded what I could achieve with my C-3030. Only you can decide what is best for you but I would encourage you to look at an SLR.

My experience with the 20D has only been on land so far (winter sucks!) but now that I am getting comfortable with the DSLR I can't wait to get under water. Reading posts from wetpixel has helped me with my decision.

I'll be interested in hearing what you end up deciding to go with. Keep us posted.

Cheers,

Joe Tobin

Thanks everyone, your helpful suggestions. I am confident that common sense will prevail and I will end up buying the dslr. Now the next question Nikon D70 or Canon Rebel, and who makes the best compact housing for the either camera. Some of the housings I have seen appear quite large and bulky. One question...how do you shoot macro if you can't use the LCD to set up your shot?

Thanks again.

Wendy

I had the same concern switching to dSLR, using a viewfinder.

Now I cannot even imagine using an LCD for composition and focus. The viewfinder IS the right tool for the job. The LCD is for after shot decisions, and works well for that.

You will get a MUCH BETTER idea of focus through the viewfinder.