Upgrading to Canon! Lenses?

[inTempus]

I didn't say "always" or "all the time."

Looks to me like "can cause" and "causes" can be used almost interchangeably in English (in certain instances):

BBC News | Health | Ecstasy causes brain damage
Oral Sex Causes Cancer, New Study Finds
Quitting Smoking: Why To Quit and How To Get Help - National Cancer Institute


You're arguing just to argue. Or at least, that's what it looks like to me.

Perhaps I misunderstood this statement:

Mr. Logic
Sure, if "getting the shot" is what counts then anything is justified. "f/8 and be there," crazy high ISO, and yes......... the focus and recompose method. I was aware.

I don't need to shoot at f/8 to achieve flawless focus using the method. I thought the implication was that such a method was only practical when using a small aperture. If I misunderstood you, then pardon me and I apologize.

My only point is that the focus and recompose method is far from useless. When shooting my 5D2 I uses it almost exclusively and I rarely miss focus. I'm forced to use the method obviously given the limitations of the camera. But I've become so comfortable using it that I also on occasion use it on my 1D.

If I can shoot roughly 80% of the time using the method and achieve proper focus, I see no issue with using the method.

But for action like sports or for macro work with a razor thin DoF (to name a few scenarios) it would be less than ideal, obviously.

So, we're probably in agreement and as such I'll drop the issue in this thread.

 

[MrLogic]

Yep.



Re: "f/8 and be there"

I only mentioned it as an example of another "trick" when "getting the shot" is crucial. Nothing more. [/tangent]

 

[MrLogic]

How does the camera know what to focus on if there are lots of potential focus points?

Here's a good read:

LensRentals.com - How Autofocus (Often) Works.

 

[Derrel]

These samples are far from useless. You're just mad because once again I'm right and you can't stand it.

These shots demonstrate quite clearly that in focus shots can be had using the method described. Yes, DoF field is on my side... that is my point that you stumbled into. LOL

I never said it was ideal. But contrary to Mr. Logics assertion that using this method yields out of focus shots and can't be trusted, it clearly doesn't if you know when it's safe to use.

There are plenty of situations where you wouldn't want to use this method as I've clearly stated before.

So, once again your rambling non-sensical post has absolutely no merit.

To recap since you have a hard time following simple conversations:

Assertion: you can't achieve an in focus shot using the focus and recompose method.

Reality: you clearly can if you know when it's safe to use it as I've clearly demonstrated.

Now, unless you can prove using this method always causes errors in focusing, kindly move along as you're wasting my time with your non-sense.

Hilarious! You think you are "right"? and that I am mad? No, I'm just pointing out your technical errors and lack of experience. The on-line depth of field calculator is a simple, objective measuring device. Your sample photos are inappropriate examples illustrating the concept. I'm not mad, but I am amused. When I see incorrect technical information on-line, or bad technique being passed off on-line by a relative newcomer to photography, I will usually make a post to correct said incorrect technical information or bad technique advice.

Using a smaller aperture like f/5.6 on a static subject is one way to safely overcome focusing system errors, subject movement, etc,etc. However, when the lens is longer in focal length, like say 200 or 300mm, or the lens aperture is wider, like say f/1.8 or f/2, and there is not a FOOT, to a FOOT AND A THIRD of depth of field to "cover" the error, which can easily be 4 inches from only 10 feet away (measured), then focus-recompose will lead to many,many out of focus photos. This has been a well-known problem ever since Leica users got the first high-speed short telephoto lenses back in the 1930's; focusing systems that focus in the ***center*** of the image or viewfinder area do NOT measure the correct distance to points that are outlying, which if you have a pencil and paper, actually measure out to be **farther away**. Also, and this is something a newcomer might not be aware of, but many faster lenses do not have a flat field of focus, but suffer from curvature of field,especially when they are used wide-open or nearly so....

So,once again, decades of experience on the part of millions of fast-lens shooters, and knowledge about real-world optics, trump a couple of quick Halloween snaps of a kid sitting down indoors...the fact is focus-recompose has very real limitations, and your f/5.6, 70mm, static subject photos do NOT address the issue in any meaningful way. Sorry, man.

 

[mhafweet]

Thanks Derrel...

Everybody else, just stop it. You're being ridiculous.

 

[inTempus]

I'll leave the rest of your post alone as you flip-flop between agreeing with me then running off on 300mm tangents. I'll just say "thank you" and move on.

I will, however, ask for clarification on your "bad technique" comment. Tell me Derrel, how would you have focused in dark conditions using your 5D you claim to love so much? Would you have used an outer AF point? Perhaps you would just shoot everything centered?

 

[ironsidephoto]

You realize that you're going to be spending over $4000 to make this switch, right? You can't get an expensive body like that and skimp on the lenses...If I were you I'd get a D300s and some nice lenses (70-200 2.8, 24-70 2.8, etc) instead of the D700/5D2 and cheaper lenses. The lenses will last you years, but the bodies will be replaced much sooner.

 

[shaunly]

You realize that you're going to be spending over $4000 to make this switch, right? You can't get an expensive body like that and skimp on the lenses...If I were you I'd get a D300s and some nice lenses (70-200 2.8, 24-70 2.8, etc) instead of the D700/5D2 and cheaper lenses. The lenses will last you years, but the bodies will be replaced much sooner.

This may be true for other bodies, but let me ask you this. Have you ever shot with D3/D700? I can assure you that even though the D3/D700 is over 2 years old, it's still the top of it's class and will still be for years to come. Until the day a cheaper DX body has better IQ/DR/ISO level and AF system, the D3/D700 will always be better.

 

[ironsidephoto]

I never said the D3 and D700 weren't better--that's absolutely true. I said that she should invest in good pro lenses instead of a pro body at this point. Coming from a recent graduate turned aspiring pro, I think she should spend $1000 less on the camera body (but still be at the D300s pro-sumer level) and get a better lens or two instead. In fact, I have a D300s and am buying a used D700 next week, but I also have pro lenses already.

 

[shaunly]

This is my recommendation. A D700 with a 24-120mm f/4. That would be a great all around solution for wedding and PJ.

 

[prodigy2k7]

...I'd get the Nikon D7000. It's great for what you do and you can keep your current lens and put the money on new faster primes/zooms.

Except that it's still consumer-level build-quality. Plastic chassis, lack of weather-sealing, etc. I would strongly recommend going for a higher-end build-quality body.

I'm not sure about the "chasis", but its worth mentioning that it has a magnesium alloy body "shell". It may just be the back and top (and bottom?) but not the front with this shell. Its better than all plastic though.

 

[Sw1tchFX]

I cannot use the focus and recompose method when I shoot with my 24mm or 50mm lenses at f/1.4-f/2.8. the DOF, even with the 24mm, is way too narrow to consistently get sharp results.

 

[usayit]

I'm no math wiz.. but.. something to consider.

Assumptions:
* 35mm frame
* recompose to 1/2 the Field of view at a specified focal length
* 10 meter subject distance
* Focal length of 24mm
* Aperture of f/1.4

Fov = 2*arctan(d/2*f)

Fov = Field of view
d = diagonal dimension (35mm for full frame)
f = focal length.

Let's just start at a 24mm focal length

Fov = 2 arctan(35/2*24)

Fov = 72.2 degrees @ 24mm. As per assumption, Frecompose = 72.2/2 = 36.1 degrees

Next... Focus plane error when camera is rotated during recomposition (Frecompose).

E = a - a * COS (t)

E = focus error (behind subject)
a = distance to subject
t = degrees rotation.

Let's just take a subject distance of 10 meters with a rotation of 36.1 degrees

E = 10 - 10 * COS(36.1)
E = 1.9 meters


Now let's lookup the DOF for the same parameters (I use dofmaster.com online calculator)

DOF in front of subject = 4.2 meters
DOF behind subject = 27.7 meters

If my calculations are correct, 1.9 meter focus error should still be within DOF for a 24mm focal length at f/1.4 at a subject distance of 10meters.


I ran through the calculations for 50mm at f/1.4 as well (same 10meter subject distance)
E = 0.15 meters
DOF in front of subject = 1.44 meters

yup still ok...

How about a super fast telephoto 200 f/1.4
E = 0.038 meters
DOF in front of subject = 0.1meters

yup still ok...


Ok ... so 10 meters might be too far.. Lets try a subject distance of 5 meters

24mm Error = 0.95 meters
DOF in front of subject = 1.34 meters.

50mm Error = 0.28 meters
DOF in front of subject = 0.39 meters

200mm Error = 0.019 meters
DOF in front of subject = 0.03 meters.


The way I see it, your are fine until you enter in to the subject distance of 3meters or less. Of course doing this on paper is different than real world use since there are so many other factors involved (CoC for different formats for example).

These are just numbers... whether or not it matters enough to worry about is a personal decision. (I'll keep mine to myself)


Then again.. I suck at math.. so if I made a mistake please point it out.

 

[Derrel]

Theory is nice. Great calculations,usayit. Bravo! Wonderful paper calculations, assuming a perfectly static subject, one that does not move toward or away from the camera, and assuming 100 percent focusing accuracy, and assuming NO curvature of field from the lens off-center, and assuming that the photographer is locked down on a tripod, and the composition is fixed (ie, not fluid), with absolutely NO subject movement. Lots of assumptions. Solid math, sketchy application to the real world.

Great math. At long distances. But as you say, under 3 meters theory becomes very tenuous,and practical considerations may become huge obstacles to achieving usable pictures.

What do you compute the average speed of a walking bridesmaid at during the processional to be? How far outside the DOF band will one stride leave you sitting, out of focus? With basically **NO** peripheral AF points, the 5D will force the photographer to rely upon center AF...the single,individual AF point on each side of the diamond array, on the periphery of the 5D F pattern, are both quite weak,and simply can NOT achieve AF lock the way, say, a 5-year-old Nikon D2x can on the edges of the frame. Same thing with the 51-point Nikon crop-body cameras; their AF points go basically from edge-to-edge of the entire frame, and can be grouped, plus they are color-sensing as well.

Oh, and the other thing is the 5D's wonderful "ehhh!ehhh!ehhh!ehhh!" focus hunting behavior....that is so,so fun! When a 5D cannot find a focus lock, it becomes confused, and recovering can take quite some time.

Your math is great. It looks like you do not suck at math! The heavy-duty math is wonderful, but does not really apply to the original poster's question. As I said...figure out the speed of a moving bride,re-compute your calculations, then get back to us and impress us all with your math abilities.

As the Original Poster wrote, "I'm shooting weddings for $$, but my ultimate goal is international photojournalism. I'm currently volunteering for my school's newspaper, shooting sports and such. I'm a student, so I don't have an endless pocket here, but I want to invest in some good glass that can be resold when I'm done with it. " I suppose if you live long enough, you MIGHT never see a 5D-II at a sporting event....you know....where focusing is a huge deal, and you often have only one,brief window of opportunity to get the shot.

Math is wonderful, it really is. But, unfortunately, all clients and editors care about are good, in-focus photos. I love to read calculations about static subjects, perfect AF systems, and .1 meter DOF bands and then imagine how that might apply if I had to center-focus and recompose on a hurdler in the left-hand lane running in the lead, coming right toward me with my 200mm f/2 wide-open. Seriously, for "action" work, the 5D is left in the dust by a several better action cameras.

 

[usayit]

The key here is "Personal Decision"

Velocity = distance / time

Whether a particular person is a fast or a slow runner, the formula doesn't change... the outcome does. The faster or slower the bride... the equipment.. the reaction time of the photographer... As you pointed out, there are always variables .... variables unforeseen.



Hence..

If I can shoot roughly 80% of the time using the method and achieve proper focus, I see no issue with using the method.

These are just numbers... whether or not it matters enough to worry about is a personal decision. (I'll keep mine to myself)

That's the beauty of human skill and intelligence... If everything fit nicely into a formula, then life would be boring and photography would be as easy as aiming at the toilet.


Still the same old place around here... eh.