Have you seen the DOF chart for the 50-200?

[EMale]

Wow man... like at f3.5 @ 200mm @ 3m subject distance, the DOF is 2.2cm!

Is that right?

Here's the page:
http://www.olympus-esystem.com/dea/products/lens/50-200_28-35/index.html

Even if you stop it down to f11, DOF is still only 7.1cm!

200mm @ 5m @ 3.5 is 6.7cm, closed up to f11 is 21cm!

Is that right?

I have another quick query: using the teleconvertor with the 50-200. It gives you a combined aperture (fully open) of f4-4.9.

Is the DOF still the old 2.8-3.5 or is it now f4-4.9? I thought the teleconvertor just dimmed the light, not added DOF optical properties?

Thanks..

I guess I'm just a bit shocked at the DOF seeming so small. I thought I had more range than that?
--

 

[Ken Whelan]

That sounds right to me. What is your FOV at that distance ? Not very big I'd say.

kw

 

[EMale]

... it's 2mm!! two millimeters FFS!!

There's also a new (to me) phenomenom going on that as FL increases, with the subject distance remain the same, the DOF decreases!

Is that right?

3.5 @ 1.2mm subject distance.

The 50mm DOF is 3.2cm
The 100mm DOF is 0.8cm (8mm)
The 200mm DOF is 0.2cm (2mm)

Have I got this right?
--

 

[Kyle Jones]

Wow man... like at f3.5 @ 200mm @ 3m subject distance, the DOF is
2.2cm!

Is that right?

Yes, which makes the 50-200 a very tricky lens to use off a tripod. The swaying of your body can take your subject out of focus in many instances. The same for the swaying of their body, or in the case of birds and insects the small movements of the branches they are sitting on can make you lose focus. Continuous AF doesn't do so well tracking these small movements. When I first bought the 50-200 it took me a while to understand how careful you have to be when using the lens at the long end.

I have another quick query: using the teleconvertor with the
50-200. It gives you a combined aperture (fully open) of f4-4.9.

Is the DOF still the old 2.8-3.5 or is it now f4-4.9? I thought the
teleconvertor just dimmed the light, not added DOF optical
properties?

The teleconverter is taking the same light and spreading it over a larger area. Meanwhile, the circle of confusion stays the same size, so DOF is effectively decreased. So use the f4-f4.9 values for computing DOF.
--
Street: http://www.wonderworks.com/streetphotographydigest.html
Flickr: http://www.flickr.com/photos/kyle_jones/

 

[FFS]

There's also a new (to me) phenomenom going on that as FL
increases, with the subject distance remain the same, the DOF
decreases!

Is that right?

Yes. To maximize DOF, zoom in and then step away for framing.

 

[Big Ga]

Wow man... like at f3.5 @ 200mm @ 3m subject distance, the DOF is
2.2cm!

Is that right?

Hmmm.... the charts are probably describing spot on sharpness. I don't have the figures but I imagine the working 'useful' range is a fair bit bigger than that, however as you have noticed, it ain't THAT much!!

Its one of the reasons I've been put off getting the 35-100 because f2 at 100mm is going to mean bugger all DOF and you are going to have to be reeeeeal careful with your focusing. I fluff a lot of shots as is with the 50-200.

 

[Big Ga]

There's also a new (to me) phenomenom going on that as FL
increases, with the subject distance remain the same, the DOF
decreases!

Is that right?

Yes. To maximize DOF, zoom in and then step away for framing.

FFS ... are you sure this is what you want to say? ... FFS

 

[EMale]

Thanks all.

I hadn't gone into this before as those DOF tables just look so 'yuk' (too complex and off putting) so I saved them for a rainy day.

I'd prefer a diagram for this info but I suppose that'll be too complex to design and draw?
--

 

[EMale]

Yes, which makes the 50-200 a very tricky lens to use off a
tripod. snipped

It's quite staggering really!

I have another quick query: using the teleconvertor with the
50-200. It gives you a combined aperture (fully open) of f4-4.9.

Is the DOF still the old 2.8-3.5 or is it now f4-4.9? I thought the
teleconvertor just dimmed the light, not added DOF optical
properties?

The teleconverter is taking the same light and spreading it over a
larger area. Meanwhile, the circle of confusion stays the same
size, so DOF is effectively decreased.

'Decreased'? I thought f4-4.9 had more DOF than f2.8-3.5?

Do you mean 'increased'?

So use the f4-f4.9 values for computing DOF.

So Kyle, let me get this straight. I thought the TC just dimmed the light, you are saying it also adds optical geometric properties so that the aperture now acts like a wider/narrower aperture.

Or in laymans terms, you seem to be saying the TC, as well as dimming the light, also bends it so it diverges or converges so as to get a different DOF than the lens aperture alone.

Sorry.. I'm just getting it stright in my head. I suppose I'm asking 'how does a teleconvertor work?'
--

 

[EMale]

Wow man... like at f3.5 @ 200mm @ 3m subject distance, the DOF is
2.2cm!

Is that right?

Hmmm.... the charts are probably describing spot on sharpness. I
don't have the figures but I imagine the working 'useful' range is
a fair bit bigger than that, however as you have noticed, it ain't
THAT much!!

It's probably where I've been going wrong!

Its one of the reasons I've been put off getting the 35-100 because
f2 at 100mm is going to mean bugger all DOF and you are going to
have to be reeeeeal careful with your focusing. I fluff a lot of
shots as is with the 50-200.

I've always wondered about these wide aperture lenses and their seemingly 'lack of' DOF.

For instance. There's a guy trying to shoot a tree/landscape just as it's going dusk. Hiis camera is stuck with ISO100 film (it's his last roll) and he's using a long tele bcos there's a big river between them and he doesn't have a tripod.

Now he's gonna have to use his brightest long tele, isn't he? and use it at a suitably bright aperture! But that means his DOF is probably not wide enough for the tree, never mind the scene.

So I know the illustration is hypothetic and unlikely, I have a ??? behind it.

These bright lenses are great for making use of naturl light if your subject has narrow DOF, if you only shoot wider DOF, you may as well get the f4-5.6 lenses. So why do guys shell out so much moolah if the scenarios you can use them in are so few?

What's the point of F2 or 2.8 if you end up shooting at f5.6 or f8 anyway?
--

 

[Louis_Dobson]

when I see:

1) Newbies buying E500s and saying "where can I get a massive tele lens." These things are a PITA. If you get your rocks off pestering wildlife, well, OK, you need them, but normally the sensible way to react to being a long way away from a non animal subject is to move closer to it, not to bung a glorified telescope on the front.

2) Nutters complaining about 4/3rds DoF. The only times 4/3rds DoF is too MUCH is when you are using a kit lens at shortish focal lengths. Buy a decent lens and / or move away a bit and zoom. Otherwise the problem is not too MUCH DoF, but too LITTLE.

I seem to spend my life scrabbling for DoF.
--
http://www.flickr.com/photos/acam
http://www.pbase.com/acam/

 

[Louis_Dobson]

reasons I have no interest in the eye-wateringly expensive, hugely heavy fast zooms.

I was reminded of this when I bought the 50mm (hardly long) f2 (hardly fast) for portraits. The number of times I have used f2 for portraits can be counted on the fingers of one foot.

Here's just about the only time I have used f2 ( no choice, one handed, dim light, trying to control my git of a dog)



And even this DoF shot is f2.8



--
http://www.flickr.com/photos/acam
http://www.pbase.com/acam/

 

[G L]

DOF is just a matter of lens geometrie

DOF calculatotor:
http://www.dofmaster.com/dofjs.html

regards
G. L.

 

[rayk]

For instance. There's a guy trying to shoot a tree/landscape just
as it's going dusk. Hiis camera is stuck with ISO100 film (it's his
last roll) and he's using a long tele bcos there's a big river
between them and he doesn't have a tripod.

Now he's gonna have to use his brightest long tele, isn't he? and
use it at a suitably bright aperture! But that means his DOF is
probably not wide enough for the tree, never mind the scene.

At f2.8, with a 200mm tele, 50 metres away (big river), by my calculations he will have 5+ metres of depth of field. And given that he doesn't want the back of the tree sharp (because it is hidden behind the front of the tree), that gives him a 10 metre diameter tree. Good size tree, I would say, and all of what he can see sharp.

Sounds ok to me.

Ray Kinnane
Saga-shi, Japan

 

[Big Ga]

These bright lenses are great for making use of natural light if
your subject has narrow DOF, if you only shoot wider DOF, you may
as well get the f4-5.6 lenses. So why do guys shell out so much
moolah if the scenarios you can use them in are so few?

What's the point of F2 or 2.8 if you end up shooting at f5.6 or f8
anyway?

Because sometimes (and for some people this means MOST of the time in some scenarios)
1. a limited DOF is better than no shot at all because of motion blur
2. You manage to get focus because of the extra light
3. The 'look' you get with the limited DOF is sometimes what makes the shot

4. You can always stop down a large aperture lens to a smaller one. Try going the other way!

If you NEVER shoot wide open and your (cheaper) lenses give good quality at the ranges you use, then yup, no point getting the f2/2.8 monsters. A lot of people would be buggered without them though.

 

[rovingtim]

When I'm doing weddings, my problem is never not enough boke (I'm spelling this wrong, aren't I?), it is almost always not enough DOF. Like Louis bird shot above (loved that, by the way, especially with his comments) unless you are constrained by a small space, getting good boke really is simply a matter of knowing your equipment. I get so tired of people with bigger sensors going on and on about how they can get part of the picture out of focus. It really is full frame rubbish.

Bigger sensors may have advantages, but DOF is rarely one of them, in my opinion.

--
http://photobucket.com/albums/y116/TGooding/

 

[rovingtim]

I should have read this one before I posted ... so all I can say in response is YES!
--
http://photobucket.com/albums/y116/TGooding/

 

[Louis_Dobson]

I'd love to have a set in the boot of the car for those rare occasions when I think I might need them (yesterday, for example).

If I needed them a LOT then I'd be questioning if 4/3rds was the right format for me.

Look at it this way:

If the same manufacturer using the same technology creates two sensors of the same MP value, one 35mmFF and other 4/3rds, the 35mm will be about two stops faster for the same noise.

So to get the same shutter speed and FOV that lens has to be double the focal length but can be two stops slower.

35mm also gives one stop less DoF (IIRC) so the resulting lens has, for the same shot, 1 stop more DoF.

Or, to put it another way, I think I'd rather have a 35mm camera with an f4 28-70 and 70-200 than a 4/3rds f2 14-35 and 35-100.

I'm not sure, but I reckon the 35mm setup would actually be lighter. It could catch the same movement. And you could add a low light lens (like the 30mm f1.4) and practically work in the dark.

In my own case, I'd rather have 4/3rds and the slower mid line zooms. The resulting kit is eminently portable, fast ENOUGH for me, and has entirely adequate DoF characteristics. All I ask for now is a high-ish resolution fast-focusing camera to put on the back of 'em.

--
http://www.flickr.com/photos/acam
http://www.pbase.com/acam/

 

[rovingtim]

A lot of people would be buggered without them
though.

buggering people again.

 

[EMale]

You buy (spend a lot on) a bright aperture lens. Why? Bcos of the bright aperture!

But you'll probably end up hardly ever using that expensive aperture bcos the DOF is too narrow.

I'm just mentioning the contradiction (aloud)

I know why guys buy them and that you can shoot a f2 lens at f4 but not vice versa.. but you pay a fortune for a 300/2.8 but chances are, you'll end up shooting at f5.6 anyway.

And there may come a time when the guy needs to shoot his lens wide open for the brightness qualities inherrent in it yet he needs the DOF of the dimmer apertures!

I guess it all boils down to bright lenses aren't the 'cure all' their price tag suggests!

[The pennys dropped! I just needed to think something thru. To put bright aperture lenses into the order of my world! I know where they fit, etc.. if you follow me? probably not! LOL! I know what I'm on about! ]

Reading this back and you all probably won't have a clue what I'm on about! Soz! I'll try to explain it.

Although I knew the following, I hadn't sorted it out into how I percieve 'my world'. Anyway, it all boils down to a £4,5000 300/2.8 is a more capable lens than a f4 version bcos you can do everything the latter does with the former.. but with 'more'! LOL (clear as mud!) Hence, you pay an extra £4,000 for the 'more'!

Jeez.. I'd better go back to bed as I'm talking broken biscuits this morning!

--