100-400 or 1.7x on 70-200 f/2.8IS?

[RichNY]

After reviewing the metadata from a photographer who shot the last equestrian event I learned he was shooting with a Canon 70-200 f/4 and kept coming up really short.

I really was hoping that a new 100-400 would be released but since that didn't happen am I better off buying a current one for the next 6-12 months or trying 340mm with a 1.7x Solignor extender?

If I do purchase the 100-400 would it be fare to say that I'd never use an extender on the 70-200 (unless I'm traveling light) and any extender I purchase would really only be used if I want to go longer than 400mm for non-sports shooting since it will be manual focus only?

[forno]

Whats the Soligor worth, might be worth while buying it and seeing how you go??

[ReF]

i think the big question here is whether the 70-200 + 1.7x soligor would focus fast enough for the kind of action you'd be shooting. might wanna try it out like forno said. i had been planning to do the same when i get a wider aperture tele.

[RichNY]

i think the big question here is whether the 70-200 + 1.7x soligor would focus fast enough for the kind of action you'd be shooting.

I totally forgot about that. Per POTN-focusing speed would be reduced somewhere between the 50-67% of a 1.4x and 75% of a 2x.

[RichNY]

I just realized what's needed in this field- a zoom extender. It would be great to be able to get an extender that went from .5 to 1.5x focal length and then be able to shoot with a prime lens. Even w/o being able to reduce the focal length it would be really convient.

A 300mm prime would become a 150-450, a 400mm would become a 200-600.

[DonSchap]

You know, Rich ... you could take 5 minutes and look at a TAMRON SP AF 200-500 f/5-6.3 Di LD on your EOS 30D. It does provide some darn decent zoom and a nice, sharp image after you pull the trigger.

No, it is not IS, so a tripod or brace would be a nice addition, you'd have more reach and you wouldn't be duplicating your lower end. You'd have the AF you crave and save a couple of bucks, also.

Also, it's not a heavy tele-prime ... so you won't have to limp to location.

20883
20882

Acch, you have to appreciate it first ... so take a peek. ;)

[coldrain]

I totally forgot about that. Per POTN-focusing speed would be reduced somewhere between the 50-67% of a 1.4x and 75% of a 2x.
Focussing speed does not get slower like that. It can GET slower when the light/contrast is low. But if there is enough light, the AF speed is only dermined by the lens motor.

**edit: yes, forno, I did mean lens motor :D

[forno]

Focussing speed does not get slower like that. It can GET slower when the light/contrast is low. But if there is enough light, the AF speed is only dermined by the camera motor.

Do you mean the lens motor?

[RichNY]

Coldy- I got my info from the POTN sticky on teleconverters:

4. Additionally, EF Extenders reduce lens drive speed. The EF 1.4x or 1.4x II reduces lens drive speed by approximately 50~67% depending on the lens in use.
The EF 2x or 2x II reduces lens drive speed by up to approximately 75%.
This speed reduction gives the AF system more time to detect focus. This can be helpful since the depth of focus is reduced with the longer effective focal length and the chance of defocus increases. However, the reduced tracking speed and smaller maximum apertures caused by the use of Extenders can be a disadvantage with fast moving subjects, particularly in low light.

Are you suggesting that they are incorrect or am I misunderstanding something?

Full thread at http://photography-on-the.net/forum/showthread.php?t=41922

Don, I think that the ability to handhold is going to be quite important for my use of a longer lens.

[adam75south]

i dunno, i'm almost convinced on the bigma 50-500mm. only 999.

[coldrain]

Coldy- I got my info from the POTN sticky on teleconverters:

4. Additionally, EF Extenders reduce lens drive speed. The EF 1.4x or 1.4x II reduces lens drive speed by approximately 50~67% depending on the lens in use.
The EF 2x or 2x II reduces lens drive speed by up to approximately 75%.
This speed reduction gives the AF system more time to detect focus. This can be helpful since the depth of focus is reduced with the longer effective focal length and the chance of defocus increases. However, the reduced tracking speed and smaller maximum apertures caused by the use of Extenders can be a disadvantage with fast moving subjects, particularly in low light.

Are you suggesting that they are incorrect or am I misunderstanding something?

Full thread at http://photography-on-the.net/forum/showthread.php?t=41922

Don, I think that the ability to handhold is going to be quite important for my use of a longer lens.
The Canon extenders actually do certain things and do have influence, but other teleconvertors are not noticed by either the camera nor the lens.
However, I do still find this lowering the AF speed of the motor story a bit odd, since the speed of the motor has nothing to do with how focus is determined.

So.. i am sceptical.

[cdifoto]

The Canon extenders actually do certain things and do have influence, but other teleconvertors are not noticed by either the camera nor the lens.
However, I do still find this lowering the AF speed of the motor story a bit odd, since the speed of the motor has nothing to do with how focus is determined.

So.. i am sceptical.

Gee if that isn't a load of crap I don't know what is. That's like saying the weight of a car has nothing to do with how fast it can go.

Teleconverters DO slow autofocus down Rich. Even in broad daylight. A lens with its native glass and motor designed for that glass is always going to be faster than that same lens with more glass added to it. The actual speed of the motor and the detection of contrast go hand-in-hand. That's why there are some lenses that are better than others in all focal lengths and brands, with tcon and without.

All the "theory" in the world spouted by Coldy doesn't change reality.

[coldrain]

Very nice post again, Don.

And a lack of understanding how AF actually works too.

More light does NOT mean faster AF. Low contast means harder to determine AF, yet does not influence motor speed.
Motor speed does also not influence AF accuracy.

And this is how AF DOES work, Don:

The Camera (not the lens) checks contrast. One thing to remember: the camera can NEVER see when something is sharp. It just can compare contrast with last reading. Whether that is the sharpest will always be unclear.
So... camera looks, detects some contrast "value". Tells lens to move the motor a bit (it is upto the lens software/electronics to determine how much).
Camera AF sensor takes a contrast reading again. Is it less? Lens moved the wrong way. Is it better? Lens moved the right way. Can't be determined? Lens will hunt.
So what is next? Camera tells the lens to move again in determined direction. If it went in the right direction, you now can actually tell a bit about focus. If the contrast reading now is better, we are still moving in the right direction. If the contrast reading is worse, we have overshot focus.
If we overshot focus, the camera tell the lens the readings, how much the motor should move back over the last two points to achieve focus.

That is how AF basically works. And where do more or less accurate lenses differ? In the motor and calibration to the camera. When the camera tells the lens to move a certain percentage back, derived from the last few contrast readings, the lens is on its own, and if the electronics/motor is in very precise or the motor is not calibrated, a lens will be inconsistent with focus.

Notice how in the whole algorytm motor speed does not play a role? Good, I noticed that too. The only thing that plays a role is in how big a steps and how many steps are taken in the contrast readings and how big the steps are the motor takes each time.

[coldrain]

And on a sidenote, I just now again tested focusspeed on my 70-200 f4 L with and without 1.7x TC, and there is NO change in focus speed at all as long as there is contrast. On low contrast of course with TC you notice some hunting, as expected.

Same with the 90mm macro and with the 18-50 f2.8.
Motor speed is NOT influenced.

[cdifoto]

Right Coldy, right. Everyone else is wrong but you're correct. As usual.

[coldrain]

Right Coldy, right. Everyone else is wrong but you're correct. As usual.
No, you refuse to think about it for yourself as usual, or even put your TC on a lens and actually VERIFY for yourself that really focus speed of the motor does NOT go down with enough contrast.

Because on some forum somewhere you just happend to read something else, or just because it is me typing the above.

But that does not all of a sudden make what I told you on how AF actually works wrong.

And about the 75% figure that POTN person came up with: The only thing that person did is look at how less light gets to the AF sensor. 2 stops is 75% less light. Does that say anything about how well the AF sensor is able to measure contrast values? No of course not. Do not tell me you need a clear cut black/white contrast over a perfect horizontal or vertical line just to be able to read a contrast value. Because only if that is the case the simpleton theory of "with 2x TC you have 25% of the AF performance/speed" would make any sense.

The only thing it means: you have 75% sooner that contrast gets lower, so you will notice hunting sooner. That is all it means.

Just put your Kenko on any lens, and notice that the AF speed of the lesn motor with good light does NOT drop down to 50%. Not a hard test at all.

[cdifoto]

No, you refuse to think about it for yourself as usual, or even put your TC on a lens and actually VERIFY for yourself that really focus speed of the motor does NOT go down with enough contrast.

Because on some forum somewhere you just happend to read something else, or just because it is me typing the above.

But that does not all of a sudden make what I told you on how AF actually works wrong.

And about the 75% figure that POTN person came up with: The only thing that person did is look at how less light gets to the AF sensor. 2 stops is 75% less light. Does that say anything about how well the AF sensor is able to measure contrast values? No of course not. Do not tell me you need a clear cut black/white contrast over a perfect horizontal or vertical line just to be able to read a contrast value. Because only if that is the case the simpleton theory of "with 2x TC you have 25% of the AF performance/speed" would make any sense.

The only thing it means: you have 75% sooner that contrast gets lower, so you will notice hunting sooner. That is all it means.

Just put your Kenko on any lens, and notice that the AF speed of the lesn motor with good light does NOT drop down to 50%. Not a hard test at all.

Hmmm. You think I actually did not own and use a TC? :rolleyes: I do have personal experience Coldy. And since when did I introdouce mathematical values when I said AF performance drops? I did not say how much performance you lose. Stop with the BS Coldy. It's old. It's tired. It's worthless.

I'm not arguing you anymore. I'm going to begin reporting you (call me a tattle-tale if you wish) because this just isn't worth it.

[DonSchap]

Don, I think that the ability to handhold is going to be quite important for my use of a longer lens.


You're right ... pitch the EOS 30D for the long stuff and get a SONY to attach to the TAMRON 200-500mm f/5-6.3 ... ahhh, "instant IS", just add a lens. ;)

What a problem-solver it is, eh?

Shake, shake, shake ... Shake, shake, shake ... Shake your body ... :cool:

My apologies to K.C. & the Sunshine Band (http://en.wikipedia.org/wiki/KC_and_the_Sunshine_Band)

[RichNY]

I slept late this morning and missed this optical feud:) Thank you for both sharing your input and suggestions to me thought its not worth making this a fight to the death!

At 8:45 I woke to my phone ringing from a person I emailed about purchasing their 100-400 lens. By 9:15 I purchased it!

The only issue I'm now second guessing is having traded my 3 month old 85 f/1.8 as part of the deal for only $300. I think I did this to bring the cost under $1000 so I wouldn't begin asking myself why I'm spending so much on photography and I'll probably repurchase this lens again the next time they have rebates on it.

[DonSchap]

Way to go, Rich.

Personally, I would have had a hell of a time deciding to go that way. I'm not big on slide-zoom. It has issues in the rain.

May this lens serve and please you, as all lenses should. :D

[cdifoto]

Way to go, Rich.

Personally, I would have had a hell of a time deciding to go that way. I'm not big on slide-zoom. It has issues in the rain.

May this lens serve and please you, as all lenses should. :D

It's not like Bigma or that Tamron you have doesn't have the same/similar issues in the rain. They all have extending barrels. The only difference is how you extend it. Twist or push/pull.

[RichNY]

Way to go, Rich.

Personally, I would have had a hell of a time deciding to go that way. I'm not big on slide-zoom. It has issues in the rain.

May this lens serve and please you, as all lenses should. :D

Thanks Don. Buying used I can always flip the lens for less than the cost of renting it if it doesn't meet my needs long term. I didn't have the ability to wait for a newer version and there were no other zooms in that focal length with IS for hand holding so it seemed the right way to go.

I'm not too concerned about issues in the rain as I'm not planning on shooting in the rain. Unless I'm out sailing I'm the first one you'll see heading for weather when the weather turns. ;)

[cdifoto]

I don't mean to keep things going but I have a question for Coldy:

If a Tcon doesn't affect AF performance, why is it that I can shoot a soccer game, in broad daylight, with my bare 70-200mm f/2.8L and 30D with very few AF problems, but once I mount my Kenko 1.5x I cannot get a fast enough AF to lock onto any successful shots?

I would really like to hear a good explanation for that. Now this is the game exact game mind you. No change whatsoever except the Tcon attached.

[adam75south]

rich i can't wait to see some hand held test shots w/ slow shutter speeds(slow for 400mm at least).

[ReF]

I'm with cdi on this one. i don't care what ideas someone has about an AF system in the lens or camera that he didn't design. The manual that came with the canon TC (it's the same manual for both 1.4x and 2x) states that AF will slow down with the TC attached. in actual use there is a difference in AF speed. i'm not so sure about the 50-67% and 75% figures though. it doesn't feel that slow with the 1.4x on the 70-200 cuz i can still shoot fast action with it (even with the f4 version on a heavy overcast day). but i'm also not going to go out and try to guestimate a numerical value for just how much the difference is :rolleyes:

can't say much about 3rd party tc's cuz i've never used one.

[DonSchap]

... can't say much about 3rd party tc's cuz i've never used one.

I'll drop you a note when I use my TAMRON SP 1.4x with the EF 70-200mm f/2.8L IS USM. See if I can detect a variation of significance from one extreme to another. :cool:

[RichNY]

rich i can't wait to see some hand held test shots w/ slow shutter speeds(slow for 400mm at least).

Do you mean slow because of the max. aperture v. a prime?

I'm imagining I will have to be shooting at ISO 800-3200 since I'm going to need a fast enough shutter speed to stop action. Of course the next step Canon leads you to is a 1Dwhatever to get the better high ISO shots w/less noise. Does this never end?

[cdifoto]

Does this never end?

Heck no. Just when you think you have it all, Canon announces Happiness Mark II - with weathersealing. :eek: :D

[coldrain]

I don't mean to keep things going but I have a question for Coldy:

If a Tcon doesn't affect AF performance, why is it that I can shoot a soccer game, in broad daylight, with my bare 70-200mm f/2.8L and 30D with very few AF problems, but once I mount my Kenko 1.5x I cannot get a fast enough AF to lock onto any successful shots?

I would really like to hear a good explanation for that. Now this is the game exact game mind you. No change whatsoever except the Tcon attached.
I never have said that a TC does not affect AF performance. Lower light always affects AF performance. You get half the light with your Kenko, so with it you get AF locking misses sooner than without.

That is not in dispute, it is why you can't really AF behond f8 in the first place. But, a TC does not make motor speed slower. It is just as if you are taking photos in darker weather, that is all.
Your camera does not know there is a TC there, and your lens does not know there is a TC there. Just notices less contrast due to less light. Just as AF gets worse when you are in poor light, focus will get harder to determine when the contrast sinks below a certain value.
That still does not mean that attaching a TC lowers the speed from the AF motor, you can try that yourself. The speed stays the same, and with enough contrast to begin with the AF focus time stays the same too.

What Canon Extenders do is a totally different story though. For one they seem to tell the camera there is an extender attached. They block lenses that would go over f8 from AF-ing in the first place. And they seem to do more too, as the AF success rate with a Canon 1.4x extender actually is LOWER than the success rate with your kenko "1.5x" or my Soligor "1.7x", with certain lenses at least.

[adam75south]

Do you mean slow because of the max. aperture v. a prime?

I'm imagining I will have to be shooting at ISO 800-3200 since I'm going to need a fast enough shutter speed to stop action. Of course the next step Canon leads you to is a 1Dwhatever to get the better high ISO shots w/less noise. Does this never end?

no i mean i wanna see how slow you can get those shutter speeds at 400mm and still keep that thing sharp...talkin about the IS.

[cwphoto]

My Canon Extenders slow down AF a bit, especially the 2x II. The 1.4x II is barely noticeable.

Oh and Rich, well done on the 100-400 L. It's NOT a lens that I would get a lot of use out of I think, but nonetheless I'd love to see some stuff from it and know more about how you find it. :)

[DonSchap]

Ok, the TAMRON SP AF 1.4x does slow down the AF, to about 50% of normal, with the EF 70-200 f/2.8L IS USM.

I checked several times ... and there is no way to say it is minor. You still acheive the same quality focus ... but at a mechanically slower rate.

So, that blank is now filled in. Enjoy. ;)