Canon 100-400 or 70-200 + 2x Convertor
Discussion
This will no doubt end in handbags at ten paces but here goes.
I've got the need for a nice zoom lens and am toying between one of the two above.
It's going to be on a 20D.
Whatcha think -
100-400 or
the 70-200 and a convertor.
I'm currently thinking personally of the 100-400 as I never really did like convertors and I don't shoot that much in the 100mm range. (My 24-70 looks after that area).
Nature shots, motorsport events etc.. e.g. Normal stuff
Thoughts, experience and practicality appreciated..
I've got the need for a nice zoom lens and am toying between one of the two above.
It's going to be on a 20D.
Whatcha think -
100-400 or
the 70-200 and a convertor.
I'm currently thinking personally of the 100-400 as I never really did like convertors and I don't shoot that much in the 100mm range. (My 24-70 looks after that area).
Nature shots, motorsport events etc.. e.g. Normal stuff
Thoughts, experience and practicality appreciated..
Well thinking back to my old 35mm days, I seem to recall my 2 x converter used to reduce the speed of my lense by about half, (if thats the right phrase), ie for example shooting at f8 at 1/500th, became f8 at 1/250th with the converter on, so I expect the same applies to digi cams.
Alternatively I could stay at 1/500th, and open up the lense to f5.6.
Its been a long time, so cant recall if figures quoted are correct, someone will tell me if thats wrong, away from home so dont have access to the old Pentax at the moment.
Either way you either compromised on speed or apature. Dont know if this helps any.
Alternatively I could stay at 1/500th, and open up the lense to f5.6.
Its been a long time, so cant recall if figures quoted are correct, someone will tell me if thats wrong, away from home so dont have access to the old Pentax at the moment.
Either way you either compromised on speed or apature. Dont know if this helps any.
vipers said:
Well thinking back to my old 35mm days, I seem to recall my 2 x converter used to reduce the speed of my lense by about half, (if thats the right phrase), ie for example shooting at f8 at 1/500th, became f8 at 1/250th with the converter on, so I expect the same applies to digi cams.
Alternatively I could stay at 1/500th, and open up the lense to f5.6.
Its been a long time, so cant recall if figures quoted are correct, someone will tell me if thats wrong, away from home so dont have access to the old Pentax at the moment.
Either way you either compromised on speed or apature. Dont know if this helps any.
it's not quite right
the 1.4x teleconverter will reduce your maximum aperture by one stop
the 2x teleconverter will reduce your maximum aperture by two stops
So if before putting on the 2x teleconverter you were shooting at 1/500 F8 the addition of a teleconverter will not modify your exposure. However if you were shooting at 1/2000 F2.8 without the 2xTC, then after putting on the 2xTC your maximum available aperture will become F5.6 and you will have to slow down to at least 1/500
Hmm.
Given that most telephoto lenses are likely to have been designed to work best close to the wide open mark, sometimes AT the wide open mark, the effects of a good quality matched extender may or may not introduce reduced image quality.
I have old Canon FD 35mm kit. I have a Tamron 2x convertor which I bought the day before going on holiday many years ago somply becaue it was the only one in stock. It never produced good results when combined with my Vivitar zoom. I have hardly ever used it.
Recently I obtained a Canon 2x extender and some used Canon FD lenses. Put the extender on the 75-210 f4 and the results are not bad at all. (This particular extender is designed for most zooms and primes up to 300mm.). The lens will still open to f4, so no optical quality lost to diffraction and so on unless due to the extender. But I loose 2 stops so I have to adjust the shutter speed (I normally shoot using shutter priority mode.) Or choose a different film stock and/or change the ISO setting. If the ISO change is available and does not increase noise to a level which is unaccaptable or untreatable the extra flexibility that digital offers over 35mm is well worth having.
(This last weekend has been a challenge in that respect with constantly changing dark clouds and bright sunshine. My first weekend out on a circuit with a 600mm prime which demands high shutter speeds to do justice to the sharp images it can deliver. So I was mostly shooting 800 ISO film stock and keeping the speed up around the 1/1000th mark or higher if the body would take it. However, when the sun was out I was having to set the lens to f8 or even f11 according to the camera's meter so I anticipate a deterioration in the images. (Mental note - must get a drop in ND filter if I can find a holder ...)
But I also shot some hand-held with the 75-210 f4 and 2x extender on 400 ISO so it will be interesting to see how that comes out. As I recall it was a little dark overhead at the time so I am not expecting much.
Anyway, in theory the 100-400 with its smaller max f stop or the smaller zoom but at f2.8 with a well matched 2x extender would give pretty much the same f-stop range at the lens's optimum apertures so the major consideration seems to be related to optical quality rather than exposure and THAT decision may be something that varies, for digital bodies, according to the sensor size as well as the pure optical design.
I guess if the two combinations were tested on a 35mm body any differences might be more easily assessed in absolute terms, subject to the resolution capability of the film stock.
Does this make sense or am I completely off track?
Given that most telephoto lenses are likely to have been designed to work best close to the wide open mark, sometimes AT the wide open mark, the effects of a good quality matched extender may or may not introduce reduced image quality.
I have old Canon FD 35mm kit. I have a Tamron 2x convertor which I bought the day before going on holiday many years ago somply becaue it was the only one in stock. It never produced good results when combined with my Vivitar zoom. I have hardly ever used it.
Recently I obtained a Canon 2x extender and some used Canon FD lenses. Put the extender on the 75-210 f4 and the results are not bad at all. (This particular extender is designed for most zooms and primes up to 300mm.). The lens will still open to f4, so no optical quality lost to diffraction and so on unless due to the extender. But I loose 2 stops so I have to adjust the shutter speed (I normally shoot using shutter priority mode.) Or choose a different film stock and/or change the ISO setting. If the ISO change is available and does not increase noise to a level which is unaccaptable or untreatable the extra flexibility that digital offers over 35mm is well worth having.
(This last weekend has been a challenge in that respect with constantly changing dark clouds and bright sunshine. My first weekend out on a circuit with a 600mm prime which demands high shutter speeds to do justice to the sharp images it can deliver. So I was mostly shooting 800 ISO film stock and keeping the speed up around the 1/1000th mark or higher if the body would take it. However, when the sun was out I was having to set the lens to f8 or even f11 according to the camera's meter so I anticipate a deterioration in the images. (Mental note - must get a drop in ND filter if I can find a holder ...)
But I also shot some hand-held with the 75-210 f4 and 2x extender on 400 ISO so it will be interesting to see how that comes out. As I recall it was a little dark overhead at the time so I am not expecting much.
Anyway, in theory the 100-400 with its smaller max f stop or the smaller zoom but at f2.8 with a well matched 2x extender would give pretty much the same f-stop range at the lens's optimum apertures so the major consideration seems to be related to optical quality rather than exposure and THAT decision may be something that varies, for digital bodies, according to the sensor size as well as the pure optical design.
I guess if the two combinations were tested on a 35mm body any differences might be more easily assessed in absolute terms, subject to the resolution capability of the film stock.
Does this make sense or am I completely off track?
scalper said:
So if before putting on the 2x teleconverter you were shooting at 1/500 F8 the addition of a teleconverter will not modify your exposure
Eh . . . aperture and shutter speed are fundamentally linked . . . you can either increase exposure by reducing shutter speed or increase exposure by using a wider aperture, both (other than DOF/motion blur) are equivalent.
There is no way to add a 1 stop teleconverter (or a 2 stop one for that matter) without changing either the shutter speed, or the aperture or both to compensate . . .
Fd
I am in a similar position, but I have the 70-200 already. i am *only* considering the 1,4x as the 2x will take away too much light and *much* more importantly you loose autofocus!!!!
I would prefer the 100-400 by far, as it has IS and the extra 100mm, but it is purely the cost which is causing me to consider compromise.
in your position, its a no brainer for me if you can afford both, its the 100-400 every time.
Martin
I would prefer the 100-400 by far, as it has IS and the extra 100mm, but it is purely the cost which is causing me to consider compromise.
in your position, its a no brainer for me if you can afford both, its the 100-400 every time.
Martin
molydood said:
I am in a similar position, but I have the 70-200 already. i am *only* considering the 1,4x as the 2x will take away too much light and *much* more importantly you loose autofocus!!!!
Martin
You wouldn't lose autofocus with a 2x on the 70-200 2.8 as it takes it to f/5.6 which is fine (or are you talking about the 70-200 f/4?)
Bee_Jay said:
I am in a similar position, but I have the 70-200 already. i am *only* considering the 1,4x as the 2x will take away too much light and *much* more importantly you loose autofocus!!!!
Martin
You wouldn't lose autofocus with a 2x on the 70-200 2.8 as it takes it to f/5.6 which is fine (or are you talking about the 70-200 f/4?)
indeed I am, I realise now that the poster is refering to the 2.8 IS
I guess this means that it is a closer race as it ends up as a similar lens to the 100-400, other than the quality issues at low F stop.
fergusd said:
So if before putting on the 2x teleconverter you were shooting at 1/500 F8 the addition of a teleconverter will not modify your exposure
Eh . . . aperture and shutter speed are fundamentally linked . . . you can either increase exposure by reducing shutter speed or increase exposure by using a wider aperture, both (other than DOF/motion blur) are equivalent.
There is no way to add a 1 stop teleconverter (or a 2 stop one for that matter) without changing either the shutter speed, or the aperture or both to compensate . . .
Fd
Unless you are shooting wide open, you don't have to change anything when adding a teleconverter
Let's assume that with your 70-200/2.8 you are shooting a subject (such as an 18% grey card on a sunny day) with a uniform luminance of 13EV. With ISO 400 film (or with your digicam set to iso 400) that equates to an exposure of 1/500 at F/8.
The addition of a teleconverter will NOT change your exposure. Since the luminance of the subject has not changed, and since with the lens stopped down to F/8 as it was before your film is being hit by the same identical amount of light you do NOT have to change your exposure. Before adding the teleconverter the correct exposure would have been 1/500 F/8, after adding the teleconverter the correct exposure will still be 1/500 F/8.
Why don't you try it out for yourself?
scalper said:
So if before putting on the 2x teleconverter you were shooting at 1/500 F8 the addition of a teleconverter will not modify your exposure
Eh . . . aperture and shutter speed are fundamentally linked . . . you can either increase exposure by reducing shutter speed or increase exposure by using a wider aperture, both (other than DOF/motion blur) are equivalent.
There is no way to add a 1 stop teleconverter (or a 2 stop one for that matter) without changing either the shutter speed, or the aperture or both to compensate . . .
Fd
Unless you are shooting wide open, you don't have to change anything when adding a teleconverter
Let's assume that with your 70-200/2.8 you are shooting a subject (such as an 18% grey card on a sunny day) with a uniform luminance of 13EV. With ISO 400 film (or with your digicam set to iso 400) that equates to an exposure of 1/500 at F/8.
The addition of a teleconverter will NOT change your exposure. Since the luminance of the subject has not changed, and since with the lens stopped down to F/8 as it was before your film is being hit by the same identical amount of light you do NOT have to change your exposure. Before adding the teleconverter the correct exposure would have been 1/500 F/8, after adding the teleconverter the correct exposure will still be 1/500 F/8.
Why don't you try it out for yourself?
I don't own a teleconverter.
What you say makes no sense to me.
A 2x teleconverter takes the light falling on the frame from the original lens and gets rid of 3/4ths of it, leaving you with 1/4 of the light falling on the film.
As the film or sensor depicts, ultimately, the amount of energy falling on it, and you now have only 1/4 of what you had, the image will not be as bright . . . so you must change your exposure, in this case to multiply by 4 the amount of light, and that is a 2 stop (double twice) exposure change.
You can do this by shutter speed, aperture or sensitivity . . .
Now I can understand the exposure change from a physics point of view as above, and all camera manufacturers will state, a 2x teleconverter loses you 2 stops of exposure . . . so I''m not sure where you're coming from . . .
Fd
fergusd said:
I don't own a teleconverter.
What you say makes no sense to me.
A 2x teleconverter takes the light falling on the frame from the original lens and gets rid of 3/4ths of it, leaving you with 1/4 of the light falling on the film.
As the film or sensor depicts, ultimately, the amount of energy falling on it, and you now have only 1/4 of what you had, the image will not be as bright . . . so you must change your exposure, in this case to multiply by 4 the amount of light, and that is a 2 stop (double twice) exposure change.
You can do this by shutter speed, aperture or sensitivity . . .
Now I can understand the exposure change from a physics point of view as above, and all camera manufacturers will state, a 2x teleconverter loses you 2 stops of exposure . . . so I''m not sure where you're coming from . . .
Fd
you have not taken into account the fact that for a given F/# the aperture diameter will be bigger when using a teleconverter
Gassing Station | Photography & Video | Top of Page | What's New | My Stuff