Telephoto lens for AF100

S

sabbott

Member
Hi - I'm wanting to invest in a good Nikon telephoto lens for my AF100 (I have the metabones Nikon to micro four thirds speed booster adapter).

It will mostly be used for shooting wildlife.

I'd like to spend less than $1000 on a lens that's not extremely heavy, and that will provide excellent, sharp images.

After doing a bit of reading, it sounds like the Nikon 300mm f/4 AF-S might be a good option.

Or the Nikon 500mm f/4G VR.

Any suggestions about what might be the best option (out of these or other lenses)?

One more thing - a friend of mine has a used Sigma 500mm lens that she's offered to sell me. Would this be a good way to go?

Thank you for any feedback!!
 
That 500mm f/4 Nikon sells new for about $7100, so I doubt you'll find even a well used one within your budget. B&H lists the gray market version of the 300mm for $949, so you might just swing that.

When I shot 35mm stills, I used Olympus OM equipment. So, one of my first purchases after I got the AF100 was an OM to M43 mount adapter. I recently found a used but very nice Olympus 300mm f/4.5 OM lens on eBay for about $225 that is quite lightweight and works well with the AF100. There's no auto iris or focus, of course, but for the special occasions I would need a lens like this, it's not a major handicap. Certainly, I'm not trying to use it for handheld run'n'gun work. You might consider looking at older manual focus Nikon, Canon, Olympus or Pentax lenses, even if you need to buy a different adapter to use them on your AF100. And the offer of a used Sigma sounds reasonable too. Any chance your friend would let you borrow it and check it out for a while before committing to buy?

Remember that you'll only be using the center of the 35mm full frame image circle when you mount any of these lenses on the AF. Aside from getting an even narrower angle of view, you'll be shooting through what is probably the best part of the glass. Any vignetting, distortion, lateral CA or corner fuzziness will probably become insignificant on the M43 sensor. Therefore, you might be able to get good results with some older or cheaper lenses that would be considered marginal on a full frame DSLR. I wouldn't worry about image stabilization much, either. Any lens this long will be impractical for hand holding while shooting video in any case. You will probably need to use it on a sturdy tripod at all times, and it's best to turn off IS anyway in that case.

Some of the bigger lenses in this category, especially that 500mm Nikkor, will be a mighty heavy load for the AF100 lens mount and body without additional support. That means you need a baseplate, rods and a lens bracket. All that makes the rig bigger, heavier and more expensive yet. The Olympus I mentioned is just light enough to get by without extra support hardware, but you should consider that in your decision as well.

Oops, I just noticed you have a speedbooster adapter. So ignore what I said about lens quality above. Since the adapter makes the field of view WIDER, using it with a long telephoto lens may be counterproductive, except for the exposure gain. But you'll need to buy a larger, heavier, more expensive tele lens to get the same shots with the speedbooster that you could get with a shorter lens and a "dumb" adapter.

- Greg
 
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I use the Nikon 300 mm f4 with my AF100. I bought mine years ago for about $1000 (new), so you may be able to find a second hand one for about that price. The quality of this lens is very good. Other than rods, a baseplate and a lens support, you will have to consider an external EVF, as focusing will be extremely difficult with the AF100. And make sure you get a very good tripod with a payload in excess of what you think it's needed, as you may want to add in the future a follow focus, an external recorder, etc. You will have to be very careful with vibrations; I used a Sachtler FSB8 with Zacuto universal baseplate, and when I am doing a still shot, I cannot touch the camera or tripod, as otherwise the vibrations will ruin the take. Together with focusing, this is another reason why I would not consider a 500 mm.

David
 
I use a lumix 100-300mm: it is a great lens, it is not expensive and it is recognized by the sw of the camera

Regards

Gary
 
+1 the Lumix. Also if you don't need a fast lens (it's f5-6.3), and you shouldn't for daytime shooting look at the Tamron 150-600. I bought one for my Canon 7D and its amazing when shooting still bursts and its right around your $1000 price point($1069) The drawback is you'd have to use it in manual focus mode. I'm not crazy about focus by wire lenses in manual mode. Also it's heavy as hell at a little over 4 lbs.
 
+1 for the Lumix also...I haven't used it for wildlife as such, but I have used it a lot over the last 9 months shooting surfing (with a cokin filter attached) on my gh2. You'll need a narrow lens support though, and the above advice concerning a good head and rig is a must. Prior to the Lumix I was borrowing a Fujinon A20x8 BEVM-28 which was challenging to mount, but a lovely lens for under a $1,000.
 
Ned Kelly said:
You'll need a narrow lens support though....
Click to expand...

Not sure why you say that? ... the Lumix 100-300 is only 520g which is well below the weight capacity of the AF100 mount.

It is also, incidentally, about 1/3 the weight of my Sigma 300mm f4 APO. The Sigma is a well-regarded lens, but at f5.6 has more CA than the Lumix, which has in-camera CA correction when used on Panasonic bodies.
 
Ned Kelly said:
You'll need a narrow lens support though....
Click to expand...

Not sure why you say that? ... the Lumix 100-300 is only 520g which is well below the weight capacity of the AF100 mount.

It is also, incidentally, about 1/3 the weight of my Sigma 300mm f4 APO. The Sigma is a well-regarded lens, but at f5.6 has more CA than the Lumix, which has in-camera CA correction when used on Panasonic bodies.
 
I'm sure the AF100 mount is far better than that on my gh2, but in addition to a lens support, I also use a rubber band to go around the lens and rails. If i'm panning and focusing on the long end without the support it shows up. I'd be interested to know how well the 100-300 fits the AF100 as I'm tempted to get one.
 
Thanks for the tips, everyone - much appreciated.

Another question: It's out of the initial price bracket I was considering, but can anyone think of a reason why the Nikon 80-400 (either AF or AF-S - I'm not sure) would be a bad choice for my set up (AF100 with metabones speedbooster)? I'm pretty keen on a telephoto zoom, as I'm trying to reduce the need for lens changes in the field as much as possible.

Also, I don't live anywhere near a shop that can assist with a baseplate, rods and a lens support - could someone let me know the sort of things I'd need to search for online to set myself up with good lens support?

Thanks again.
sarah
 
I can't comment on the Nikon, except to recommend that you confirm how easy it is to manual focus. Some AF lenses are fine, but with others the throw of the focus ring is so short that precise MF become challenging.

I recently bought this basic lens support, and am perfectly happy with it: http://www.amazon.com/gp/product/B00VLZ015M If you search on "Smallrig" on Amazon, you will find a range of rods and basic plates.
 
The more I think about this, the less I like the idea of using the Speedbooster adapter with a telephoto lens. It reduces the effective focal length while making the lens unit longer and heavier. Compare:

Nikon 80-400mm w/1 stop Speedbooster
Effective focal lengths 57-285mm
Effective apertures f3.2-4.0
Weight 1570g (lens) plus adapter (couldn't find this)
Length 20cm
Price $2700

Panasonic Lumix 100-300mm
Effective focal lengths 100-300mm
Effective apertures f4.0-5.6
Weight 520g
Length 13cm
Price $600

The Lumix is less than a quarter of the price and weighs one third as much, and still has a slightly longer reach at the telephoto end. You do give up about a stop of aperture and a bit of the zoom ratio for this, but I assume you're more interested in the long end anyway. The ability to potentially handhold it and get by without a rod and lens support system would, I think, more than make up for having to operate with an extra 6 dB gain in some situations.

I have a Canon 100-400mm, which is roughly the same size, weight and focal length range as the Nikon, that I've used on my AF100 a few times. It is excellent, but the combination is large and heavy enough that I wouldn't want to use it without a tripod or move around much without assistants to help carry everything.

- Greg
 
Hi Greg,

Thanks so much for your advice on this. I just wonder if you can help clarify your answer by addressing some really fundamental questions I have....

If I've understood Barry Green's book correctly, crop factor affects the angle of view (and thus field of view) but NOT magnification of any given lens. So, when put on my AF100 (with crop factor of 2) a 100mm lens made for a full frame sensor camera has the same angle of view and field of view as a 200mm lens, but still just the magnification of a 100mm lens. Is this correct?

If so, when people refer to 'effective focal lengths' after doing crop factor maths, are they really only considering the angle of view of a lens with the focal length they've mentioned, and NOT magnification? If that's the case, why is so much fuss made of 'effective focal lengths' if it says nothing at all about the 'effective magnification'?

Also, the information that comes with my speedbooster says it 'increases angle of view by 0.71'). So, I can use this to find the effective angle of view of any given lens when I use it on my speedbooster, but that's it. Width of shot is all it changes, so 'effective angle of view' is all I can find out by doing maths with the 0.71 figure.

I guess I'm at a loss as to why people talk in focal lengths at all, when magnification of an image and how much of the image fits into the frame are really what concerns photographers and filmmakers. Why do we obsess with the distance between the optical centre of the lens and the camera's sensor??

SO confused!! Thanks in abundance if you can shed some light on this basic stuff for me.

sarah
 
sabbott said:
Hi Greg,

Thanks so much for your advice on this. I just wonder if you can help clarify your answer by addressing some really fundamental questions I have....

If I've understood Barry Green's book correctly, crop factor affects the angle of view (and thus field of view) but NOT magnification of any given lens. So, when put on my AF100 (with crop factor of 2) a 100mm lens made for a full frame sensor camera has the same angle of view and field of view as a 200mm lens, but still just the magnification of a 100mm lens. Is this correct?

If so, when people refer to 'effective focal lengths' after doing crop factor maths, are they really only considering the angle of view of a lens with the focal length they've mentioned, and NOT magnification? If that's the case, why is so much fuss made of 'effective focal lengths' if it says nothing at all about the 'effective magnification'?

Also, the information that comes with my speedbooster says it 'increases angle of view by 0.71'). So, I can use this to find the effective angle of view of any given lens when I use it on my speedbooster, but that's it. Width of shot is all it changes, so 'effective angle of view' is all I can find out by doing maths with the 0.71 figure.

I guess I'm at a loss as to why people talk in focal lengths at all, when magnification of an image and how much of the image fits into the frame are really what concerns photographers and filmmakers. Why do we obsess with the distance between the optical centre of the lens and the camera's sensor??

SO confused!! Thanks in abundance if you can shed some light on this basic stuff for me.

sarah
Click to expand...

Sarah, imagine removing the lens from the camera and holding it so it projects a little upside down image on a piece of cardboard. A 100mm lens will produce a more "magnified" image than a 50mm, right? Now imagine taping different size rectangular sensors onto the cardboard - the image the lens is producing obviously doesn't change, but the field of view that gets recorded does - because it depends on the size of the sensor.

People use effective focal length as a shorthand to describe what's recorded, because saying the field of view is "like a 100mm lens on a 35mm camera" is easier to visualize than saying "a 15 degree field of view ". It's just a convenient shorthand.
 
sabbott said:
Hi Greg,

Thanks so much for your advice on this. I just wonder if you can help clarify your answer by addressing some really fundamental questions I have....

If I've understood Barry Green's book correctly, crop factor affects the angle of view (and thus field of view) but NOT magnification of any given lens. So, when put on my AF100 (with crop factor of 2) a 100mm lens made for a full frame sensor camera has the same angle of view and field of view as a 200mm lens, but still just the magnification of a 100mm lens. Is this correct?

If so, when people refer to 'effective focal lengths' after doing crop factor maths, are they really only considering the angle of view of a lens with the focal length they've mentioned, and NOT magnification? If that's the case, why is so much fuss made of 'effective focal lengths' if it says nothing at all about the 'effective magnification'?

Also, the information that comes with my speedbooster says it 'increases angle of view by 0.71'). So, I can use this to find the effective angle of view of any given lens when I use it on my speedbooster, but that's it. Width of shot is all it changes, so 'effective angle of view' is all I can find out by doing maths with the 0.71 figure.

I guess I'm at a loss as to why people talk in focal lengths at all, when magnification of an image and how much of the image fits into the frame are really what concerns photographers and filmmakers. Why do we obsess with the distance between the optical centre of the lens and the camera's sensor??

SO confused!! Thanks in abundance if you can shed some light on this basic stuff for me.

sarah
Click to expand...

I tried hard to avoid using the phrase "crop factor" in my last message, and I'm going to stay away from it here, too.

A lens with a particular focal length, used with a sensor of a particular size, will produce a fixed angle of view. A 300mm lens, zoom or prime, will act as a pretty strong telephoto on the AF100, and any lens with a 300mm focal length will see the same angle, side to side and top to bottom, when mounted on the camera. Yes, you can relate this to some different focal length that would cover the same subject on a different sized sensor, but that's not really the point. What you need to get used to is what angle of view and perspective you get using a 300mm lens on YOUR camera, in this case the AF100.

If you had the Lumix 100-300mm lens, that's what you'd get -- a range of different angles of view that, at the long end, would be just like any other 300mm lens would produce on the AF100.

But the Speedbooster performs an optical trick. It reduces the focal length of the lens by compressing the projected image circle onto a sensor that is smaller than the lens was originally designed to cover. This lets you take advantage of the fact that there are many fine lenses out there that were originally designed for 35mm still cameras and therefore project an image circle that is much larger than the m43 sensor. The Speedbooster reduces this circle to one closer to the size of the AF100 sensor and therefore lets you take advantage of the side and corner areas that would normally be wasted when using a 35mm stills lens. As a happy consequence, because the light energy passing through the lens is now concentrated on a smaller sensor area, it also makes the image effectively brighter. The factor of 0.71 was selected because it yields almost exactly a one-stop improvement in exposure.

So what the Speedbooster is doing is actually modifying the specifications of a full-frame lens when using it on a smaller sensor. It decreases the focal length by a factor of 0.71, and increases the relative aperture by one stop (the entrance pupil and iris diameters stay the same, but the focal length is shorter, so the ratio of focal length to clear diameter is less -- and that's the simple definition of an f/stop). You have to consider a lens used with the Speedbooster as not the same lens anymore; it's one that has been altered to have a larger relative aperture and a shorter focal length. The Nikon 80-400mm would become a 56.8-284mm (multiplying the two lengths by 0.71) and gain a stop of speed, from f/4.5-5.6 to f/3.2-4.0 (also multiplying both numbers by 0.71).

Now nobody would object to gaining that stop of exposure. But the focal length reduction may not be what you want. With telephoto lenses, every millimeter of focal length comes dearly, in the form of a larger, heavier and more expensive lens. The Speedbooster technology is really at its best helping out short focal length (wide angle) lenses, where you can have access to a much greater variety of optics that will deliver the full angle of view they're designed to produce. And you gain some speed as well.

To me, it just makes more sense to get a lightweight telephoto designed for the M43 format than to purchase a much larger and heavier 35mm stills lens and then, in effect, throw away 29% of its expensive millimeters by using the Speedbooster. That is, unless that extra stop of exposure is much more critical to you than the telephoto capabilities.

Hope this helps.

- Greg
 
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