Two teleconverters on AF-S Nikkor 300mm f/4D IF-ED?

[ploverphotography]

Hello there,

I am interested in expanding my possible focal length for bird photography. Currently, I am using an AF-S Nikkor 300mm f/4D IF-ED with an AF-S Teleconverter TC-20E III mounted on a Nikon D7100. I shoot in RAW.

My focal length is currently at a maximum of 600mm, but I've been wondering for a while if it would be possible to add another TC to it and bump it up to 1,200mm. I know there will be a loss of quality, but do you think it would be worthwhile and I would still be able to get sharp photos? And, if so, do you have any tips for me when shooting with that setup?

Thank you very much for your help!

 

[tirediron]

Nope. You're already at a maximum aperture of f8 having used the 2x TC; if you add another 2x, that's going to put you at a maximum aperture of f16 making it too dark for your camera to AF (unless perhaps you're in the dessert at high noon) and likely very difficult to manually focus as well.

 

[Overread]

A few thoughts:

1) You've already seen the image quality drop and performance changes of using a 2*TC - if you add a second one all that will double. Image quality wise you'll see a big hit, even closed down one full stop from wide open you'll still get a very soft shot. Ok for a record shot but nothing really that high quality.

2) As mentioned you're going beyond the AF limit point. So long a the camera detects both teleconverters (it might not) your cameras AF will simply not engage at f16. If it fails to detect them both or one you'll find that the reason for that disabled AF is that the sensors simply don't get enough light to give reliable AF performance. At f16 you'd have to be in very very bright weather just to get the AF sensors to respond - even then it will be slow and prone to hunting.

Manual focusing will also be tricky - you'll also have a darker viewfinder which will make manual focusing much harder (I've used a Canon MPE 65mm which closes down to small apertures when the magnification increases and then I find that I've got to use a light source to help provide enough lighting to really help see when the focus lands in the right spot - so really strong lighting is essential).

3) At 1200mm you're going to start encountering more atmospheric haze and effects on your shots; that is going to further degrade the image quality. Now this will vary a lot on where and when you shoot and upon the weather, but in general its going to be an element much of the time.

4) If you could get to that range you'll need a rock steady tripod setup; handholding in theory would work at 1/1200sec but chances are in real world practical terms the rule of thumb won't work and you'll likely have to start pushing to 1/2000sec or faster. So a very steady tripod would be the only way to shoot with this setup.


Honestly even on a 300mm f2.8 L MII you're pushing it with two 2*TCs - on the f4 version you're really pushing it way too far. I do understand the desire to get that increased focal length, but at a practical level I think the only way to get to 1200mm is to start saving for a 600mm L or a 500mm L.
Or if you've specific projects/events in mind you can always use rental companies to give you the range you need.
Sigma also has a 300-80mm that has very good performance and might work with a 1.4TC and get to 1120mm. I don't know if that lens will work well with a 1.4TC but it would be worth looking into. However its also very heavy, very large and still in the very high price brackets along with those big primes.

 

[runnah]

I saw a video recently where BH was showing off a 1200mm prime lens. To be honest the reach was impressive but the image quality was poor.

I tried playing around with a 2x extender and quite frankly it sucked. Even with a rick steady tripod and plenty of light the images came out soft.