View Full Version : Lenses for wildlife filming


Mike Edgecombe
May 1st, 2011, 09:02 AM
Would really like some advice on lenses to use on my recently acquired Z7E. I use this solely for wildlife (mainly birds). I have moved up from using a Canon XM2 with a convertor.

I find the stock lens superb even with a 1.6 convertor on the front. I have purchased an MTF Nikon to Z7E adaptor and have put a Nikon 28-300 on the front. The results from this have been very disappointing (worse than my XM2), with a real drop in quality of the image from using the standard Zeiss lens!

I have thought about a number of combinations to provide me with not only a better focal length but also sharper footage. I have narrowed down the following;

1. A better quality Nikon lens i.e.(80-400mm or 70-200—f2.8).

2. Using a 2x extender with the Sony Zeiss lens ( century XF213B)

3. Using a 2/3 lens such as the Fujinon XA20sx8.5BRM with ACM-17 adaptor. I presume this will give me an affective focal length of 40x on the 1/3 Sony camera?

I am not sure whether options 2 and 3 will work either, but would value anyone’s advice on this. Also the quality of the Fujinon lens, this is much cheaper than all other 2/3 HD lenses- so can i expect real HD quality from this?

Many thanks
Mike

Zach Love
May 1st, 2011, 07:39 PM
Don't think so much about the "magnification" about putting different lenses from larger imager cameras on the Z7.

Zoom the stock Zeiss lens to 50mm & you'll see exactly the same image if you put a 50mm Nikon lens on the front. If you get a 2/3" lens that goes to 120mm, you'll have the same telephoto FOV as a Nikon 120mm lens.

The MTF adatper doesn't have any glass in it, so if you're disappointed with the image from a Nikon lens then it is the lens. If you upgrade the Nikon glass you should be able to have a better image.

One big advantage is that nearly every major city has a pro camera store where you can try out gear. (Not the case for pro video lenses.) Take your Z7 to a local camera store & check out a higher quality Nikon lens & see if it is good enough for you.

One thing to keep in mind is that lenses provide different quality at different f-stops. Many lenses don't perform well wide open or closed down as they do in their mid range. So make sure you check out a lens at different f-stops to see how the picture looks.

Mike Edgecombe
May 2nd, 2011, 02:34 AM
Thanks for your reply. especillay the tips re using f stops. However I am a bit puzzled by the fact that you say a 50m Nikon will be the same as 50mm set to the dial of the stock Zeiss lens? Surely with the
7x crop factor a 50 mm nikon will be the equivalent of 300mm in SLR terms. perhaps I did not make myself clear- apologies if this is the case. I suppose what I am after with a lens is trying to obtain a 1500mm to 2000mm (in SLR terms).

The fujinon lens has marked on it a 170mm max focal length which on a 1/3rd camera such as the Z7E equates to a 340mm which with a crop factor gives a 2380mm in SLR terms? Or am I totally wrong with these calculations?

Mike

Zach Love
May 2nd, 2011, 10:40 PM
Why are you measuring a Z7 against a 35mm SLR camera? I know everyone does it, but why?

35mm SLR cameras are all but dead. Why do we still use a 35mm SLR camera as yard stick?

We don't measure how fast a car goes in relation to how fast a horse goes. "This race car has a 5x magnification factor top speed in relation to the top speed of a horse." That is just confusing, inefficient & silly. Instead we say a car can go #mph or #kmph.

Then length of a lens is not measured by the camera it is attached to. A 50mm lens is a 50mm lens is a 50mm lens. No matter what camera you put it onto.

But the FOV of a 50mm lens will change when you change the imager (CCD / CMOS / negative). A 50mm lens will have a "normal" angle of view (aka FOV) of 47 degrees when on a 35mm film SLR.

To get that same "normal FOV" on a Canon 7D, you'll need a 35mm lens. (35 x 1.4"crop" = 50)
To get that same "normal FOV" on a Z7, you'll need a 7mm lens. (7mm x 7"crop" = 50mm)

If you put a 300mm lens on a Z7, it does NOT turn the lens into a 2100mm lens. Just the FOV of a 300mm lens on a Z7 is the same FOV of a 2100mm lens on a 35mm film SLR camera.

Make sense? Or am I making things worse?

Mike Edgecombe
May 3rd, 2011, 01:12 AM
Hi Zach,

I see your point. You are being precise here and what youa re saying is of course technicaly right.

I suppose I am following on from the way others have described things on this forum and elsewhere. I also think there are quite a few folks who have perhaps taken up the use of video cameras to film wildlife having previously been SLR users, so still think in these terms

Mike

Doug Jensen
May 3rd, 2011, 04:38 AM
Why are you measuring a Z7 against a 35mm SLR camera? I know everyone does it, but why?

Zach, great post! You have summed it up perfectly.

Zach Love
May 4th, 2011, 07:31 PM
I also think there are quite a few folks who have perhaps taken up the use of video cameras to film wildlife having previously been SLR users, so still think in these terms

Mike

Myself too. But after being confused & taking a good long while to really understand what is going on with all these new cameras b/c everyone was referencing SLRs, I've cemented to the opinion that the old way of thinking should not be the way we think anymore.

I loved the time I spent in a dark room and really hope that film is still being manufactured in 50 years for students to learn on & for people who want to work with it as a hobby.

Since the reality is digital & think we need to let go of thinking in terms of the old way. Its like going from imperial to metric. There will be the ones who stick with the old way & then those who go to a base-10 system that is nicer & easier to convert.

If anything, I'll probably still use my SLR as a reference point in my mind, b/c I originally only had prime lenses. Those big jumps from 35mm; 50mm to 135mm (my first 3 lenses) can give me a good reference of 0.7x wide (35mm); 1.0x normal (50mm) & 2.7x telephoto (135mm).

So when I think of my Z7 zoomed to 5mm, I know I'll have the same FOV as my wide angle lens on my SLR, but I'll also know that I'll have a TON of everything in focus b/c it is at 5mm.