Canon lens info request

[Journeyman]

Good day,
I have an opportunity to buy a Canon ef400 f5.6.
It does not have image stabilising and I am a bird photographer
Can anyone tell me if this could be a problem please? Other than that it looks like a great lens.
Thank you,
Dennis, (Journeyman)

[Tannin]

Hi Dennis.

The 400/5.6 is so old that it's practically a legend, but it's still in production after all these years because, aside from adding IS, there is very little anyone could do to improve it. A real classic. It is small and light, sharp as you like, and focuses quickly and accurately. Years ago it was the unquestioned king of flight shot lenses, and some people still prefer it to any other in that role.

The lack of IS is key. Some people regard that as a minor issue, the majority see it as a significant drawback. That argument has been going on for the best part of 20 years and I don't think that there will ever be a resolution to it: you simply have to try some relevant examples of IS and non-IS lenses (or IS lenses with the IS switched off) and see what your own experience is.

My own view is that yes, it is a significant issue. You can take great shots with a 400/5.6 but you are very restricted and have to work in suitable light. Rainforest, heavy shade, heavy overcasts, twilight, early morning and late afternoon - all of these are no-go zones. (Other than working with flash, that is, and a flash setup suitable for using with a 400mm lens isn't cheap.) Moderate overcasts and lighter shadows are possible but much more difficult than with an IS lens. You miss a lot of shots.

Obviously, you can ameliorate these issues by using a tripod or monopod - but what's the point of having a lovely little lightweight lens if you have to cart a clumsy great pod around to use it?

In the old days - say 10 years ago - the choice was between the 400/5.6 and the 100-400 Mark I. The prime was slightly longer (the 100-400 I was actually more like a 110-390 where the 400/5.6 really is 400mm), slightly but noticeably sharper, focused faster, and tangibly nicer to handle because of the light weight and narrow barrel. The 100-400, on the other hand, was much more usable with its IS (early model IS, but still more than useful), and with the ability to zoom.

I chose the 100-400, but later on I owned a 400 prime as well for a short while. It was a lovely lens and I liked it a lot, but the reality was that it was never going to get much use alongside the much more versatile stabilised lens.

These days, the choice is more clear cut: the 100-400 Mark II has incredibly good optics, equal in all respects to the 400 prime, leaving the 400/5.6 with only the minor advantage of light weight. The new 100-400 also has the latest IS system and it is hand-holdable down to crazy-crazy low shutter speeds. It is the best bird lens you can buy short of the mega-expensive big whites (500/4, 600/4, 400/2.8, 400/4 DO II, 800/5.6, 300/2.8 and 200-400/4). It costs around $3000. I guess you'd pick up a second-hand 400/5.6 for less than $1000. If you can live without IS, you'd be getting a lens just as sharp as the best bird lens any sensible money can buy for a third of the price. But can you live without IS?

[Journeyman]

Thanks for the info Tony.
I will try the 400, the 100-400 price is a bit of a stretch. May be in need of a mono pod I reckon. I’ll post some results shortly. I am keeping my Tamron 18-400.
Kind regards,
Dennis

[Journeyman]

Good day,

When referring to 400 lenses, all things being equal, do they all produce the same size images of the object central to the photo?

Does a ?? - 400 Sigma or Tamron return the same sized image as a 400 prime or 100 - 400 Canon/Nikon lens with the larger diameters objective lens? (when all set to 400).

Granting that focal lengths are not always as shown with on the lens. Do the lens diameters make any difference.

Thanks and regards,
Journeyman

[ameerat42]

Reply mainly to Post #4 above...

No, the diameter of the objective lens (the one at the front of the assembly) does not make
for any extra accuracy in the FL of the lens. That diameter determines the [fastest] "speed"
of the lens. It's an idea that meant if you had a larger diameter lens then your shutter speed
could be "faster" (poor description aside, as it should be "shorter", but can you imagine talking
about short and long lenses then??? - Awp!)

So in "short" the wider front glass lets the lens gather more total light. What happens to the
intensity of that light on the film/sensor is determined mainly by the aperture of the diaphragm
that the light then has to travel through. - Ie, how much it is attenuated. The attenuation is
expressed as focal ratio, referred to as f-stops (q.v. - I don't want to hold forth...)

So in summary: No.

[Journeyman]

Thanks Ameerat,
The reason I asked about this is related to the results of a couple of images.

The lenses are Tamron 18-400 (crop frame) and a Canon EF 400 L (suitable for full frame and crop). The exit lens in the two lenses are different sizes, as goes with the job they do.

I completed several shots from each lens. The images of the subject (no processing) are different sizes. The attached photos have been reduced to fit using the same aspect ratio.
The smaller can image was using the Tamron, the larger one using the Canon lens. This is how the images downloaded. Taken only for the image check, no polished shots.

My query is, do the different exit lens have an effect on the photo?

Thanks and regards,
Journeyman

[Journeyman]

Good day,
I can see that I was looking through the wrong end of this.
If it is 400 then that is what it is.

I was out birding this morning and removed the UV filter from the Tamron. The result was images of the same size. I have read that filters can effect focus. That would seem the case on the lenses I use.
All in all a fairly good morning.
Thanks and regards,
Journeyman

[ameerat42]

An interesting result at first look. Some key information is missing, but I am betting that
you used the same camera body and just changed lenses. It is clear from the images that
you maintained the subject distances, to the extent that the different lens sizes let you.

The image here have a 1.36X magnification ratio, which at first sight would have meant
two different sized sensors, given the conditions. But your camera has a crop factor of
1.6X compared to "full-frame".

The only thing that comes to mind (and it seems unlikely given what you have said) is that
you changed the focal length between lenses/shots (but not the subject distance).

So, I've got no answer to give you as to why Now there was no camera
camera data when I checked Exif, but if you can, check that to see what focal length
was reported in each shot.