Four Ways to Shoot 400mm --- AGAIN!

I tried my little experiment again today. I was killing time this morning at a construction site, and decided to repeat the process using a different subject, and with the lenses wide open whenever possible. This time, there really is a 4th lens. I also shot with my 70-200 using the 2X extender. The loss of two f-stops meant I had to shoot this particular shot at f8, but everything else is the same. These are all 100% (screen resolution) crops of the actual images. As before, there has been absolutely no post processing in any of these pictures.

I don’t know what conclusions can reasonably be drawn from this except to say that they’re all pretty darned good. To my eye (such as it is), they fall just about where you’d expect them to. The prime is best, the 100-400 does well, and the two lenses with the doubler on them are surprising.

I don’t question that these pictures could be improved by not shooting them wide open, but then, this was a test.

Opinions?

This is the actual view from where I was shooting. I took this with my 50mm f1.4, and include it for reference only. My subject was the house right in the middle with the windows in the garage door.

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Tom - I'm on the laptop so its hard to tell, but it looks like the 400 prime is a little darker again. Can you go to the RAW and bump it up a half stop? Or am I seeing things wrong on the LCD.

You're right. I deliberately left it that way for the sake of intellectual honesty---all the pictures are exactly the way they came out of the camera. I didn't do anything except re-size and crop. It is interesting, though, isn't it? It defintely has some effect on the camera's metering.

Yes, there is some kind of effect going on. Just for fun, I'd like to see what would happen if you equalized the brightness a little. I'm wondering if the slightly darker first image is making it even sharper than it is.

This is hard for me as I'm on the LCD tonight. I'll look at them tomorrow on the CRT. They all look pretty doggone good, but the first two do have the advantage.

To me eyes the prime is sharper but as noted darker.
The other 3 shots are not slouches by any stretch.
It would be interesting to see the same pictures again with the lens stopped down equally.

Intersesting that the Prime looks darker and with more contrast. Must be a problem with the metering between them but its hard to understand why this should be the case. As said elsewhere it would be interesting to have a series of shots at the same aperture setting. Would also be interesting to see that series at say 300%.

Are we getting close to being measurebators?

Maybe someday soon I'll do that. I'd like to try them all at, say, f/8 or higher. That's what the 2X extender does to thee 70-200 f4 (2 full f stops). I think the differences would be even more pronounced.

Tom

Actually, I think that the prime is reporting f/5.6 to the camera but its aperture is slightly smaller, say 1/3 or so stops smaller. Its not a big differrence, and if the pictures weren't adjacent to each other, one probably would never notice.

That said, I'm looking at them on my CRT now. Yes, the prime has a slight edge in contrast and resolution, but none of the other 3 are anywhere close to bad. They're all very sharp.

I find this test very interesting in light of the test done by the Luminous Landscape which found a drastic difference between the 100-400L and the 400 prime. I respect LL's testing, but I can't help but think that something went wrong with that particular comparison.

Tom, any 200% + crops available? I don't think they're necessary but I'd like to put this issue to rest.

For me the prime is definitely more contrasty with less flare, whether it's actual exposure is much darker is harder to say. Also resolution assessment is hard since there isn't much detail (any?) in the picture. But overall the images do seem to get softer as expected.

The 100-400mm is definitely the "shortest" lens in the bunch...apparently the 375mm reported is accurate. So I guess it isn't really a 400mm lens.

TomW:
I'm on my way out the door right now (to take wifey to the hair dresser). I'm guessing I won't get a chance to work on this until much later today if at all, but I will try to work those up for you.

I can't comment on Luminous Landscape's test. I've seen it, and all I can say is, my results appear to be different.

You may be right about the cause of the 5.6 image being darker. Initially I thought the result of the first series might have just been an anomaly, but the result in the second set is nearly identical.

I think the thing that surprised me most was the quality of the two 70-200 zooms. I certainly would not have predicted it, especially based on earlier experiences with the 2X extender. Admittedly, the f/4 lens had a little advantage in that the lowest effective aperture I could get out of it was f/8---the 2X extender slows the lens down two full f-stops. I felt I could partially overcome some of that advantage by using a subject far enough away to eliminate any possible benefit from the additional depth of field.

Ultimately the question boils down to: Do I really need 4 different lens/lens combinations capable of shooting 400mm? I think I have to sell something.

You know, now that you mention it, maybe its the greater contrast that makes the prime appear darker. Look at the white diagonal trim - its as bright, if not brighter, on the prime as it is on the 100-400 zoom. Perhaps its the wider range of contrast that makes it appear darker.

Really hard to say, and we're probably splitting hairs on that issue.

Just a note, the Canon 2x extender adds 2 stops to the aperture display to compensate for the loss of light it causes, but it does not change the lenses aperture.

Example, if you want to compare the performance of the lenses with apertures at f/8 you would have to stop down an additional 2 stops when the extender is attached, to f/16.

Otherwise you are comparing the prime with aperture at f/8 to the 70-200 with aperture at f/4.

Interesting....

I usually find shots from primes to be sharper out of the camera. In addition, they tend to have more contrast and usually much better colour rendition.

The Prime image is obviously darker for the shadow areas and the background (mountains), but the white of the boards doesn't look much (if any) lighter. I would say it is giving you image with much more contrast, which is good in my book.

But anyway, all shots are close. So close I wouldn't bother with the prime to be honest. I will take it off your hands for nothing, if you pay shipping.

Cheers

Ian

belmondo wrote:
TomW:
Ultimately the question boils down to: Do I really need 4 different lens/lens combinations capable of shooting 400mm? I think I have to sell something.

Clearly you don't require the 70-200 f2.8L IS or 2x converter.

Please send them to me.

Actually, I think testing the lenses at the same effective aperture is the most appropriate "apples to apples" comparison. A 70-200/4 zoomed to 200mm and with diaphragm set to f/4 with a 2x tele-converter is a 400mm lens at f/8 in all respects, from exposure to depth of field, etc.
-harry