Not really a review as such, but I've now had this sucker for over two years and hardly used it.
Due to the misnomer that is global warming and it;s current effects on Melbourne .. I got stuck into it more thoroughly, and all I can say is that it;s a damned hard lens to work with, even though it produces some astonishing results.. but there's a catch..
For a year I persevered with it on my D70s and got mostly dreadful results, and there was a two or three fold issue to resolve. They were mirror lockup, viewfinder and metering. At the time I didn't realise how vital Live View was to become, and it was last on the list, as a reason to upgrade to a better body, but I had my three reasons and they were enough at the time.
Live View was to become the single most important factor in making bets use of this lens, and I bet there are many other folks out there persevering with lenses that are more than capable, but they just don't know it yet. I haven't got endless reserves of money to waste on camera related gear, but high on the list of priorities is a proper tripod and head. Without which this lens is only really 1/3rd capable... make no mistake the tripod is going to help you more than a better body and or better lens when we start to talk about long-ish focal length.
of course there are those that argue that their tripod is good and can capture the images well and so forth and etc... but they are most likely referring to shutter speeds where it doesn't become a factor anyhow. If you want to prove the point(your point) about the tripod issue do so with samples of shutter speeds in the less than 1/10s range(nothing else is of interest to me ATM.. for my purposes) I've hand held at 1/100 or so and simply lucked a same shot that was presentable to the web, and very low resolution.
What I found out over the ast two years is that for less than about 1/60s, if the tripod is average, the IQ will suffer.
So here are the sample shots:
WB was preset.
each positive integer numbered image is the entire scene, full view, 100% view(call it what you like!).
The algebraic sub image of each of the integer series, is just the 100% cropped view, but resized to keep file sizes small and to allow a better overall view of the focused area. The 100% cropped view are good representations of a proper 100% view.
840mm f/5.6 2sec ISO160
840mm f/8 3sec ISO160
840mm f/11 6sec ISO160
840mm f/16 13sec ISO160
In 1(and hence 1a) I did apply some sharpening(the minimum of 1 using ViewNX) and it looks slightly better, but not entirely convincing(at 100% pixel view), yet more than enough for large , say to A4-A3 and not be affected IQ wise.
Instantly you'll see that stopped down 'one click' the 300mm f/2.8 and stacked 1.4x and 2x TC's actually work quite well. I did apply the same sharpening amount as a comparison, it didn't affect IQ all that much and just saved the image anyhow. Didn't need it, and I wasn't expecting the Ca to disappear at only 1 stop down.
DOF is the issue and you;re free to work it out for yourself but it's less than 1cm at a focus distance of less than 4 meters. This toy is only 2 or 3 inches high, and appears larger in these downsized shots than it is in real life.
So it just gets a little better stopped down a bit more to f/11 and then you'd think that diffraction takes hold, but it doesn't.. at f/16.
All apertures are actual apertures, taking into account the doubling of the lens aperture, as a stacked 2x and 1.4 times TC only affect apertures by 2 stops. ie. adding a 1.4x TC to a 2x TC doesn't lose another stop of aperture as you'd expect, over a 2x TC alone :the:
So why use a 2x TC, when a 2x plus 1.4x doesn't slow you down? .
I gave up at f/22 anyhow.. only proving to myself that diffraction is a silly topic of discussion that doesn't conform to any known universal constant
Yep! it just got better again, resolving more detail due to slightly better contrast(at f/22!! )
anyhow.. back on the topic of the day(which was global warming I think) what does all this mean?
Well there is no info on how bad this lens really is, having searched the net a long time ago for it, and there are massive important caveats to take into consideration.
it;' the most vital ingredient to maximise the usefulness of a useful lens that appears tobe useless!
Whao! now my head is spinning too, as that doesn't make sense .... until you do it for yourself.
On the D70s this lens is next to useless and expect a keeper ratio of 1 in 100.
On a D80/90 which has exposure delay you may get better mileage, but form what I saw, at 840mm the vibrations due to breathing when near the setup don't dissipate for about 3 seconds.
(damned I need a D90 with movie mode to show you all how this is such an issue!.. and you thought movie mode on a DSLR was useless huh?? )
Mirror lockup is the only way to get clear sharp shots form this setup, but admittedly to a slightly lesser degree without the TC's.
Point is you need a good.. NO! excellent tripod if you don't want to be disappointed in the lenses ability at low shutter speeds. ADd to that the fact that you just can't focus with such a shallow DOF to play with and it's easy to assume that the lens is terrible, where I can clearly see that with two TC's it's actually exceptional!
At f/22 on my test shots of my mantle clock the detail it resolved is so far out of whack with conventional wisdom of aperture and stacked TC's.
I'll post more samples later after I get some sleep(sheet!... it's 1:37AM ).
So what does all this mean, apart from the fact that global warming has induced a massive case of stir craziness, but I don't mind that as it was relaxing.
1. Cheap tripods don't (always work)..as they say you get what you pay for, and one day when the funds are available I'll set out to prove that point too.
2. Cheap lenses are better than the collective common consensus allows us to believe
3. Upgrading bodies can sometimes be more appropriate if the reason is there to do so... ie. with your old lenses you may be wasting money on a lens upgrade if your body can provide a similar return.
I'll try to make that point more clear with an example again:
With a D70s(at least) and possible with a D80/D90 body you wil almost certainly not get similar results to what I got with the D300 here. These shots are sharp.. super sharp considering the lens used and the stacked TC's.. but without the ability to use a proper Mirror lockup function, which is not the same as exposure delay!! You just won't get the same results.. trust me on the D70s factor.. I've tried!
In good light where shutter maybe in the 1/500 region..maybe so, but then you need to factor in the inability to focus correctly anyhow. with such a shallow DOF you can't see it, I suspect that your AF system doesn;' either and then you go away assuming that the lens and the attempt at stacking 2 TC's was useless and futile. Wrong!
Live View helped me focus in these shots, and without it, I reckon I may have only got 1 of those shots focused(where I wanted). I focused via the viewfinder in each shot, and then switched to Lv only to see that the focus point was not where I though. It was that simple. but in using liveview only revealed the limitation of my tripod!!
with barely a feathers touch on the large easy to use focus ring the image is easily vibrated causing motion sickness movement, so it had to be done in steps, with barely 1/2 a millimeter of adjustment! DOF is too shallow even with the f/22 aperture.
4. Tamron 300mm F/2.8 is a good cheap fast telephoto lens if you have patience.
if you want to shoot flighty twitchy birds, get an hypersonic mull million dollar lens and be happy in it's consistency.
If you want to shoot some sports and have massive amounts of ability, this lens may work nicely.. but you have to work at it. I've used it for cricket for my own personal recreational reasons(not in a professional sense) and it's more than good enough.
From memory I got about 4 in 20 or so shots with the 1.4TC added. But you have to work at it, just as the real pros did way back when everything was manually focused in the 80's and 90's!!
5. Do you want to buy it? Check ebay and suchlike they usually sell for approx $800ish to $1K, but they should come in a hard case with a 1.4xTC.
My reason for getting this one was not only that I'm totally cheap, but that I didn't want to waste excessive amounts of money on a lens type that I may not get full use of!!
More often than not I never use this lens, and it usually stays home!?
Only because it's so damned big( considering all the other stuff I carry.
I was thinking of selling it this afternoon, but after seeing how well it works, I changed my mind(I'm allowed to do that, I think.. blame it on Global Warming )
Damned, because I really want an AF version now!!
I think for my purposes though I'm better off with a lens that's more like a 300 f/4.. I'm not a compulsive sportster or birder so my main attraction is to still life and hence more time to focus and stop down(more) but I need to be able to carry the damned thing in my backpack. hence why I like zooms, so maybe a Sigma 100-300/4??
Anyhow I got it, and I love it
I'll try to post some more images(which I've already got) and hopefully one day I'll get a set of legs to properly support it, and it may actually surprise in it's ability to capture birds on the odd occasion too.
ps, if you're looking at those bike images and thinking, that's ot all that good, I can asure you that bike is exactly as you see it! not very good details and very shoddy and rough. It's my sons throw around the room toy bike, and not only has it copped a pounding over the years, it;s also very cheaply made.. you get what you pay for
The (coming)clock face images show much more contrast and clarity of detail.