From gnu.mat.uc.pt!news.rccn.net!Portugal.EU.net!EU.net!howland.reston.ans.net!news.sprintlink.net!news3.insinc.net!newsfeed.direct.ca!usenet Tue Sep 26 13:01:30 1995 Path: gnu.mat.uc.pt!news.rccn.net!Portugal.EU.net!EU.net!howland.reston.ans.net!news.sprintlink.net!news3.insinc.net!newsfeed.direct.ca!usenet From: gmunzel@direct.ca (gunther munzel) Newsgroups: rec.photo.misc,rec.photo.advanced Subject: Sigma 400/5.6 Macro review (LONG!) Date: 21 Sep 1995 03:09:00 GMT Organization: Internet Direct Inc. Lines: 133 Message-ID: <43ql0c$q9p@grid.Direct.CA> NNTP-Posting-Host: 204.174.244.80 X-Newsreader: WinVN 0.92.6+ Xref: gnu.mat.uc.pt rec.photo.misc:23544 rec.photo.advanced:29664 Having seen an endless number of postings asking for reviews or opinions of new lenses, I'm going to be proactive. Below are my impressions of the recent Sigma 400 mm f/5.6 APO Macro, which I bought from B&H earlier this month. I tried the Nikon version of this lens; users of other camera brands can decide for themselves which portions of the following are relevant to them. >>>Why I bought it<<< I needed a lens for bird/wildlife and aircraft work with more reach than my AF-Nikkor 300 f/4. My budget ruled out fast lenses, and I said no to the Nikkor 400/5.6 or TC-14B because I expected that I'd regret the lack of autofocus. I have tried the Tamron 1.4x converter and didn't like it. I picked the Sigma 400 macro because I've been very satisfied with my Sigma 28-70/2.8, and because I thought the close-focus ability would be useful. My 300 focuses to about 9', and the 400 promises closer range or a larger image at the same distance. The cost with warranty and shipping was $769 U.S., or about $1160 Canadian after taxes and delivery fees. Not an item to buy on impulse! >>>Physical features<<< The 400 is a bit longer than the AF-Nikkor 300/4, but noticeably lighter. It feels like metal, but a much thinner gauge of it. Balance in the hand is better than the Nikon. All the components have a very tight, precise feel. Switches and rings have no slop or play, and it can be hard to slide out the hood. The lens has internal focus and a non-rotating (77mm) front element. I really like the removable tripod collar, though I wish the inside diameter was a bit greater so that it would fit on my Nikon 80-200/2.8! There is a switch that limits the focus range to infinity-12' or 9'-minimum (about 5'). On an F90x (Canadian N90s, eh?), auto-focusing was faster and more positive than I expected -- for high-contrast targets, at least. Pick a subject with less detail and the focus will shuffle around the optimum, occasionally getting it right but usually seeking for as long as the button is held down. For stationary or slow-moving subjects, setting the focus mode to "S" (single- servo, focus-priority) solves the problem. In action situations ("C" mode), you need to cross your fingers, as the AF will positively track a subject only about half the time. For the other half, you can press the focus lock button once things look sharp through the finder, and hope your subject doesn't move too far before you shoot. The erratic focusing behaviour is probably due to the small f/5.6 maximum aperture. Don't expect focusing manually will make things better. In manual, the focus ring throw is short, and it's easy to turn too far. This is such a serious problem near infinity that I would hesitate to buy this lens for MF use. Inside of about 15', things are manageable, though. The focus ring has a comfortable amount of resistance, too. Incidentally, Nikon users, manual focus works with the lens switch on "MF" and the body one on "AF." This is much better than on Nikon OEM lenses -- one easy-to-reach ring to turn! >>>What really matters: optical performance<<< First, sharpness. I shot detailed but flat scenes -- newspaper classified sections taped to a fence -- at different distances and apertures to check the this. All pictures were taken using a tripod and cable release, although "mirror slap" could not be controlled. I refocused (AF) between every shot. A picture of the same scene at f/8 through my 300mm lens served as a reference, except at 5'. Film was my standard, Fuji Sensia 100. I evaluated the results on a light box at 10x magnification. 500': (Actually, a condo, not a newspaper!) Sharp in the centre at f/5.6, equal to the 300 at f/8-f/16. (I didn't go slower at this distance, and I never tried f/32. Sorry.) 50': Crisp enough for me at f/5.6 in centre AND corners. f/8 and f/16 great. Extremely sharp everywhere at f/11. Things a bit fuzzy at f/22. 10': Everything excellent at 5.6 through 16; everything a bit blurry at f/22. 5': Corners are noticeably soft at 5.6-11, though centre sharpness is always good. Everything well-defined at f/16, but soft at f/22. Incidentally, a ruler shows that the image size is about 3" x 4 1/2" at this distance. Note that the above really evaluates contrast, or how well-defined edges are. Resolution, which is how much fine detail is visible, seems about equal to the Nikkor 300 at the same distance. Since the Nikkor image is smaller, this implies that the Sigma's resolution is lower. There's still a lot there, like paper texture, though. (Better to have a high-contrast, low-resolution lens than the opposite, anyways.) In general, there is minor pincushion distortion near the frame edges. Light falloff is conspicuous at f/5.6, but barely there at f/8 and absebt at f/11. Backlighting does not cause much flare at all. Colours are as saturated and clean as they are through a Nikkor. Then there's depth of field. I took a few plant pictures to see how convenient the lens was for macro work, and until you've used a 400 mm lens focused at 6', you don't realize how shallow DOF can be. This is a comment, not a criticism, as any 400 lens has the same fault. You can't help but blur away all backgound distractions in macro shots. Stop way, way down! I also took the lens out to the airport to try it on moving subjects, including passing cars. (After all, I've never encountered resolution test targets in the wild.) The 400+F90x combination was able to autofocus and track with some success. My reject rate was higher than normal -- a few shots at f/8 had the absolute sharpness and clarity of the 300, but many were a bit blurry. This is probably due more to camera shake (I was closed down one stop with both lenses, meaning that 300 shutter speeds were faster) than any focusing difficulty. Pictures taken using a monopod matched the quality of 300 ones. Overall, I didn't uncover any unexpected vices in the field. I still need to test the new lens at panning and tracking smaller subjects at closer range, and I haven't used it with flash yet. Finally, a philosophical comment on the focal length. Subjects photographed through a 400 mm lens do not look much different than they do through a 300. At the same distance, subjects appear bigger -- lines are about 30% (400/300-1) longer and things occupy about about 70% ((400/300)^2-1) more film area. The longer lens can make small or otherwise "iffy" subjects worthwhile. However, the jump from 400 to 300 is less than that from 200 to 300, and angle of view is similar for both "big" lenses. If you have a 300 already, buy a 400 for the extra "reach," not to create a unique photo style. >>>Summary<<< I'm keeping mine. The Sigma 400 macro is not perfect -- it has strange focusing habits, images are soft in the corners up close, and it's slow. But for my intended uses I feel that I can adapt to it (by using "S" focus mode when possible, by shooting at f/8 or less and keeping the shutter speed up with faster film, and by using a monopod or tripod more often). I can make the lens do what I need it to do, and I like it. Sorry this is so long but hope it's useful. I'll shut up now. Mark M. The exclusive opinion of: | c/o gmunzel@direct.ca Mark Munzel BASc (Mech) 1994 | ...with lots of ASCII smoke & jet noise | ----------==========/=\==========---------- o'o o'o ----\*/---- o'o o'o