peter_may

Chuck,

Don't know how far you're willing to drive, so this may be a bit out of your range. A fantastic birding area in the Eustis area is Emeralda Marsh Conservation Area. I do weekly bird censuses in one small section of EMCA and have been getting 70-80 species in a 4 hour census in the last few weeks. Lots of photo ops for wading and aquatic birds as well. See <a href="http://www.stetson.edu/~pmay/emeralda">here </a> for an idea of the birding possibilities. E-mail me if you'd like specific information on best areas to visit and driving directions.

If you're still in or near your vehicle, turn your window defroster on with temperature set to heat, and point the front of the lens at the airstream coming from one of the vents. The condensation will disappear almost immediately, and there is no risk of scratching the lens.

John,

 

Also try doing a search with Orlando as the key word - you'll get a bunch of other threads that cover specific sites you might want to consider.

John,

 

See <a href="http://www.stetson.edu/~pmay/woodruff/">this site</a> for a wildlife photographer's guide to Lake Woodruff NWR, about 1 hour north of Orlando. Things should be picking up by October, though it's at its best in winter.

Ryan,

Sorry to hear about the disappointing results - hope you get another chance soon. I don't know if this is at all relevant since it deals with Nikon equipment, but my experience with macro shots (loosely defined - anywhere from 1:5 or so to 1:1)with TTL metering is that my rig (and this happens with 2 different Nikon N70 bodies) routinely underexposes these shots. I would think that the most likely exposure error when shooting frogs at night against a water background would be for TTL to overexpose the frog, especially if there's a significant amount of open water in the frame. My experience is that animals sitting at the surface of the water typically have a higher reflectance than the surrounding water surface, especially if you're shooting anywhere close to eye level of the animal, and the meter can be fooled by all the low-reflectance water surface around the subject and thus cause overflashing (unless there are irregular wet surfaces that cause bright reflections and shut off the flash prematurely). So it's especially confusing when underexposure results. None the less, when doing macro stuff with my Nikon bodies, a 200mm macro lens, and SB-28 flash, I routinely dial in +0.7 or +1.0 overexposure on the flash, depending on the color of the subject, and generally it gives me perfect exposure. Incidentally, I've read on one of these forums that at least some other Nikon users have found the same problem, though it's never been adequately explained for me. How about posting one of the underexposed shots on the critique forum and let some of the whizzes there have a go at the problem?

Since nobody else is offering much on this question, I'll give you my $0.02. I used a Sigma 180 5.6 macro for about 3 years until I replaced it with a 200 mm Nikkor Micro. I generally had very good results with the Sigma. The sharpness, contrast and color rendition are all very good, though noticeably inferior to the Nikkor (duh). A big plus of the Sigma (at least the 5.6) is its compactness. One negative is that it will only go to 1:2, but I frequently used it with a Nikon 6T diopter to get 1:1 magnification, with very little loss of image quality. Although it seemed generally quite sturdily built, in the last few months before I bought the Nikkor, the distal segment of the lens (in front of the focusing ring) became loose, and local repair shops wouldn't touch it. I never did send it back to Sigma, so can't tell you if they're responsive. I never did use it AF, either, so I can't tell you what to expect in that regard. All thing considered, I thought it was a fine lens for the $300 I paid and the several years of good service it gave me. Though I know you can't judge sharpness from web images, you can see a couple of shots taken with this lens at http://www.stetson.edu/~pmay/moth.jpg and http://www.stetson.edu/~pmay/anole7.jpg.

Rob,

 

Snake venom (broadly defined) is a hot field in herpetological and pharmacological research right now, and consequently generalizations about the topic are changing pretty constantly. I'll e-mail you off list with more details so as not to prolong this thread too much, but I've used either a 180 or 200mm macro lens for most of my snake shots.

 

Peter

Most colubrid snakes have a functional Duvernoy's gland, a modified salivary gland, that is an active part of the prey capture, manipulation, and swallowing process. The venom gland of Viperids and Elapids is in many structural aspects similar to Duvernoy's gland, and may be homologous (evolutionarily derived from it). It is becoming more widely recognized by herpetologists that many, and maybe most, snake species that have classically been considered "non-venomous" produce Duvernoy's secretions with active enzymatic components that act in some manner to help subdue or otherwise impair prey. Harry Greene, an expert in the field of snake evolution, estimates that as many as half of the species of "advanced snakes" (which includes the majority of living species) produce venoms. The enzyme components of venoms and Duvernoy's gland secretions are complex and multifunctional - one common target of attack by venom components is the clotting mechanism of the prey organism. Other enzymes are strongly proteolytic (protein digesting), so even though they may not directly inhibit clotting, they might increase bleeding at the injection site. I'm not aware of any research on water snake Duvernoy's secretions per se, but I know of folks bitten by garter snakes, a closely related natricine colubrid, that have shown evidence of local hemolysis/proteolysis at the site of the bite suggesting they have active Duvernoy's gland secretions. I wouldn't be surprised if <i>Nerodia</i> is similar. Still, they are for practical purposes, "non-venomous", since the effect of even a severe bite to a human is slight and local. Because all colubrids have multiple rows of small but very sharp teeth, a fair amount of bleeding from multiple punctures is a typical outcome of most decent bites from medium- to large-sized colubrids. The best advice that anyone encountering an unknown snake can follow is simply to leave it alone. Snake bites, venomous are not, are almost always cooperative ventures reqiring participation of both the biter and the bitee.

No photo, Bob? What were you thinking? Snakes too primitive a life form to waste film on? ID'ing snakes from descriptions is always iffy, but my bet is that you had a species of <i>Nerodia</i>, probably <i>sipedon</i>, the northern water snake. I'm assuming by no real coloration you mean no obvious patterning; <i>Nerodia</i>s are real variable in the degree of pattern, from prominently banded to solid coloration. They can be aggressive when cornered, and like many harmless colubrid snakes, they can flare the rear margin of their skull and jaws when threatened to give their head a decidedly triangular appearance. They also bite and musk repeatedly if you're foolish enough to persist in your pestering of the poor little beast. Completely harmless though. You are within the range of copperheads, but they are usually prominently patterned, and a healthy snake 18" long would be decidedly bigger than 1" diameter at midbody. No cottonmouths where you are, and timber rattlesnakes are also usually boldly patterned and heavy bodied. That takes care of the venomous species in your area, I think - I'll be interested to hear the opinions of other ophidiophiles, but my bet's on a <i>Nerodea</i>. Oh, the fact that it was near water supports that diagnosis as well - might have just been emerging from a hibernaculum in the pile of rocks.

 

And next time, take a picture! In the case of snake ID's, it really is worth a thousand words.

Uwe,

Night macrophotography is tough, but can be productive as you can sometimes find and closely approach arthropods and some vertebrates much more closely in the dark than you ever could in daytime. In my neck of the woods, for example, leopard frogs are incredibly wary in daytime, but after dark, you can touch the tip of their nose with your finger - sometimes they'll even bite it!! To do night photography, I use a small headlamp (several companies make a similar model - Browning has one they call the Lightning bug, I think - ~$19.95 at Cabela's or similar outdoor supply stores) that comes with an elastic headband as well as several other means of attachment, including velcro patches. I put a couple of pieces of velcro on top of my electronic flash, then attach the headlamp. Its so tiny that the added weight is insignificant, but its pretty bright. You can position the lamp and swivel the head so that its beam falls directly into the center of your field of view at whatever distance you're shooting. A lot easier than trying to manage the camera with one hand and hold the flashlight with the other...

Ben,

I have found the same problem as you, the only difference being that I use an N70 with the SB-28 and 200mm Micro Nikkor. In non-macro shots, exposures with no compensation in either TTL or matrix mode are generally fine. When shooting macro, I found slides are typically underexposed. This also happened with a Sigma 180 macro lens that I used before I got the Nikkor, so its not the lens. I routinely set the flash to 0.7-1.0 stops overexposure using straight flash at ratios above 1:4 or so, and if I use a diffuser or bounce attachment I'll sometimes add another +0.3 stops, and I always do macro flash photography in straight TTL mode, as I seem to get more consistent results than when in matrix. I don't get underexposure warnings until I stop down to about f16 or 22, depending on the reflectance of the subject and background, so it seems to me the problem is in the metering, not insufficient power from the flash. I've never understood how it works either in terms of the physics of the metering process; I've just learned to live with it. The important thing is that it consistently underexposes, so its easy to compensate and get consistently well exposed slides.

Can anybody give me information about nature photo possibilities at

Highlands Hammock State Park in Sebring, FL this time of year? I am

interested in most all types of nature and wildlife photography, so

specific information about types of habitats, critters or plants

likely to be encountered, or any general impressions on this site

would be welcomed. Thanks in advance.

Gary,

Sunnyhill Restoration Area is a big parcel of land being reclaimed by the St. Johns River Water Management District. I've only been there once, and access seems to be primarily on foot, so I didn't get very far in. Nearby, however, is a fantastic birding location called Emeralda Marsh Conservation Area - Sunnyhill is north of Rte. 42, while Emeralda Marsh is about 5 miles south of 42 near the small town of Lisbon. You can take St.Rd. 452 south from 42 to get there, and there are numerous access points on 452, and on Emeralda Island Rd. which parallels 452. If you write the St. Johns River WMD at P.O. Box 1429, Palatka, FL 32178, and request a current map and regulations for Emeralda Marsh WMA, this will show you all the roads that traverse the area as well as parking areas and access points. I would particularly recommend the levee road surrounding Area 3, accessed via the Wood Duck Parking Area, S.M. Knight Parking area, or the West Yale Canal Parking areas. Area 3 is a big reclaimed flow-through wetland that is being used to filter and clean water pulled out of nearby Lake Griffin. It is loaded with ducks, coots, egrets and herons, and all sorts of other wetland birds right now, and in another month or two, breeding rookeries will start activity along the shore of Lake Griffin. It is foot access only from the parking areas, so be prepared to hike a bit. There are also some beautiful, mature live oak hammocks with huge masses of festooning Spanish moss in areas along Emeralda I. Road (esp. at the Bull Hammock Parking area). This whole WMA is a fantastic, and relatively little known gem for wildlife viewing. Blue Spring is a standard Florida state park - very user friendly, well-maintained trails and boardwalks, a beautiful spring run full of cool fish (native and introduced, fresh and salt-water) which can be viewed with relative ease if you're into that. It also has a variety of habitats, from riparian hammock to scrub, and a couple of clans of relatively tame scrub jays around the campground area. Manatees are consistently present in the spring run until about March, or whenever the St. Johns River temperature exceeds 72, and they move out. L. Woodruff NWR can be hit or miss for photography - I've spent 1000's of hours there, and have seen a ton of cool stuff. Sometimes it can be slow, though. Its centered around floodplain cordgrass marsh that borders the St. John's River, but includes some forested habitat as well, from hydric hammock to dry xeric hammock. It includes 3 large managed impoundments and about 10 miles of levees surrounding them where wading birds can sometimes be abundant. Photography of many of the birds will require a pretty long lens, although I occasionally get decent shots with a 400 (you can see some habitat shots and birds from Woodruff at www.stetson.edu/~pmay/). Limpkins can be conspicuous and easily photographable at times, as can gators and other typical marsh inhabitants. There are gopher tortoises and diamondbacks in the drier habitats along the railroad as you enter the refuge, though the db's can be quite difficult to find most of the time. Even if the wildlife isn't cooperating photographically, it is a beautiful and relaxing place with a real feel of isolation if you get far enough away from the parking lot. Unlike the Florida state parks, the number of people that use the area is much lower, and you can feel like you have the place to yourself sometimes. That's my brief (ha!) overview - feel free to e-mail me if you have more specific questions.

The photographer who first did this was a biologist/lepidopterist/photographer named Kjell Sandved. I think he was associated with the Smithsonian Institution at the time. I'm sure the idea has been copied many times since then - I think Sandved first did this back in the 70's or 80's.

Thanks to everyone for your thoughtful answers. The $20 figure for the filter was off the top of my head; the point was that I didn't want to spend more money for a better filter only to experience the same effect. I don't particularly like it. I haven't carefully inspected the filter for the aberrations you suggested, Kurt, but there was nothing obviously weird about it on superficial inspection. The artifacts are most apparent in a brightly lit scene, with lots of detail in the background. Sunlight coming through foliage produces it big time, but only when the the foliage is way out of focus. I have no feeling for the effect of aperture, since my N70 doesn't have DOF preview, and with the 400 I'm usually shooting at or near wide-open. If I have any more profound insight (yeah, right) about this subject I'll pass it on.

Bob,

 

Thanks for your response. Yes, it is a real effect, and is definitely originating from the filter. I played with the filter/lens combination on a tripod-mounted camera for quite awhile a couple of days ago to convince myself that it was so. The parallel lines that are so apparent in the viewfinder when viewing some out of focus highlights COMPLETELY disappear when the filter is removed and the same scene is viewed again seconds later. I've had this lens for a couple of years, and for the first year and a half didn't use a filter (a la John Shaw's opinions about sharpness). After reading several discussions here about most photographers never reaching the resolution limits of their equipment due to imperfect technique, I figured a filter wouldn't make a noticeable difference, and started using it. I first started noticing these bokeh artifacts in some slides soon thereafter, but really didn't make the connection to the filter until recently (these artifact are only obvious under fairly specific lighting and background conditions). Maybe I just got a bad filter - but I really don't feel like kicking $20 for a replacement if its going to happen with any filter I replace it with.

I'm posting this to the Nature forum because it is a problem that I've

encountered only when using a long telephoto lens, and I figured

nature shooters would be more likely to have encountered it. Some

pros (John Shaw for one, I think) don't routinely use UV skylight

filters on all of their lenses because any filter, regardless of

quality, will degrade image quality somewhat. Others feel that

the benefits of protection outweigh any slight image degradation.

I've never seen this problem discussed, though. When using a Sigma 400

APO lens with a UV skylight filter, I've noticed on many shots where

this a brightly lit, heterogeneous background, the out of focus

highlights sometimes take on the appearance of a series of parallel

diagonal lines. Sometimes it is quite apparent. You can see an

example (I hope) in this photo of a

<a href="http://www.stetson.edu/~pmay/moorhen.jpg">moorhen </a>,

particularly in the area above the bird's head. Recently, while

viewing a brightly lit background through the lens, I found that when

I took the filter off, these lines in the bokeh completely

disappeared, so apparently it is due to some sort of diffraction

effects originating with the filter (its a Tiffen). Questions: Can

anyone explain the physical basis of this phenomenon? Is it specific

to longer focal length lenses? Are there any ways to minimize it

while still using the filter for protection? Is this peculiar to only

some filters? Thanks for any help you can offer.

Ditto the suggestion about Orlando Wetlands Park. If you take State Rd. 46 to I-95 to get to Merritt Island, you should be there in less than an hour. 46 can be reached from I-4 or 17-92 just south of Sanford, and the drive between Sanford and Mims on 46 goes through some beautiful habitat, and crosses over tribuaties of the St. John's River a couple of times; eagles and a variety of wading birds can be seen at many points along this route. Once you reach I-95, its only a couple of miles until you reach the exit to Merritt Island (Rte. 206?). It's certainly quicker than taking I-4 south to Rte. 50, and a more relaxing drive as well. If you're interested in unique Florida habitats, there are some nice natural areas off of 46 west of Sanford. Take I-4 north to the Rte. 46 exit, go west, and in a few miles you'll see entrances to several state parks and forests - Seminole State Forest on the north side of 46, and Rock Springs Run State Park on the south of 46 a couple of miles after you cross the Wekiwa River. Habitats range from small semi-permanent wetland depressions to xeric upland habitats within a few hundred yards, as well as big stands of pine flatwoods and some beautiful oak hammocks. Whereas the bird photography opportunities are not quite as plentiful as at Merritt Island or Orlando Wetlands, there are a variety of birds there, and the habitats are really nice. Lots of black bears in the area too (you'll notice big black bear exclusion fences and underpasses along several stretches of 46), although they are not predictably seen. Drive a few miles further north on I-4 to Orange City and visit Blue Springs State Park if you're interested in manatees - they are always present in the spring run throughout the winter, and there is some beautiful habitat in the park as well (although way too many people, esp. on weekends). There are also a few clans of fairly tame scrub jays in the park, usually near the campground area. Ask for the park naturalist, Rich Harris, at the entry station for specific info about where the scrub jays have been hanging out recently. If you have specific target species or habitats, feel free to e-mail me for more suggestions. You'll enjoy it wherever you go; February is a great time to be in central Florida.

Chris, (you twit)-

You're correct; this isn't a question. It is one of the more interesting threads (to me) to appear recently, though. I hope others continue to contribute. There are no spring wildflowers to speak of in central Florida, so things are pretty much normal here. We get to bask while northerners suffer through their miserable winters, but we do miss the vernal explosion of life that those in more temperate climes experience. (Just kidding about the twit thing, Chris).

I know this subject has been covered before either here or in

photo.net, but I've searched the archives in both places a couple of

times and can't find the thread, so please direct me to it if anyone

knows of it. Bogen's Quick Release plates have a thin cork layer that

is very poorly glued to the metal. It creeps sideways everytime any

torque is put on the lens; this is especially bothersome with longer

lenses. Eventually the cork pad becomes tattered and fragmented.

Someone suggested replacing the cork with another material and a

specific adhesive, but I can't recall the details. I think it was

automotive gasket material and gasket cement, but I'm not sure.

Anybody have a solution for this problem? Thanks in advance for any

advice.

Part II. Eggs hatch about 70 days after laying, so baby gators start showing up in late August-September.

Brian,

 

Females build nests and lay eggs in late June-July. Males start bellowing and courting females around May. You can hear the males bellowing just about anywhere in Florida where there are decent gator populations (which is just about everywhere) if you're at the right place at the right time. However, they seem to be a bit reticent about doing it out in the open, in my experience. If the NG special you saw was "Realm of the Alligator", most of the filming of alligator behavior was done at the St. Augustine Alligator Farm. Dr. Kent Vliet did his doctoral dissertation on courtship behavior, and spent hundreds of hours in the water with them there documenting their behavior; he coined the term "water dance" for the way the subsonic portion of the bellow makes the water boil up. My guess is that one of the alligator farms would be your best bet for observing this neat behavior.

 

Peter

Don et al.,

One more superfluous comment and then I'll shut up about Florida scrub

jays. I didn't intend to be contrary or obstreperous, but just wanted

to point out that in the many decades during which development has

proceeded in Florida, scrub jays have not adapted to urban

environments. They will use suburban areas/lawns/gardens

occasionally, but only when there is real scrub habitat nearby. They

are in many ways genetically and behaviorally distinct from western

scrub jays (they are the only scrub jays except for some populations

in Mexico that breed cooperatively, for example), so it may be that

they have evolved fairly rigid "habitat templates" that simply prevent

them from expanding into other non-native habitats. I did completely

misinterpret your original comments, Don, and thought you were arguing

that habitat destruction/modification was somehow "good" for some

native species because it forces them to adapt to new, more widespread

habitats. That might be a new paradigm for conservation biology that

developers would love, but it would be disastrous for the majority of

organisms. Peace out.

Archbold Biological Station is in Lake Placid, and the phone # is

(941) 699-1927. This is a great place to see native Florida scrub in

all its glory (sic). It is a private research facility, however, so

there are no naturalists or staff to guide visitors. There is a

self-guiding nature trail open to the public. Group tours can be

arranged by appointment. They ask that all visitors register at the

main office and sign an insurance waiver when they visit the station.

As Kevin suggests, the scrub jay population here is one of the most

thoroughly studied in the world, and as such is interesting from both

a scientific and historical perspective.

I realize that this has gotten way off topic, but I had to throw in my

worthless opinion anyway. Urbanization has certainly not benefitted

the scrub jay in Florida. I don't know anything about habitat

selection in western scrub jays, but in the Florida species it is very

specific. They will only breed in recently disturbed scrub, and

abandon it about 10 years post-disturbance. I don't know how many of

you are familiar with Florida scrub, but appreciation for

the esthetic qualities of regenerating scrub is definitely an acquired

taste for most people. Not the sort of landscape that

homeowners/urbanites want to live near. Combine that with the fact

that the normal disturbance regime is fire, which most homeowners are

not fond of either, and you've got a habitat type that disappears

rapidly when humans encroach. They don't "acclimate" to sub-optimal

habitat. People and the habitat modifications they bring are the

Florida scrub jay's worst enemies.