Observation 11097: Cortinarius alboviolaceus (Pers.) Fr.
When: 2008-09-10
No herbarium specimen

Notes: Orange marks on grey-violet stem and gills. Might be a milky, but if so it’s not in my field guide.

Proposed Names

40% (3)
Recognized by sight
57% (1)
Eye3 Eyes3
Recognized by sight: I now concur that the orange marks are rust-colored spores stuck to what’s left of a cortina, after seeing similar markings on undeniable C. alboviolaceus specimens.

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Improvements
By: Paul Derbyshire (Twizzler)
2008-09-14 08:05:46 BST (+0100)

The improved photographs starting around Sept. 10 are the result of a few simple tips that might prove useful for others.
1. Use a tripod. It should have telescoping legs that can be made very short, only a few cm long. Metal parts. It should also collapse into a fairly small bundle that will fit in a backpack. Good enough ones can be had fairly cheap.
2. You’ll need to use the LCD viewfinder a lot if you don’t want to crawl in mud to peer into the traditional kind. That in turn will chew through battery power. Bring at least three times whatever the camera uses, fully charged. Use rechargeables or you will be hemmorhaging money buying batteries. Also turn off the camera once you’ve got good photos of the current specimen, and turn it on again when you find your next, to conserve power.
3. Use the 10 second timer that your camera almost certainly has. This also adds to battery power used as the camera is on for longer, but it ensures that the camera is rock-steady when the photo is taken since your hands can be completely off it at that time.
4. Tape a piece of paper (the corner torn off a utility bill will do) over the flash. This will reduce and diffuse the flash a fair bit and is easily reversible when you need a strong flash again. You won’t for subjects only a foot or less from the lens. This will stop pale/white mushrooms being washed-out white blobs.
5. Learn how to use the image browser built into the camera, both to examine the most recently taken photo and to zoom into the currently displayed photo to show a subset at 1:1 pixel resolution. This lets you check image quality in the field and retake a photo until the focus is just right.
6. Put a blank card behind the mushroom when you press the trigger and start the countdown, then remove it before the camera goes off (or leave it there to avoid having a cluttered background, if you prefer; if you’ve made a field ID you might also use a card labeled with the species name). The autofocus will trigger on most camera models when you first depress the trigger, rather than when the camera actually takes the picture, so the card will be there during focusing and will leave the autofocus with little but the mushroom to focus on and thereby make it more accurate sometimes.

Somewhat adapted from suggestions seen at mushroomexpert.com. And based on the results I’ve had with pictures like these two, they work.

Needed:
Bit of paper (free)
Blank white card (essentially free)
Tripod ($30 and up, but you may already have one)
3MP or more digital camera with timer, LCD viewfinder, image browser that can magnify, and at least 3x optical zoom. Should either have upwards of 1GB of on-board memory or a memory slot, preferably SD. ($200 and up, but you may already have one)
1GB or more of storage, either built into the camera or (often more convenient for moving data around) removable. (A 1GB SD card can be had for about $20.)

The camera used to take these was an HP Photosmart 735, which is near the bottom of the above specs and produced the gorgeous 2048×1536 gills close-up in this observation. It doesn’t take gobs of money and high-end equipment — it takes under $300!

Recommended additional equipment:

  • Bug spray is essential in many of the best mushroom-finding habitats! Something with over 20% DEET is recommended. Wait several minutes after applying before handling your camera, or the camera’s plastic parts may become marred.
  • A backpack is useful. Camera cases don’t usually have room for a tripod! The backpack also provides more protection for your electronics and data if bad weather develops while you are in the field. The backpack also lets you pack a field guide or two and any other tools you might find useful.
  • Wax paper bags, many small ones, if you intend to collect specimens and not just photograph them in situ. This may be to submit to a herbarium, make your own, take spore prints, or cook and eat the edible varieties for that matter.
  • If you are collecting specimens, they may not react well to being put in the backpack; an open-top basket may be useful for transporting specimens. Still have a backpack for everything else.

Created: 2008-09-14 06:20:12 BST (+0100)
Last modified: 2008-09-14 06:20:12 BST (+0100)
Viewed: 32 times, last viewed: 2016-03-20 22:36:01 GMT (+0000)