Observation 44830: Agaricales sensu lato
When: 2010-03-18
No herbarium specimen

Notes: This fungi had widely separated gills, no smell and a thick stipe. There was a touch of pink showing in the centre of the cap. The cap was about 6cm across.The cap was dry and firm to touch. I thought the stipe was short and unuasully thick in comparison to the size of the cap.

Images

84508
Copyright © 2010 Ian Dodd Kundabung NSW Australia

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So
By: Paul Derbyshire (Twizzler)
2010-05-02 08:49:24 CDT (-0400)

the basic problem is that you’re enlarging a 300×300 pixel area to something bigger. This will generally blur the image. To get the area of interest sharper under these conditions the only thing you can do is make the subject get covered by a larger number of pixels to begin with. For this, there are four possibilities.

1. Get the subject larger in the camera’s field of view, by moving the camera closer to the subject, using a different lens, or something.

2. Use a camera with more megapixels.

3. Use low-ISO film and have it enlarged. (Ick.)

4. Use an additional tool, like a magnifying glass, between the camera and the subject.

Paul

I havent probably explained in enough detail. Paul, your second paragraph is close to being right but you must remember you are looking at the untouched image on the screen zoomed to 1:1 at say 3000×3000 pixels per inch.. Surmising you understand resolution and say the image is 3000×3000 pixels. I then extract an area 1/10 of that image and show it at the original physical size of the taken image. The cropped image size will be for example 300×300 pixels spread over the same original area of 3000×3000 pixels. If the original image is not pin sharp, and then a section cropped, the resulting image will show increased poor resolution, 300×300 pixels, (Loss of detail)and increased edge blur. If the original image is sharp no problemo. Determination of this can only be verified in Photoshop or similar software. (not possible on the little screen.
The viewing (rear screen) on the camera (D300) for example has a 3inch TFT LCD screen. What is actually happening is you are looking at a high resolution image file crammed into a 3 inch monitor and only shown as a jpg, when the VGA: is 640×480x 3 colours. Most point and shoot cameras do all the funny bits, like sharpening, saturation etc in camera.(you have no control over it.) The Dslrs used in RAW mode do not alter the image in any way. The rear screen allows you to zoom 1:1 of the Original Image.
I always shoot Raw and at the lowest possible ISO without flash to render the closest possible true colours. I do all my own printing and have just had an exhibition opened (with other photographers) on a social documentry .( 140 images were hung.)
What I am trying to say is that when the image is cropped (in photoshop), then you only have say 300×300 pixels to spread over the original size of presentation. There is an article about the screen at ………>>>>>
http:www.Cameralabs.com/reviews/Nikon D300/screen.shtml
It only gives the specs and doesnt give you all the detail I have commented on, but is worth a read. Chow, kk

This
By: Paul Derbyshire (Twizzler)
2010-05-02 00:23:22 CDT (-0400)

is not making much sense. Are you saying that the camera’s image view mode doesn’t let you get down to 1:1 pixel resolution (albeit with only a small region of the photo visible at a time)? That would be odd, since my $100 disposa-point-and-shoot would then beat your Nikon D300 on at least one important feature, which in turn seems implausible.

If you mean you get blurry images if you crop and blow up a part, digital images will do that. There’s nothing “between the pixels” that the computer can use to magically extract more detail that wasn’t in the image data to begin with. Getting closer to the subject and/or using a magnifying lens in the field is the only way to increase the detail. Or take a film photo with very low ISO and have it enlarged by a professional, but that gets very expensive very quickly unlike digital photography.

Paul

The Nikon D300 (semi-pro body),has a facility called “Live view” which can be programmed to be used in two ways, (Tripod mounted or hand held.) I always use the tripod mounted menu setting. This live view facility is quite excellent especially for Macro work. When checking the result with the viewed image facilty, which does exactly the same thing and allows you to zoom in to the same degree. (the same amount as the live view zoom.) It works on the principle of focus contrast selection.
70% of the time this is successful. What happens is if I crop the final image (see 44915 2nd image {Myxomycete}) This image could only be varified as sharp when I download the cf and check the image for sharpness in Photoshop. The camera image review screen on full zoom would look sharp but in truth when cropping is carried out, this is not the case. In other words the Live View and Review Image have limitations that present themselves in Macro cropping. Hope I have explained this feature sufficiently. chow. kk

How are you checking focus?
By: Paul Derbyshire (Twizzler)
2010-05-01 21:35:34 CDT (-0400)

With an optical viewfinder or something before the shot? I was talking about reviewing the digital image, using the camera’s browser, after the shot and retaking it if necessary.

Paul FYI

I find what you say true. What happens though, with macro, is the display is not able (at full magnification) to give a real review, especially when shooting at 1:1 and as close as possible to frame the image. When using the normal shoot mode, & (not using a macro lens), this works fine to check say the birds eye, etc for detail and sharpness.. I have learnt with regret , not to rely on the rear screen view for macro. I also use several Pro bodies (Nikon), and the newer bodies do give a far better idea than say the D2x’s. I also use live view for macro work, but that only works whilst you take the image. The replay is far less accurate. I also shoot in Raw mode, 14bit,. so I can crop heavily and still provide a reasonable resolution image. Saying this, thanks for the responce and effort to aid me. My problem is usually with the wet forest floors the tripod settling into position. I also use remote shutter release to reduce blurring. (Most of my images are taken at the lowest ISO available without flash. When I say I deleted an image, some would use it I suppose, but I try to only put up images that are sharp on my monitor at 100%. (I currently use a D300 for most of my macro work with an 180mm macro lens f3.5 or 105mm f2.5)) Thanks for your input on my other images, most appreciated. kk

Photography
By: Paul Derbyshire (Twizzler)
2010-04-30 22:26:09 CDT (-0400)

My last 2 cameras, and I think most modern cameras, provide a way to zoom into the stored photos until you’re seeing a small bit at 1:1 pixel scale instead of a downsampled thumb of the whole photo. Checking the small bit that was at the focal point of your image this way tends to suffice to tell if it’s sharp or not.

Paul

Yes I usually check the image and the histograms, but with very small fungi that is shown on the site at 100%, it doesnt take much for the image to be unsuitable for evaluation. It can look ok on the rear screen and still be useless. Obviously a laptop is the way to go, but then you need someone to carry it. I do not get many offers even for the tripod. (smile)…. I usually carry two professional bodies, two lenses, (macro and 300mm f2.8) and flash gear and the usual necessary bits and pieces. I also do bird photography.

That sort of thing
By: Paul Derbyshire (Twizzler)
2010-04-29 19:13:49 CDT (-0400)

is why I always check my photos for problems in the field these days, using the display function of my camera, and reshoot as necessary.

Okay at least you tried.
By: Johannes Harnisch (Johann Harnisch)
2010-04-28 22:11:00 CDT (-0400)
Reply comment

I did take a shot of the gills, but the image was so blurred I deleted it..Just my luck. I think the tripod moved in the wet soil.

nice pictures
By: Johannes Harnisch (Johann Harnisch)
2010-04-28 13:04:46 CDT (-0400)

a picture of the gills would help, are they notched free, attached etc

Created: 2010-04-28 01:04:49 CDT (-0400)
Last modified: 2012-09-06 06:32:53 CDT (-0400)
Viewed: 148 times, last viewed: 2016-10-24 17:46:54 CDT (-0400)
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