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Focus Stacking for macrophotography – easy as pie with Olympus cameras

Friday, July 14th, 2017

One of the main problems with macrophotography is inadequate depth of field – that is, not being able to get your whole subject in adequate focus.

In the macrophotography realm, it is common to only have around 1-2mm of subject depth in focus, forcing one to either use very small apertures such as f/16 (which then drops resolution due to diffraction effects, increases how annoyingly busy the background is as well as requiring much longer exposures).

Die hard macrophotographers resort to a very complex, time consuming technique to address this called focus stacking whereby they take a number of shots at slightly different focus distances and then on a computer, use special software to merge these together to give an apparent expanded depth of view.

Olympus has recently come to the rescue for those of us who are not quite as obsessive, and added a brilliant little feature to their latest cameras which does all this automatically – albeit, with some limitations, critically you can only do 8 shots, you have to use the electronic shutter, and the final merged image is a slightly cropped jpeg image – not a RAW file, so you really need to get your exposure correct, your white balance correct (DON’T USE Auto White Balance!) and your picture style correct BEFORE you shoot.

For more information on this, see Olympus focus stacking feature on my wikipedia.

It does take a little trial and error in choosing the best aperture and the step differential for a given lens and subject.

The step differential is the distance the camera will adjust the lens focus between each shot, and Olympus allow you to choose a number between 1 and 9, but they incorporate a complex algorithm to determine how much 1 step equates to depending upon the aperture and focus distance chosen – in practice it seems that 1 step is approximately 1/3rd of the depth of field, and thus for most subjects you probably are best to use a setting of 3-5.

All of the following were shot with the Olympus OM-D E-M1 II Micro Four Thirds camera with Olympus mZD 60mm f/2.8 macro lens (jpegs straight from camera just re-sized for web), and whilst not true 1:1 macros, they are good examples of what most people might try outdoors:

Here is a single shot straight from camera to show that you can often get away without focus stacking by using a small aperture, but the cost is a very busy background – this is a small 2cm toadstool attached to the side of a eucalypt tree in a dark forest shot at f/16 with an 8 sec exposure at ISO 200:

fungi

Here is the same shot taken with automatic in camera focus stacking, 8 images, f/4 at 0.5 sec at ISO 200 – note it is slightly cropped, but the background is now a lovely soft blur while the mushrooms are still adequately in focus – just amazing that the camera’s algorithms can create such an image!

fungi

Here is a closer shot of same subject at f/6.3, 0.6sec, ISO 200 with 8 image focus stacking:

fungi

Another example of some tiny mushrooms on a tree stump taken with focus stacking – without focus stacking I could only get 1 or 2 of these in focus even using a small aperture, and even with 8 image focus stacking I needed to resort to f/11, 2 sec exposures at ISO 200 to get as much as this in focus. These were only about 8mm height for the tallest one:

fungi

One more example, of a larger group of mushrooms which had a dead mosquito stuck to the surface and a couple of minute mite-like insects nearby – this was taken with the 8 image focus stacking at f/8, 0.5 sec at ISO 200 and the image has been cropped into portrait aspect (it was getting late and dark and I couldn’t be bothered adjusting the camera into portrait on the tripod and re-composing).

fungi

Not all shots will work for you, and you do need to avoid camera shake when triggering the exposure – unfortunately, it seems you cannot set a self timer delay in this mode, and you must remember to focus on the CLOSEST part you want in focus – the bracketing is a bit of a misnomer here as it doesn’t bracket either side of your focus point.

In addition, you need to use a tripod, and a lens which is compatible with this mode, and remember to reset your manual focus after each shot.

The native live view of mirrorless cameras, ability to get accurate manual focus with magnified view, and the ergonomics of the flip out screen makes this kind of photography far more enjoyable than with a clunky dSLR. It would be nice if the Olympus smartphone app allowed focus stacking in remote control as this would allow a total no touch technique and less camera shake, but alas it doesn’t as yet.

You will be surprised at how useful this is.

Of course, if you want the BEST image quality you should use focus bracketing mode without in-camera focus stacking to give you a self timer and lots more images to play with -  this will allow you may to use a smaller step differential of 1-2 and MANY images – perhaps a hundred! Then you can load them up in your favorite focus stacking software and hopefully get less artefacts.

Amazing multicoloured bioluminescent Ghost Fungi mushrooms at night under an auroral glow

Saturday, May 27th, 2017

I went for a bush walk in a rather remote Victorian forest today and, unexpectedly, stumbled across an isolated patch of Omphalotus Nidiformis mushrooms – the “Ghost Fungi” which give off a very dim eerie glow in the forest at night (to our naked eyes without colour vision, using only rods in the dim light, they appear white).

He they are just after sunset taken hand held with the Olympus OM-D E-M1 II Micro Four Thirds camera with Olympus mZD 25mm f/1.2 lens (jpegs straight from camera just re-sized for web):

Ghost fungi

The above was hand held resting on my thigh at 1/4sec, f/3.5, ISO 1250.

Ghost fungi

The above was hand held resting on my boot at 1/4sec, f/2.5, ISO 640.

Ghost fungi

The above was hand held resting on my thigh at 0.6sec, f/4.5, ISO 1250.

So, hoping I was correct, I headed back into the closest town, had a quick bite, then headed back well after twilight had finished, and there they were, once my eyes had adjusted to night vision, the patch of fungi giving off their strange light.

Here are a few I shot with the Olympus OM-D E-M1 mark II with Olympus mZD 25mm f/1.2 lens sitting on a towel as a support (jpegs straight from camera just re-sized for web – no light painting or artificial lights, and white balance for these was set to sunny day):

Ghost fungi

The above was at f/2.8 (trying to get some more DOF), ISO 1600, noise filter = LOW, long exposure NR on with an 8 minute exposure using the very handy Live Timed function (I didn’t bring a remote to activate a BULB mode – thankfully the OM-D’s don’t need one!) and shows some lovely orange as well as green, with the top left corner being the brighter night sky (perhaps 2 stops brighter) illuminated by an Aurora Australis or Southern Lights.

The still night air without a breeze to be felt allowed me to use these nice long exposures, rather than having to open the aperture up to f/1.2 and loose depth of field even more than I was losing.

I could just imagine all the local insects coming out to dance and sing under the soft light – but it was too cold for most of them tonight – which saved me getting a few bites at least!

Ghost fungi

The above was as for the previous one but f/2.0 at 4 minutes exposure.

And, finally, just for a little fun at 10pm on a winter’s night, all alone in a remote forest, a fisheye view – taken with the unique Olympus mZD 8mm f/1.8 fisheye lens sitting on a towel at f/1.8, ISO 1600, 2 minutes to avoid the bright auroral sky washing out – and yes, you can tell it is looking south from the out of focus star trails making an arc around the South Celestial Pole somewhere near the centre of the image.

Ghost fungi

Camera settings for shooting these ghost fungi at night:

  • I used a 25mm lens (50mm in full frame terms) but one could go wider than this
  • getting adequate depth of field while keeping ISO low and exposure duration a minimum is a challenge without resorting to complicated post-processing focus stacking techniques – for the 25mm Olympus lens I prefer the f/2.8 setting but this required 8 minutes exposure at ISO 1600, if using an equivalent 50mm lens on full frame this would require using f/5.6, 8 minutes at ISO 6400 – so any high ISO benefit of full frame is lost.
    • if it is windy, then you will not be able to achieve nice imagery, even if you chose to shoot at f/1.2 and ISO 12800 to gain a shorter shutter speed, it may still be too long if the fungi are moving – go on a still night without wind, and suffer the pea soup fog on your drive home.
    • if you can’t shoot BULB (you didn’t buy an Olympus and you forgot your remote control), then you may need settle with f/1.8, ISO 6400 and 30secs
  • manual focus and a torch is a must – and it helps if your lens has a nice MF clutch, and your camera can do magnified view to allow you to accurately manual focus using a torch to assist
  • I chose to shoot sunny day white balance as I wanted to see what the colours were like compared to our normal visual experience of a sunny day
  • Noise filter should be set to LOW or OFF as ideally you should be removing noise in post-processing (I haven’t done this in these images – I will wait til I get a chance to process the RAW files)
  • Long exposure noise reduction should be set to Auto or ON – this does double the length of waiting for exposure to finish but it removes the thermal noise and you don’t need that!
  • I decided not to use my tripod as I wanted to be at ground level so i rested the camera on a towel
  • turn IS OFF
  • If you don’t have an Olympus camera then you will need to bring a remote trigger for your BULB mode to get past 30secs

The Olympus OM-D E-M1 Mark II with 25mm f/1.2 is great for this type of photography as:

  • the image stabiliser is fantastic when using it hand held for the dusk shots
  • ISO 1600 or 3200 is usable, and that is all you really need for the night shots
  • the flip out LCD screen means you don’t have to get down level with the camera on your stomach and get real dirty or have crawlies all over you
  • the 25mm f/1.2 not only is an amazing lens which focuses twice as close as similar full frame lenses, but it has a wonderful manual focus clutch
  • accurate manual focus is easy using magnified view mode
  • noise reduction phase displays a count down so you know how long you have left
  • if your torch is getting dim, you can have the Live Timed mode automatically activate Live Boost so you can see in the dark better
  • normal timed exposures go to 60 secs not like most other cameras where you need a remote control to activate BULB mode to get past 30secs
  • Live Timed mode allows you to visualise how the image is developing (eg. every 30 secs):
    • if you stuffed something up like composition, just terminate the exposure rather than wait until your planned exposure finishes
    • you can see how the histogram and image exposure is devloping, and then terminate when desired – this is how I chose to terminate the fisheye shot – when I saw the sky was starting to blow out
    • unlike BULB mode, you can set a duration for it to last and it will self-terminate the exposure without you having to be there with a remote control – this allows you to use another camera to do something else such as take Milky Way astroscapes while you wait 16 minutes for an 8 minute exposure and 8minute dark frame.
    • you don’t need a remote control – just wait for it to time out or press the shutter button to terminate exposure.
    • you can see from 5m away what the status is – is exposure still occurring or is it in noise reduction phase when its OK to turn torches on, or is exposure complete

For more mushrooms, see my previous post

Is this the biggest documented Amanita farinacea (Australian Flour Lepidella) mushroom – cap of 30cm diameter?

Sunday, May 21st, 2017

It’s Autumn in Australia and mushroom time.

I stumbled upon an amazing white mushroom in a Eucalypt forest at altitude around 800m on Mt Macedon in Victoria after the rains which was so big and white with a veil of delicate frills all around blowing in the wind and white drops on the ground nearby (hence the Flour in its name)  that it looked like it was artificial and someone had just dropped a can of white paint on to it!

As I understand it, all species of Amanita mushrooms have white gills underneath, and most are poisonous – these ones are not likely to be fatal, unlike the Death Cap (Amanita phalloides) with its amanitin toxins which destroy the liver in a few days.

Amanita Farinacea

The gigantic Amanita farinacea mushroom was adjacent a massive Eucalypt tree – I placed my iPhone 6s for reference and although I did not have a ruler, the cap of it measured at least 30cm in diameter – this species is usually said to grow to 10cm diameter.

A few days later, I found a more juvenile specimen some 10 meters away which stood some 6″ tall and perhaps 4-5″ in diameter:

Amanita Farinacea

Both of the above were taken in low light at dusk, hand held with the Olympus OM-D E-M1 II Micro Four Thirds camera and Panasonic Leica-D 25mm f/1.4 lens for Four Thirds, the first image shot at f/2.8, ISO 800 and 1/20th sec while the second image was shot at f/5.6, ISO 800 and 1/30th sec.

Some more common poisonous Amanita mushrooms:

Everyone’s favorite fairy tale fantasy mushroom – the colorful, warty, Fly Agaric (Amanita muscaria) from an oak forest:

Amanita

Olympus OM–D E-M1 II with Olympus mZD 75mm f/1.8 lens at f/1.8, ISO 200 and 1/100th sec.

The Fly Agaric is likely to cause delirium, hallucinations and possibly coma and seizures within 2hrs of ingestion – if someone was stupid enough to try eating one.

and presumably a related couple in a pine forest:

Amanita

The above was taken in very low light under dense pine forest canopy hiding adjacent to a fallen tree trunk, taken hand held with the Olympus OM-D E-M1 II Micro Four Thirds camera and Panasonic Leica-D 25mm f/1.4 lens for Four Thirds – f/2.5, ISO 500, 1/10th sec – thanks to the awesome image stabilizer in the E-M1 II.

And, who can resist some fall foliage?

foliage

The above was taken in very low light at dusk under a canopy of trees, taken hand held with the Olympus OM-D E-M1 II Micro Four Thirds camera and Panasonic Leica-D 25mm f/1.4 lens for Four Thirds – f/1.4, ISO 200, 1/15th sec – again, thanks to the awesome image stabilizer in the E-M1 II.

 

 

Panasonic GH-1 with Leica-D 25mm f/1.4 on a quick forest walk

Wednesday, April 7th, 2010

On Easter Monday, I thought i would check out a local forest which was hand planted some 100 years ago in central Victorian highlands which makes it rather unique in Australia as it is mainly trees from northern hemisphere origin.

I had never been to this forest before and as it was a beautiful sunny early Autumn day, it would be great for a walk, but probably too sunny for great photographic forest landscape shots.

I only had an hour or so, so I took my beloved Panasonic GH-1 and Leica-D 25mm f/1.4 lens with the primary aim just to document ideas for shots in better lighting and when I had more time.

In stark contrast to native Australian Eucalypt forests, this man made forest of diversified trees including conifers, and oaks, had a very different ecology – most noticeable were the multitude of introduced mushroom species including the poisonous, hallucinogenic, Fly Agaric (Amanita muscaria) and the very weird absence of the usually omnipresent Australian native bull ant – which I must say made the walking a lot more relaxed, as no-one enjoys being stung by those ants!

Maybe the bull ants are killed by the Amanita, or they need Eucalypt habitat?

The flip out swivel LCD screen of the GH-1 was fantastic as usual for ground level work of hand held shots of mushrooms – the following two are at the closest focus of this lens and show the difference between f/1.4 (the first one) and f/2.8, – oh, and I do love native 16:9 image aspect ratio which is available on the GH-1!

at f/1.4:

f/1.4

and at f/2.8:

f/2.8

and here is a more mature Amanita muscara:

mature

and of course, I better show a sample of this lovely forest:

forest

more photos from the walk here