Single shots/stacks

I have recently been using stacking most of the time rather than single shots for botanical subjects. I had a slow start from late 2016 when I first tried stacking using post focus with a Panasonic FZ330. This was limited to experimental use of stacking, as was my first year or so with a Panasonic G80. 

The reason my use of stacking was so limited was that I encountered sufficient problems with doing the stacking that it put me off. The main problem was halos, but there were also issues with ghost images and backgrounds being very noisy and/or posterised and looking very ugly. Dealing with images with those problems could be very time-consuming, more so than seemed worthwhile. It was only during 2018 that I slowly came to a better understanding of the causes of the problems and how to deal with them, and when to give up because the problem was too difficult to be worth trying to solve.

With the FZ330 I was limited to using post focus to derive JPEGs for stacking, and this used 4K video from which I could extract 8 megapixel JPEGs. The G80 also did post focus, with 8 megapixel 4K video, but it also did focus bracketing. This allowed the use of full size images, raw as well as JPEG. It therefore seemed the better bet in terms of image quality. 

Focus bracketing could indeed produce very good results, but there were downsides. I like to work hand-held, and I could do this when using post focus, which captures frames at a rate of 30 frames per second. This meant that the time needed to capture the images was typically from between two and six seconds, which worked fine hand-held. Focus bracketing worked over six times slower, at around 4.5 captures per second. That made capture times uncomfortably long for hand-holding. Also, managing large numbers of individual images, especially large numbers of raw files, proved significantly more onerous than managing a single video file per capture. 

I was also not convinced that using raw rather than JPEG or using focus bracketing rather than post focus produced better image quality. That seemed to be determined largely by how well the stacking worked and what measures I had to take to cure the problems.

It was when I got the G9 in late 2018 that my use of stacking really took off. The G9 can use 6K post focus and this produces 18 megapixel images, which is actually more pixels than full size G80 images. Also it lets you use a very flat camera profile, Cinelike D, and I found that using this coupled with minimising JPEG noise reduction and sharpening led to stacked images from Helicon Focus with tonality that I liked and which responded well and easily to post processing, although much to my surprise, they turned out to need very little adjustment a lot of the time.

And what about the halos, ghost images and nasty backgrounds? They seem to be less of a problem now. Partly this may be because Helicon Focus has had an upgrade and can deal with some of the issues better.  And partly it may be a matter of having more experience with the stacking software and coming to a better understanding of how to use it effectively, and how to use other software such as Lightroom and occasionally Photoshop better to deal with problems that Helicon Focus can't. And perhaps I am a bit more relaxed about the imperfections. I have come to realise the obvious reality that single shot botanical images have their own issues and that on balance even with their imperfections I often prefer stacked images to single shot images of the same subjects with their different imperfections.

I think my main problem with botanical stacking at the moment may be that I am using it too much, hardly using single shots at all. Looking back through a large number of botanical images in preparing these blog entries I realise that there are many that I like just as much as I like some of the recent stacked images, and so I would probably do best to use both single and stacked imaging for botanical subjects. The G9 makes it quick and easy to switch between exposure bracketing and post focus.

As for invertebrates, I know that it is possible to produce wonderful stacked images of the sort of subject matter and magnifications I deal with using kit that I have - G80 or G9 with and without Raynox lenses and/or extension tubes. I am hugely impressed with what this photographer does with stacked images of invertebrates using this kit, and using it hand-held I think. However, in my limited experiments so far with a couple of dead insects I have found around the house my results have not been good. I will try with live subjects when the invertebrates reappear, but it may be this is a tecnique that is not going to work for me. One thing that has become clear in discussing techniques and results with other close-up/macro photographers over the years is that what works for one person may not work for another, even amongst equally competent photographers.