Bellows and sand macrophotography planing.

 Trying to wrap my head around sand macrophotography.

One issue is that the sands can be thick enough that they can't be completely in focus when magnified, so will definitely need to do focus bracketing/stacking. 

Olympus camera with in-camera focus stacking is pretty attractive since a person can take a photo and get a photo, instead of transferring files and doing the stacking on a computer with an adobe license.

For in camera focus stacking, on micro-4/3rd cameras, Panasonic does in camera stacking by taking a video and blending the frames, Olympus does normal focus bracketing and the blends them together. There's an issue where the individual frames in the Panasonic are smaller, around 8 megapixel, if I understand correctly. The Panasonic cameras that can do this seem to be expensive too. A used Olympus omd m-5 mark ii, alternatively, can be had for under $300.

With a bellows you can control magnification. Combining this with a macro lens should produce good results. Olympus focus stacking only works with a few cameras and a few lenses. The camera controls it's own lens, changes focus, then combines the photo. If the camera and lens are separated by a bellows, then there needs to be an electronic connection between them in order to do this.

Alternatively the whole thing can be put on top of a motorized rail made for focus bracketing, which will move the whole camera in steps to get the frames to build the stacked image out of. But of course doing this means you can't do the stacking in the camera.

Moving the camera for each frame can produce distortions, since each frame is now looking at the object from a different position. There is also a similar issue when the lens if being moved in order to get the frames for the stack, but apparently if only the camera, and not the lense, are being moved, there is no or much less distortion (again as far as I understand it at the moment).

This makes me think the best route is to use Olympus in camera focus stacking with a macro lens on a bellows.

So the equipment is

Olympus OMD e m-5 mark ii (I think an Olympus OM-D E-M1 can do it too i bet the bigger grip will get in the way, otherwise they're mostly the same camera inside)

$300

Bellows

$1000

Cross-bellows connection

(part of novoflex bellows)

Macro lens

$499

Teleconverter

$429

Reproduction stand 

$250

Total

Bellows

The bellows allows for magnification, probably for most bellows up to / no more than 7X beyond whatever the lens is putting out. Further magnification would be done electronically (and getting good results there would depend on the image quality and resolution of the original photo, so the lens but also the camera position during stacking issue now comes back up).

This bellows set includes the connection between the camera and lens:

https://www.adorama.com/nvbalmft.html 

The 'automatic' here refers to the ability to use the normal camera focusing feature, not the expansion/contraction of the bellows. This one is nice because it's available in an M43 connection size. Doesn't really seem like many other places make a bellows with the electronic connection, which is probably why Novoflex is able to force people to buy at such a high price. Other good basic bellows are $50. This is a thousand.

Reproduction stand

The camera needs to be mounted and held steady but also be able to be moved closed to the sand, which is going to be laying flat. Some people use a separate focusing rail that holds the camera and bellows system and allows that system to be racked back and forth along the rail, in order to set initial focus of the subject. You obviously can also use that to do the 'steps' in manual focus bracketing. There are also control systems that have motorized focus rails, an controller, and a camera connection, that will perform all the steps needed for focus bracketing.  Anyway the focusing rail then needs to be tripod mounted or something like that to hold everything in place and pointed at the subject.

A "reproduction stand" is a different way to do this. Repro stands basically end up looking like a microscope, with a vertical post that the camera+bellows can rack/slide up and down. This keeps the camera pointed straight down and orthogonal with the subject. Usually it's used to photograph slides in order to reproduce them. The subject has to sit flat like it's sitting on a table. This is perfect for sands and powders. Even for rocks it would be fine, though a rock broken at an angle might work better with a movable tripod (of course you can simply move the rock). Could even use a tilt-shift bellows to line up everything with the tilted face of a rock, but again cheaper to move the rock (it's another thousand dollars for a Novoflex tilt shift automatic bellows). Macrophotography of rocks in teh field might benefit from tilt-shift rails (apparently the technique is primarily used in landscape and architectural photography, so this seems to fit).

https://www.bhphotovideo.com/c/product/1336075-REG/smith_victor_402180_36_pro_duty_copy_stand.html

Macro lens

Now the lens.

Lenses that work with Olympus in camera focus stacking

https://learnandsupport.getolympus.com/support/e-m5-mark-iii/which-lenses-are-compatible-with-the-focus-stacking-mode

This includes a 1.4 and 2X teleconverter.

M.Zuiko ED 60mm f2.8 Macro

Includes a claim about not changing the lens length while focusing to avoid the distortion problem.

Teleconverter?

A teleconverter would allow even more magnifcation, as much as 2X, which could make a big difference here. Teleconverters make for dimmer and softer images but they don't affect the Depth of Field of the original lens.
https://www.getolympus.com/us/en/m-zuiko-digital-2x-teleconverter-mc-20.html

$429

Can skip the teleconverter and use a tripod I already have and save $750.

Alternatives

What if I skip the bellows too?

Can use cheap extension tubes with electrical contacts, plus macro lens and maybe plus the teleconverter and can then get a little more than 2X magnification.

What about alternative bellows? Novoflex sells a m43 'reverse adapter' that can be used without reversing the lens and that provides for electrical contacts. It's pretty clearly the ends and wiring that are part of the fully automatic bellows, but $500 less. Can buy a fotodiox m43 bellows for $30 and use that novoflex adaptor to keep contact.  Could also skip the teleconverter and stand to save another $750.

 Oly M2, reverse adaptor, macro lens, fotodiox bellows = around $1200.

Add 

So long as there are the electrical contacts, can use the in camera focus stacking. This allows for quick setup, one click for the shutter, and get a jpeg that is the photo stack.

Can also throw the whole thing out and start with a probe lens (which gets to maybe 2X). This can not do in camera stacking or bracketing since the lens is totally manual. People seem to be using these lens to shift focus manually for focus stacking, and they're expensive lenses (Venus Laowa costs $1700, Compacto series is 2K and more), so can't buy much else. Don't really need the thin probing feature for sand on a table I think.

Scattered thoughts on the origins of viruses

"Everything is either living or non-living"

THis is a classificationist/essentialist/didactic ontology or way of dividing the world and unlike most simple divisions it seems like it holds up well. Except for viruses.

Ask probably any teacher or professor and they'll tell you that viruses are non-living because they don't meet part of some list of criteria. Only a few will engage in an consideration of them being alive; for comparison only the most philosophical will suspend disbelief and entertain the idea that rocks are alive.

But the people who agree that viruses are non-living will also easily say that they evolve. This for a long time would've been contradictory, but now where we consider memes to be subject to evolution and definitely not alive, the tension between non-living and evolving isn't apparent. There should be tension because evolution came out of biology, no one looking at non-living but evolving things would've ever come up with the idea of evolution, I suspect.

Nothing that isn't man-made or alive evolves, except viruses. Perhaps rather than being an exception to the general rule they're subject to it and were in the past somehow connected to living things.

Living things reproduce, move, grow, and have some sort of metabolism. In the debates about the origin of life the main focus in fact is between reproduction and metabolism, rather than movement and growth. So perhaps those main features of living things are expressed very different across the whole tree of life. Some things practically don't grow at all. There's a gigantic (essentialist) division between life that reproduces by fission and life that reproduces sexually. Some living things don't move at all, like bacterial mats. And as far as growth, there are things that have the same form and simply grow bigger, and things that take radically different forms as part of growth.

But there's nothing that doesn't have metabolism. What would something without a metabolism look like? It probably can't move much and probably doesn't grow much and probably doesn't have much of an ability to reproduce. It'd look like a virus. So what if viruses evolved from very primitive life forms that slowly lost their metabolism as they became more evolved to live off of and inside bacterial cells?

Alternatively, what if viruses are the product of living cells? Cells could've produced a viral like protein coat/cluster that they pushed out into the world, in order to alter the environment around them, or perhaps even as a type of waste or holdfast structure at the earliest stages. If these holdfasts instead of attached to a neutral substrate were interlocking with proteins expressed on the surface of other cells, they could evolve with even more specificity. Perhaps viral capsules are a bizarre evolution of whatever mechanisms allowed cells to hold on to each other, either in making bacterial mats or as a way to leach off of other cells.

 

Viruses do move. Beyond their brownian motion through a media, once they meet a host cell they attach and undergo molecular movements to flex and introduce their genetic material into the host cell. They attack not by a normal sort of grabbing though but by a lock-and-key like interaction between molecules on the viral surface and molecules on the cellular surface, and in this way have evolved to become host-cell specific.

Everyone takes for granted that viruses evolved this specificity in order to be injected into the cell and hijack it for reproduction. But what would an intermediate stage of that evolution look like? We've learned a tremendous amount about the evolutionary history of birds and reptiles and primates and humans because we have access to intermediate stages, and those intermediate stages have shown us that we should reject orthogenetic evolution or directed and striving evolution. Monkey's didn't evolve into humans with large brains because of some pre-programmed tendency within all of monekydom to have larger brains. Primates didn't rearrange the functional capsules of their face and skull in order to make room  for bulbous brains. Reptiles didn't slowly extend the length and lightness of their scales because eventually it'd pay off in flight. The intermediate stages were undirected and functional on their own often in ways that were totally different than what we recognize the current function is.  Viral latching mechanisms didn't have to evolve in order to inject viral genetic material into a host cell.

Perhaps an imaginary cell growing in competition with early bacteria that were forming matts or volvox like sphere developed viral particles that interrupted the bacterial cellular adhesion of those structures. THis could be a tremendous advantage for a non-colonial organism against a colonial one. Later packaging off some genetic material in it, which isn't so surprising in cells without nuclear organisation and with plasmids circulating in the intercellular fluid, could end up making the interrupting capsules more host/target specific. It'd be an investment with a heck of a payoff, evolutionarily speaking, because the producing cells wouldn't have to invest all that much of their own energy in it, produce a few replicating capsules, and then let their own reproduction propel them on. A free defense mechanism. 

Alternatively, something more like a modern virus could've evolved as a type of machinery that a living cell sends out to attack and lyse nearby competing cells, allowing the producing cell to live off the spilled and lysed materials, like a fly spreading digestive juices onto it's prey and sucking up the mottled remains, or a starfish everting its stomach onto it's prey. An evolutionary scenario like that would provide selection for attachment specificity and the ability to reproduce inside a host-cell.

In any case once these molecular machines are produced, their evolutionary history is decoupled form the producing cells. Perhaps the producing cells went extinct in the Archean for all we know and the machinery has been whirring on ever since. 90% or more of all life has gone extinct so the odds are simply in favor of the producing cells being extinct. The intermediate forms and the producing cells, unlike whole dinosaurs in the case of birds or ape teeth in the case of humans, won't preserve well and would be in rocks that are potentially astoundingly old and rare and metamorphosed when still extant,  we'll likely never find those intermediate forms. And evolution sometimes seems to repeat, flight evolved several times, in birds, pterosaurs, bats, and insects. But notice that besides insects the other groups are somewhat closely related, used relatively similar mechanisms and anatomical structures to evolve flight, and probably did so in very similar environmental circumstances (like arboreality). So if viral producing cells are still extant we'd have to look in environments that would select for it, just like the environments that select for flight. WHich means we need to have better ideas about what those environments and functions are. If it's for lysing cells to digest them, we perhaps need to look at places where autotrophy doesn't work (deep sea environments away from hydrothermal vents? Deeply buried anaerobic soils?)  and heterotrophy has some extreme requirements (like preying on bactieral cells that are too big or too durable for phagocytosis). We'd also want to look for groups of cells that are best candidates for this sort of behavior, just like we'd want to look at vertebrates when studying flight. "Vertebrates" might seem like an absurdly wide group to look for, but the bacterial world is much more diverse than the world of normal macroscopic organism that we're used to (which is basically vertebrates, arthropods, molluscs, and  'plants'), so having something like that would probably help greatly in finding if these types of cells are still alive. Find the target environment, then do something like environmental DNA studies to even see if the 'right' groups are present at all before doing more detailed study.

So in this way we're applying the major themes of evolution across life to the evolution of viruses.

[this is an off the cuff set of thoughts that I'm not even going to bother editing and may return to to wildly change/revise things or may never look at again, just getting some dumb thoughts on 'paper'.)

"In the Trenches" on Field Trips

NAGT's newsletter, "In the Trences" (January 2019, Vol 9(1) ) has a few articles on field trips in geoscience education.

Tarin Weiss from Westfield State University starts off by noting that field trips are common in college geoscience, and that during the recession K--12 field trips had a big drop off (around a third) from normal. So there's instantly a rationale for having trips in the first place ("colleges do it") and a rationale for promoting them ("schools are willing to cut them easily'). Interestingly schools not only eliminated field trips, but then replaced them with test prep activities. THat sounds like there's more than just a cost consideration going on, if it was just the cost of field trips then the schools might replace trips with normal classroom time. Perhaps test prep is just taking everything over whenever it gets the oppurtunity.

 They're advocating for college geoscience instructors to in effect curate field trip sites and activities and then go out to the schools to recruit teachers to have their classes particpate in the trips. Trips can be field locations or museums. To that end they place field trips with the concept of place based education and the Next Generation Science Standards.

They also note a few times that field trips need to be accessible for students with different physical abilities, and suggest that virutal trips and/or activieis in more accessible parts of a park/location have to be considered.

As for the point of the field trip, they not that students should be, like researchers in the field, observing new things that become a problemt to be solved. So this impllies needing a preceding framework that the new observation creates a problem with. They go on to not that there need to be pre-trip and post-trip activities to frame questions and get this framework.
They recommend three to four learning goals within a trip and conclude that the purpose of a field trip is to construct explanations about the natural world, so again an explanation is a thing that deals with a problem for a given framework.
Among the citations is a reference to a study on NYC schools using Museums like the AMNH for field trips, and how that correlates with test scores; Whitesell 2015, "A Day at the Museum: The Impact of Field Trips to Informal Science Education Instutions on MIddle School Science Achievement", NYU's Institute for Education and Social Policy Working paper #03-15. This worker looked at six years worth of student data at 200 schools. Their main positive result is a broad statistically significant ~1% increased likeliehood of science exam proficiency. Apparently there hasn't been all that much quantitative and large sample work done on relating the number of science field trips to test scores.

Along the lines of virtual field trips, this issue has an article showing how students build up 3D immersive trips and locations from Frank Granshaw at Portland State. Making the VR site itself is a project, but then the completed site can be used by incomming students to prepare for field activities. They refer ot the product as a Virtual Field Experience (VFE).
The popularity of VR/Augmented reality at the consumer level has made it a little easier to accomlish this, education lags industry. This despite the large amount of educational interst in VR and the use of VR for even UNESCO meetings.
The author primarily discusses Holobuilder, which uses the Ricoh Theta panoramic camera. Holobuilder is apparently a construction/real estate focused company that uses these cameras, sometimes left in place/streaming, to document site construction. Projects at the PDX campus include the creation of VFE for a biology/geology community college field course at a trail along an estuary; fir undergrads in a sustainability and climate courses creating VFEs of urban farms; Middle School students doing a summer science camp on a section of a stream, including micro-photographs of collected diatoms (including SEM photos); and  virtual tours of monitoring sites.
Immediately a lot of this fits right into our capabilities; SEM, civic engagement; site monitoring; urban farms. Many of their products are  360 panoramas at trail waypoints, linked to a GIS map, where you can clicked markers to move between waypoint, and while at a point clink on floating links to get more information, like this one in Germany. The interaction for a user than can be through a webbrowser on a site hosted by the college. Holobuilder is what allows them to do that--- integrating with GIS, putting up clickable data, or even splitting the screen to show the location at different dates---very easily.
Some of the VFEs are more involved that others, this one not only shows a view, but is linked up more detailed notes/instruction, and allows measurements, including using a 'virtual clinometer'.
They do caution that when they started doing VFE's in 2013, there was a large amoung of instructor work required; students would collect photos and panormas and 360sphere photos, but the instructor would end up having to stitch sites together out of the field.  But now in 2019 using Holosuite's plans, the site assembly can take place entirely in the field.

Field Notes Digitzation

Together with another student in the CUNY Graduate Center, I was able to get a grant from the Provost"s Digital Initiatives Grant. This grant allows us to start something exciting, the digitization of the notes taken by scientists in the field.
There's a few jsutifcations for this type of project. On the one hand, field notes are an important part of thproduction of science.  Workers record observations ---actual data--- in their notebooks and use that later on to produce scientific ideas and publications. Nearly everything else we do is heavily computerized and digitized, But taking an iPad out to a field station is very rarely a realistic option. If it's not clear why, field sites are often remote, with no electricity and no connectivity. Field sites are also often harsh, without proper shade; high temperatures; extremely high humidity, all things that can wear on electronics. Despite that however most of us still take our cell phones into the field. But paper and pen, that's a technology that continues to stand up to the field environment.   Field notes are also a pastiche of what in the digital world are multiple types of media: sketches of an outcrop; maps of field sites; tables of data; lists of GPS coordinates; alongside spontaneously recorded blocks of text. Most digital solutions to this mixture of media are simply replications of paper and pen notes on a screen. Digital pens reverse the process of digitization; they insert digitzation into our already existing processess.
But why digitize at all? Digitizating your field notes creates a back up of them. Most of us do this by photocopying and scanning the pages in our notebooks. This is a timeconsuming nuissance that sometimes still produces unreadable sections of our notes. Some people go so far as to cut out the spine outof their notebooks in order to make scanning easier. With a digital pen, the only extra work to produce a visual backup of your notes is turning syncing to your phone or simply turning on your phone and opening an app before writing. This alone makes the digitiation of field notes through smart pens worth investigating.  As long as  pen system can be found that fits into research budgets; that produces accurate renditions of handwritting; and that is manageable and portable, you've got something worth investigating and potentiallyy incorporating.
But I think smart pens offer us a lot more than redundant back ups. They make field notes shareable. Even if you previously had a set of scanned pages from your notebook, sharing them can be difficult. The files tend to be large if they're high quality. You may've scanned to PDF or TIFF,  and that decision may've dependded on the scanner you were using. Whoever you want to send the files too may need you to make the files smaller, or even the email program their campus uses may require that! And if you didn't bundle every page together, that'd mean you have to batch resize every file. A digital pen system should manage your files, it should let you send entire notebooks or ranges of pages in a choice of formats
If another worker, or you yourself, want to search for a particular passage or subject in your notes, digitzation has tremendous potential to aid in that. When I use a notebook, I put a table of contents or index in the first few pages and I add to it over time. That's how most of us make our notes "searchable". Really important things I flag with a post-it type of sticker. Usually I put a header on each page. When I really start getting desperate I'm drawing stars, using highlighers, or anything to make a page stand out; because more often than note when I'm searching through a notebook I'm flipping through the pages quickly and need something jarring to make a page or passage stand out. A digital system should be able to do that and expand beyond it. A digital system should handle indices and tags, but also should make note searchable from the start. When we're evaluating these systems, handwriting recognition and searchability are prime criteria.
Not all field notes are spontaneous. A lot of field notes are very patterned and regular: you're measuring or estimating the size, colors, rock types, strike and dip of beds at an outcrop, thickness of beds, etc. Or you're recording the location, body mass, length, species, and sex of a dozens of living specimens at multiple locations. We're doing that because this data will be used later on. We're building databases from our notes. For most of us this means getting back from the field, to our labs and computerrs, cracking open our notebooks, marveling at the amount of dust they've taken in, and then entering by hand all of the data. Sometimes we're lucky enough to have junior lab workers that can be assigned this tasks, and often we're the more junior worker that get's assigned it. With smart pens we should be able to save time, by writing the notes we should be also be generating text that can then be copied as a whole into a database. In fact we should be able to have that entire process automated. And if we have some connectivity at our field locations, we should practically be able to build databases in real time or nightly. But one thing that should be apparent in academia is that saving time often isn't much of a draw. What does the PI care if a digital process saves a student's time? Well one added benefit of digitization is that it can result in less errors. The data entered into fields can be set to be numbers, text, or a mix of both, just like in a spreadsheet. This prevents the handwriting recognition system from mistaking a "7" for an "h" or something along those lines. Or it can at least throw a flag up for a human to review when it hits a contradiction like that. It also allows for errors to be addressed while there is still someone in the field. Even with a notebook alone, there can be confusion about what's recorded. If it's months later, even the person who took the notes can be unsure of what they were recording and why. Having the people back at the lab able to contact a field worker while on location can clear up errors and make us more confident in our decisions regarding how we've resolved errors.

There are a few other possibilities and abilities that digitzed notes offer beyond handwritten notes. By having searchable text, the frequency and co-occurence of words can be tabulated and studied. This potentially can tell us something about how a worker learns about their field site. Perhaps there are differences in word occurence between people new to the location and others who are experts about the field site? Perhaps there's a difference, or similarity, between expert scientists and expert non-scientists about the site. Those are more distant possibilities for this project. At the moment, we're just trying to figure out what digital processes and practices work best for a variety of scientific fields.

Dangerous Fieldwork

We've known for a long time that scientific fieldwork can be dangerous. Roy Chapman Andrews was attacked by bandits for example. And for women, it's been publicly known for a few years now that there is massive harassment, by their scientific colleagues, in the field (and the lab, and the classroom, and the rest of academia. Yikes.).

But the foreign government allowing the research in the first place? They're not supposed to represent much of a physical danger. Yet here we have a researcher,  28 year-old Cambridge PhD student Giulio Regeni, who was apparently tortured and killed by the security apparatus of "President" Sisi in Egypt. Sisi came to power in what amounted to a counter-democratic coup. The longtime Egyptian dictator Hosni Mubarak resigned after public protests over his reign, and Mohammed Morsi, a member of the Muslim Brotherhood political party, was elected afterwards. The Egyptian military ultimately balked at this, initiated a coup, and used a tremendous amount of violence (killing more than 800 people in one instance) to suppress not only the Muslim Brotherhood but any dissent.

So perhaps it shouldn't be surprising to learn that they kidnapped him, burnt and tortured him, and ultimately killed him. In addition to the plain old evilness of this regime, it shows that the Sisi government is not really thinking about researchers in Egypt. It should be obvious that there's a tremendous amount of field and other research going on in the land of the Pharaohs & Fatimids. Also recall that the dinosaur Spinosaurus aegypticus was first discovered there, and that the Fayum is an amazing and important primate fossil site. There's a huge number of researchers there, in fact there's entire field schools that operate under this same government and security apparatus.

Luwians the Trojan War and wannabe Schliemanns

Schliemann was the famous discoverer of Troy, who made the possibility of it's fabled Trojan War seem a little more realistic. He bucked the authorities and the prevailing knowledge of his time.

Also a straight up pimp?

So, ever since his discovery, people have tried to emulate him. In fact this isn't really something that was brought about by Schliemann's success; people certainly claimed to be rebel scientists before even Galileo was around. Schliemann particularly comes up here because of this article interesting and highly critical article from Jason Colavito:

http://www.jasoncolavito.com/blog/swiss-geoarchaeologist-claims-lost-luwian-civilization-caused-the-bronze-age-collapse-and-the-trojan-war

There Colavito discusses Eberhard Zangger's idea that Troy, and it's fall, is the ground-source for the Atlantis mythos. Zangger ties this Atlantis-via-Troy idea up with 'secret and suppressed history' and ancient lines of kinds. So Aeneas meets the Davinci Code I guess.

The Luwians did it?

Here's Zangger's site promoting the idea. The other thing that gets distorted here is that the Luwian language---a real thing---is blown up into 'the Luwian people' These Luwians are part and parcel of the fall of Troy. Except they didn't exist.  It's a language, but not a people, not like, say, German or Hittite, which were both languages and peoples.
This is an odd thing that lots of people seem to do, assuming a language group also represents an ethnic people and a culture. This isn't the case now, you don't need to be an Anglo practising the English culture just because you speak English. More people today speak English as a second language than as a primary language too. In the past this sort of thing would've also happened. So lots of people could be Luwian speakers without being 'the Luwians'.

So the Luwians, apparently, didn't do it.

GIS or Lidar experience?

Got an undergrad degree in Geology?
Have at least a year's worth of grad coursework in GPS (and didn't end up in a lake?) and/or LIDAR and the like? 
Then apply for this USGS job in California. The work involves GIS and mapping in a science center.
The listing closes in about a week.


https://www.usajobs.gov/GetJob/ViewDetails/437878400/

Surprising space limitations

I bought a new 1Tb portable, external (and "shock proof") USB3.0 hard drive a little while ago. But I've already got so many CT scans and 3D model objects that it's filling up. At the moment I only have one set of CT stacks and models (which are then backed up).  I don't like the idea of having a small 'working set' of objects and CT scan tiff stacks on my portable drive and then another set backup to a few places. For the CT stacks I guess that can work, since they don't normally need to be edited; new stacks can just be deposited and the stack collection can accumulate over time. But for the models that's definitely not a good idea, I'd very quickly start loosing track of what was "in" each model. I'd think that the only way to deal with that is with some sort of model version control system, which in some ways would be nice, but that's an entire area that I don't think I can even look into at this point, and while models don't take up as much space as CT-stacks, they're not small either.

 I think for the duration of the PhD I can stick with a portable drive that has all my data, CT stacks, and objects, but after that I'll almost certainly have to start splitting things up. Right now I'm using Robocopy (and also dropbox) to back up everything, and even in that process I have to split out a few things, (like separating my 3D objects from my CT-Stacks, instead of having them in the same subfolder). A problem with Robocopy (and Dropbox, if you have a shared folders) is that it's pretty easy to delete and entire set of data. Telling Robocopy to "mirror", instead of "copy"  a small, working set of CT-Stacks on one drive to a backup would delete anything on the backup that's not in the 'working' set. There are distinct commands for preventing that, but the huge amount of damage that'd result from even a rare 'mistake' in commands is too high risk. And for dropbox it's almost worse; it's easy to forget that they folder someone shares with you is editable.

The problem with CT-stacks is that for some I'm the person that scanned them and the AMNH doesn't store those files long term, so my copies are the only copies. And even for loaned items, you can't go back to the loaner and say 'hey I lost those files, can you resend them". I'd hate to loose a model that I spent a long time working on, but as long as I have the CT stack I can more or less recreate the model, but without the stack, there's nothing.