Stackshot Rail

bob1 · Post by **bob1** » Fri Mar 09, 2012 4:02 pm

Just about to order a stackshot
Which rail are most people using the standard or extended
any comments would be of help
Bob

Craig Gerard · Post by **Craig Gerard** » Fri Mar 09, 2012 5:21 pm

Bob,

What are your intentions (current and future) for the StackShot?

Depending on your requirements, there are a number of variables and potential advantages when considering both versions of the StackShot rail.

Are you incorporating it into an existing studio type setup and/or for use in-the-field?

If for use in a studio/tabletop setup, are you working on an horizontal or vertical configeration and what range of magnification interests you?

Craig

ChrisR · Post by **ChrisR** » Fri Mar 09, 2012 5:47 pm

What disadvantage is there in the extended rail?

Craig Gerard · Post by **Craig Gerard** » Fri Mar 09, 2012 6:26 pm

ChrisR wrote:What disadvantage is there in the extended rail?

None, if it is appropriate to your requirements, otherwise, it can be overkill.

In this situation (see link below) it is used for sub-positioning of the camera/lens and for focus stacking. The main column provides course focus capabilities. Some users find the extra length of the extended rail to be convenient.

I prefer to have the stepper motor at the base when used in a vertical setup so that it does not interfere with physical access to the viewfinder. Changes to camera orientation are also less problematic, in so far as clearance issues are concerned.

Contrary to the Visionary Digital example below, my camera is not 'reverse orientated' (you are not forced to look through the viewfinder upside down) and I can position the camera at any orientation on a 360 degree radius courtesy of a Nikon PN-11. I use the standard StackShot rail and the optional Arca Clamp Mount. Most of the 'course' focus is achieved using the facilities provided by PF-4 vertical coulmn.

http://www.visionarydigital.com/Passpor ... ort_II.jpg

Craig

AndrewC · Post by **AndrewC** » Sat Mar 10, 2012 1:51 am

Look at it from a different angle - why did they start selling an extended rail ? Hmmm, maybe because a lot of customers felt limited by the standard length ?

Most of the rails I use only have a movement of about 50mm - much more than I need for a typical stack but I often find myself hankering for more when changing lenses, adjusting setup etc. It is convenient to be able to fully retract the camera away from the subject while you, ahem, optimise it. Of course you can do that by mounting the stackshot rail on a static rail but design wise I usually follow the mantra of less is more.

If you were being really picky you might think a long rail gives you more of a potential problem for vibration when your camera is at mid rail, but I'd think that that contribution would be almost insignificant .

Craig Gerard · Post by **Craig Gerard** » Sat Mar 10, 2012 4:04 am

Look at it from a different angle - why did they start selling an extended rail ?

http://www.cognisys-inc.com/stackshot/extended_rail.php

Craig

johnsankey · Post by **johnsankey** » Sat Mar 10, 2012 7:34 am

I got the 100 mm. The only times I need focus stacking are when DoF problems are insurmountable without it, with insects that means a lot smaller than 100 mm. When I can, I take photos of live insects in the field. The smaller slide is easier to position at any angle and keep everything rigid.

ChrisR · Post by **ChrisR** » Sat Mar 10, 2012 8:34 am

It looks like rather a high % cost, to go longer later, after buying the basic kit.

$525 for the short rail kit, or $600 for the longer rail kit.
The only option for going longer later appears to be to buy the long rail at
$375. Ouch.
If they would sell what looks from here to be a base rail, two guide rods and a lead screw, to change, for nearer to the $75 (600 -525), that would make the choice easier.
Perhaps it's not that simple. But the only problems I've had taking rails and bellows units apart has been dealing with microscopic screws buried in thread-lock compound. The Stackshot rail doesn't look the sort of thing to be loaded with those.

bob1 · Post by **bob1** » Sat Mar 10, 2012 11:24 am

Hi Craig

not sure how I will be using the rail, a change of direction with my photography
I was thinking of macro work in the field to get some close ups of insects
and the idea of focus stacking seems a good idea
must say I like your studio set up
do you know if the unimarm flex arms will support 2 canon 580 flash units

Craig Gerard · Post by **Craig Gerard** » Sat Mar 10, 2012 3:02 pm

Bob,

Sounds like the standard StackShot rail will suit your requirements. The extended rail is much longer and as a consequence much heavier.

To clarify, the image I linked in an earlier post is not my setup. It is one of the commercially available configerations from Visionary Digital.

http://www.visionarydigital.com/Passport_II.html

.....do you know if the unimarm flex arms will support 2 canon 580 flash units

I'm not sure about that as I have not used the goose neck arms for that purpose; but these arms (see link below) may be more applicable. I have used them with a 580EX II in the field without any problem, but the weight of the speedlight does place some stress on the ball joints of the arm. I tend to use a smaller speedlight such as the 270EX.
http://www.photomacrography.net/forum/u ... orum_1.jpg

http://www.ebay.com/itm/250820173077

Craig

ChrisLilley · Post by **ChrisLilley** » Sat Mar 10, 2012 3:24 pm

AndrewC wrote:Look at it from a different angle - why did they start selling an extended rail ? Hmmm, maybe because a lot of customers felt limited by the standard length ?

Yes, presumably a lot of their customers are using it more for 'close up' than for macro photography. With a large step size (cm or mm rather than μm) a longer rail might well be needed.

rjlittlefield · Post by **rjlittlefield** » Sat Mar 10, 2012 3:58 pm

ChrisLilley wrote:Yes, presumably a lot of their customers are using it more for 'close up' than for macro photography. With a large step size (cm or mm rather than μm) a longer rail might well be needed.

I hope it's not that, or they're going to be getting a lot of parallax errors. Such large steps should be done by turning the focus ring, not moving the camera.

Best info I have is that it's a matter of convenience for changing lenses and magnifications without having to move the base of the rail.

--Rik

AndrewC · Post by **AndrewC** » Sun Mar 11, 2012 3:50 am

rjlittlefield wrote:...

Best info I have is that it's a matter of convenience for changing lenses and magnifications without having to move the base of the rail.

--Rik

Pretty much what I said

The nice thing about writing your own control software is that you can have things like a button called "RETRACT TO PARK", doesn't need a great leap of imagination to guess what that might do ! Of course the disadvantage of writing your own software and constantly playing with hardware is that "RETRACT TO PARK" might become "ADVANCE THROUGH SUBJECT AND DESTROY IT" or with the linear induction motor I'm playing with at the moment "quick, come and look at my rail gun"

I think the other advantage of having a long rail comes in when you don't have an easily adjustable stage base (eg shooting in the field with a tripod as a base) you might want 10 or 15cm or coarse adjustment followed by your fine stack.