Focus rail purchase

[Houdini87]

Hi everyone, I was thinking to start doing good focus staking, to buy a rail, what do you advise me to buy? A manual rail, are there any valid ones? An automatic rail? I don't know, I hope someone can help me

[ChrisR]

Hi H87
The Wemacro, as you mentioned in this thread https://www.photomacrography.net/forum/viewtopic.php would be good for your "very small threads", if you mean a field of view of around 5mm (4x), up to much higher magnifications.

AT 4x with a modest microscope objective, you will get alarmingly (probably!) little depth of field. It'll be something like 50 microns. 1/20th of a millimeter. So if your subject is say 3mm deep you'll need something like 60 images, to focus-stack. That's to get all the quality you can. If you only need small pictures, eg for web use, you can do it with far fewer images in the stack.
You could , instead of the microscope objective, use a good enlarger lens reversed, such as the Schneider Componon-S0mm f/2.8.
The quality is a little below the same-price objective, but they are mor versatile.
60 is a very doable number of exposures, manually, until you get it wrong and need to start again, 3 or 4 times
Then you'll be very glad if you have an automatic rail.

However if you search the forum for ideas you will find a lot.
Check the FAQ section, expecially the second post on "how to focus".

Y0u will possibly aalso need an extra flash unit, perhaps a Godox. You will usually need flattyer lighting than you expect. Diffusers , eg paper, are cheap but it's easier if you have more than one light.

DO start using flash. Otherwise you will almost certainly be plagued with vibration problems.
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Chris R