I bought the aforementioned Tokina lens when it was newly introduced (I forgot when, but it was shortly after Asahi started the SuperA/SuperProgram).
And I still use it sometimes. My SMC Pentax-A 4/70-210 is so much better, but that comes at an extreme price (size and weight!).
Rimfiredude and Sagitta said it all, so i just add some points specially for this lens.
- The "macro" reach is down to 1:4, and this is at 210mm. No need to do anything like switching to another mode.
- There should be a blue "MACRO" mark on the right end of the distance scale. The mark points to a couple of blue lines on the barrel, which show the macro ratio for your actual zoom and distance setting.
- The red line is for infrared (it replaces the white center line for the DOF scale). It may give you "some" idea about the needed distance/DOF range correction for infrared photography - but as it's a zoom, you will have to kind of interpolate mentally.
- If you have to fiddle with distance scales for some special application, mind that these scales are counting from the sensor to the subject (NOT from the front lens). That's true for ALL lenses.
- As far as I know, this Tokina lens does not exist as a "SD II". Most people think the strange sign on the front ring of nearly all Tokina lenses means "II", but I once read it is some kind of symbol for the original full name of the company.
- If you want to use it for things like reproductions, keep in mind this lens, like all "macro" zooms, is NOT a flat field one! For such applications you should use a true macro lens, or an enlarger lens with extensions or bellows.
On request of another member, I once posted a translation of the small German booklet coming with this lens, but it seems the PF search function does not reach further than 2 years to the past.
EDIT
In case you got this lens used:
Unfortunately, most used copies do not come with the original lens shade. Thatīs a clip-on one, which is nearly as long as the lens, and not much thicker. If not in use, it can be reversely attached, where it covers nearly all of the lens, and does not need any additional space. And you will certainly need something like that - Tokina RMC from the beginning of the eighties is nothing like the Pentax SMC!
EDIT2
Found my posting with the booklet translation. It is in the lens review section, and covers nearly everything said until now in this thread. Search for my name.
https://www.pentaxforums.com/userreviews/tokina-sd-70-210mm-f4-0-5-6.html EDIT3:
I just found 2 errors in the data sheet of our lens reviews.
Min Focus: 1.3M is wrong, must read 1.1M
Macro Ratio: 1:5.1 is wrong, must read 1:4.