Scale of 1 to 10. How would you rate the old Sigma 50mm f/2.8 Macro lens today?

I was given an old Sigma 50mm f/2.8 1:1 Manual Focus Macro Lens for Pentax KA/K7/PKA/K-1. I am just wondering how you would rate this lens in comparison with what is available today? On a scale of 1 thru 10, 1 being a cheap kit macro lens and 10 being the best macro lens money can buy; where would you rate this sigma macro lens?

Virtually all true macro lenses will be very sharp even if they're old. Where they're likely to be worse is in the coatings, which are likely to be less effective in reducing glare and increasing contrast. With Sigma it's also possible that they will add a very slight colour cast.

0 it's a Sigma.
Might be good opticaly but very poor mechanicaly.

What do you base that on,
Plenty of us happily using sigma on here.
No better or worse than any other brand.

Here are some test shots I took last night. Tell me what you think of how the lens performed with a focus and what could be improved in another lens choice (if anything)

Mode: Auto with LED computer reading light for light source.









Mode: Auto with LED computer reading light for light source.






Mode: Auto Superior with LED computer reading light for light source.







Mode: Shutter Priority with shoe mounted External flash with diffuser






Mode: Shutter Priority with shoe mounted External flash with diffuser






Mode Auto with late afternoon natural light.

Certainly seems to be performing well judging by those sample shots.
If you don't like it, let me know

Thanks. I do think it is sharp and will work well for most of my needs. The one thing that worries me is that I like to take shots of living insects, and with this lens, I have to get to really close to get a close-up macro. I mean like an inch away. Is there a way to extend this distance out somehow, or do a need another lens for that.

This lens also takes pretty good portraits.

If you want to be further away, you need a longer lens. You could try a 2x multiplier as a "cheap" option. That should allow you to be twice the distance. Other than that you need a longer lens, Most "common" are the 100mm macros. The MF ones (which in my mind are better for macro work than AF) can be had quite cheaply. Though most MF ones only focus to half life size whereas the AF ones tend to go to lifesize. However, that is easily solved by using an extension ring. Good news is that using a ring has no effect on the optical quality.

Could you give me an example fo a good quality low cost 100mm MF macro lens?

Sigma 105mm macro lens is af, and can be bought quite cheaply, just because it has af, doesnt mean you have to use it.
Its the macro lens I use, and I use it with bellows and ext tubes.
Cracking lens.
You'll probably see some sample shots on my posts.
Plenty of other 100mm options and 90mm

The Sigma mentioned above has a good reputation. I just sold a Pentax (Cosina made) 100/3.5 FA for less than a £100. Tamron used to do a cracking 90mm in both AF and MF. Sigma also did a 90mm MF macro as did Tokina and Vivitar. Samyang also do a 100mm macro.

Then there are the Pentax MF 100mm macro lenses

There are so many excellent manual focus 100mm macro lenses that it's hard to imagine we could find a really bad one.

I've several Sigma lenses, 8-16mm 12-24mm, 17-70mm, 100-300mm and they are all superb lenses.

There have been various threads both here and on other forums about Sigma lenses breaking, either the zoom mech of the AF. To be fair to Sigma, it has also been said that they have repaired the lens at reasonable cost. Then there was the case of a certain lens having to be returned to Sigma for the mount to be changed as it wouldn't fit the K1. Add to that the threads about incorrect exif data because Sigma back engineer their lenses rather than pay royalties. I may well have missed them but I have not seen such threads from any of the other after market lens producers.

So to go back to the original post quoted "might be good optically but very poor mechanically.