[dfeld]

Hi all,

I have a k-x and recently acquired the smc pentax-A 100mm f/4 macro.
(SMC Pentax-A 100mm F4 Macro Reviews - A Prime Lenses - Pentax Lens Reviews & Lens Database).

The trouble is-- There's no "A" setting on the lens to let me adjust the aperture when I'm shooting in Av and the body doesn't seem to be responsive when I manually adjust the aperture on the lens.

I'm sure I'm missing something silly. Can you point me in the right direction?

Thanks!
Danielle

[jatrax]

Info here on using all manual lenses: https://www.pentaxforums.com/forums/58-pentax-beginners-corner-q/110658-using...x-dslrs-f.html Because like @Twitch says if there is no 'A' setting, then it's not an 'A' lens.

[dfeld]

Ah I feel so silly! It was described incorrectly when I purchased and I didn't even think to check before attaching it.
That's unfortunate...

[Adam]

The lens you have will still work just fine, but you just have to stop-down meter with it as per this guide:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

The only thing is that the camera won't know what the f stop value is.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

[Just1MoreDave]

Yes, unfortunate. It's probably worth tracking down the real A version. I like to use the 90-100mm length for all kinds of photos. The A version makes all that easier. The M version is the same optical formula, but the price and usability are much different.

[dfeld]

The seller did offer a refund, I believe it was a genuine mistake.
After playing with it a bit, I do like the lens and will probably keep it as it's still a good price for the M (relative to ebay, anyway).

If it was sold to you as an "A" version then you have good grounds to get your money back.

Thanks for the link, I've been meaning to read that article and now I have good reason.

The lens you have will still work just fine, but you just have to stop-down meter with it as per this guide:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

The only thing is that the camera won't know what the f stop value is.

Thanks all for your quick help!

[thewebgal]

if I may ask a Q along the same lines - I just bought
Pentax SMC DA 18-55 mm F/3.5-5.6 II AL Lens

Its in the mail right now - so, I should expect it will have an A button to allow me to set Aperature?

[BrianR]

if I may ask a Q along the same lines - I just bought
Pentax SMC DA 18-55 mm F/3.5-5.6 II AL Lens

Its in the mail right now - so, I should expect it will have an A button to allow me to set Aperature?

Nope, no A-button on the lens, no aperture ring at all, nothing on the lens you need to set. The aperture is controlled from the camera either by you or the camera itself depending on the mode it's in (M, Av, Tv, etc). Just mount the lens and you're ready to go.

[thewebgal]

Nope, no A-button on the lens, no aperture ring at all, nothing on the lens you need to set. The aperture is controlled from the camera either by you or the camera itself depending on the mode it's in (M, Av, Tv, etc). Just mount the lens and you're ready to go.

Great - seems fine - thank you!
My old Quantray 85-300 K mount lens works, the old Soligor 35-70 K mount lens won't mount.
The old 50mm 1:2 ASAHI Pentax lens from my ME-Super mounts fine, of course.