[MightyJRC]

Hi guys. I'm trying to find a Pentax lens that offers auto focus but still has an aperture ring. I shoot video so I use a lot of my lens from Pentax on my GH1/GH2. I have a 35-70mm 2.8 Nikon F mount but I am looking for a lens in the 18-35 or even a 16-50 range. Any help? I've looked every where and the tamron and sigmas don't seem to have any. Thanks!

[biz-engineer]

Tamron 28-75 has an aperture ring.

[boriscleto]

Sigma 15-30mm F3.5-4.5 EX DG Lens Reviews - Sigma Lenses - Pentax Lens Review Database

[stevebrot]

Any help? I've looked every where and the tamron and sigmas don't seem to have any. Thanks!

Perhaps an adapter for your GH1/GH2 that has an adapter aperture ring? I know they are expensive, but if you must have a short zoom your options are limited.


Steve

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Last edited by stevebrot; 02-18-2015 at 09:04 PM.

[MightyJRC]

Sigma 15-30mm F3.5-4.5 EX DG Lens Reviews - Sigma Lenses - Pentax Lens Review Database

I have not seen this but thank you for the idea. I'll do some research!

Perhaps an adapter for your GH1/GH2 that has an adapter ring? I know they are expensive, but if you must have a short zoom your options are limited.


Steve

I have a speed booster on my 35-70mm , but I have thought about that idea, but I would like to use a speed booster on the short zoom as well, but the adapter ring will be my last option. Thanks!

Tamron 28-75 has an aperture ring.

I've been thinking about this one but I already have the 35-70 2.8 thanks though!

[Digitalis]

it's an interesting lens, capable of covering full frame.



Here is a size comparison:


Pentax K 24mm f/2.8, SMCP-FA31mm f/1.8 Limited, Sigma 15-30mm f/3.5-4.5, Sigma 18-35mm f/1.8

Image quality is generally excellent at the 15mm~24mm range. However, the image quality at the corners @ 30mm cannot match the FA31 at any aperture.


Pentax K5IIs - Sigma 15-30mm f/3.5-4.5 @ 20mm f/8 1/30th ISO80


Pentax K5IIs - Sigma 15-30mm f/3.5-4.5 @ 15mm f/11 ISO 80 1/60th

[MightyJRC]

it's an interesting lens, capable of covering full frame.



Here is a size comparison:


Pentax K 24mm f/2.8, SMCP-FA31mm f/1.8 Limited, Sigma 15-30mm f/3.5-4.5, Sigma 18-35mm f/1.8

Image quality is generally excellent at the 15mm~24mm range. However, the image quality at the corners @ 30mm cannot match the FA31 at any aperture.


Pentax K5IIs - Sigma 15-30mm f/3.5-4.5 @ 20mm f/8 1/30th ISO80


Pentax K5IIs - Sigma 15-30mm f/3.5-4.5 @ 15mm f/11 ISO 80 1/60th

Thank you! And that's even better knowing it could cover full frame. Any idea of where I can look to pick one up? I tried looking at eBay, but none in the k-mount.

[Digitalis]

it isn't a common lens, it is rare to find one in K mount. Most are in Nikon F and Canon EF mount.


Pentax K5IIs -Sigma 15-30mm f/3.5-4.5 @ 15mm f/11 3s ISO 80

[MightyJRC]

I see. I'll keep looking out for it, unless any one else has any other ideas or options. Thanks again for all the details on the lens.

[Digitalis]

There is also the Sigma 20-40mm f/2.8 which is of a similar vintage to the 15-30mm f/3.5-4.5 - both have aperture rings, cover full frame and are certainly worth a look.

[MightyJRC]

Yeah that is the other lens I have been trying to find as well, but it isn't common like the 15-30. Do you still shoot with the 15-30?

[Digitalis]

Do you still shoot with the 15-30?

Yes, I do. It is a very useful focal range on APS-C. On Film the lens is really fun to use, as it has a gel filter holder - it gave me an excuse to break out my filter material, and I forgot how much fun it is to use them.


Pentax K5IIs - Sigma 15-30mm f/3.5-4.5 @ 15mm f/11 1/15th ISO 80

[MightyJRC]

Yes, I do. It is a very useful focal range on APS-C. On Film the lens is really fun to use, as it has a gel filter holder - it gave me an excuse to break out my filter material, and I forgot how much fun it is to use them.

Great to know. I am looking forward to hunting one down. Any where I can see some more of your shots with the lens? Thanks.