[MikeNArk]

Hello. I have had the DG version of this lens since March 2020, and use it on on my K-5IIs, at least weekly. In most of my photography, I use it at 500mm. Last year, I finally performed a lens adjustment in camera and now focus is more dialed in. It will definitely hunt in low light. I normally shot at F8, however it is not bad at 6.7 at 500mm. I do have to add contrast to most images in processing.. If you want to look at some results, look at my threads under Post your Photos. I usually identify the camera and lens used when I post.
PS. I purchased a second copy of this lens for my grandson.

[nap_746]

Thanks for your reply! I looked at your pictures, they are very impressive. I see you're well equipped with large telephoto lenses. Yes, the DG version was judged much better.

[angerdan]

So its about these two lenses:
Sigma APO 170-500mm F5-6.3 Lens Reviews - Sigma Lenses - Pentax Lens Review Database
Sigma APO DG 170-500mm F5-6.3 Lens Reviews - Sigma Lenses - Pentax Lens Review Database

is the non-DG version, optically, just a version with slightly older coatings?

Yes, i assume exactly this.


Sigma Marketing praised DG like this:

SIGMA DG LENS
High-performance SLR lenses with full-frame sensor coverage Designed to deliver the ultimate in performance on full-frame digital SLRs, Sigma DG lenses also bring out the best in 35mm SLR film cameras and APS-C size DSLRs.
Remarkable image rendition is achieved by comprehensive correction of aberrations and distortions.
Special care is taken to thoroughly minimize color fringing caused by lateral chromatic aberration, which is particularly noticeable at high resolution in digital photography.
DG lenses can offer both high contrast and subtle tonal gradations, unmarred by flare and ghosting, thanks to Sigma's digitally optimized optical design and original Super Multi-Layer Coating technology, which suppress reflections between image sensor and lens surfaces.
Large image circles assure ample peripheral brightness to prevent vignetting.

About SIGMA lenses – Sigma UK


Press article said:

The new multi-layer lens coating and lens design reduces flare and ghosting, and creates an optimum color balance resulting in better picture quality through the entire zoom range on both film and digital SLRs.

Sigma 170-500mm F5-6.3 APO DG Launched November 2005 – Sigma UK

[nap_746]

Based on all this, we can separate the DG version, but there are several versions of the non-DG. Although they are older lenses, I am increasingly interested in what is the most important difference between them?

[MikeNArk]

Based on all this, we can separate the DG version, but there are several versions of the non-DG. Although they are older lenses, I am increasingly interested in what is the most important difference between them?

In your earlier post, you noted a "D" version of this lens. I have an old Nikon D700 and I think the designation may be for the older Nikon cameras.