[wervog]

Aim here was to compare the below mentioned Lenses with Focus set to infinity. All shot were made handheld with shutter speed of 1/400 between 11:01 and 11:35 a.m. with an aperture of 8. Pictures have been cropped to show the same mountain in the distance, which has been center or near center in the uncropped images. There has been no postprocessing of any kind. All pictures were taken w/o lenshood, unless the one indicated. All pictures were taken in full manual mode with manual focussing, with exception the one indicated as AF.

Lenses:
SMC Pentax-M 28mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database copy 1
SMC Pentax-M 28mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database copy 2
SMC Pentax 30mm F2.8 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

SMC Pentax-M 35mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database
Tamron Adaptall-2 24mm f/2.5 (01B) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database
Tamron Adaptall-2 24mm F2.5 (01BB) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database
Sigma 18-300mm F3.5-6.3 DC Macro HSM (Contemporary) Lens Reviews - Sigma Lenses - Pentax Lens Review Database

Conclusion:
At f8 interestingly there was a significant difference between 2 copies of the same 28 mm lens.

Also you can see how much better the Tamron Adaptall-2 24mm f/2.5 (01BB) performed than theTamron Adaptall-2 24mm f/2.5 (01B). Adding a lens hood (which is a very short one on this lens) did not improve the image significantly.

I was impressed of the sharpness and contrast of the 35mm lens compared to the 30mm lens.

The CA in all lenses is nearly neglectable in these shots
A modern Sigma Zoom does a decent job, which can be a little further improved by manual focusing.

Here is the better image: https://imgur.com/kbZw4yG

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Last edited by wervog; 02-23-2020 at 01:30 PM.

[normhead]

SO, what did you learn? The little blue images are really hard to interpret.

[clickclick]

Are the M 28/2.8 copies early (silver ring around the front) or late (no ring) versions?

[wervog]

SO, what did you learn? The little blue images are really hard to interpret.

Look at the link in my post, there is a better image provided. Regards

---------- Post added 02-23-20 at 10:07 AM ----------

Are the M 28/2.8 copies early (silver ring around the front) or late (no ring) versions?

On the focus ring is a small silver ring visible, did you mean that?

[SSGGeezer]

Are they exposed correctly? The Tamron flares, what are your other conclusions?

---------- Post added 02-23-20 at 12:43 ----------

And why did you not use the available hoods? What camera? What are you expecting from your experiment? I suspect you would have better luck seeing a difference with one of the HD coated new model of Pentax lenses like the 35mm f/2.8 Macro.

[wervog]

Are they exposed correctly? The Tamron flares, what are your other conclusions?



---------- Post added 02-23-20 at 12:43 ----------

And why did you not use the available hoods? What camera? What are you expecting from your experiment? I suspect you would have better luck seeing a difference with one of the HD coated new model of Pentax lenses like the 35mm f/2.8 Macro.

Yes the histograms look fine, the samples shown are 1:1 crops (979*979px) from 6000*4000px images. As mentioned the newer Tamron did perform so much better than the older model and has less lens flare. Main conclusion is that i was surprised how good the modern Sigma 18-300mm Zoom performed in comparison with the older primes. Next conclusion is that each lens even of the same model could be so different. Furthermore I was really surprised about the performance of the 35mm lens, cause it has a lot more wear, than the other lenses.
Goal of the comparison was my feeling, that the smc-PENTAX 30 mm is not so sharp in the distance.So I compared it to my other lenses in this focal length range.

I did not use hoods, cause i had not hoods for all the lenses tested. Camera was a K-70. I do not own HD coated lenses right now.

[stevebrot]

Look at the link in my post, there is a better image provided. Regards

Thanks

These would be more useful if we knew what format was used for the capture as well a seeing the full frame rather than cropping for similar magnification. One suggestion regarding the Tamron 24mm pair. I use a somewhat deeper hood than the 21FH when shooting my 01BB on APS-C.


Steve

[ChristianRock]

From the images it seems like you learned more about flare control than about sharpness and color...

[wervog]

From the images it seems like you learned more about flare control than about sharpness and color...

sorry, I thought sharing my tests could be useful to some forum members, I wont do it again. Really helpful your comment.

[ChristianRock]

sorry, I thought sharing my tests could be useful to some forum members, I wont do it again. Really helpful your comment.

Sorry, I don't mean to be unhelpful, I was trying to state a fact... when flare control is the thing that is causing the most difference between the images from different lenses, that makes it hard to analyze any other factors.
So for a sharpness and/or color/contrast analysis, you need to take the flare element out of the way by not shooting into light.

Another point is that there are two very different versions of the SMC-M 28mm f/2.8 Pentax lens, with different optical formulas and coatings (the latter being the same as SMC-A in terms of optical formula but coatings are likely again to have changed). It would be useful to see if you have two of the same version, or two different versions, which would explain the difference between them, again especially when shooting straight into a light source.

Finally, don't underestimate the flare control aspect It is indeed useful to see how differently these lenses handle flare - for example, that modern lenses handle it quite better than older primes... that is useful information indeed

[SSGGeezer]

sorry, I thought sharing my tests could be useful to some forum members, I wont do it again. Really helpful your comment.

Don't get defensive if you are asking for comments on a post like this.
Sometimes it is easier when doing a comparison to State what you suspect or believe will be the results, then show us the results and in closing, tell us if your hypothesis was right, wrong or somewhere in between.
I asked about the hoods because they are the biggest tool for avoiding the flare in the older Tamron
So especially if you are working in a second language, (I am assuming English as your second or third language, forgive me if I am wrong.) Use the BLUF method where the
Bottom Line is Up Front. Tell us what you are going to tell us, show us, then see if folks agree based on your evidence.

[clickclick]

On the focus ring is a small silver ring visible, did you mean that?

sorry, I thought sharing my tests could be useful to some forum members, I wont do it again. Really helpful your comment.

Yep, the silver ring on the focus is what I was referring to. There were two versions of the lens, and the one with the sliver ring is the earlier version (which I have).

And don't feel bad on posting this or refrain from future posts with image samples. I've gone through some of this before, and it's a learning experience for all of us. I have posted comparison shots which didn't come across/show what I hoped or intended, but I've been able to learn from it all. This really is a good forum with a lot of friendly people who enjoy photography and have a passion for Pentax. Keep at it, and I think you'll find it worthwhile and enjoyable.