[Michael Piziak]

Also I suspect your chart is too close. Try setting the 50 prime at f8 and moving back until the top bar loses resolution on its right hand side.

I didn't move it until resolution ws lost on its right hand side; however, I did grab the floor tripod and moved it back about 1.5 to 2 feet. Also, I set both lens to F8. Here are the results. Oh, I also did a levels adjustment so both would be closer to the same brightness:

1


2



Yours, and anyones comments ?

---------- Post added 01-07-23 at 05:59 PM ----------

The farther one gets back, the more the prime lens holds on to its detail. So I moved the tripod back even further. Here's 2 more:

1


and 2


I think the lines where the "40" is show the kit lens starting to blend together the lines into a gray swatch. But again, the kit lens is no sloucher compared to other brands kit lens (as what peeps had commented a year or so back when I did similar shots like this)... Also, I think if one examines some things on the bulletin board at top right, which exposes the edges of the image, then the prime lens begins to shine more here too....Smiles, I can pick out the prime lens nearly every time....


comments again please

---

Last edited by Michael Piziak; 01-07-2023 at 06:10 PM.

[GUB]

Yes resolution as well as contrast is kicking in now. It pretty well sums up why I feel my migration from the kit zooms to old primes revolutionised my digital photography.

[Michael Piziak]

Yes resolution as well as contrast is kicking in now. It pretty well sums up why I feel my migration from the kit zooms to old primes revolutionised my digital photography.

Using the old manual lens has two great benefits, well 4. First, they are so much more affordable. Second, the image quality of the old Pentax manual primes have top notch image sharpness. And third, using them at first forces you to use the 3 basics cornerstones of photography (ISO, shutter speed, & aperture) and then becomes a joy to use them - you learn so much about photography. And four, and again, they are fun to use!

Personally, I'll never pay $800 plus for a modern automatic lens if I can find an equivalent manual one, especially made by Pentax, available for a fraction of the cost! I see people posting photos using expensive macro lens, which is my favorite type of photography, but I get images just as good from my two Pentax 50mm and 100mm M macro prime lens, and they each cost $150 and less.... I once bought a cheaper verson of a Pentax automatic macro lens & found the automatic focus was basically useless with such a narrow field of focus on macros - I sold it...

[GUB]

First, they are so much more affordable

Unfortunately once the addiction kicks in this is not the case after buying almost 400 of them

[iheiramo]

Using the old manual lens has two great benefits, well 4. First, they are so much more affordable. Second, the image quality of the old Pentax manual primes have top notch image sharpness. And third, using them at first forces you to use the 3 basics cornerstones of photography (ISO, shutter speed, & aperture) and then becomes a joy to use them - you learn so much about photography. And four, and again, they are fun to use!

Personally, I'll never pay $800 plus for a modern automatic lens if I can find an equivalent manual one, especially made by Pentax, available for a fraction of the cost! I see people posting photos using expensive macro lens, which is my favorite type of photography, but I get images just as good from my two Pentax 50mm and 100mm M macro prime lens, and they each cost $150 and less.... I once bought a cheaper verson of a Pentax automatic macro lens & found the automatic focus was basically useless with such a narrow field of focus on macros - I sold it...

Personally it seems I don't buy under 1000€ modern primes. Old cheap primes are so good that there is no gain in getting anything but the very best of the modern gear.

[Michael Piziak]

Unfortunately once the addiction kicks in this is not the case after buying almost 400 of them

Wow, how many years ago did your addiction kick in ?

---------- Post added 01-09-23 at 09:01 PM ----------

So, I decided to grab the kit lens and take some shots from F5.6 up to around F16. I didn't do any auto leveling or any type of post processing, so try to just look at the sharpness only please.
So, someone in the thread said that F8 is the aperture that starts to hide the flaws of most any lens or makes a lens shine as much as it will. Someone do tell me, since you guys/gals told me to take the previous photos wide open, I assume that wide open shows most lens flaw(s), eh? And is it generally true that the higher the F number then the less flaw? Or, does the lens get better as it approaches F8 from either end of the aperture spectrum?

ok, here are the photos from the kit lens (the Pentax 18-55mm kit that comes/came with so many Pentax DSLRs).

Starting with the first photo, the F numbers of the photos are 5.6, 6.3, 7.1, 8, 9, 10, 11, & 16. All photos taken at 50mm
Of course, keep clicking on any image to keep zooming in closer and closer to view sharpness
I haven't looked at the results yet myself, but here they are.

f5.6



f6.3



f7.1



f8



f9



f10



f11



f16



Again, I haven't looked at them yet. But a year or so ago someone said the Pentax 18-55 was no slouch for a kit. You tell me. Also, I'm still interested in your comments on how the kit compares to my other 3 Pentax M lens in this thread...
Lens set at 50mm Question about that, what mm would one/should one consider the lens to be the sharpest?

---------- Post added 01-09-23 at 09:14 PM ----------

For a quick comparison,

Here is the Pentax 100mm M macro prime at its best:


The Pentax 50mm F1.7 prime lens


& the Pentax M 50mm macro prime


The F.17 and 50mm macro didn't have the luxury of being shot many times to pick out the best like the 100mm macro and kit lens did....

---------- Post added 01-09-23 at 09:37 PM ----------

And a side by side comparison using low resolution Screen Shots via the computers Print Screen key. I didn't shoot the 50mm macro many times to give it a chance. But question: Should one consider the 50mm macro to be less sharp than the 100mm macro for some physics reason (?)

The 50mm M Macro F4 was updated t 5:05am U.S. Eastern Time



100mm Macro F4


F1.7at F1.7


50mmMacroF4




KitLensatF5.6


kitlensF5.6 byMichael Piziak, on Flickr

55-300mm lens F4 - just added on 1/12/2023 at 11pm

[iheiramo]

So, someone in the thread said that F8 is the aperture that starts to hide the flaws of most any lens or makes a lens shine as much as it will. Someone do tell me, since you guys/gals told me to take the previous photos wide open, I assume that wide open shows most lens flaw(s), eh? And is it generally true that the higher the F number then the less flaw? Or, does the lens get better as it approaches F8 from either end of the aperture spectrum?

Somewhere above f8 diffraction will kick in and sharpness will start to weaken. Therefore I find there is very rarely use for smaller apertures, but then I'm more of the wide open kind of guy. For some lenses f5.6 is the sweet spot I rather not cross, like DFA*85. Landscape at f8 with it is just dull with all perfectly corrected perfectness.

[Michael Piziak]

I gave the Pentax M 50mm macro f4 another chance - all 3 at F4

I'll pick one and go back and change the side by side comparison above

[Michael Piziak]

I decided to grab my automatic SMC Pentax-DA 1:4-5.8 55-300mm ED and shoot a few shots at my test chart. I probably should have put this in my thread titled related to comparing M lens to kit lens, but this thread has the newer test chart I've been using.

55-300mm F4 Autolevels in post



Addendum: Going to add a "swatch" of this one to the side by side's above in my previous post in this thread

[reh321]

I believe the term “kit lens” has picked up inappropriate baggage. The term simply means “lens kitted with some body”. When I purchased a “ME/SE”, a Pentax-M 50mm F/2 was kitted with it.When I purchased a “Super Program”, a Pentax-A F/1.7 was kitted with it. When I first got a K-30, I used it with the latter, and I surprised at how sharp it is.

[reh321]

Somewhere above f8 diffraction will kick in and sharpness will start to weaken. Therefore I find there is very rarely use for smaller apertures, but then I'm more of the wide open kind of guy. For some lenses f5.6 is the sweet spot I rather not cross, like DFA*85. Landscape at f8 with it is just dull with all perfectly corrected perfectness.

Diffraction depends on the size of the frame. With 35mm film, I often use F/16. I happen to prefer the “perfectness”.

[iheiramo]

Diffraction depends on the size of the frame. With 35mm film, I often use F/16. I happen to prefer the “perfectness”.

Ooooooops, I can see some bad wording in my text

What I really ment was that at f8 I prefer rendering of M85 over the more corrected DFA*85. To my eye the little distortions in M85 somehow give better 3D feeling to the shot. At that point difference in sharpness is irrelevant. I also rarely need more DOF than what f8 gives, so therefore no point going for smaller aperture, as the sharpness doesn't improve anymore. So perfectness referred to better CA correction of the modern 85 compared to old. Not to sharpness of the shot or anything like that.