NikonGear'23

Gear Talk => Lens Talk => Topic started by: Zang on November 26, 2022, 02:57:08

Title: A mini story about a mini-wide...
Post by: Zang on November 26, 2022, 02:57:08
A couple of years ago, I found an online ad from a gentleman who wanted to give away a vintage film camera. I was lucky enough to be the winner who picked the camera up. It turned out that the camera was owned by the man's late father who died in 1988. He kept his dad's camera for many years before decided it needs a new home. The camera was brand new and based on the model's name, it was released to the market in 1985. That means the father did not have a chance to enjoy it for too long. On another hand, the lens - Sigma Mini-Wide 28mm f2.8 - was old and was not functioning well. I put the camera in my office as an display item and it had been there for the last few years. Today, I decided to take the lens apart for cleaning, hopping to bring it back to its wonderful life. After a couple of hours, the lens is back in one piece, fresh, clean and functioning smoothly like it just left the production line yesterday. It turned out to be a wonderful performer. The papers are my notes on how to reassemble the lens back.
Title: Re: A mini story about a mini-wide...
Post by: Hugh_3170 on November 26, 2022, 05:05:42
"He who dares wins" is an apt quote for your well executed success.  Kudos Zang.


A couple of years ago, I found an online ad from a gentleman who wanted to give away a vintage film camera. I was lucky enough to be the winner who picked the camera up. It turned out that the camera was owned by the man's late father who died in 1988. He kept his dad's camera for many years before decided it needs a new home. The camera was brand new and based on the model's name, it was released to the market in 1985. That means the father did not have a chance to enjoy it for too long. On another hand, the lens - Sigma Mini-Wide 28mm f2.8 - was old and was not functioning well. I put the camera in my office as an display item and it had been there for the last few years. Today, I decided to take the lens apart for cleaning, hopping to bring it back to its wonderful life. After a couple of hours, the lens is back in one piece, fresh, clean and functioning smoothly like it just left the production line yesterday. It turned out to be a wonderful performer. The papers are my notes on how to reassemble the lens back.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 26, 2022, 05:57:54
Thanks Hugh :) Have a nice weekend!
Title: Re: A mini story about a mini-wide...
Post by: Hugh_3170 on November 26, 2022, 09:38:41
You too.  May your team win.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 01:41:55
You too.  May your team win.

Thanks Hugh! :)

My quick test (on APSC) showed Mini Wide outperforming Nikkor AIS 28/2.8 at longer distances at 5.6 and wider. Close up, Nikkor edges Mini Wide a bit but it is hardly noticeable. Quite surprising to me!
Title: Re: A mini story about a mini-wide...
Post by: Fons Baerken on November 27, 2022, 09:28:20
Great project, show some results please Zang!
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 15:38:03
Thanks Fons!

I have taken some close-up test only, nothing 'photographic'. At close distances, the lens is pretty good. Not quite as sharp at infinity, but the CA is very well controlled. The first picture bellow was taken at 2.8 in low light condition using Sony Nex 6. The second picture was taken at 5.6 (Note that both files have aggressive compression to fits NG requirements).
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 15:49:38
And the lens itself, on NEX-6
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 15:57:19
Again, 2.8 and 5.6.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 16:03:15
Comparing with Nikon 2.8 AIS at 2.8 and near infinity (center crops). Nikon is the worse one.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 16:13:07
Portrait at 2.8 and 5.6. 100% crop look both very sharp.
Title: Re: A mini story about a mini-wide...
Post by: MEPER on November 27, 2022, 16:36:49
Comparing with Nikon 2.8 AIS at 2.8 and near infinity. Nikon is the worst one.

I assume that last one is the "Nikkor"?

The first one looks like DOF is much larger. Sharp at infinity but also a bit sharp at close distance?
The Nikkor looks more like a "toy-lens" not like a Nikkor?    .....not sharp anywhere?
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 18:10:30
I assume that last one is the "Nikkor"?

The first one looks like DOF is much larger. Sharp at infinity but also a bit sharp at close distance?
The Nikkor looks more like a "toy-lens" not like a Nikkor?    .....not sharp anywhere?

Yes, the later one was from Nikkor. Stopped down, Nikkor is doing OK. Close up Nikkor wins by edges. I hope it's sample variation, but sample variation is also a quality indication of a brand.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 27, 2022, 22:51:40
I notice the photo from Nikkor was overexposed a bit due to auto-ISO out of range. I corrected the exposure and both the sharpness and CA at 2.8 were improved a lot. I did not know exposure can affect sharpness and contrast. However, the level of CA still remains higher than the one from Sigma Mini Wide. I tested the whole bunch of my wide lenses including Nikkor 24mm f2.8, Nikkor 28mm f3.5, Contax Zeiss 28mm f2.8, Canon FD 24mm f2.8, Minolta MD 28mm f2.8 and Niikor 24mm f2.8 is the winner. Wide open, CA is absent. It is also the sharpest at infinity wide open. Nikkor 28mm f3.5 also does not suffer from CA wide open, but the sharpness falls off so quick toward the edges.
Title: Re: A mini story about a mini-wide...
Post by: Hugh_3170 on November 28, 2022, 03:31:30
Do you have the opportunity to compare these two 28mm f/2.8 lenses on a camera with a larger sized FX/24x36mm (aka "Full Frame") sensor?

To some extent the small DX/APS-C sized sensors tend to be a great "leveller" in the sense that they only show us the the central area of an FX/24x36mm sensor (~the middle 50% of "full frame"), and the edge performance of the format that they were designed for is excluded when used with the smaller sensor.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 28, 2022, 05:10:11
Do you have the opportunity to compare these two 28mm f/2.8 lenses on a camera with a larger sized FX/24x36mm (aka "Full Frame") sensor?

To some extent the small DX/APS-C sized sensors tend to be a great "leveller" in the sense that they only show us the the central area of an FX/24x36mm sensor (~the middle 50% of "full frame"), and the edge performance of the format that they were designed for is excluded when used with the smaller sensor.

Hi Hugh,

I do not have adapter for Minolta MD on my Z5 but will check the other lenses on FF sensor for sure. I'll repeat the test on APS-C with proper exposure tomorrow to make sure the test if fair.
Title: Re: A mini story about a mini-wide...
Post by: Zang on November 28, 2022, 23:23:48
OK, I have repeated the test with proper exposure and Nikkor does not look that terrible anymore, it just looks bad :)

I think the main issue with Nikkor is the high level of CA. Sharpness and contrast look OK. Sigma has CA barely noticeable wide open. At 5.6 it is gone completely for that lens. Nikkor has CA almost unnoticeable at 5.6 and color and contrast look better than the ones from Sigma.
Title: Re: A mini story about a mini-wide...
Post by: Zang on December 03, 2022, 22:24:55
At the end, I got a chance to take the Mini Wide for a ride for some real world pictures :)