PENTAX Q-mount MS-SONNETAR 25mm F1.1

A review and sample photos using the Ms-Optics SONNETAR 25mm F1.1 (Miyazaki Optical) with a PENTAX Q series camera.

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Table of contents

Gallery

The sample photos taken with the PENTAX Q7 and PENTAX Q10

Review

1．Overview

The MS-SONNETAR 25mm F1.1 is a lens for the PENTAX Q from MS-Optics (Miyazaki Optical).

The lens’s focal length of 25mm is equivalent to the following in 35mm format:

• For the Q/Q10 (1/2.3-inch sensor), 5.5x magnification is equivalent to 137.5mm.
• For the Q7/Q-S1 (1/1.7-inch sensor), 4.7x magnification is equivalent to 117.5mm.

The lens features a Sonnar-type construction with 5 elements in 4 groups. The minimum focusing distance is 0.5m, which is equivalent to 35mm format, but this is a cropped result, so it can also be said to be a lens that can get close.

This lens is about the same size as the Q-mount Standard 01 and is only available in black.

2．Usability

The MS-SONNETAR 25mm F1.1 produces a soft image at the widest aperture of F1.1, and since focusing is done using the camera’s rear LCD screen, it can be difficult to align the focus peak with the subject.

When shooting at widest aperture, the Pentax Q7’s focus peak display is vague and almost unreliable when shooting. It’s safest to check the focus position by zooming in.

Since it’s a digital camera, I think it’s less hassle to at least take several shots using focus bracketing as a safeguard, and then select the best ones when developing them.

When photographing raindrops illuminated by artificial light or sunlight, the peripheral blur is poor and false colors occur, making it difficult to use in some situations.

As a medium telephoto lens that fits in one hand when attached to a Q camera, it’s convenient to carry around when you want to add a telephoto lens.

Since this lens does not have a leaf shutter, it uses the camera’s sensor shutter, so you need to be careful of rolling distortion of moving subjects.

3．Summary

In conclusion, to sum up the MS-SONNETAR 25mm F1.1 is no different from using a C-mount or D-mount lens. The image quality is also unpredictable at many maximum apertures, just like bright C-mount or D-mount lenses, so it’s not suitable for general use. If you buy it expecting a high-performance lens, you’ll be disappointed.

Specifications, considerations, etc.

Excluding simple lenses like pinhole lenses, this lens is the only third-party lens with a Q mount.

Considering the improving performance of tiny sensors in devices like smartphones, I wish the Q mount had continued with the Q series and offered a camera with a high-performance EVF. As mentioned above, it’s difficult to shoot with a fast lens using the rear LCD screen.

Apparently, a small number of prototypes of this lens with the same focal length of 25mm were also made for Micro Four Thirds, but unfortunately I wasn’t able to get one.

Micro Four Thirds cameras are equipped with mechanical shutters, so they can be used as regular lenses, and I wanted to compare it with other 25mm lenses. However, please note that when a lens without electronic contacts is attached to the Panasonic Lumix GM5, the mechanical shutter will not function and only the electronic shutter will be used.

Item	Value	note
focal length(mm)	25
Maximum aperture	1.1
Minimum aperture	11
Lens configuration	4groups 5elements
Leaf blade	12
Minimum distance(m)	0.5
Lens length(mm)	24.5	Distance form mount frange
Lens max diameter(mm)	40
Filter diameter(mm)	34
Weight(g)	75g	with hood
Release date	Year 2013
List price(Yen)	48,000

Reference links

• Description of the Sonnar-type lens according to Wikipedia.
• MS-SONNETAR 1.1/50 (Link in “Shige “s hooby)
• MS-SONNETAR 1.3/50 (Link in “Shige “s hooby)

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Update history

• 2025.8.24
• 2024.07.31
• 2024.03.24
• 2023.06.13