5 lenses and telescopes for wide-field deep-sky astrophotography

Astrophotography allows us to capture the beauty of the cosmos, revealing intricate details of deep-space objects like nebulae, galaxies, and star clusters. For wide-field deep-sky imaging, lenses, and telescopes in the 135mm to 230mm focal length range offer an excellent balance of field of view, detail, and ease of tracking.

This article explores five of the best lenses and telescopes for wide-field deep-sky astrophotography, all between 135 mm to 230mm. Astrophotographers widely use these optics for their superior sharpness, light-gathering ability, and minimal optical aberrations. Whether you’re capturing the Milky Way, large nebulae, or galaxies, these choices will help you achieve stunning images of the night sky.

Sigma 135mm f/1.8 DG HSM Art

The Sigma 135mm f/1.8 Art ($1,399) is a powerhouse for deep-sky imaging, thanks to its ultra-fast f/1.8 aperture. This allows for shorter exposure times, reducing noise and making it possible to capture faint details without long tracking sessions. The lens is known for its exceptional sharpness, even when used wide open, and has minimal chromatic aberration, ensuring stars remain pinpoint across the frame.

This lens works exceptionally well for wide-field astrophotography, capturing large nebulae and galaxy fields with incredible detail. It pairs beautifully with full-frame and APS-C cameras and can be mounted on a star tracker for long-exposure imaging.

Specifications:

• Focal Length: 135mm
• Aperture: f/1.8
• Mounts Available: Canon EF, Nikon F, Sony E, Sigma
• Weight: 1.13 kg
• Autofocus: Yes (not necessary for astrophotography)

Samyang/Rokinon 135mm f/2 ED UMC

The Samyang 135mm f/2 ($409) is widely regarded as one of the best budget-friendly lenses for astrophotography. Despite its low price, it delivers incredible sharpness, minimal coma, and almost no chromatic aberration. The f/2 aperture is fast enough to gather plenty of light, making it perfect for deep-sky objects and wide-field star fields.

Because it is fully manual, focusing is precise and reliable—ideal for astrophotography, where autofocus isn’t needed. Many astrophotographers use this lens for hydrogen-alpha imaging with modified cameras, as it performs well in capturing faint nebulae.

Specifications:

• Focal Length: 135mm
• Aperture: f/2
• Mounts Available: Canon EF, Nikon F, Sony E, Pentax K, Fuji X
• Weight: 830g

Askar FMA180 Pro

The Askar FMA180 Pro is a small refractor telescope designed specifically for astrophotography. It has a sextuplet design, ensuring stars remain sharp across the entire image frame without additional corrective optics. This makes it an excellent choice for those looking for hassle-free deep-sky imaging.

With a 180mm focal length and an f/4.5 aperture, the FRA180 Pro provides a balance between wide-field imaging and detail resolution, making it perfect for capturing large nebulae and star clusters. The high-quality glass and optical design minimize aberrations, delivering sharp, color-accurate images.

Specifications:

• Focal Length: 180mm
• Aperture: f/4.5
• Type: Refractor (Flat-Field Astrograph)
• Weight: 0.8 kg
• Field Flattener: Built-in

Askar ACL200

The Askar ACL200 is a unique lens-telescope hybrid designed specifically for astrophotography. Unlike traditional camera lenses, it features optimized optics for deep-sky imaging, providing sharp stars across the entire field of view. With a fast f/4 aperture, it gathers enough light to capture faint nebulae and galaxies while maintaining excellent contrast.

It features a built-in helical focuser, making precise focusing much easier. Additionally, its lightweight design makes it an excellent option for portable setups, working well with star trackers and small equatorial mounts.

Although this product has been discontinued, you can check with your local dealer if they still have one in stock.

Specifications:

• Focal Length: 200mm
• Aperture: f/4
• Type: APO Refractor (Lens-Telescope Hybrid)
• Weight: 1.8 kg
• Focuser: Precision Helical Focuser

Askar FMA230

The Askar FMA230 is a compact and lightweight refractor that offers exceptional optical quality in a small package. With a 230mm focal length, it provides more magnification than standard camera lenses while still maintaining a wide field of view for capturing large nebulae and galaxy clusters.

Its built-in reducer ensures versatility and sharpness, making it perfect for astrophotography with DSLRs, mirrorless cameras, or dedicated astronomy cameras. The f/4.5 aperture gathers plenty of light, making it a great choice for capturing deep-sky objects with high detail.

Specifications:

• Focal Length: 230mm
• Aperture: f/4.5
• Type: Refractor
• Weight: ~1.5 kg
• Field Flattener: Built-in

Each of these lenses and telescopes provides high-quality deep-sky imaging capabilities, whether you’re using a DSLR, mirrorless, or dedicated astro camera. If you’re looking for a fast, wide-field lens, the Sigma 135mm f/1.8 and Samyang 135mm f/2 are fantastic choices. If you prefer a dedicated telescope, the Askar FRA180 Pro, Askar ACL200, and Askar FMA230 offer superior optics and built-in field flatteners for pinpoint stars. One of the best things about these lenses and telescopes is that they are highly portable and can be used with a small star tracker like iOptron Skyguider Pro. This means you can take these lenses and telescopes on dark sky trips and enjoy the best of astrophotography.

Clear skies!