Samyang 800mm Mirror Lens Test

[Mandy D]

@DaveL59 Image of Moon with 800 mm Samyang mirror lens. This has just had some simple processing in GIMP to sharpen and adjust contrast. I could not get a good stack from my images. As you can see the quality is far from perfect.

[DaveL59]

Thanks Mandy, but isn't me looking to buy one of these 😉

If your skies are anything like mine at the mo the moon is swimming in cloud soup stirred by fast winds so not much chance of a good view or pic.

[Mr Spock]

If I may Quote from Cameralabs

"But the worst thing about this lens is the dismal sharpness: try as I might I couldn't take sharp picture with two copies of the lens. This could be down to sample variations and you might want to try it nonetheless. But I'd strongly suggest getting it from a dealer with a good return policy."

Source: https://www.cameralabs.com/samyang-800mm-f8-0-review/

[Craney]

Yes, I agree with the above.   

I bought a 600mm mirrored from a less well known brand off of Amazon.  Cheap and cheerful.... indeed.....  thought it might be a good wildlife and lunar lens.

Really difficult to focus at any distant object with any degree of precision.   In fact I think 'infinity' occurred about a fifth of a rotation before the end stop !!!

Compared to my old Celestron C90 I might as well been using a pin hole camera !!

Being small and compact, the 600mm now makes a nice paper-weight.

 

Sean.

[Mandy D]

On 12/11/2022 at 08:35, Craney said:

Yes, I agree with the above.   

I bought a 600mm mirrored from a less well known brand off of Amazon.  Cheap and cheerful.... indeed.....  thought it might be a good wildlife and lunar lens.

Really difficult to focus at any distant object with any degree of precision.   In fact I think 'infinity' occurred about a fifth of a rotation before the end stop !!!

Compared to my old Celestron C90 I might as well been using a pin hole camera !!

Being small and compact, the 600mm now makes a nice paper-weight.

 

Sean.

I found the best way to achieve focus was to point the lens at something, get it focussed as well as possible, then move the camera backwards and forwards until focus is near perfect. Or, alternatively, photograph something that is moving as it passes through the point of focus. Just keep shooting and one image will be reasonably sharp.

Of course, all of this only works for stuff that is fairly close to the camera. With no aperture adjustment possible, the depth of field is almost non-existant.

What surprise me is how poor this lens is on the Moon, even when the D800 indicates perfect focus has been achieved. Yet, for closer work it will focus quite sharply.