Samyang 500m f8

[Thailander]

Just got delivery of this today. Having had a quick play with neighbourhood birds I am slightly disappointed with the sharpness. I was hoping to get some usable moon shots but reckon I will have to experiment more on the night.

Has anyone else got shots for me to emulate?

[Celestron]

The only thing i can tell you is i have a similiar lens i bought for an old Film SLR camera and was well disappointed myself . I do not recommend these type lens for anything . If you can get your money back i'd do so , if not then sell it and get a better lens and take it as a lesson learned about lens . You get what you pay for .

[Bernoulli]

I've never seen a mirror lens that I thought was especially sharp. For that matter I don't even like them in telescopes!

[Thailander]

Does a filter and longer exposure work?

[Thailander]

This is a cropped image taken from around 80 ft

[Celestron]

Originally Posted by Thailander

Does a filter and longer exposure work?

No .........

[Celestron]

Originally Posted by Thailander

This is a cropped image taken from around 80 ft

Pretty much what you can expect all the time . Sell it ........

[ameerat42]

If you want a 500/8 mirror lens I know that the Tamron one (long discontinued, I think) is tops. I got one after I had tried a Celestron 90 telescope (apologies to Celestron here). At the focus point they (at least mine) is pin sharp. At 80 feet, you depth of field is about an inch.

Canon and Nikon also make mirror lenses but I know nothing about how good they are.
Am.

[archer1960]

Canon's mirror lens is well-regarded, but like the Tamron, is long discontinued. I don't know about the Nikon, but I would imagine it would also be good, or they wouldn't put their name on it.

[archer1960]

It would seem to me that there would be a market (small, but enough to make some money in) for a GOOD mirror lens, something along the lines of a small (3 to 4 inch aperture?) R-C telescope with a built-in camera mount and tripod collar. IMO it could be manual focus and even a fixed f/ratio as long as it was sharp.

[Thailander]

Price dependant I guess. I researched a bit before buying this and the images on flickr were impressive so maybe the QC in manufacture is questionable.

[archer1960]

Originally Posted by Thailander

This is a cropped image taken from around 80 ft

Actually, the sharpness of that picture doesn't look too bad; it looks like it's front-focused about an inch, because the gutter the bird is standing on looks pretty sharp. The biggest thing you are missing is contrast, and that's an inherent weakness of reflector lenses. Just like reflector telescopes, the center obstruction reduces your contrast a bit. In addition, was it humid when you took that shot? It looks like the transparency wasn't very good. Or maybe you took it through a glass window or screen?

[Thailander]

On the focus agreed. humidity was an issue too. on looking through a window no but what I did notice was if a window was slightly dirty focussing through it was nigh on impossible.

[ameerat42]

I don't know how many pictures you've taken with it so far. Maybe persevere a bit and try different subjects, like the moon. Make sure you keep it steady, as they can be tricky - long focal length in a very sort body. With mine I use nothing less than about 1/160 sec. If you haven't already, you might notice the unusual doughnut-shaped bokeh of the highlights it produces.
Am.

[Bernoulli]

If you take that image and compress the contrast it's not that bad. Archer1960 is right, the problem with mirror lenses is scattered light and, while that affects sharpness, it does more harm to contrast. The gutter does seem to be in good focus.

I still prefer refractors!