Sigma 600mm f8.0 Mirror for Canon MF

wxwax

So what about this lens, eh?



It's a weird bird. Fixed f8 aperature. Manual focus. But dirt cheap, at less than $400.

I have a 300 f4, and know how short that leaves me for animal shots. I'm unhappy with the results of a 1.4x and 2x on the lens. And been left staggering and clutching at my heart when looking at the prices for big Canon glass.

So I was wondering if this cheapo lens might not be a bad idea for limited use: daytime, outdoors, animals that know how to hold a pose? I've only found 4 reviews online, none of those say it's soft, which is my single biggest concern.

Anyone have any thoughts? :ear

pathfinder

wxwax wrote:

So what about this lens, eh?



It's a weird bird. Fixed f8 aperature. Manual focus. But dirt cheap, at less than $400.

I have a 300 f4, and know how short that leaves me for animal shots. I'm unhappy with the results of a 1.4x and 2x on the lens. And been left staggering and clutching at my heart when looking at the prices for big Canon glass.

So I was wondering if this cheapo lens might not be a bad idea for limited use: daytime, outdoors, animals that know how to hold a pose? I've only found 4 reviews online, none of those say it's soft, which is my single biggest concern.

Anyone have any thoughts?

Catadiotric lenses have been around for over 30 years - they are a fixed single aperature - for example F8 to view and manually focus through.. Manually focusing AF viewfinders, without a split image rangefinder reticle, may be a challenge, Sid. The bokeh is similar to that of a Diffractive Optics lens only worse - all highlights are usually distinctively a donut shape. Fish - take notice!! Herbert Keppler has written articles in Pop Photo Magazine for years about them. Their one real advantage is that they are smaller and lighter than a glass telephoto of the same focal length.

They can sometimes be found for significantly less than $400 - frequently $200-300 USD for a used cat is more typical by companies you have never heard of. Sigma probably makes a pretty sharp cat lens - their optical reputation is very good of course. Mirror lense can be very sharp as they do not suffer from chromatic aberration as the light is reflected and not refracted by a lens body.

But try focusing a long lens at sunrise at f8 manually. I can't do that at f2.8 or f4. I think if you plan to shoot non-moving targets that allow you to focus leisurely in bright sunlight they might be useful. As for me, I prefer the very best of tools in the long run - the Canon long lenses are less than the price of a new motorcycle for example.:D Somebody said that the joy of using a great tool remains long after the pain of purchasing it, and I wholly agree.

Nobody seem to make an F2.8 or an F4 cat - not sure why - they might be more inviting than a F8 cat.

wxwax

Great post, Pathfinder. I appreciate the detailed info. I've run into trouble trying to manually focus before, so I'm sensitive to the issues with this lens. Good stuff, thanks.

ian408

I have an old Series 1 solid cat with a Nikon mount.

In addition to what PF says, you'll also notice "donuts" in bright
backgrounds (shooting towards the sun for example).

In it's day, it was a good lens. I bought it because I couldn't afford
better and because it was fairly compact.

Ian

wxwax

ian408 wrote:

I have an old Series 1 solid cat with a Nikon mount.

In addition to what PF says, you'll also notice "donuts" in bright
backgrounds (shooting towards the sun for example).

In it's day, it was a good lens. I bought it because I couldn't afford
better and because it was fairly compact.

Ian

Hmmm, bad bokeh and manual focus issues sink this idea. I'm glad you guys have experience with these lenses.

ian408

wxwax wrote:

Hmmm, bad bokeh and manual focus issues sink this idea. I'm glad you guys have experience with these lenses.

I wouldn't go with bad bokeh. Just different If you know how it works, you can
work with it to produce interesting results.

I've never thought about it but would imagine if I could come up with a Canon
mount for it, I could use it. For these lenses, Vivitar used a threaded mount with
the appropriate conversion. The telescope threaded mount might fit. If it does,
I'll let you know and you can take it for a spin in Yosemite.


Ian

wxwax

ian408 wrote:

I wouldn't go with bad bokeh. Just different If you know how it works, you can
work with it to produce interesting results.

I've never thought about it but would imagine if I could come up with a Canon
mount for it, I could use it. For these lenses, Vivitar used a threaded mount with
the appropriate conversion. The telescope threaded mount might fit. If it does,
I'll let you know and you can take it for a spin in Yosemite.


Ian

Cool, that sounds like fun.