[Ash]

Been a while since I'd picked up my trust Tamron 500...
another few from this beauty:

At MFD:


At short to mid-distance:


At longer distance:




No sharpening required.

[Miserere]

Picked up a Sigma CAT 600mm f/8 on eBay just before Christmas. It's even harder to focus and hold still than my Sigma CAT 400mm f/5.6, but I'm getting the hang of it

Here is an American Robin I caught eating earlier this week. Click for larger size.



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[Ash]

Sharp and nicely contrasted there Miserere.
Looks like a fine lens, and perhaps more compact than your f/5.6 version.

[w0jt]

Has anyone ever tried a monocular convereter on their mirror lens? B&H has a Pentax clone for $40 and I was wondering how well it would work as a spotting scope. I'm about to visit florida for a few weeks of sun.

ivoire: Does the device in your photo simply screw onto the M42 lens mount and convert it into a spotting scope? I have believed for a long time that such things existed, but none of the camera shops or even one telescope shop around where I live are aware of such a device existing. Please tell me more, such as a specific part number or listing of the device on the web.

I haven't tried a commercial one but I made a T mount eyepiece from an old Tasco telescope erecting prism and an old T mount. I can use it with one of several cheap telescope eyepieces but at present it is fitted with an old microscope eyepiece. It actually workes remarkably well - your eye is much more forgiving of poor sharpness and contrast then film of digital sensors. I imagine that a commercial one will give better image quality than my lash up so if you want a spotting scope it's probably worth a try. Also if you intend to take your mirror lens with you anyway then you have a spotting scope for almost no additional weight.

Matt: I would love to learn more about your design. I'm not too handy at metalworking myself, but I have a friend who works in a machine shop and has helped me out with various projects in the past, so I might actually have a chance of accomplishing it with your design. I have a Samyang 500mm f/8 that looks almost identical to the one in your photo, and I always thought it would be neat to be able to use it as a compact telescope.

[ivoire]

ivoire: Does the device in your photo simply screw onto the M42 lens mount and convert it into a spotting scope? I have believed for a long time that such things existed, but none of the camera shops or even one telescope shop around where I live are aware of such a device existing. Please tell me more, such as a specific part number or listing of the device on the web.

It is a K mount. I put the m42 to k-mount on the 500mm mirror lens and then attach the adapter. It makes a great spotting scope as it offers a 5x magnification (viewing a bird the size of a sparrow from 50 ft makes it look like you have it in your hand in front of your face). The weight of the russian mirror lens is a plus when viewing on a tripod. Pentax made one but they are very difficult to find. This is made by Bower. Bower PATP APK Telephoto Lens Adapter is written on the adapter. It is commonly known as a monocular converter. buy it here for $40:

General Brand | Pentax K-Mount Lens Monocular Converter | BT828

Thy also have one in m42 screw mount. I got the Kmount so it will work with any of my other lenses. Screw mount is here:

http://www.bhphotovideo.com/c/product/82254-REG/General_Brand_BT831_M42_Univ...t_Lens_to.html

[Miserere]

Sharp and nicely contrasted there Miserere.

Thanks! And I didn't touch up the contrast more than I do for my "normal" photographs. I did bump up the saturation a bit, but not much.

Looks like a fine lens,

I'm liking it so far, despite being tough to focus. It would probably be easier if I used it on a monopod, but haven't so far.

and perhaps more compact than your f/5.6 version.

Not sure what you mean. My Sigma CAT 400mm f/5.6 is shorter and smaller; 86mm filter thread vs 95mm for the 600mm f/8. Did you mean something else?

[Ash]

I assumed your f/5.6 lens is a straight (non-mirror) lens, and further assumed that if so it would be bulkier than your 600 mirror.
My bad.

[Biro]

This looks like too much fun to miss - especially at such low prices. So... of the few 500mm and longer mirror lenses that one can still purchase new these days, is there a consensus on which is best? Or are they all fairly close in IQ? Currently, I'm leaning toward the Rokinon 500mm f/6.3. But I assume the Rokinon, Vivitar, Opteka, Pro-Optic and Samyang-branded lenses are all the same product. Is this correct? And one more question, I also assume there is expansion and contraction of the mirror element (aluminum?). if this is correct, is there any noticeable difference in performance of the all-black vs. the black and white models?

[MattGunn]

Matt: I would love to learn more about your design. I'm not too handy at metalworking myself, but I have a friend who works in a machine shop and has helped me out with various projects in the past, so I might actually have a chance of accomplishing it with your design. I have a Samyang 500mm f/8 that looks almost identical to the one in your photo, and I always thought it would be neat to be able to use it as a compact telescope.

It was made out of old bits from a cheep nasty tasco telescope. I modified an old T mount adapter so I could screw the telescope erecting prism to it and the eyepiece just push fits into this. It reaches infinity focus - more by luck than judgement - but this will only works with a T mount lens. It should be possible to make something similar for K or M42 mount etc but these have a shorter registration distance than T mount so it probably won't be possible to maintain infinity focus and have an erecting prism. I will take some close up photos showing the assembly when I get a chance.

This looks like too much fun to miss - especially at such low prices. So... of the few 500mm and longer mirror lenses that one can still purchase new these days, is there a consensus on which is best? Or are they all fairly close in IQ? Currently, I'm leaning toward the Rokinon 500mm f/6.3. But I assume the Rokinon, Vivitar, Opteka, Pro-Optic and Samyang-branded lenses are all the same product. Is this correct? And one more question, I also assume there is expansion and contraction of the mirror element (aluminum?). if this is correct, is there any noticeable difference in performance of the all-black vs. the black and white models?

I have not tried any of the Rokinon / samyang etc variants but I have both a Centon and the Tamron 55BB. Based on my experience and the information in this thread and elsewher the Tamron is markedly better than almost everything else. You should be able to get a second hand Tamron for a little more than one of the new Rokinon ones and I doubt you would be dissapointed if you did.
The mirrors are an aluminium film on glass as with astronomical telescopes and so thermal expansion should not be a significat problem unless the temperature there is very extreme.

[danielchtong]

I want donuts. I expected to see a lot here. But no.
The images in here proves that mirror lenses are viable and certainly affordable

Daniel

[ovim]

Here's couple of shots from the MC3M-7K 5.6/300mm from today. Conditions weren't very good but with some PP these turned out OK (when the sun came out the bird was long gone).

[MattGunn]

Here's couple of shots from the MC3M-7K 5.6/300mm from today. Conditions weren't very good but with some PP these turned out OK (when the sun came out the bird was long gone).

Superb photos and not a donut in sight! What is this lens like to use in comparison to 500mm f/8 mirror lens?

[ovim]

Thanks MattGunn!

And no I didn't stop by the donut shop actually I have couple of other shots with headache inducing bokeh.

If this lens had the reach of the 500mm it'd be perfect. It's much smaller and lighter than my 3M-5A 8/500mm and focusing is easier. Focus ring is just perfectly damped and of course it's one stop faster.

After 2hrs in -20C I noticed that the focusring on my 500mm had gotten really stiff, and it's a little too stiff even in the summer. Also my splitscreen partially blacks out around f8 so that's another gripe with the 500mm. I posted one shot with 500mm on the minimalist thread but here it's again:

[danielchtong]

Picked up a Sigma CAT 600mm f/8 on eBay just before Christmas. It's even harder to focus and hold still than my Sigma CAT 400mm f/5.6, but I'm getting the hang of it

Here is an American Robin I caught eating earlier this week. Click for larger size.



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Hahaha I took some images really close to what you did. But not with mirror lens. I would love to have your reach










Daniel

[Miserere]

Hahaha I took some images really close to what you did. But not with mirror lens. I would love to have your reach

Daniel

Looks like your robin had fresh berries, mine had to do with old ones.

You seem to have enough reach, Daniel. No need to complain!

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