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300mm Mirror Lenses
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PostPosted: Tue Aug 01, 2017 5:33 pm    Post subject: Reply with quote

kds315* wrote:
calvin83 wrote:
kds315* wrote:
Shall I be a bit mean and throw in this one...?

It depends on who is reading this thread. Wink


Yep, for some (like me, maybe others..) it is a treasure... Wink


Klaus: Have you posted images from the lens? Or is it a special purpose lens only? I saw a similar lens recently that was a 5/300.


PostPosted: Tue Aug 01, 2017 7:57 pm    Post subject: Reply with quote

woodrim wrote:
kds315* wrote:
calvin83 wrote:
kds315* wrote:
Shall I be a bit mean and throw in this one...?

It depends on who is reading this thread. Wink


Yep, for some (like me, maybe others..) it is a treasure... Wink


Klaus: Have you posted images from the lens? Or is it a special purpose lens only? I saw a similar lens recently that was a 5/300.


Really, where did you see that? Never knew he made a 5/300mm!!


PostPosted: Tue Aug 01, 2017 11:12 pm    Post subject: Reply with quote

kds315* wrote:
woodrim wrote:
kds315* wrote:
calvin83 wrote:
kds315* wrote:
Shall I be a bit mean and throw in this one...?

It depends on who is reading this thread. Wink


Yep, for some (like me, maybe others..) it is a treasure... Wink


Klaus: Have you posted images from the lens? Or is it a special purpose lens only? I saw a similar lens recently that was a 5/300.


Really, where did you see that? Never knew he made a 5/300mm!!


Not necessarily by him, just similar in that it is a fast mirror made for IR.


PostPosted: Tue Aug 01, 2017 11:46 pm    Post subject: Reply with quote

150mm 1.4 ! Just a bit challenging to nail THAT focus I'm guessing!


PostPosted: Sun Aug 27, 2017 12:09 am    Post subject: Reply with quote

Status... I have been doing lots of testing, adjusting, testing, adjusting, well, you get it. I now have three 300mm mirror lenses but will likely have one when the dust settles. I have discovered much about these difficult beasts and will report back here after I've made my full conclusions.

At the moment, the two lenses I'm evaluating are the unbranded Makinon and an Ohnar. Another Makinon will eventually show up. I have noticed that the last distance before infinity on the Ohnar focus ring is 100 feet, 30 meters. The Makinon has 50 feet, 15 meters. Perhaps this is why the Ohnar focuses more easily. I have so far also observed that the Ohnar is weak at close distance and the Makinon is weak at distance. The Ohnar is very good from around 20 yards to infinity. The Makinon is not performing as well as I would like at close distance and something occurred to me. When I first received it, it had a funky mount arrangement that made it fall well short of infinity. It also included a shot extension tube, so it was obvious the previous owner used it for close up work.

I have a question that I'm asking here because it applies to this Makinon. I have found its sweet spot to be at intermediate distance, not real close and definitely not infinity. Is it possible that by adding an extension, thus making the intermediate position on the focus ring a closer distance, the sweet spot will have been brought closer for better macro? Did I explain that well enough?


PostPosted: Sun Aug 27, 2017 7:17 am    Post subject: Reply with quote

woodrim wrote:
Status... I have been doing lots of testing, adjusting, testing, adjusting, well, you get it. I now have three 300mm mirror lenses but will likely have one when the dust settles. I have discovered much about these difficult beasts and will report back here after I've made my full conclusions.

At the moment, the two lenses I'm evaluating are the unbranded Makinon and an Ohnar. Another Makinon will eventually show up. I have noticed that the last distance before infinity on the Ohnar focus ring is 100 feet, 30 meters. The Makinon has 50 feet, 15 meters. Perhaps this is why the Ohnar focuses more easily. I have so far also observed that the Ohnar is weak at close distance and the Makinon is weak at distance. The Ohnar is very good from around 20 yards to infinity. The Makinon is not performing as well as I would like at close distance and something occurred to me. When I first received it, it had a funky mount arrangement that made it fall well short of infinity. It also included a shot extension tube, so it was obvious the previous owner used it for close up work.

I have a question that I'm asking here because it applies to this Makinon. I have found its sweet spot to be at intermediate distance, not real close and definitely not infinity. Is it possible that by adding an extension, thus making the intermediate position on the focus ring a closer distance, the sweet spot will have been brought closer for better macro? Did I explain that well enough?


An interesting idea. With a non IF refractor I can't see it would make any difference, but with a reflector it may do. Worth a try IMO.


PostPosted: Sun Aug 27, 2017 4:01 pm    Post subject: Reply with quote

woodrim wrote:
I have a question that I'm asking here because it applies to this Makinon. I have found its sweet spot to be at intermediate distance, not real close and definitely not infinity. Is it possible that by adding an extension, thus making the intermediate position on the focus ring a closer distance, the sweet spot will have been brought closer for better macro? Did I explain that well enough?


I would say yes. What you're doing is moving that particular focal range closer by using the extension tube. Probably a lot closer.

I look forward to your report on the short mirrors.


PostPosted: Sun Aug 27, 2017 6:50 pm    Post subject: Reply with quote

Hmm, looking forward to your individual ratings and the final decision.
I have a few mirror lenses myself, but was never really convinced...


PostPosted: Sun Aug 27, 2017 10:13 pm    Post subject: Reply with quote

Thanks for your thoughts. I have thought about it again and am not convinced but did get better images from the Makinon before I started messing with the mount. Perhaps the previous owner knew something,

Klaus: I will say this again when reporting findings. When using mirrors, all descriptive terms become relative, especially when describing sharpness. What keeps me going and hooked is the unique rendering and pleasing look when all falls into place well. Here is an example of one that is to my taste. It is from the Ohnar on my friend's FF Nikon.


PostPosted: Mon Aug 28, 2017 4:53 pm    Post subject: Reply with quote

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