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300mm Mirror Lenses
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PostPosted: Tue May 29, 2018 5:06 pm    Post subject: Reply with quote

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PostPosted: Thu May 31, 2018 6:42 pm    Post subject: Reply with quote

woodrim wrote:
My first images from Super Danubia 5.6/300, which I believe to be the same lens as Ohnar.



All, very nice images--I thing the 4th one is superb! jt


PostPosted: Mon Jun 11, 2018 7:41 pm    Post subject: Reply with quote

Thanks to all following this thread.

It was a very poor day for shooting, dark and bleak. Even with the ISO up at 500, there were times when I got caught with too slow a shutter. The frog picture is an example and pushing my luck at 1/30th second handheld. The peacock pictures were 1/60, a testament to the Sony IBIS.

These are from the Super Danubia 5.6/300 on a FF A7 II.



















PostPosted: Mon Jun 11, 2018 8:11 pm    Post subject: Reply with quote

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PostPosted: Sun Oct 28, 2018 6:49 pm    Post subject: Reply with quote

A few using my CELESTRON f5.6/300mm







Not the sharpest mirror for sure, but I like its drawing...


PostPosted: Sun Oct 28, 2018 11:21 pm    Post subject: Reply with quote

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PostPosted: Tue Nov 20, 2018 12:35 am    Post subject: Reply with quote

More from the Super Danubia 5.6/300 on FF A7 II.











PostPosted: Tue Nov 20, 2018 1:32 am    Post subject: Reply with quote

Those images are very good indeed and a credit to you and the lens.
Well taken
Tom


PostPosted: Tue Nov 20, 2018 5:57 pm    Post subject: Reply with quote

Cannot agree more - excellent shots!! Like 1 Like 1 Like 1


PostPosted: Tue Nov 20, 2018 10:09 pm    Post subject: Reply with quote

Much thanks, guys.


PostPosted: Thu Nov 22, 2018 1:41 am    Post subject: Reply with quote

woodrim wrote:
More from the Super Danubia 5.6/300 on FF A7 II.


This one is outstanding!

Cheers!

Abbazz


PostPosted: Mon Dec 02, 2019 10:13 pm    Post subject: Reply with quote

Pentax KP+Alfo 300/5.6 Catadioptric Lens - approximate distance (googlemaps estimate) 1400 meters.



Where can I find some informations about this lens?


PostPosted: Tue Dec 03, 2019 12:06 am    Post subject: Reply with quote

I have never heard of that branding. Post pictures; it is likely one we have seen before under a different name.


PostPosted: Thu Sep 23, 2021 1:34 pm    Post subject: Comparison of 300mm (350mm) mirror lenses. Reply with quote

I have just acquired an optomax 300mm f5.6, which is basically the same as the ohnar et al. It came with a 34mm rear filter and case, all immaculate. First results quite good, will post.
I just found this interesting comparison on dpreview. CKS probably also has the test on his blog albeit in chinese. it seems that there are two slight variants of this 300mm 5.6 mirror lens: ones with a larger rear element and ones like my optomax.

Comparison of 300mm (350mm) mirror lenses by Ching Kuane Shene.

Click on the jpg link in the slide show to pull up the full sized images in a new tab. Of note: the iq of the russian 3M-7K (is this also found as a rubinar?), the good res but poor contrast of the makinon, the tamron 350mm result doesn't quite hit the spot for me, tamron adaptamatic 300mm knocks the spots off all the mirrors at f11.


PostPosted: Thu Sep 23, 2021 3:15 pm    Post subject: Re: Comparison of 300mm (350mm) mirror lenses. Reply with quote

marcusBMG wrote:
I have just acquired an optomax 300mm f5.6, which is basically the same as the ohnar et al. It came with a 34mm rear filter and case, all immaculate. First results quite good, will post.
I just found this interesting comparison on dpreview. CKS probably also has the test on his blog albeit in chinese. it seems that there are two slight variants of this 300mm 5.6 mirror lens: ones with a larger rear element and ones like my optomax.

Comparison of 300mm (350mm) mirror lenses by Ching Kuane Shene.

Click on the jpg link in the slide show to pull up the full sized images in a new tab. Of note: the iq of the russian 3M-7K (is this also found as a rubinar?), the good res but poor contrast of the makinon, the tamron 350mm result doesn't quite hit the spot for me, tamron adaptamatic 300mm knocks the spots off all the mirrors at f11.


To my knowledge, the 3M-7K is not sold as a Rubinar. Rubinar has a 4.5/300. Most of the 300mm mirrors are either the same or very similar. However, there is a great deal of copy variance. I imagine the same is true for the Makinon but I managed to get two bad ones. Even the good ones don't seem to match up well to the other good 300mm mirrors. Then, if one collects enough of these mirrors to make comparisons, assuming all are good copies, focusing accuracy comes into play. In the end, your luck in finding a good copy and experience with it will be most important.

I do not believe it is fair or even meaningful to compare a good mirror to a good refractor as they are very different and offer different benefits and disadvantages. That aside, I would never use a long lens stopped down to f/11 (unless a fixed f/11 at greater than 700mm) because I value a shallow DoF for better separation of the subject and background.

The Tamron SP 350 is very expensive for good reason. That lens has much better quality control. It does suffer from balsam separation in the rear elements, so care has to be exercised when selecting one. Although I have been fortunate to find an excellent Ohnar, the SP 350 is a clear step above. Any differences in mirror lenses will be more obvious in use than controlled resolution tests. I have used my Ohnar extensively but have used it less since acquiring an SP 350. The SP 350 is now splitting time with my Vectis 400, which is, in my opinion, even better but vignettes a little on FF due to having been made for APS.

CK has an extensive collection of mirror lenses. He has some of the ultra-expensive Zeiss mirrors and most of any of the others that are of any value. I value his opinion and have shared mine with him. I have started this thread here for 300mm mirror lenses, have posted from my SP 350 and even the Vectis 400. I started another for the 500mm mirrors. I should probably post more results from the Vectis, which gets a lot of use now.




PostPosted: Fri Sep 24, 2021 12:09 am    Post subject: Re: Comparison of 300mm (350mm) mirror lenses. Reply with quote

marcusBMG wrote:
I have just acquired an optomax 300mm f5.6, which is basically the same as the ohnar et al. It came with a 34mm rear filter and case, all immaculate. First results quite good, will post.
I just found this interesting comparison on dpreview. CKS probably also has the test on his blog albeit in chinese. it seems that there are two slight variants of this 300mm 5.6 mirror lens: ones with a larger rear element and ones like my optomax.

Comparison of 300mm (350mm) mirror lenses by Ching Kuane Shene.

Click on the jpg link in the slide show to pull up the full sized images in a new tab. Of note: the iq of the russian 3M-7K (is this also found as a rubinar?), the good res but poor contrast of the makinon, the tamron 350mm result doesn't quite hit the spot for me, tamron adaptamatic 300mm knocks the spots off all the mirrors at f11.


marcus, thanks for reviving this thread.
That's a very comprehensive comparison by CKS.

I do have a couple of (related) additions to the list.

First, in the "almost 300mm" category is a Canon 250 f4 video lens, see eBay
https://www.ebay.com/itm/362874237484?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
I don't know what sensor it will cover, may be worth buying and playing with.
Also, refer this mflenses thread, seems it will cover m4/3 anyway,
http://forum.mflenses.com/spring-with-canon-cl-4-250mm-cat-t80314.html

Secondly, as a follow-up to an earlier suggestion, I added a 0.7X Speedbooster to my Zeiss 500/8 Mirotar, giving me effectively a Zeiss 350mm f5.6. It works extremenly well on m4/3, and on astro targets too.


PostPosted: Fri Sep 24, 2021 1:55 pm    Post subject: Reply with quote

Here's my optomax (bare lens with rear filter):



My first set of pics were rather dull, this is no doubt partly because I don't have a good 67mm hood. I have ordered a straight metal screw in hood. But these pics buffed up ok mainly by shifting the levels in faststone (+crop, resize, sharpen). Pentax K3-ii.





PostPosted: Fri Sep 24, 2021 4:54 pm    Post subject: Reply with quote

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PostPosted: Sat Sep 25, 2021 1:08 pm    Post subject: Reply with quote

I was just starting to knock dinner together when I though "that gravy granules tub looks exactly the right size". Sure enough, a bit of cutting, painting and gluing later:





I used a deglassed 67mm filter for the thread.


PostPosted: Sat Sep 25, 2021 1:24 pm    Post subject: Reply with quote

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PostPosted: Sat Sep 25, 2021 2:36 pm    Post subject: Reply with quote

marcusBMG wrote:
I was just starting to knock dinner together when I though "that gravy granules tub looks exactly the right size". Sure enough, a bit of cutting, painting and gluing later:

I used a deglassed 67mm filter for the thread.


I think the word for that today is repurposing. Love it.


PostPosted: Sun Sep 26, 2021 9:59 am    Post subject: Reply with quote

Some pics from a construction site with the Rubinar 4.5/300mm (Sony A7II 24Mpx)


#1


#2


#3


#4


#5


#6

100% crop out of #4


PostPosted: Sun Sep 26, 2021 3:33 pm    Post subject: Reply with quote

Wolfgang: Thanks for adding the Rubinar images to this thread. Those images leave little doubt to the lens' reputation. Very sharp!


PostPosted: Sun Sep 26, 2021 5:08 pm    Post subject: Reply with quote

Hood works well. This is Conwy quayside. test pic compares quite well with same pic taken with pentax FA 100-300mm, @ f5.6



PostPosted: Tue Sep 28, 2021 7:30 pm    Post subject: Reply with quote

I have found a cheap long hood with a 67mm thread on eBay and ordered it. It's quite decent. But your gravy can will no doubt work just as well!