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12-22-2009, 11:51 AM   #211
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No catch in focus on my t-mount mirror on my K200D, either - it just fires away no matter what. Presumably the lens isn't shorting the contacts like it needs to, or the camera sense the lack of an aperture lever, or something. I suppose you might also try playing with the custom option having to do with focus indicators and screw mount lenses. Not worth it, as far as I am cconcerned - I find trap focus hopelessly ineffective (too many false hits until I turn the focus ring slower than I ever would normally need to, plus it only fires on perfectly center subjects, can't distinguish objects (like branches) in front of the subject from subject itself, etc.

12-23-2009, 05:40 AM   #212
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QuoteOriginally posted by jogiba Quote
BTW the 500-1000mm F6.3 mirror lenses have F6.3 @500mm and F12.6 @1000mm . I have the Rokinon 500mm F6.3 and to get 1000mm I would just add a 2x TC just like they do with the 500-1000mm on ebay but I prefer to use my lenses without a TC like my Celestron 9.25 that is 1480mm @F6.3.
Interesting - do you have a motor drive on an equatorial mount for the Celestron? Presumably that would make it much more useful for photographing anything at night other than the moon?

Rob
12-23-2009, 05:45 AM   #213
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QuoteOriginally posted by Marc Sabatella Quote
No catch in focus on my t-mount mirror on my K200D, either - it just fires away no matter what. Presumably the lens isn't shorting the contacts like it needs to, or the camera sense the lack of an aperture lever, or something.
That's what I guess as well.

QuoteQuote:
I suppose you might also try playing with the custom option having to do with focus indicators and screw mount lenses. Not worth it, as far as I am cconcerned - I find trap focus hopelessly ineffective (too many false hits until I turn the focus ring slower than I ever would normally need to, plus it only fires on perfectly center subjects, can't distinguish objects (like branches) in front of the subject from subject itself, etc.
Well, I expect the only situation where trap focus with a mirror lens would be especially useful with birds or animals would be where it was focussed on a point the creature was known to frequent - like a nest or a favourite perch etc.

That was what was described elsewhere - setting up the camera on a tripod with a cable release and walking away to let the camera catch the bird when the photographer no longer disturbed it.

On the other hand, the technique might be useful handheld with a MF lens that had more DOF.

Rob
12-23-2009, 10:33 AM   #214
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The T-Mount on my Opteka has a heavy black paint which causes the contacts not to short out. I keep a piece of alum. foil in my camera bag for the mirror, just tear off a thin strip and position it to cover the contacts. One of these days I'll try sanding off the paint from the mount. Of course, if your mount is plastic then the foil fix is the only way to get around it other than getting another all metal T mount.

12-24-2009, 12:45 AM   #215
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Just yesterday picked up my Christmas present for myself. A russian MC3M-7K 5.6/300mm mirror with a set filters and a russian M42->PK adapter (which doesn't fit my K200D). It seems to be quite rare as google doesn't know much about it. Hopefully I'll get a change to test it outside sometime today although it's not very bright outside.

Here's a few quick shots of the lens:


Size comparison next to SMCP-A 1.7/50mm
12-24-2009, 02:38 AM   #216
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QuoteOriginally posted by reeftool Quote
I keep a piece of alum. foil in my camera bag for the mirror, just tear off a thin strip and position it to cover the contacts.
Do you short all the contacts or only specific ones?

Rob
12-24-2009, 03:00 AM   #217
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Ovim, if it's like the 500mm version I'd be expecting you to have a very enjoyable lens. I'm looking forward to seeing some pics from the lens soon.
12-24-2009, 04:25 AM   #218
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QuoteOriginally posted by xjjohnno Quote
Ovim, if it's like the 500mm version I'd be expecting you to have a very enjoyable lens. I'm looking forward to seeing some pics from the lens soon.
I'm expecting that too as I already have the 3M-5A 8/500mm which I like a lot. Too much christmas going on to try the lens out today. Maybe tomorrow...

12-25-2009, 06:04 PM - 1 Like   #219
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Here's a few pics that didn't turn out too bad. Shot raw, fixed exposures (all underexposed by 1 to 2 stops), incresead contrast, fixed vignetting (amount 20, midpoint 20 in LR), white balance tweaked... Lens is Rokinon 500mm f/6.3. Colors are always a bit weird with this lens. I wish I had a standard color char to calibrate it. And the sensor has some dirt.
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12-25-2009, 08:02 PM   #220
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Who says you can't do close up work with a mirror? (Tamron 500mm f8)

12-27-2009, 01:21 AM   #221
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The weather hasn't been too bright and I 've been busy with Christmas stuff so I still haven't had the time or optimal conditions to really test the MC3M-7K 5.6/300mm.

Here's one shot I managed to get so far. Converted from Raw with LR defaults/auto setting (exposure upped ~1,5). Looks promising.

12-27-2009, 05:46 AM   #222
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QuoteOriginally posted by ovim Quote
The weather hasn't been too bright and I 've been busy with Christmas stuff so I still haven't had the time or optimal conditions to really test the MC3M-7K 5.6/300mm.

Here's one shot I managed to get so far. Converted from Raw with LR defaults/auto setting (exposure upped ~1,5). Looks promising.

That is really pretty impressive! I can't wait for more shots
01-01-2010, 11:04 AM   #223
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Ovim - That 300mm f/5.6 looks interesting, where did you get it from?

Hereis a photo taken earlier today from about 12 feet with the Tamron 55BB. Slight crop and re-size but no PP.
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01-01-2010, 11:27 AM   #224
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Nice bird Matt. How far away was it? I got the 300mm from a guy who has collected cameras and microscopes for 20 years. He always has something listed on a local auction site.
01-03-2010, 12:14 AM   #225
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I just received my Rokinon 500mm f6.3.

I haven't had a chance to play with it yet...

I found a lens hood on ebay:

Sonia Metal 95mm 95 Tele Telephoto Lens Hood Shade NEW - eBay Lens Hoods, Lens Accessories, Lenses Filters, Cameras Photo. (end time 15-Jan-10 17:43:28 AEDST)

which I have ordered. Hopefully it will fit - it is supposed to be a 95mm thread, both sides, so it shoulde fit on forwards and backwards (for storage). I'll let you know once it arrives, hopefully soon as I am off to the beach for some relaxation time at the end of the week. Unfortunately for me it is coming from the USA and I am in Australia...

I also have to work out how to get the exposures to work with the fixed aperature...

Cheers
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