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Forum: Winners' Showcase
05-09-2022, 07:38 AM
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I would like to nominate this photo
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Forum: Lens Clubs
04-14-2011, 08:55 PM
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I figuresd it's about time to join the club. I've had the 10-20mm f4-5.6 for some time, but haven't used it for much other then boring job pics. I took this today while on a job site taking some more boring shots. I was standing at the fence and turned around to see this cow sniffing me through the fence. I think I was about 8" to 12 off his nose with this shot. Got the whole cow, nose to tail from just a few inches. Gotta love 10mm.
Attachment 88686 |
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Forum: Lens Clubs
09-14-2011, 09:19 AM
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Yes, I made a shoulder type lens mount like the original using a Dremel. I know, I'm crazy. As I said, it wasn't pretty, but it worked. I've always been the type to do the best I can with what I have. Unfortunately, I don't have a lathe, otherwise I would have attempted that route instead. I set the mount in my vice, and cut a circle in a 1/4" thick piece of birch plywood with a hole saw. Then sanded that slightly larger using a drum sander so the router path would cut out far enough. Using the pattern guide for the router attachment, I milled the face of the mount down in two separate passes. The second pass I went a little two deep. Yes, the router attachment is a pain to work with. I actualy should have used my big router, but I couldn't find my pattern guides for it (my shop is a mess right now) and I was a little afraid that the big router, being a powerful as it is, might just grab on to the mount and shoot it across the room. Anyway, what I did was not the best way of going about the conversion. I realized when I was almost done that I could have done it with a lot less effort if I had simply purchased a different reverse ring. Hind sights - twenty/twenty. I never thought of using parts of a step ring to hold the aperture ring down. That may still be the way to go if I ever decide to revise the mount on the 58mm 1.8.
The mount for the Topcor 58mm 1.4 will be a simple 3 step process (famous last words). One, determine if the 62mm reverse ring is thick enough for infinity and possibly cut a spacer out of plastic/metal/aluminum foil/etc. to make it correct. Two, sand down the thread side of the reverse ring so the reverse threads fit just over the inner ridge of the aperture ring with the inside of the new mount properly seated against the inner mount ring on the lens barrel. I may also need to thin out the thread ring a little to fit over the inner aperture ring ridge. Three, drill holes and mount with original screws. This method will give me a small space inside, between the inner aperture ring and inner raised mount ring on the barrel. In this space the small leaf spring should fit correctly and allow me to keep the clicks at the f-stops. I actually have drawn up a drawing in AutoCad to confirm my theory.
I Like what you did there with the plastic spacer. And you are right, I could have, and should have just tried making a ring out of card stock or thin plastic to hold the aperture ring in place. It didn't occur to me to try that type of spacer until I was finished and had it all assembled. That would have worked great now that I think about it. It could have been left free floating and slightly thinner then the space it sits in to allow the aperture ring to turn freely. Hmmm, I might have to try that, but then I would have to sacrifice another mount.
Here's a quick drawing I did of the Topcor 58mm f1.4 to help illustrate what I'm talking about doing. It also helped me think through the problem. I'm a visual thinker. A drawing always makes it easier for me.
Attachment 103610 |
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Forum: Pentax SLR Lens Discussion
03-07-2011, 10:53 AM
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Sample images, apparently taken with this lens are now available on the Samyang Site.
Samyang.pl news |
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Forum: Pentax SLR Lens Discussion
11-12-2010, 08:02 AM
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Here's my suggestion for a reversed "stacked" setup. Get yourself an old parfocal slide zoom (with the 'a' on the aperture ring) and reverse and old fast prime in front of it.
The slide zoom needs to be the type that does not change in length as it is zoomed. Like an old Kiron or Vivitar series one, but there are plenty of other brands out there that will work as well. The reason I mention Kiron or Vivitar is that they are known to be decent lenses from that time period. It has to be a parfocal (a lens that stays in focus while the focal length - zoom - is changed) for this to work properly. Preferably something with a zoom lock so it doesn't creep on you when you get everything just right.
The prime doesn't even have to be one you can or would use on your camera. I have and old non-Ai Nikkor 50 f2 that I use for reversing. It doesn't have to be a 50, you could use any of the myriad of 28 f2.8's out there if you can find one cheap enough. Just something that is sharp, fast and considered to be 'good glass'. It could be an old Tak, or M42 mount or another lens brand or mount all together.
Now here's the why behind all this. The beauty of this setup is that you can set up your reverse macro, zoom all the way in and get the focus just right, then pull the zoom back (widen) to get the composition you are looking for and still have everything perfectly in focus. Basically, if you find that you are too close, and there is not enough interest at 4:1 or whatever, you can back out to 3.5:1 or 2:1 or anywhere in between. All the while keeping the subject in focus. Since it's a non-extending zoom, you can zoom in and out all day long without having to move your rig back and forth. Once you nail the focus, you are set to try multiple magnifications all you wish.
Don't forget the reversing filter thread adapter and any step up or down filter rings you might need to make this work.
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Forum: Pentax SLR Lens Discussion
10-25-2010, 07:15 AM
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Ehlacore,
Good for you. I'm glad you were able to find some lenses to work with. Looks like you have the beginnings of a pretty decent kit. That 24-135mmm should serve you very well as a walk around lens. Next thing to get, when time and money allow it, is a good sharp prime. Again, I'd say the A50mm 1.7. If you have problems with manual focus, pick up a diagonal split prism focus screen for $25.00. They aren't perfect but they sure do help.
Have fun with your new lenses.
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Forum: Pentax SLR Lens Discussion
10-23-2010, 10:14 AM
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I just thought of another one. I'm sure I'm going to be lamb basted for this because it's not a true macro, but, it will give you a lot more working distance and you could use the Raynox 150 or 250 with it to get better magnification if you wish.
Tamron AF 70-300mm F/4-5.6 Di LD MACRO 1:2
or
Quantaray 70-300mm F4-5.6 LD Macro 1:2
Now the great thing about this is you get a long telephoto zoom and a 180-300mm macro in the same package. Wide open image quality will not be as good with a dedicated macro lens, but stopped down (as you would normally use a macro to get better DOF) it should produce good results. I don't actually own one, but I've seen some very impressive macro shots online taken with both of these lenses. You can pick one of these up for anywhere form $50 to $150.
Again, this is just another option, and not necessarily the best. Just kind of a value for the money option.
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