It is among the locals here.

Went out and got a fresh supply. Good for a few days.

Well it is the Sierra Mt. range, not the Sierra, locals call it living in the Sierras.

Yes, law enforcement does recommend carrying, not official policy, but they do look the other way for the law abiding citizen.

Nope, not trying to stir up trouble and don't think the OP was either. But it seems that you and some others do not recommend standing up for yourselves, or your loved ones. Everything is just roses. If you will "read" his topic statement it has nothing to do with politics. Folks like you have made it political. It must be wonderful to live in such an idyllic world.

As for the OP's question, my gear gets extra padding, PVC tubes for tele lenses too big for pack. Depending on how long I'm going to be out, it might be mounted to a pack frame with minimal survival gear, side arm (first two rounds are snake shot), snake bite kit, para cord, small hatchet, matches in a dry tin, thermal blanket, fish line and hooks, and most important, Snickers bars and coffee. When the snickers and coffee run out, I'm gone.

Ron

Well I live in La La land, in what was a nice small community in the Sierras (so we were lead to believe). Our local news paper just posted from local camera groups that it is advised to carry a fire arm when in the Sierras. Seem as there are two legged predators that are collecting camera gear or what ever else they deem of value from even small groups (drug habits are expensive). Even our local sheriff advised me to carry after seeing our gear and our ages. I asked about a permit, they (Sheriff, HP, Forrest Service ) said point blank, "don't sweat it, we can't contain the criminal element and are not going to worry about the average citizen having protection."

Bad enough having to worry about the four legged critters and belly crawlers, but the two legged scum are much worse. So much for living in La La Land. Do I want to carry, hell no! Do I,..?

Time to run to the store for a new batch of pop corn, this is going to get lively but for all the wrong reasons.

Ron

Stumbling across mommy and her cubs gets pretty exciting, a cat and its' lunch (I wasn't invited), wild dog packs (worse than wolves), and the occasional exotic cultivation patch (real unfriendly bunch), the loner that has staked out his personal piece of secluded Forrest, the pervert stalking a couple of young ladies (oh so sad, sheriff got him, had a record). Yep pretty tame out there, if you stay on the beaten path as most folks do.

Ron.

Aperture design does affect the bokeh. Straight, curved, number of blades, surface finish. If I recall Raytheon (sp), Kodak, and Bell & Howell were at one time working on making a one piece optical element that a current could be passed through to change it's density. It worked, but things got complicated and the tech wasn't there at the time.

If you have a mechanical aperture at the focal point theoretically,you will not affect the image. This is the point where you lens elements have been working to achieve an image capable of being rendered on your camera sensor or film. Every thing is focused to a theoretical point, passing through it and ending up inverted, so placing an aperture here will theoretically have no effect. But, not every light ray can be completely directed to this point, but I don't believe there would be significant effect of an aperture at this point.

If you are just interested in the type of bokeh, you have to look at the aperture design, and to a small point the shutter type. If you are looking into an opaque changing element, they are not affordable with present tech, and I haven't kept up with it. I do know they have made window glass that can diffuse light, and some designs can go from clear to completely opaque. They are far from optical quality. If you are really brave and don't mind possibly destroying a few lenses, you can play around with disassembling some old lenses and reshaping the leaves or their leading edges. Most of the time you end up with an element that sticks from mishandling or shavings or burs, but a fun experiment.

Hope this helps.

Ron

No, the aperture is not located near the focal point of the lens. It is in most cases located between the front element (light gathering element) and the primary focusing element. It controls the volume of light entering the optical elements. Depending on the design of the aperture or it's quality, it can degrade an image to the point where it "may appear" out of focus, (This is entirely a separate issue). This in most cases appears in extreme light conditions (mostly brightly lit environments) at numerically high apertures. The actual focus point of a lens occurs at a distance between the rear element of the lens and the camera sensor or film plane.

Hope this helps, if not, keep asking.

Ron

Yes, if we assume he is asking about depth of field. There have be discussions about light refraction and diffraction off of the aperture blades at small f#, discussions about heat and humidity affecting sharpness over long distances and in studio use. Who knows what he has read on this forum or others that has him asking a question, and looking for clarification? The OP, as I read it, did not specifically ask about depth of field, he asked about light "quality or characteristics" at f stops. Until he chimes in, this is moot.

Ron

May I ask what information prompted you to ask this question? That way maybe we can get your topic back on track. Hopefully someone can help with out hijacking your thread.

Ron

Why? Every lens and camera situation is different, the distance to subject is different, environment is different. It gets you within the ball park, and you can adjust from there for your specific gear. I have lenses that are way better than the published DOF charts, others fall short, but it also depends on which camera I use them and how much I want to (think anal) pixel peep. To throw another monkey wrench into the mix, what about the hardware and software used? I certainly do not have the sophisticated software and hardware used to determine these results that labs use.

For me,DOF charts are usefull if you are trying to decide between lenses type from different manufacturers. Is it worth spending the money for this X lens or will Y do the same thing for what I do.

I hope this does not come across as an offensive or argumentative reply, but as another way of looking at supposed bench marks. In the real world bench marks go out the window for the most part.

Still, I don't think we have resolved "why" the OP asked his question. I personally would like to know what prompted him.

Well, yes, "if" you are in a lab, tightly controlled conditions, engineering the design on paper, or you have some magical lens that can compensate for humidity changes, wind current, temp differences between subject and capture element, take into consideration light diffraction from the surrounding, lens and camera are within ideal tolerances, ect.

In the real world not so much. Rule of thumb is about the best guess.

But, this is not what the OP was asking about.

Ron

They are also on YouTube.

Right on!! Could not have said it better.

Ron

Very well stated.
Ron

Thanks for replying.

I was trying to do the 2 star alignment, with out the scope attached, just to check things out. The housing for the DEC slews to a configuration where it crashes into the panel as it searches for the 2nd star in the alignment procedure. I did try to manually move the Dec 180 from what is (supposed to be ?) the start configuration and it does the same when searching for the 2nd star in the procedure. I'm guessing it might be the hand controller, it gets kind of finicky at times which is not a good sign and will not let me do a reset. Hope to find one that I can try before I have to purchase one.

Yes, your concerns over the weight of the tube troubled most who had this unit. I believe, and from what I have read, that the modifications to the motors and gears by the initial owner, addressed this situation as I was told that he did a lot of photo tracking. I modified the counter weights (it did not come with the unit) to use less weight further out to balance the system. Seems to work well and allows more sensitivity when changes are made.

Ron

(Download)