Search found 2653 matches

by ray_parkhurst
Thu Aug 06, 2020 12:07 pm
Forum: Equipment Discussions
Topic: Nikon TM 5X Objective Extension Distance Help
Replies: 5
Views: 116

Re: Nikon TM 5X Objective Extension Distance Help

I think the MM objectives are part of the 210mm system, not 160mm, so the extension required for rated mag is 200mm from the sensor to the thread shoulder plane. At least that's what gives my 5x objective exactly 5x magnification.
by ray_parkhurst
Thu Aug 06, 2020 8:43 am
Forum: General Discussion Forum and Community Announcements
Topic: Electronics Swap canceled for 2020
Replies: 2
Views: 51

Re: Electronics Swap canceled for 2020

Ray There is an emoji "HAND WITH INDEX AND MIDDLE FINGERS CROSSED": 🤞 See 129310 on this page: http://www.alanwood.net/unicode/supplemental-symbols-and-pictographs.html If the emoji is visible, it means that the recent forum upgrade allows us to use all sorts of Unicode characters. Alan Wood Cool, ...
by ray_parkhurst
Thu Aug 06, 2020 7:37 am
Forum: General Discussion Forum and Community Announcements
Topic: Electronics Swap canceled for 2020
Replies: 2
Views: 51

Electronics Swap canceled for 2020

Just read that they've decided to cancel the remaining Sunnyvale electronics swaps for rest of 2020. If the shutdown situation improves it might pick up again in March. That makes a full year of cancelations. When the swap picks up again in March (is there a crossing fingers emoticon?) I expect a hu...
by ray_parkhurst
Wed Jul 29, 2020 8:25 am
Forum: Equipment Discussions
Topic: best controller for THK KR2
Replies: 7
Views: 298

Re: best controller for THK KR2

When these controllers coupled with the superb THK rails KR15, 20 and 26 with quality 400 step motors you have, think this is the SOTA for stepper based focus rails. Probably true, but I got the sense that the OP was looking for a more plug and play solution like I was when I bought the mjkzz contr...
by ray_parkhurst
Tue Jul 28, 2020 8:46 pm
Forum: Equipment Discussions
Topic: Schneider macro varon 85/4.5 CAS @1x
Replies: 10
Views: 556

Re: Schneider macro varon 85/4.5 CAS @1x

Seems I'm not using the lens to full potential on my lowly APS-C sensor! But maybe someday I'll graduate to FF, and it will still be useful. What surprised me the most was its control of colour aberrations at the edge. If you use shift-shift shooting, this increases the range of movement. I think t...
by ray_parkhurst
Tue Jul 28, 2020 2:43 pm
Forum: Equipment Discussions
Topic: best controller for THK KR2
Replies: 7
Views: 298

Re: best controller for THK KR2

I use KR15, KR20, and KR26 with various stepper motors, mostly from Lin Engineering. I control the steppers with the mjkzz controller. It is quite easy to use, and inexpensive. Prior to using the mjkzz I used Helicon Remote via a USB-RS interface to a Trinamic controller IC. This system worked well ...
by ray_parkhurst
Tue Jul 28, 2020 5:32 am
Forum: Equipment Discussions
Topic: Schneider macro varon 85/4.5 CAS @1x
Replies: 10
Views: 556

Re: Schneider macro varon 85/4.5 CAS @1x

Seems I'm not using the lens to full potential on my lowly APS-C sensor! But maybe someday I'll graduate to FF, and it will still be useful.
by ray_parkhurst
Sat Jul 18, 2020 8:33 pm
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

A little while ago you said that it was not a matter of whether or not to wear masks, but for how long to wear them. For a moment we agreed, and I let out a sigh of relief. But now we are back to this. I've been very consistent with my position, Lou. I feel that wearing masks is important in order ...
by ray_parkhurst
Sat Jul 18, 2020 8:32 pm
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

There is no need for a US-wide mask mandate, since 90+% of the US has no major problem. It is such a small effort, and so sensible, and it seems to be the main thing that distinguishes successful and unsuccessful efforts. 90% of the country is not alright; the majority of states have higher numbers...
by ray_parkhurst
Sat Jul 18, 2020 1:18 pm
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

Your answer to any study that shows this is that the subjects were lying. I suppose sometimes they might be lying, but in the absence of more information, this looks very much like outcome-motivated reasoning. Nevertheless, I agree with you that we don't really know how important this is. The WHO a...
by ray_parkhurst
Sat Jul 18, 2020 11:11 am
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

this means at least some percentage of folks would not be caught by temperature measurements but could still be contagious. Ray, as we've discussed above, we already knew (according to most experts) that many people are completely asymptomatic and also contagious, or pre-symptomatic and contagious....
by ray_parkhurst
Sat Jul 18, 2020 11:06 am
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

All have given us demonstrably false and misleading narratives. I'm afraid you are right about most of that (I don't know about John Hopkins, but the rest yes). That's why it is so important to look at other countries and actually see what works and what doesn't. Earlier you said you don't care abo...
by ray_parkhurst
Sat Jul 18, 2020 10:51 am
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

The recent stories about the 6 "types" of CoViD-19 seems interesting. It highlights combinations of symptoms of increasing severity. Most interesting to me is that the lowest form, "flu-like", comes without a fever, and this means at least some percentage of folks would not be caught by temperature ...
by ray_parkhurst
Sat Jul 18, 2020 10:39 am
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

but indeed we don't know the actual overcounting number. But as I say, it's not really important at this time. Whether it's 5% or 10% of the total doesn't change the fact that some states are doing far worse this month than they were last month. It will inflate the mortality rate for those that cou...
by ray_parkhurst
Sat Jul 18, 2020 8:59 am
Forum: General Discussion Forum and Community Announcements
Topic: On Lockdown
Replies: 252
Views: 11993

Re: On Lockdown

... At the end of all of this, a lot of the death statistics are going to be corrected for using historical death rates for each country, region, city etc. It's only then that we will have a true picture of how many lives were lost primarily due to COVID-19 and the impact it had on the health secto...