Newport Damped Optical Posts

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kaleun96
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Newport Damped Optical Posts

Post by kaleun96 »

Has anyone here tried using a damped optical post for a vertical setup? Melles Griot make them, as well as Newport.

They can be had on eBay for significantly less (if you're in the US) and the vibration damping seems suited for our hobby. Two considerations: I'm not sure how much weight the rack and pinion mount might tolerate when not clamped in-place (I haven't been able to get an answer from them on that) and the total height is perhaps a touch less than I'd like (355mm / 14").

But even without the vibration damping I think these could make good vertical stands given their compatibility with optical breadboards and relative affordability secondhand. I did manage to find one person who used them for macrophotography but I'd be a bit worried about how far their camera is mounted from the post - it likely doesn't do any favours for both vibration and the wear on the rack and pinion.
- Cam

RobertOToole
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Re: Newport Damped Optical Posts

Post by RobertOToole »

Hi Cam,

I have tried a dampened post years ago but I did not like the nylon geared rail strip that was mounted on the post.

Have you seen the dual post Z column that Thorlabs sells? They pop up on Ebay sometimes for tempting prices.
Screen Shot 2020-08-30 at 10.33.25 AM.jpg
Best,

rjlittlefield
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Re: Newport Damped Optical Posts

Post by rjlittlefield »

kaleun96 wrote:
Sun Aug 30, 2020 6:30 am
Has anyone here tried using a damped optical post for a vertical setup?
My standard setup consists of an optical breadboard, a 14" post with rack and pinion mount, and a long Arca-Swiss rail fastened to the breadboard.

Depending on what I'm shooting, I configure either horizontal or vertical mode. In horizontal, the camera and focus stepper mount on the baseboard rail, while the subject positioning stack mounts vertically on the post rack and pinion. In vertical mode the modules switch places, so the camera and focus stepper mount on the rack and pinion of the post, while the positioning stack mounts horizontally on the baseboard rail.

In vertical mode, it looks much like the one that you found at dpreview, except that my camera often hangs out even farther because of the way the system has evolved. I confess that I do not often show pictures of the overall setup because it looks dangerously overhung. But in practice it works fine. I have used it for several years with no strong urges to modify it.

Despite the large overhang, stability is not much problem. In the configuration shown here, a sharp rap on the camera body settles out in under 3 seconds as shown by 100% Live View at 50X. (The picture shows a 10X.) A larger problem is environmental vibration. If I were to shoot with continuous illumination at 50X in this configuration, I would need a day with no wind, and turn off the house ventilation fan.

VerticalConfiguration.jpg

I'm not sure how much weight the rack and pinion mount might tolerate when not clamped in-place.
I do not trust my mount to hold any weight at all unless it is clamped. When the mount is heavily loaded, it tends to stick against the rod so that it is difficult to move in either direction and feels like it might drop suddenly leading to catastrophe. So, I adjust the position of the mount as a two-handed operation. There is always either one hand holding the knob that drives the pinion, or one hand holding the weight of whatever is attached to the mount. With the weight taken off the mount so that it moves freely, I use the pinion knob to adjust the position. When all is positioned correctly, I continue to hold the pinion knob in position while tightening the clamp. This all sounds awkward, but I found that it soon became so natural that just now I had to go actually do it, to write these words describing how I do it.

I just now weighed the assortment of stuff that is hung off the mount as shown above. It weighs 10.5 pounds with my Canon T1i camera as shown above, roughly 1 pound more with Nikon D800E.
the total height is perhaps a touch less than I'd like
Note that in the dpreview picture, the user has mounted his post on a large block of aluminum to raise the whole post. It may be helpful to think of the 14" post as 11" of adjustment.

--Rik

Macro_Cosmos
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Re: Newport Damped Optical Posts

Post by Macro_Cosmos »

I can personally recommend that VAP stage Robert linked, the posts are damped.
I also know the seller that sells them (commercialcomponentsrus), he likely has more. Easy person to deal with, fast shipping and good packaging.

It does have left and right wobble, you can use a hex wrench on the middle hex screw, that's their high precision mode where wobble then becomes minimised. Not sure why.
Don't lower it too much, there's a bottom screw that may come loose, you can fix it by tightening that screw. Placing an object like a small plastic box under to make sure you never lower it too much helps.

lothman
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Re: Newport Damped Optical Posts

Post by lothman »

I use the 66mm rail of Thorlabs bolted to a T-shape. Together with two wooden feet which adapt wobble-free to any surface and can be used horizontal or vertical. Very sturdy in itself, on the wooden feet I used rubber cones which came from loud speaker equipment.

The best is, the dovetails on all four sides are compatible to Arca-Clamps. So it is very easy to attach anything to the rail and to flip if from vertical to horizontal. The pics show the version I made for a buddy, in mine I use two sledges in the rail for more stability also some other features in the xy- table... If there is interest I could do a documentation.

regards
Lothar
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kaleun96
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Re: Newport Damped Optical Posts

Post by kaleun96 »

RobertOToole wrote:
Sun Aug 30, 2020 10:36 am
Hi Cam,

I have tried a dampened post years ago but I did not like the nylon geared rail strip that was mounted on the post.

Have you seen the dual post Z column that Thorlabs sells? They pop up on Ebay sometimes for tempting prices.
Hey Robert,

What was it about the nylon rack that you didn't like? Was the mechanism a bit sticky given the weight or did it require a lot of tightening to clamp down properly etc?

That Thorlabs setup would be ideal, I'd much prefer that kind of vertical adjustment mechanism too. One trouble with buying things like this from eBay US is that they're almost always the imperial versions, and most of what I have is in metric. I've actually just bought the Newport 14" optical post with rack and pinion mechanism off eBay US but the post itself seems to be compatible with both metric and imperial breadboards from what I can tell. The rack and pinion is more tricky but I think I've found a way to adapt it to metric.

rjlittlefield wrote:
Sun Aug 30, 2020 12:44 pm
Despite the large overhang, stability is not much problem. In the configuration shown here, a sharp rap on the camera body settles out in under 3 seconds as shown by 100% Live View at 50X. (The picture shows a 10X.) A larger problem is environmental vibration. If I were to shoot with continuous illumination at 50X in this configuration, I would need a day with no wind, and turn off the house ventilation fan.
Thanks for sharing your setup, Rik! That's exactly the kind of thing I was hoping to find. Seeing the weight and torque of your assembly on the rack and pinion mechanism is encouraging, as I'd have a similarly heavy setup mounted to it. I would have expected there to be some axial play in the rack and pinion though, does it not tilt forward slightly and thus bringing your camera out of perfect vertical alignment relative to the breadboard?
rjlittlefield wrote:
Sun Aug 30, 2020 12:44 pm
I'm not sure how much weight the rack and pinion mount might tolerate when not clamped in-place.
I do not trust my mount to hold any weight at all unless it is clamped. When the mount is heavily loaded, it tends to stick against the rod so that it is difficult to move in either direction and feels like it might drop suddenly leading to catastrophe. So, I adjust the position of the mount as a two-handed operation. There is always either one hand holding the knob that drives the pinion, or one hand holding the weight of whatever is attached to the mount. With the weight taken off the mount so that it moves freely, I use the pinion knob to adjust the position. When all is positioned correctly, I continue to hold the pinion knob in position while tightening the clamp. This all sounds awkward, but I found that it soon became so natural that just now I had to go actually do it, to write these words describing how I do it.
That's good to know, I was planning on doing something similar. I've thought about buying something like this to fasten around the post as a collar as a backup in case the rack and pinion gave way or I accidentally dropped it while adjusting the height. But I'm not sure it's compatible with the Model 75 post, though a distributor of Newport products in the Nordics mentioned it to me.
rjlittlefield wrote:
Sun Aug 30, 2020 12:44 pm
I just now weighed the assortment of stuff that is hung off the mount as shown above. It weighs 10.5 pounds with my Canon T1i camera as shown above, roughly 1 pound more with Nikon D800E.
Thanks for taking the time to measure. I don't have scales on hand but adding up various components, my assembly will clock in at about 8-9 pounds without camera and lens.
- Cam

kaleun96
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Re: Newport Damped Optical Posts

Post by kaleun96 »

lothman wrote:
Sun Aug 30, 2020 2:09 pm
I use the 66mm rail of Thorlabs bolted to a T-shape. Together with two wooden feet which adapt wobble-free to any surface and can be used horizontal or vertical. Very sturdy in itself, on the wooden feet I used rubber cones which came from loud speaker equipment.

The best is, the dovetails on all four sides are compatible to Arca-Clamps. So it is very easy to attach anything to the rail and to flip if from vertical to horizontal. The pics show the version I made for a buddy, in mine I use two sledges in the rail for more stability also some other features in the xy- table... If there is interest I could do a documentation.

regards
Lothar
Hey Lothar, that's a great looking setup. The prices do not seem too bad either. Are the dovetails of the same specifications as Arca-Clamp dovetails, or is it more that they work well enough together? If they work perfectly together, that is a huge benefit. If I had not already bought an optical post, I might have looked more into this option.

Do you need to fill the 66mm rail with sand or anything else to help damp vibration?
- Cam

lothman
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Re: Newport Damped Optical Posts

Post by lothman »

kaleun96 wrote:
Mon Aug 31, 2020 12:24 am
Hey Lothar, that's a great looking setup. The prices do not seem too bad either. Are the dovetails of the same specifications as Arca-Clamp dovetails, or is it more that they work well enough together? If they work perfectly together, that is a huge benefit. If I had not already bought an optical post, I might have looked more into this option.

Do you need to fill the 66mm rail with sand or anything else to help damp vibration?
Hi,
the rails dovetail seems to be is a tiny little bit wider than arca. Some of my clamps a can snap on when wide opened, some have to be slided on from the open end. But they work perfect together, and with Arca double clamps you can stick everything together. I also connected the rail with Arca clamps to the rig so I can loosen it shift it, flip it to the face end and can stack photos directly from on the floor. If I unscrew the t-bar I have a pure horizontal rig what can be beared in the same wooden feet. Everything within seconds most by hand or a hex tool (t-connectors).

I have not filled it with sand but is so rock solid and heavy that I have no vibration problems (40x lens was the max).

I also don't think on vibration problems it is the rig itself but more a wobbling rail what will cause the problems. That's why I use a "low profile" setup and inserted a second sledge (without a nut) in rail in order to make this stiffer similar to those THK rails with two sledges.

regards
Lothar

Macro_Cosmos
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Re: Newport Damped Optical Posts

Post by Macro_Cosmos »

Thorlabs XT66 width: 40.33mm

Arca Swiss dovetail:
Sunwayfoto: 39.02mm
iShoot: 38.62mm
RRS: 38.15mm
Hejnar: 38.10mm
Stackshot: 38.14mm
Wemacro: 40.15mm
Sirui: 38.94mm
Leofoto: 38.03mm
Generic: 39.4mm
(Measured with a calibrated Sylvac caliper)


XT66 confirmed to work with iShoot, Leofoto, RRS, Hejnar, Sunwayfoto, and a couple generic clamps I have.

It's safe to say that it works with most clamps on the market. Some that can't open as wide, just slide it in from the top.

Use it with this: https://www.reallyrightstuff.com/b2-duo-clamp
Saves the headache of mounting. Wemacro offer through-holes, stackshot doesn't.
Generic ones work too, just colour code the screw knobs. Don't want to loosen the wrong knob, that's how I destroyed one of my objectives.

jmc
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Re: Newport Damped Optical Posts

Post by jmc »

Lothar,
Thanks for posting the images of your setup. It's a really neat design. Good to know the Thorlabs 66mm rails are compatible with the Arca fittings.
Jonathan
Jonathan Crowther

kaleun96
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Re: Newport Damped Optical Posts

Post by kaleun96 »

Macro_Cosmos wrote:
Mon Aug 31, 2020 4:29 am
Thorlabs XT66 width: 40.33mm

Arca Swiss dovetail:
Sunwayfoto: 39.02mm
iShoot: 38.62mm
RRS: 38.15mm
Hejnar: 38.10mm
Stackshot: 38.14mm
Wemacro: 40.15mm
Sirui: 38.94mm
Leofoto: 38.03mm
Generic: 39.4mm
(Measured with a calibrated Sylvac caliper)


XT66 confirmed to work with iShoot, Leofoto, RRS, Hejnar, Sunwayfoto, and a couple generic clamps I have.

It's safe to say that it works with most clamps on the market. Some that can't open as wide, just slide it in from the top.

Use it with this: https://www.reallyrightstuff.com/b2-duo-clamp
Saves the headache of mounting. Wemacro offer through-holes, stackshot doesn't.
Generic ones work too, just colour code the screw knobs. Don't want to loosen the wrong knob, that's how I destroyed one of my objectives.
Brilliant, thanks! Do you use XT66 yourself?
- Cam

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Re: Newport Damped Optical Posts

Post by Macro_Cosmos »

kaleun96 wrote:
Mon Aug 31, 2020 6:56 am
Brilliant, thanks! Do you use XT66 yourself?
Happy to help.

Nope. I use XT95. I do have an assortment of XT66 stuff for setups not related to photomacrography.

rjlittlefield
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Re: Newport Damped Optical Posts

Post by rjlittlefield »

kaleun96 wrote:
Mon Aug 31, 2020 12:21 am
rjlittlefield wrote:
Sun Aug 30, 2020 12:44 pm
Despite the large overhang, stability is not much problem. In the configuration shown here, a sharp rap on the camera body settles out in under 3 seconds as shown by 100% Live View at 50X. (The picture shows a 10X.) A larger problem is environmental vibration. If I were to shoot with continuous illumination at 50X in this configuration, I would need a day with no wind, and turn off the house ventilation fan.
Thanks for sharing your setup, Rik! That's exactly the kind of thing I was hoping to find. Seeing the weight and torque of your assembly on the rack and pinion mechanism is encouraging, as I'd have a similarly heavy setup mounted to it. I would have expected there to be some axial play in the rack and pinion though, does it not tilt forward slightly and thus bringing your camera out of perfect vertical alignment relative to the breadboard?
Surely there is some flexibility in the system, because I can see a Live View image shift focus when I stop holding the weight with my hand.

I have just now measured that shift, and was surprised to find that it is only about 200 microns at the end of the lever arm where the objective sits. That point is about 300 mm away from the post, so around 0.04 degrees of angular shift.

In any case, (1) there are lots of other places for the angles to get off, but (2) none of that makes any difference to me. When I care about precise alignment between the subject and the optical axis, that gets achieved by angular adjustments of the rotary table and goniometer on the positioning stack. Even if I knew that the optical axis were perfectly perpendicular to the baseboard, I would have to adjust those same components of the positioning stack to be sure that they were not messing up the subject alignment.

Of greater concern is that the optical axis lines up well enough with the focus stepping axis. I have emphasized "well enough" because in my opinion this issue causes far more worry than it deserves. I can certainly imagine situations where precise alignment would matter, such as measuring lateral distance between two points at different depths. But for non-measurement purposes, just aligning the axes "by eye" has always given me image quality that I could not distinguish from an alignment done with precision tools.

--Rik

mawyatt
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Re: Newport Damped Optical Posts

Post by mawyatt »

I have and use a Thorlabs XT95 based setup, it's very sturdy and works well in either V or H modes. Classic design with large heavy thick optical base with a 1000mm XT95 half rail bolted to the optical base, and a 600mm vertical bar XT95 full rail mounting to the horizontal half rail with a Thorlabs clamp. This allows the vertical bar easy movement along the horizontal axis.

Also use a modified WeMacro Vertical Stand for both V and H use. It's actually pretty good as it comes, but adding a couple simple modifications really makes it very useful for precision use.

Best,
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kaleun96
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Re: Newport Damped Optical Posts

Post by kaleun96 »

I have just now measured that shift, and was surprised to find that it is only about 200 microns at the end of the lever arm where the objective sits. That point is about 300 mm away from the post, so around 0.04 degrees of angular shift.

In any case, (1) there are lots of other places for the angles to get off, but (2) none of that makes any difference to me.
I'm surprised the shift is so little as well, definitely speaks to the rest of your setup between the camera and post too. But you make good points and if you're not concerned, then I definitely don't have any right to be either. I'm only shooting 10x and below for the time being too. Thanks for your insight as always.
I have and use a Thorlabs XT95 based setup
Thanks for sharing Mike, makes me wish I had all of these components and could try multiple setups before deciding on one. I'd like to have a vertical-to-horizontal convertible setup and my current one using breadboards is perhaps not best suited for that. I'll have to screw in the post, unscrew the rail from the breadboard, and then mount it to the post. And that's not even including shifting the specimen holder, which for the time being can't easily be used in a vertical orientation setup.

By the way, do the XT95 optical rails have the same dovetail dimensions as the XT66, or are you doing something else to adapt the Arca clamps to them?
- Cam

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