CFI Plan 10x questions

ohdeeremee · Post by **ohdeeremee** » Tue Nov 25, 2014 1:15 pm

A little background first....
For the last several years I have been using a DX Nikon D80, PB-5 Bellows, extension tubes for camera to clear bellows, and one of the following lens, either normal or reversed:
Nikor H 28mm f/3.5 AI
Nikon E 50mm f1.8
Nikon E 100mm f/2.8

This setup will take me up to about 11X max.
Anything much above 5X starts to get fuzzy, I suspect this is poor optics or most likely difraction.
So......
Just got a CFI Plan 10X MRL00102 infinity. Tried it on the bellows setup, no tube lens. Not as sharp as I like, and gets worse toward the outside edges.
About 325 images at 5.0uM steps using Helicon Soft 6.2.2 (sorry 'bout that..).

D81_1893-2218_M=C.jpg

The question is: Is this what you should expect on this configuration?

Next I put the CFI Plan 10x on a 18-200mm DX lens as a tube lens. Getting vignette in the corners. About 250 images at 5.0uM steps. Different fly eye than the first one. I also do not like the color that came out.

D81_3019-3265_M=C.jpg

Just for grins, put it on a 18-105mm DX lens. Way too much vignette, about half the image. (no pix for this one)

Now tried it on a 70-300mm (FX in Nikon world) lens. Should be about 15X. Think it is the same fly eye as the previous, but not sure. Big difference in quality across the complete image (except for the stuff on top and on the right), and notice the difference in color. This is 500 images at 2.0uM steps. Have not tried this combo at 200mm yet.

D81_3268-3770_M=C.jpg

I suspect the top and right side streaks has to do with the lens not being in alignment with the stacker travel. Any suggestions here? Is this alignment or something else?

And for reference I use ISO at 100, lighting is 4 each 250 lumen at 3200K which is enough light to keep the shutter speed around 1/5 or 1/10 second on the CFI.

Any comments would be appreciated.

Thanks,
George

ChrisR · Post by **ChrisR** » Tue Nov 25, 2014 2:24 pm

Hi George
Welcome to the forum
OK, well there's quite a lot to cover. First I'll direct you to the FAQ section. I expect you've been there before, but some of it may need a couple of reads.
The most important one would be How can I hook a microscope objective to my camera, though it's getting rather long now, most of the important stuff is on P1.

Your CFI objective would be bad on bellows. Being an "Infinite" it needs a "tube" or "converging" lens - as you suspected.
Zoom lenses can be ok for that, but some aren't good at all. There are quite a few mentioned through the forum, but we don't have a list. They usually only work well when near their "long" end.
Long zoom ratios tend to be poor, though Rik's 55-200 Canon does OK.
My Nikkor 28-300 is awful, Nikkor 80 - 200 OK at the long end, Canon 70 - 300 L ditto, Nikkor 70 - 210 ditto.

The 100mm Series E isn't great as a "tube" lens compared with others of the same Focal Length.
You're much more likely to get vignetting with any shorter lens, but it does depend how they're made. The corners are going dark/poor on a 100mm E lens on a DX format for the CFI 10x you have, iirc. A 135mm prime is fine.

The "smearing" you're getting at the edge of the stacked image is normal, it's because of the magnification change through the stack. If you stack from the other end, that part won't be included. Yes, the asymmetry indicates that your rig's not quite in line. (normal for me!)

1/5 or 1/10 is about the worst shutter speed range for gathering vibrations, so be careful. If you use 2seconds +, the initial wobble is usually invisible. You can't avoid shutter vibrations with a Nikon, you just have to keep their effect out of the way. Flash (use Rear Curtain sync) is useful as a comparison, if you're trying to track down blur sources.
I don't remember seeing tests of the Nikkor 50mmE reversed, but I expect it's reasonable for low magnifications. The edges may hold up better if you reverse it on the 100, unless you lose them completely! Your 28 has been reported as "OK", reversed.

A definite option would be to get hold of a Raynox M-250 (125mm Focal length) and M-150 (210mm FL), plus the bits to reverse them on bellows and take your CFI10x. That would give you a decent 10.05x and 6.25x.
The CFI 4x BE Objective, pro rata.

rjlittlefield · Post by **rjlittlefield** » Tue Nov 25, 2014 3:29 pm

Chris has told you the important stuff, but I want to emphasize his point about vibrations. Every image that you've posted here looks to me like it's motion-blurred. The MRL00102 should be tack sharp when viewing entire frames at web resolution.

I strongly recommend shooting another stack using flash illumination at low power so you get those nice short pulses of light. I expect that will give you much sharper images.

If it doesn't, then I'd suspect the objective has been knocked around so its insides are out of kilter, and in that case I'd be looking for a refund or exchange.

--Rik

ChrisR · Post by **ChrisR** » Tue Nov 25, 2014 3:54 pm

On reflection yes, it does look like vibration. Colouring my words was another lens, not mentioned, which I think was a Sigma 28-105 or thereabouts. It didn't seem terrible as a camera lens but was hopeless with an objectve, so it put me off wide range/short zooms for that purpose. Your Nikkor would hopefully be better!

ohdeeremee · Post by **ohdeeremee** » Thu Nov 27, 2014 12:26 pm

Chris & Rik...Thanks for the quick reply.

Yes, I have been all over the forum the last couple weeks...there is a lot of data there to read. I just wish I could find it the second time! Search for me is iffy...

I need to play with some more lenses with the CFI just to see what they will do. I have a 70-200mm f/2.8 that should work nice with the CFI at about 10X, but haven't tried it yet. I did not even consider the 100mm Series E for a tube lens, that is just what I can use for 0.93x to 2.3x in Normal mode or 0.40x to 1.8x in Reversed mode on the bellows, but I usually use the 105mm Macro for less then 1.0x. The 50mm is poor in Normal mode, but OK in Reversed, 2.31x to 5.13x. The 28mm won't even focus in Normal mode on my rig, but does good in Reversed, 5.55x to 10.73x, but gets soft in the upper values (why I got the CFI). This combination gives a nice spread of values, pick the power range you need.

I thought about flash, but haven't built up something that can handle 500 shots in a row, and I think multiple source would be nice. (Suggestions anyone??) Maybe this winter..... I could do a simple test with single flash to see if it is the issue on that 15x CFI stack. Only get a few shots for the stack, as my flash is currently battery. Everything I have done up to this point has been manual exposure, might have to use a real lens as a tube lens using flash. Haven't thought about that aspect yet.

You mentioned a Raynox on the bellows, how is that set up? CFI, Raynox, bellows, camera, or CFI, Bellows, Raynox, camera? The Raynox might be something to try, lot cheaper than a real lens on the bellows.

Here is a pix of the macro rig I used earlier, it is a Bessler 23C modified and tightened up, a Vello Mag Slider (now replaced with StackShot) with the home made lighting (the 4 white boxes on the blue/orange hose). These are the four moveable 250 lumen LED sources. The blue & orange line is a flexable cooling/cutting oil line used in a machine shop. The gauge is calibrated in 0.001 inch for stacking manually. I had to rework the MagSlider to get the slop out of it, but now it seems fair, but because it is a 2-way adjust, the camera is mounted several inches above the Bessler. The StackShot is shorter and I think it should be more solid. This rig is set up on a heavy 2x4 workbench on concrete floor, so the table is real solid.

303_4981.jpg

I plan on trying a different camera than the D80. Shutter delay is only 0.4 sec, but on the d300s I can push this up to about 1 sec. The other thing I thought about was the StackShot motor movement and the delay for it. Longer settle times might help.

Thanks for the ideas, guys....
George

ChrisR · Post by **ChrisR** » Thu Nov 27, 2014 1:42 pm

A Manual flash setting will be low, so you should get a LOT of flashes per set of rechargeable batteries. A single flash, eg through a tube of white paper, should be OK
Try a stack just to check for the difference in sharpness?

Yes, "Search " isn't ideal. There is a post by Rik of a reversed Raynox as a tube lens, I'll update this when I've found it.

rjlittlefield · Post by **rjlittlefield** » Thu Nov 27, 2014 5:02 pm

Raynox DCR-150 and DCR-250 as tube lenses:

http://www.photomacrography.net/forum/v ... 195#143195

--Rik

ohdeeremee · Post by **ohdeeremee** » Tue Dec 02, 2014 1:30 pm

Rik
Think I just confused myself.....
looking at your last post pointing to article:
http://www.photomacrography.net/forum/v ... 195#143195
which says:

Here is using a Raynox DCR-250 in conjunction with a Nikon CFI BE 10X NA 0.25 microscope objective. In theory this gives magnification of 10*(125/200) = 6.25X, so about 3.5mm across my sensor

.
The 125 is the distance from the sensor to the Raynox?
The 200 is the focal length the objective is made for?

Same idea here:

Here is using a Raynox DCR-150 instead. In theory this gives magnification of (208/200)*10 = 10.4X, so about 2.1 mm across my sensor.

208 is FL sensor to Raynox?
200 is FL the objective expects?

But later on you said:

2. Several sets of the cheapest available M42 extension tubes assembled so as to place the Raynox lenses near their infinity focus points.

How did you get the "Raynox lenses near their infinity focus point"? What determines that?

----------------------
Next question is about the difference in the two pictures on the cone end.
One has the M42 to RMS cone adapter close to the Raynox and the other has a 50mm (??) extension. Why?

I have the CFI Plan 10x Infinity MRL00102 with a flat adapter 52-25mm rather than cone. I am guessing the flat adapter would work in this configuration ( your CFI BE is RMS? , but both are Infinity) instead of the cone adapter (using correct threads, of course...) What does moving the objective so far from the Raynox do? In using a telephoto as tube lens, the flat adapter puts the objective right against the front element.

Or must you put space (looks like about 100mm or so) between the Raynox and the objective?

Who was it said:
"The more I learn, the less I know!"

Thanks,
George

ChrisR · Post by **ChrisR** » Tue Dec 02, 2014 2:29 pm

I had this sketch used before somewhere - might illustrate :

In this case the "tube" lens was 150mm FL, the Objective 20mm (a 10x) - drawn as simple lenses.
Both lenses are operating "at infinity", though the tube lens (Raynox) is reversed.

The distance between the lenses doesn't affect the magnification, that's set by the ratio of the two lenses' FLs.
It can/does affect the viewable image circle (close, to not restrict it), and to a small extent the image quality.
If they're very close you can get more stray light reflections between the two. Some combinations are found to work best quality-wise with a gap of around 50 - 100mm, but it doesn't seem to be very important.

To get your Raynox focused at infinity, with the objective removed just focus an image of something distant, through the viewfinder.
NB you'd use a 200mm "tube" lens to achieve the magnification marked on the objective barrel, so 150mm would give you 7.5x with a 10x objective.

rjlittlefield · Post by **rjlittlefield** » Tue Dec 02, 2014 5:21 pm

ohdeeremee wrote:Rik
Think I just confused myself.....
looking at your last post pointing to article:
http://www.photomacrography.net/forum/v ... 195#143195

The answers are what Chris says, but I'll try to say the same thing in different words in hopes that one or the other clicks for you.

Here is using a Raynox DCR-250 in conjunction with a Nikon CFI BE 10X NA 0.25 microscope objective. In theory this gives magnification of 10*(125/200) = 6.25X, so about 3.5mm across my sensor
.
The 125 is the distance from the sensor to the Raynox?
The 200 is the focal length the objective is made for?

Yes.

2. Several sets of the cheapest available M42 extension tubes assembled so as to place the Raynox lenses near their infinity focus points.
How did you get the "Raynox lenses near their infinity focus point"? What determines that?

If you take off the objective, so you just have the Raynox on the end of extension tubes, then the camera will be able to look out your window and focus on things far away. The Raynox is focused "at infinity". This is determined by the distance from the Raynox to the camera. If you want to get it exact then use bellows instead of extension tubes. The notes on my two Raynox lenses say this:

Raynox DCR-150: "Infinity focus at 175.9 mm from male shoulder of reversed lens to flange of Canon camera"
Raynox DCR-250: "Infinity focus at 90.5 mm from male shoulder of reversed lens to flange of Canon camera."

Based on their nominal focal lengths, you would expect the Raynox DCR-150 to be infinity focused at 208 mm total extension and the Raynox DCR-250 at 125 mm total extension. The differences between 208 and 175.9, and between 125 and 90.5, are due to the space between camera mount and sensor, the physical lengths of the Raynox mounts, and the exact location of the lenses within the mounst.

Next question is about the difference in the two pictures on the cone end.
One has the M42 to RMS cone adapter close to the Raynox and the other has a 50mm (??) extension. Why?
...
Or must you put space (looks like about 100mm or so) between the Raynox and the objective?

The image quality is a little better with some space between the objective and the Raynox. In each of the setups as shown, the amount of space is about as long as it can be without vignetting. (The shorter Raynox requires less space because it vignettes sooner.) Less space also works OK -- the differences are really small until you get down to no space at all.

--Rik