JML lens Q&D unstacked images

[dunksargent]

JML 21mm lens arrived in Peterborough UK today and was adapted for use with my Olympus E-1 camera as described here http://www.photomacrography.net/forum/v ... php?t=9597

This is the Q&D set-up utilising a halogen penlight torch and reflector for illumination


Close up of the simple penlight illumination which was sufficient to illuminate individual letters on the coin. The battery powered halogen penlight is focusable and can be used as a miniature spotlight ... it is supported in a Fisso mini clamp on a miniature Fisso articulated arm.



This is the coin used - image taken with Fuji f30 compact


And these are the uncropped images of the 2mm high letter 'P' in 'PENNY' with three different bellows extensions. The largest image is at maximum bellows extension with additional 3cm extension comprising tubes and adaptors.

Magnifications are approx: 3.5x, 5.5x and 7x assuming sensor width of 17.3mm

I used the mirror up/shutter delay function with a delay of 2 seconds to prevent mirror vibration blurring the image.





These are straight shots ie no stacking and no cropping - focusing achieved via the Manfrotto 454 slide which has 1mm movement per revolution.

I'm quite pleased with the $9.99 lens

Cheers

dunk

[enricosavazzi]

Hi,

your results are quite consistent with mine. It seems the JML lens is a uniformly good performer. We have yet to see any bad specimens of this lens.

By the way, what bellows are those? I don't recognize the make/model. I do recognize the Manfrotto fine focuser at the bottom.
Edit: Never mind, I got the information in the attached link.

Incidentally, did anyone try to use the JML lens reversed (i.e. with the hollow part of the mount toward the subject)?

[rjlittlefield]

Incidentally, did anyone try to use the JML lens reversed (i.e. with the hollow part of the mount toward the subject)?

I took a quick look on first arrival and decided it was not made to be used that way. The focal point is several mm inside the barrel. At minimum extension of my Olympus bellows, I can get only about 3 mm of working distance. So I tested the other way around, and when both center and corner sharpness were good, I stopped. I will be interested to hear if other people have run solid tests.

--Rik

[enricosavazzi]

Hi Rik,

the reason I am asking is that I have a lens of shorter focal length in a similar barrel, which can be used on a microscope with the hollow barrel end toward a subject (with about 3-4 mm of working distance) but cannot be focused onto a subject the other way around (pupil too deep within the lens, apparently). This lens seems designed for use with a microfiche close to the hollow end. Image quality is terrible, so perhaps this is not the complete optical system of the microfiche reader.

[PaulFurman]

...no stacking and no cropping - focusing achieved via the Manfrotto 454 slide which has 1mm movement per revolution

I know this is off-topic, and you've now got a microscope focus block but for purposes of low mag. work and field work:

That Manfrotto slide looks handy. The knobs are pretty small so I'm guessing maybe 10 little tweaks are doable, so 0.1mm steps or 100 microns. I figure I can get about half that resolution with a nice rack & pinion bellows (not as good) plus this type of lead screw device is ideal for vertical setups or steep angles on a tripod. I figure it's good for 2x or maybe 3x stacks.

I just picked up a UN x,y focus rail (ebay 200469710966), with similar mechanics but kind of a cheap build. I paid $110 and it includes both directions of movement. I see B&H has that Manfrotto 454 for $85, so $170 for two directions. The UN model has some nudge room for rotation in the two connections which is disconcerting but not a huge problem in practice. The knobs and end caps are plastic though

Adding a larger diameter knob can help get smaller increments. I measured by just giving 50 small comfortable twists, without stressing out about the smallest physically possible movement and it moved 5 mm. Could you try that test on the Manfrotto? The same test gave 10mm of movement on Nikon PB4 and Minolta bellows.

Incidentally, did anyone try to use the JML lens reversed (i.e. with the hollow part of the mount toward the subject)?

I took a quick look on first arrival and decided it was not made to be used that way. The focal point is several mm inside the barrel. At minimum extension of my Olympus bellows, I can get only about 3 mm of working distance. So I tested the other way around, and when both center and corner sharpness were good, I stopped. I will be interested to hear if other people have run solid tests.

I just checked at 12x both ways: backwards is obviously worse. I did stacks of just 8 each with 10 micron steps.

[dunksargent]

That Manfrotto slide looks handy. The knobs are pretty small so I'm guessing maybe 10 little tweaks are doable, so 0.1mm steps or 100 microns. I figure I can get about half that resolution with a nice rack & pinion bellows (not as good) plus this type of lead screw device is ideal for vertical setups or steep angles on a tripod. I figure it's good for 2x or maybe 3x stacks.

Adding a larger diameter knob can help get smaller increments. I measured by just giving 50 small comfortable twists, without stressing out about the smallest physically possible movement and it moved 5 mm. Could you try that test on the Manfrotto? The same test gave 10mm of movement on Nikon PB4 and Minolta bellows.

s.

Hi Paul, I tried the micro wrist twist test with the Manfrotto slide horizontal and without any load on it ie no camera or bellows attached. Firstly I cut a small slither off a self adhesive label to provide a marker on the finger knob so could then ensure a 360 degree total twist. surprisingly, the first time I tried twisting in smallest increments I managed 85 and some of those were a bit 'long' so then tried again ... and managed 120 ... and even some of those went a bit long ... so with practice and maybe with a bit of light grease on the screw threads it might be possible to make more than 120 increments. But as it is, 100 is very possible ie 0.01 = 10 microns. I have some trombone slide grease which is light so will try again when have lubed the screw threads. And need to establish the optimum friction setting ie the slide dovetail is tightened by a separate brass screw which alters the drag.

EDIT: tried again and managed 160 ... but need to set it up on a copystand or tripod and turn it under load with a camera and bellows on it.

Cheers

dunk

[Bob^3]

I borrowed the tip from Charles regarding the his Velmex stage. I recently purchased two of them from one eBay vendor (A2500 series, 3.5" and 13.5" travel), total = $20 for both. They come up on eBay every few weeks. They are light weight but robust, low-profile and have good load capacity. The A2500 series have a fine-pitch lead screw (0.65mm/turn) which allows movements under 5 microns per step (if your careful). I intend to add a stepper motor to one of them for a portable automated rail for field use. The best versions have a release lever on the bearing so the rail can be quickly repositioned.

[Cyclops]

Fabulous job! Great detail.
Is it me though or is there a lot of noise in the Olympus images?

[PaulFurman]

Thanks. If I really try the smallest increment, I get 3mm movement out of 50 nudges, so 0.06 or 60 microns, but that's kind of iffy. The plastic knob connection stretches a tad before taking hold. I also use a small micrometer to nudge my bellows, which has much smoother movement and allows 2.5 micron steps. I see now the Manfrotto has a quick release spring loaded mechanism so more like the scientific slides with a micrometer. The UN model is only a drive screw so a little tedious to move longer distances but can go for 2-1/4 inches continuously. That would be perfect for 2x-3x with an extremely deep stack of 500 frames but not much good at 4x-5x.

Bob, that Velmex A2500 sounds fantastic but I only see one used 3.5" that sold for $57 in recent months and they look like about $600 new, or maybe this model so you got a deal!

[elf]

It's always fun to see what else is in the gear picture. In this case it appears that with a few simple modifications you could get some great shots of boiling water or frying fish

[Bob^3]

Bob, that Velmex A2500 sounds fantastic but I only see one used 3.5" that sold for $57 in recent months and they look like about $600 new, or maybe this model so you got a deal!

Paul, yes that's the model. Here is the closed listing:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... K:MEWNX:IT

Sometimes you get lucky...like the item $1000+ dollar stepper drive, linear stage and joystick I bid on the other day from a local guy. The 3 stage units were HUGE (>150 lbs total) so the shipping was freight or pickup only. I was the only bidder. So I got it for $0.99! I felt bad when I went to the guy's house (he was clearly very unhappy) to pick up the items. So I gave him $20, and told him that's probably the first and last 2000% over-payment you'll ever receive!

[dunksargent]

Thanks. If I really try the smallest increment, I get 3mm movement out of 50 nudges, so 0.06 or 60 microns, but that's kind of iffy. The plastic knob connection stretches a tad before taking hold. I also use a small micrometer to nudge my bellows, which has much smoother movement and allows 2.5 micron steps. I see now the Manfrotto has a quick release spring loaded mechanism so more like the scientific slides with a micrometer. The UN model is only a drive screw so a little tedious to move longer distances but can go for 2-1/4 inches continuously. That would be perfect for 2x-3x with an extremely deep stack of 500 frames but not much good at 4x-5x.

Bob, that Velmex A2500 sounds fantastic but I only see one used 3.5" that sold for $57 in recent months and they look like about $600 new, or maybe this model so you got a deal!

I just tried the Manfrotto slide with a Leitz bellows and Visoflex loaded onto it and attached to a copystand. I managed over 200 steps - it's easier to turn in small increments when loaded vertically. The screw was greased before the attempt. Now have to find a spool which will fit over the screw's finger grip(s) and which can be calibrated in eg 2 degree increments = 180 steps per mm or 4 degree increments = 90 steps per mm. Marking out a large disk is easy enough and then would need to be reduced in diameter to match the spool diameter and then need a marker arrangement on top of the calibrated spool.

dunk

[dunksargent]

It's always fun to see what else is in the gear picture. In this case it appears that with a few simple modifications you could get some great shots of boiling water or frying fish

Space is at a premium in my kitchen and the gas stove has a convenient fold down worktop. I am contemplating converting a spare bedroom into a photomacrography studio.

dunk