BD Objective Survey / Options

[ray_parkhurst]

I've become very interested in BD objectives for some of my imaging applications, and would like to take a survey of the options available. Here is what I have tried and some comments:

Nikon BD Plan 5: Similar IQ vs MPlan 5. High lighting angle is good for coin imaging.
Nikon BD Plan 10: Similar to MPlan 10. Lighting angle ~45-deg is good for my phono stylus imaging but WD too short for broad usage. Good for coins.
Nikon BD Plan 20: Too short WD for phono stylus imaging and too low lighting angle for coins.
Nikon BD Plan 20 EWLD: Very good IQ. Lighting angle excellent for phono stylus but magnification a bit high for coins.
Nikon BD Plan 40 EWLD: Good IQ and lighting angle for phono stylus. Too high magnification for coins.
I have built an illuminator housing for use with the above 26mm BD objectives

Bausch & Lomb 8x: IQ similar to Nikon BD Plan 10. Excellent lighting angle for coins but too high for stylus imaging
Bausch & Lomb 10x: Coverage not as good as 8x. Epi lighting angle too low for either stylus or coin imaging.
Bausch & Lomb 20x: Good IQ. Short WD and shallow lighting angle (epi type).
Bausch & Lomb 40x: Good IQ but very short WD and shallow lighting.
I have built an illuminator housing for use with the above RMS BD objectives

AO 10x, 20x, 40x: Relatively poor coverage and CAs. RMS mount works with illuminator made for B&L above.

Unitron MFD 20x: Similar to the B&L 20x, epi type lighting angle and short WD. RMS.
I am looking for the Unitron MFD 10x as it might be good for coin imaging.

I know there are Mitty BD Plan objectives with presumably same optics as their MPlan Apos. Can anyone comment on these? What mount do they use? They look quite large. If anyone has a 5x, 10x, or 20x, I'd love to know their lighting angles. For my stylus imaging I need an angle of ~45-deg for best results. For coins I'm looking for higher angles.

Are there any other series of BD objectives available in the 5x-20x mag range which might have good IQ, coverage, and CA performance which might be good for various photograhic applications?

Would like to hear from folks about any types I have not listed, or comments on the ones above.

[Scarodactyl]

Olympus neo splans are good, and do cover 26.5mm eyepieces. I think I like them better than the nikon finite bd plans I have (more axial CA in thr nikons). The olympus splans do need correcting eyepieces and I think the tube lens is doing something specific too (my mitutoyos don't like the tube lens in the corners--lots of coma which the splans don't get). For widest field you might need to go afocal through a swf 30mm eyepiece (expensive).
I note you're using a number of objectives that need particular corrections--are you using matching tube lenses/eyepieces?

[Lou Jost]

You haven't mentioned whether the Nikon objectives are finite or infinite. The Nikon finite 210mm 50x 0.90 apo is a very good value for the price though won't quite cover FF. Needs a 1.4x teleconverter.

[ray_parkhurst]

Olympus neo splans are good, and do cover 26.5mm eyepieces. I think I like them better than the nikon finite bd plans I have (more axial CA in thr nikons). The olympus splans do need correcting eyepieces and I think the tube lens is doing something specific too (my mitutoyos don't like the tube lens in the corners--lots of coma which the splans don't get). For widest field you might need to go afocal through a swf 30mm eyepiece (expensive).
I note you're using a number of objectives that need particular corrections--are you using matching tube lenses/eyepieces?

You haven't mentioned whether the Nikon objectives are finite or infinite. The Nikon finite 210mm 50x 0.90 apo is very good though won't quite cover FF. Needs a 1.4x teleconverter.

I'm mounting these in a photo setup, not on a microscope. The Nikons are finites and AFAIK are CF, no correction needed. The B&L are finites as well and also need no correction. The AO are infinites and for sure need correction. I used a Nikon tube lens with them that gives no correction and the CAs were obvious and consistent across the 3 magnifications.

I'll look into the Neo SPlans.

I could use 50x for my phono stylus imaging, but I'd expect the WD to be quite short for the Nikon apo lens, correct?

[ray_parkhurst]

Olympus neo splans are good, and do cover 26.5mm eyepieces.

I looked on eBay and I don't see any Neo SPlans which are BD type. Can you point me to an example?

[Lou Jost]

Yes, working distance is miniscule. But of course the BD lighting isn't hurt by that. For objects that are very irregular, the short working distance can be limiting.

[ray_parkhurst]

Yes, working distance is miniscule. But of course the BD lighting isn't hurt by that. For objects that are very irregular, the short working distance can be limiting.

For coin imaging short WD for a BD objective is OK, but 10x is the practical max magnification. For my stylus imaging, I need a lot more WD at higher magnification, so much more challenging.

[Scarodactyl]

I looked on eBay and I don't see any Neo SPlans which are BD type. Can you point me to an example?

The "neo" means BD in olympus speak, so these are all bd with a 26mm thread (identical to mitutoyo).
Bausch and Lomb didn't make any objectives that don't need compensations as far as I know. I think their BD objectives would likely be off a balplan which from what I understand has some essential bits built into its weird ideosyncratic tube lens assembly. Impressive if it can get acceptable resulta without.

[ray_parkhurst]

I looked on eBay and I don't see any Neo SPlans which are BD type. Can you point me to an example?

The "neo" means BD in olympus speak, so these are all bd with a 26mm thread (identical to mitutoyo).
Bausch and Lomb didn't make any objectives that don't need compensations as far as I know. I think their BD objectives would likely be off a balplan which from what I understand has some essential bits built into its weird ideosyncratic tube lens assembly. Impressive if it can get acceptable resulta without.

OK, makes sense. I see a 20x ULWD available that might work well for me. Not sure the WD of the 10x. Anyone have a link to the specs on these Neo SPlans?

The 8x B&L is really good, in fact it is now my go-to objective for higher mag coin imaging. I am able to push it down to 5x with good results. The lighting angles are excellent and it is very sharp, with low CAs. I have not been as lucky with the other magnifications.

[Alan Wood]

The Olympus LBM Objectives Prices and Specifications document gives the working distances of the Neo SPlan objectives, available as a free PDF here:

http://www.alanwood.net/olympus/downloa ... allurgical

Alan Wood

[Duke]

Regarding Olympus DPlan/SPlan, both finite and infinite, as I've been told, they require LCA-compensation projection eyepiece, such as NFK-2.5x, for example. However, I've not tested it, and cannot verify exatly, but this confirms with what I've seen on AH-2, it came with WFK eyepieces.
This doesn't apply to UPlanFL/UPlanApo, some of them I do own and they work fine with direct projection. So be aware.

[ray_parkhurst]

The Olympus LBM Objectives Prices and Specifications document gives the working distances of the Neo SPlan objectives, available as a free PDF here:

http://www.alanwood.net/olympus/downloa ... allurgical

Thanks Alan!

It looks like the 10x is out for stylus imaging, with "only" 4.1mm WD, but the 20x ULWD would work with its 11mm WD. Does anyone have experience with the 20X ULWD Neo objective?

[ray_parkhurst]

Regarding Olympus DPlan/SPlan, both finite and infinite, as I've been told, they require LCA-compensation projection eyepiece, such as NFK-2.5x, for example. However, I've not tested it, and cannot verify exatly, but this confirms with what I've seen on AH-2, it came with WFK eyepieces.
This doesn't apply to UPlanFL/UPlanApo, some of them I do own and they work fine with direct projection. So be aware.

Based on Alan's pdf, only the 20x ULWD will work. Will be interested to know from anyone if they are getting good CAs from this objective in direct projection.

[ray_parkhurst]

It looks like the Mitty 20x isn't going to work for me, ironically because its working distance is too large compared to its diameter, making the light angles too high, but the 50x has enough WD as well as what I believe is an acceptable range of light angles. I've summarized the angles and annotated them in the diagram below:

20x: from 22-deg to 35-deg (nominal 28.5-deg)
50x: from 34-deg to 49-deg (nominal 41.5-deg)

It's impossible to say how the light intensity is distributed vs angle, and that will of course be affected by the source, but it may be that the 50x would work well for planar contact dimensional imaging.

[Scarodactyl]

Maybe not ideal but there are 32mm ID fiber optic ring lights that slip onto the outside of an m plan apo. I have one but haven't really tried it out yet.