Consistent edge to edge sharpness and CA control, all for only $17, and no problems covering APS-C.Directly below are $17 images, right below that are $17 crop images next to the Canon MP-E 65 1-5x lens. This is interesting since these are the cheapest and most expensive lenses in this coparison.

Nikon CFI Plan Achro 4X Gold Barrel center crop at 100% actual pixel view. Clicking on an image will open a larger version.

4x objective lenstotal magnification

$17 Amscope 4x/0.1 160/0.17 Plan Achromatic Objective Lens with Knurled RingWorking Distance: Spec is 29.04mm. The real working distance: 16mm or 18mm with lens front cover removed.Amscope Part Number: PA4XK-V300Mount: RMSNotes: Cover Glass Thickness is 0.17mm but there is no performance penalty for not using a coverslip with an NA this low. Lens made in China. Manufacturer unknown. Sold by Amscope.Retail / Ebay price new from Amscope: $17 with free shipping.

Just for fun lets compare these two lenses, the least expensive @ $17 with free shipping, and the most expensive at over $1000 USD.

What do you think? The Canon MP-E 65 does have better, more consistent performance across the frame, but the images are very close to my eyes, with a slight fine detail advantage going to the $17 Amscope objective, and surprisingly, better chromatic aberration control in the corners. The Amscope objective nominal aperture is f/4 (NA 0.10), compared to the MP-E at f/2.8, which is a disadvantage when it comes to resolving fine detail, yet it seems to do better than the MP-E 65 in this comparison. Not bad for $17.

Nikon BE Plan 4x/0.10, Infinity Corrected Microscope ObjectiveThis objective offers good performance for the modest, for Nikon, price. It is definitely worth the $60-80 USD cost. Sharp in the center center and good corners, but, this is not Plan corrected, even though its printed on the barrel. Because of this I had to use two images for the center and corner comparisons because the field was definitely not flat. Nikon specs for the lens are OFN18, or 18mm field number, but, like the plan designation, its not correct, the lens does cover an APS-C sensor that is 23.5mm across. For an even bigger field you can unscrew the black front barrel cover.

10xobjective lens

This is a first part of a test where I compared 33 lenses at 4X magnification. Since most of the optics in the comparison were not designed with an image circle large enough to cover a full frame sensor, I chose to use an APS-C sensor equipped Sony α6300 body.

High powerobjective lens

Left to right; Lomo 3,7x; Fluor 4x; $17 4x; Nikon BE Plan 4x; Nikon E Plan 4x; and Nikon Plan 4x (gold barrel). For full specs on all of these lenses, see the list at the bottom of the page.

Objective lensmicroscope

Camera: Sony α6300, model # ILCE-6300, also known as: A6300, ALPHA 6300, and alpha 6300. Flash: Godox TT350s wireless flash x 2Wireless controller: Godox X1s 2.4G wireless flash trigger/transmitter

The infinity corrected objectives were mounted on my 52mm extension tube set-up, with a Sigma 52mm life-size attachment diopter as a tube lens. For more information on this tube lens set-up follow this link:https://www.closeuphotography.com/52mm-setup

Types ofobjectivelenses

Nikon CFI E Plan Achro 4X/0.1 ∞/- Microscope ObjectiveWorking distance: 30mmNikon part number: MRP70040Mount: M25 x 0.75Notes: OFN20. Silver and Black BarrelFull retail price: $ $99.00Typical used Ebay price: $80-100

For the test, the finite objectives were mounted on my 42mm extension tube set-up with Thorlabs CR2C clamps. For more information on the 42mm setup, follow this  link:  https://www.closeuphotography.com/42mm-setup/

Low powerobjective lens

This no-name lens was sharp and CA free in the center but it did not get close to covering the A6300 APS-C sensor so I would not recommend this lens.

Nikon CFI Plan Achro 4X Gold Barrel Microscope Objective. crop at 100% actual pixel view. Clicking on an image will open a larger version.

Nikon CFI BE PLAN ACHROMAT 4X  /0.1 ∞/- Microscope ObjectiveWorking distance: 25mmNikon part number: MRN70040 RMSNotes: OFN18Full retail price: $ 82.45 USD, I am told this lens is £31 in the UK, thats $40 something USD.Typical used Ebay price: $100++Price at online retailers: $60-80.

The Sony α6300 camera used for the test was vertically mounted on a Nikon MM-11 stand. Manual mode was used at ISO 80, with EFCS. To avoid any sharpness loss due to vibration I used the two Godox TT350s, at 1/128th to 1/4 power. The flashes remained in place for the entire test to avoid changes in light angle, the flash was mounted on a flash bracket bolted to an optical breadboard shooting into a 4-3/4 inch (12 cm) Godox plastic half dome diffuser placed over the target which was a 6 inch silicon wafer purchased on Ebay. For more about the flash setup used in this test, follow this link: https://www.closeuphotography.com/godox

These low-priced objectives all cost less than $100 new, and have an Numerical Aperture, or NA, of around 0.10, or a nominal f/4.

Nikon CFI Plan Achro 4X/0.1 ∞/- Microscope ObjectiveWorking Distance: 30Nikon Part number: MRL00042Note: OFN 25, Gold BarrelMount: M25 x 0.75Retail Price: $165.00Typical used Ebay price: $90

Nikon CFI Plan Achro 4X Gold Barrel corner crop at 100% actual pixel view. Clicking on an image will open a larger version.

Objective lensmagnification

4x objective lensname

Center sharpness is a little lacking in fine detail and the chromatic aberration levels are the highest out of all the Nikon objectives I tested here.

A friend offered this lens as a loan for the test and I am glad I took him up on the offer, the image quality was one of the surprises of the test, I was so impressed by the performance lens that I actually bought one. The Lomo 3,7 lens should be labeled APO. Most of the other lenses in the comparison that are labeled APO but do not have high level of chromatic aberration correction of the Lomo. I knew nothing about this lens before the test, so the APO CA performance was a nice surprise. The sharpness was crisp corner to corner.This is not a flat-field Plan objective so you will need to stack to get sharp corners. The Lomo covers APS-C format no problem. This lens was a little sensitive to flare due to the lack of good multi-coating. I taped black paper around the barrel as a lens hood to stop the flare issue.

Overall best lens under $100 winner: Lomo 3.7x 0.11The Lomo 3,7 has a awesome center resolution (a little better than the $17 4x), great corners and APO chromatic aberration control. This lens is only $30-45 on Ebay and it beats all of the Nikon 4x 0.1 lenses I have shot with.  Amazing, thanks for the loan Fan!

$17 Amscope 4x Objective on the left, and the Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens on the right, corner crops at 100% actual pixel view. Click on an image to open a larger version.

Each lens was focus bracketed and the single sharpest image for flat field lenses was chosen at 100% view in Photoshop (for non flat field lenses the best center and best corner image were selected). For lenses with an iris, the widest two or three apertures were shot, and the sharpest was chosen for the comparison.All images were shot as RAW ARW files and processed in PS CC with all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images.

Lomo 3.7x 0.11Working distance: about 30mmMount: RMS threadNote: Single coated or uncoated so the lens is prone to flare, a hood should be used.Typical used Ebay price: $25-50

$17 Amscope 4x Objective on the left, and the Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens on the right, center crops at 100% actual pixel view. Click on an image to open a larger version.

Price vs Performance winner and runner up: $17 Amscope 4x/0.1This little lens has great overall image quality but the center had slightly less detail than the Lomo, so it gets bumped from top.It does put up a good fight against the MP-E 65, coming out very slighting on top!

Recommended: Nikon CFI BE PLAN ACHROMAT 4X  /0.1 ∞/-Clean and sharp and great IQ overall. I am hanging on to my BE Plan 4x!

No-name Fluor 4x/0.10 finite Microscope ObjectiveMount: RMS threadNote: Not a recommended lens for photography. Lens made in China. Manufacturer unknown.Typical new Ebay price: $20