• Graph showing the transmission levels across different wavelengths for a bandpass filter with a central wavelength (CWL) of 420nm and a bandwidth (FWHM) of 20nm.
  • Blue bandpass filter with black rim on a white background
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BP420-20 Bandpass Filter(CWL=420nm,FWHM=20nm)

BP420-20 Bandpass Filter(CWL=420nm,FWHM=20nm)

PartNumber:SO3010130

$50.00 USD
$50.00 USD
Sale Sold out
Shipping calculated at checkout.
Center Wavelength (CWL) // FWHM
Optical Density // Peak Transmission (Tpk)
Dimension

In Stock.

Ships within 5 working days of order.
  • Wavelength: Center wavelength 420nm with 20nm FWHM for narrow spectral isolation
  • Spectral Features: High transmission in passband with steep edge transitions for superior selectivity
  • Optical Density: OD3 blocking for effective out-of-band rejection
  • Filter Dimension Availability: Multiple mounting options available to fit standard optical systems

Request Raw Data

You can request the raw transmission data from us.

Copy the link of the product page and send email to shop@syronoptics.com, you will get reply within 1 working days.

Shipment & Delivery

  • Stocked products ship within 5 business days after order confirmation.
  • Custom-made products typically ship within 4–8 weeks.
  • Delivery times may be affected by holidays, customs clearance, or other unforeseen events.
  • Tracking information becomes available 3–5 days after dispatch when the parcel is handed to the local courier.
  • Some deliveries may require customer pickup. Please ensure your contact information is correct and respond promptly to courier communications.
  • General international parcel shipping cost: USD 35 (for reference).

Return & Refund

1. Eligible Products

Stocked (catalog) products with a unit price under USD 500 are eligible for return within 14 days after delivery.

Custom-made or non-stock items are not eligible for no-reason returns.

2. No-Reason Return (Buyer’s Remorse)

If you wish to return an item for reasons other than product defect or seller error:

  • Please email shop@syronoptics.com to request a return authorization and return address.
  • Buyer is responsible for all return shipping costs.
  • Items must be unused, in original condition, and with original packaging.
  • Refund will be issued after inspection of the returned item.

3. Seller’s Fault (Defective / Wrong / Damaged Item)

If the return is due to seller error (defective product, wrong item shipped, or damage during shipping):

Please provide clear evidence (photos or videos) showing the issue.

We will evaluate the case and either:

  • Provide a replacement, or
    Issue a refund (with or without requiring the item to be returned).
  • Return shipping cost will be covered by the seller in confirmed seller-fault cases.

4. Important Notes

  • Returned items are subject to inspection before refund approval.
  • Shipping fees, customs duties, and taxes are non-refundable unless the return is due to seller fault.
  • Unauthorized returns will not be accepted.

Custom Sizing

Custom sizing is available from 3 × 3 mm (or Ø5 mm) up to 60 × 60 mm. For custom cut sizes, please contact shop@syronoptics.com for a quotation.

Pricing is not significantly lower for small-size orders in low quantities due to operational costs.

Payment Terms

Payments can be made online using Credit Card, Apple Pay, Google Pay, WeChat Pay, and Alipay.

If you prefer to pay by bank transfer, please contact shop@syronoptics.com to request an invoice with our banking details.

If you require deferred payment terms, you may request NET 7 or NET 30 at the time of placing your order.

All requests for deferred payment are subject to approval and will be confirmed by SyronOptics via email.

View full details
  • BP420-20 Bandpass Filter - Fluorescence Imaging (Emission Filter)

    BP420-20 Bandpass Filter - Fluorescence Imaging (Emission Filter)

    Fluorescence Imaging (Emission Filter)

    • It is often used to detect the blue fluorescence emission from samples excited by deep UV light (e.g., 365nm or 385nm).
    • Specific Dyes/Stains: Used for detecting DAPI (emission peak ~460nm, but the 420nm tail can be relevant in specific setups), BFP (Blue Fluorescent Protein), or Cascade Blue.

    Recommended Light Sources

    • High-Power LED (415nm or 420nm): Cleans up the LED output, ensuring no green/red light hits the sample.
    • UV LED (365nm or 385nm): The light source excites the sample; the filter is placed in front of the camera to block the UV source and pass only the blue fluorescence.
  • BP420-20 Bandpass Filter - Fluorescence Microscopy (as an Excitation Filter)

    BP420-20 Bandpass Filter - Fluorescence Microscopy (as an Excitation Filter)

    Fluorescence Microscopy (as an Excitation Filter)

    • Function: This filter is commonly used to clean up the light source before it hits the sample, allowing only the 420 nm violet light to excite the fluorophores.
    • Target Dyes: It is ideal for exciting fluorophores with absorption peaks near 420 nm, such as Alexa Fluor 430, AmCyan, Lucifer Yellow, or Poroshell. It can also be used for some "Long-Stokes-shift" dyes.

    Recommended Light Sources

    • Broadband Arc Lamps (Xenon or Mercury-Xenon): These provide high intensity across the spectrum. The BP420 filter will "slice out" the violet 420 nm portion.

    Why: Mercury lamps have strong peaks nearby (405 nm and 436 nm); the filter isolates the continuum between them or cleans up a specific region.

    • Violet LEDs (420 nm or 415 nm): High-power LEDs manufactured specifically for 420 nm are available.

    Why: While LEDs are already narrow, they often have "tails" of light in unwanted wavelengths. The BP420 filter cleans these up for precision measurements (e.g., to prevent "crosstalk" in fluorescence).

Fequently Asked Questions

Different Types of Filter Mountings

Unmounted:

  • a bare glass optical filter

Mounted:

  • Smooth Mount for protection of the optics. No thread is there on the mount.

Metric Mount:

  • Start with M as prefix, usually seens as M25.5x0.5mm. Mostly used as camera filters

Imperial Mount:

  • Start with SM as prefix, usually seen SM1, SM05 etc... Mostly used in Optical system. (You will have a SM external thread to connecting to other objects)

C-Mount:

  • Very frequently used mounting. C-Mount is 1‘’-32TPI. And it is not the same thing as SM1, or M25.5x0.5mm.

What are the Thickness of the Optical Filters?

For Unmounted Optics:

  • 0.5mm
  • 1.1mm
  • 2.0mm

*Most of our optics are coming with 1.1mm and 2.0mm

With Standard Mounting (Mounted, No Thread):

  • 3.5mm (Default)
  • 6mm (Upon Request)

Thread Mounted:

  • 6mm - 8mm

  • dia12.5mm(unmounted)

    Clear Aperture:

    >90%

    Mounting Thickness:

    n.a

    Internal/External Thread:

    n.a/n.a

  • dia12.5mm(mounted)

    Clear Aperture:

    dia9mm

    Mounting Thickness:

    3.5mm

    Internal/External Thread:

    n.a/n.a

  • dia25mm(mounted)

    Clear Aperture:

    dia21mm

    Mounting Thickness:

    3.5mm

    Internal/External Thread:

    n.a/n.a

  • dia25mm(unmounted)

    Clear Aperture:

    >90%

    Mounting Thickness:

    n.a

    Internal/External Thread:

    n.a/n.a

  • SM05(0.535″-40TPI)

    Clear Aperture:

    dia9mm

    Mounting Thickness:

    7.62mm

    Internal/External Thread:

    SM05/SM05

  • SM1(1.035″-40TPI)

    Clear Aperture:

    dia21mm

    Mounting Thickness:

    7.62mm

    Internal/External Thread:

    SM1/SM1

  • C-Mount(1″-32TPI)

    Clear Aperture:

    dia21mm

    Mounting Thickness:

    Internal/External Thread:

    C-Mount/C-Mount

  • M25.5x0.5mm(mounted)

    Clear Aperture:

    dia20.5mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M25.5x0.5mm/M25.5x0.5mm

  • M27x0.5mm(mounted)

    Clear Aperture:

    dia22mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M27x0.5mm/M27x0.5mm

  • M30.5x0.5mm(mounted)

    Clear Aperture:

    dia25.5mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M30.5x0.5mm/M30.5x0.5mm

  • M34x0.5mm(mounted)

    Clear Aperture:

    dia29mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M34x0.5mm/M34x0.5mm

  • M35.5x0.5mm(mounted)

    Clear Aperture:

    dia30.5mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M35.5x0.5mm/M35.5x0.5mm

  • M37x0.5mm(mounted)

    Clear Aperture:

    dia32mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M37x0.5mm/M37x0.5mm

  • M52x0.75mm(mounted)

    Clear Aperture:

    dia47mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M52x0.75mm/M52x0.75mm

  • M55x0.75mm(mounted)

    Clear Aperture:

    dia50mm

    Mounting Thickness:

    6.5mm

    Internal/External Thread:

    M55x0.75mm/M55x0.75mm

  • dia27mm(unmounted)

    Clear Aperture:

    >90%

    Mounting Thickness:

    n.a

    Internal/External Thread:

    n.a/n.a

  • dia34mm(unmounted)

    Clear Aperture:

    >90%

    Mounting Thickness:

    n.a

    Internal/External Thread:

    n.a/n.a

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