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LACERTA GmbH | Wien | Linz
 
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Teleskop Austria Logo
LACERTA GmbH | Wien | Linz
 

LACERTA Herschel prism set with Brewster angle, incl. heat shield, ND3 Filter, T2 threads and 31,7mm eyepiece-adaptors on both sides. Free optical window is 30mm.
(--Lacerta hot product: Herschel-LAC1s)


227.89 EUR
(Gross prices are calculated with 19% or 7% VAT. If your country-specific VAT is higher, we take over LACERTA GmbH the additional tax costs)
plus shipping
 




   
Brandname:  --Lacerta hot product
Connention: 31,7mm/T2
Reflection: 0,008%
Degree: 67°
Shipping weight:  1kg (Shipping costs)

Availability
(The stock is for information only and includes items that have already been reserved)
Wien: only 2  remaining
Linz: only 1 Stk.
Warehouse: in Stock
Opening hours

Seen cheaper weiter...
We recommend:
Herschel-LAC2s
332.89 EUR
 
polar
22.90 EUR
 
KG3-IRND3POL
94.90 EUR
 
BaSolCon
118.00 EUR
 

The LACERTA Herschel prism is built quite different compared to others on the market (INTES, Lunt, Scopium etc...). It makes use of the full polarization possibility at Brewster angle, compared to only partial at the 90-degree versions.

Why Brewster angle?
Since the polarization comes close to 100% at Brewster angle (57°), it enables continuous and even complete dimming with the mandatory ND3 neutral density filter and an additional Polarisation filter - in reality a dimming range between ND4.07 and 6.37 - usually even more (equivalent to 240x dimming factor)!
Without Polar filter the Herschel prism operates at ND 4.07 - good for photos. The 90° "traditional" Herschel prisms can do 4:24 to 5:00 (equivalent to 6x dimming factor only).
The visual perception at various neutral densities are shown in the images below. It can be seen that the granulation in traditional Herschel prisms is well observable only with an additional third filter (ND3 and polarizing filters are required!). Herschel prisms with Brewster angle do not need an extra filter, because the dimming range here continues to until ND6.37!

How to use the Herschel prism?
- First the ND3 filter is screwed as directly as possible into the Herschel prism (eyepiece side). If no filter thread exists there, the filter must be screwed into the eyepiece. With Herschel LAC2s, the 2" ND3 filter glass is removed from the filter frame, and fixed directly into the Rotation-adapter (using its own fixing ring from the filter frame)
- Then the polar filter is screwed into the rotation adapter end. If we have a Herschel prism without rotation system, the Polar filter must be screwed into the eyepiece. The overall brightness then is adjusted by the rotation of the eyepiece.
- Please note, that the optical elements strictly need to have the following sequence: Telescope - Herschel prism - ND3 filter - Polar filter - additional filter (eg IR block or contrast filters of your choice) - eyepiece (or camera)
- Be aware that when switching eyepieces, all the filters must be used again in the correct order. When using a rotation adapter, switching eyepieces is much easier, since both filters are screwed into the rotation adapter: the ND3 sitting in rotation adapter lower part and the Polar filter in rotatable end. In this case, the eyepiece can be changed easily!

Why is the Lacerta Herschel prism open at the bottom?
- The open design enables a much better ventilation than other designs available on the market
- The amount of stray light that enters through the open part is totally negligible compared to the bright sun entering from the telescope
- no light escapes through the open part, so your shoes wont be on fire!

Here is the thread on the german board, where the design was discussed: www.forum.astronomie.de/phpapps/ubbthreads/ubbthreads.php/topics/1116653

Whats in the package(Herschel LAC2s):
- Lacerta Herschel prism (core product) in Brewster angle, telescope side with M48 thread, the eyepiece with M54 thread,
- M48M48 37mm barrel as telescope side plug-adaptation,
- RotaM54p Rotation Adapter with internal M48 thread to take 2" filter glass
- ND3 filter (2"), incorporated into the fixed RotaM54p rotation adapter,
- RoteM48 Rotation Adapter with 2" filter thread on both sides (positive and negative).


We recommend:
- 2" polarizing filter for continuous dimming.
- KG3-IFIRUV2 for additional infrared dampening with telescopes > 120mm aperture


backfocus needs:
1.25" Version: 61mm from T2 to T2 ("S"-Version ca. 89mm)
2" Version: 81mm  from M48 to M54 ("S"-Version with Rotationadapter ca. 106mm)





Attention: Herschel prisms are generally relatively bright - an ND3 filter needs to be used mandatory! Continuous dimming is only possible if a polarizer is taken. But as many Astro friends have these two filters already, we offer the "naked" prism also solo as "core product". Please refer to the "recommended products" below!



We recommend:
Herschel-LAC2s LACERTA Herschel prism set (2") with Brewster angle, incl. heat shield. Included 2" to telescope, T2 rotation-adaptor to eyepiece or camera, 2" ND3 filter. Free optical window is 48mm. 332.89 EUR
 
polar Polarising filter 30% average transmission (M28.5x0.6) 22.90 EUR
 
KG3-IRND3POL Optolong IF/IR/UV-Block ND3-polarfilter on KG3 Glas - Blocked UV and IR to 5000nm (31,7mm) 94.90 EUR
 
BaSolCon Baader 7,5nm Solar Continuum 1¼" Filter (540nm) 118.00 EUR
 
A508T2 Adaptor 2" to T2, with 2" Filter thread 28.89 EUR
 
T2p317 Eyepiece adaptor: T2 external thread and 31.7 hole for eyepieces 24.90 EUR
 
CleanSetLa LACERTA Cleaning Set 4 in 1 (Cleaning Fluid, Microfiber Cloth, Cleaning Brush and Air Blower) 19.90 EUR
 

SUPPORT

Video

Photos
Herschel-LAC1s 20160413sfl AR 12529 Schroefl WAA
Herschel-LAC1s Astrocamp-MTT2016
Herschel-LAC1s Design from Hungary-PRESS
Herschel-LAC1s HotSpot
Herschel-LAC1s ND3-Filter-richtig-zusammengebaut
Herschel-LAC1s ND3-Filter falsch
Herschel-LAC1s Prototype-PRESS
Herschel-LAC1s Prototype-Prism-PRESS
Herschel-LAC1s with IRcut-ND3-Polarfilter-PRESS

 KALENDARIUM
INFO!
Code: MGEN-3 | The delivery situation is still stable:
All required components are currently in stock in our central warehouse.
New orders will be completed in about 2-3 working days after receipt of payment.

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INFO!
Code: FN2008c-new | The delivery situation has improved:
Delivery time for new orders: ca. 120 days
Payments are requested ASAP after our finalization and test notification!

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INFO!
Code: FN25010c-new | The delivery situation has improved:
Delivery time for new orders: ca. 120 days
Payments are requested ASAP after our notification that the FN is finished and tested!

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INFO!
Darkfieldmicroscopes We configure your dark field microscope according to your wishes.
New orders will be completed in about 2 months after receipt of payment.

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2024-04-05
TELESCOPIC EVENING

Together we will explore the world of telescopes and start from “zero” for beginners. We show the basics of how a telescope actually works, what differences there are and combine this with hands-on practice.
Everyone is welcome to bring their own instrument and get to know it better with our telescope experts, including Gerhard Rehak.

more infos


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