Filter definition, help needed?

Is a butterworth filter defined as:

The Butterworth filter is one type of electronic filter design. It is designed to have a frequency response which is as flat as mathematically possible in the passband. Another name for them is 'maximally flat magnitude' filters.
There is a load of stuff on the link below it sounds to me like it can be both, but electrics isnt my biggy im, afraid check it out.

http://en.wikipedia.org/wiki/Butterworth_filter

GTA San Andreas High Definition Test + enbseries filter

US Auctions Australian Auctions Austrian Auctions Belgian Auctions Canadian Auctions French Auctions German Auctions Indian Auctions Irish Auctions Italian Auctions Dutch Auctions Polish Auctions Spanish Auctions Swiss Auctions UK Auctions

Best Match Time: ending soonest Time: newly listed Price: lowest first Price: highest first Price + Shipping: lowest first Price + Shipping: highest first

55mm UV Digital High Definition Filter    US $.99

Hoya HD High Definition Digital UV Lens Filter 77mm USA Authorized Dealer    US $69.50

Hoya High Definition 58mm Multi Coated Digital UV Filter    US $9.99

Hoya HD High Definition Digital UV Filter 77 77mm    US $79.99

52 mm Multi Coated UV Filter Fits 52 mm Lenses NEW High Definition    US $3.46

30mm High Definition Filter KIT For Sony HDR CX360 PJ50 PJ30 tripod Card ca    US $9.99

46mm High Definition Filter KIT F Panasonic HS900 TM900 TM700 TM750 Tripod    US $10.99

HOYA 77mm UV HD High Definition Lens Filter 77 mm UK    US $69.56

040x High definition wide angle macro UV filter lens f Nikon D80 D60    US $42.74

Genuine Hoya 52mm HD Circular PL CIR PL Filter High Definition C PL CPL 52 mm    US $55.00

Genuine Hoya 67mm HD Circular PL CIR PL Filter High Definition C PL CPL 67 mm    US $83.00

Hoya HD 72mm 72 mm High Definition UV Filter R071    US $59.50

Hoya HD 58mm 58 mm High Definition UV Filter R068    US $39.90

High definition UV CPL FLD filter kit hood lens for Nikon D60 D5100 D3100    US $17.09

Genuine Hoya 82mm HD Circular PL CIR PL Filter High Definition C PL CPL 82 mm    US $117.00

Hoya HD 52mm 52 mm High Definition UV Filter R066    US $36.10

Genuine Hoya 72mm HD Circular PL CIR PL Filter High Definition C PL CPL 72 mm    US $91.00

New 52mm neutral density HD High Definition filter ND8 VIV ND8 52    US $7.99

Genuine Hoya 82mm HD UV Filter 82 mm Digital High Definition Lens Protector    US $75.00

Genuine Hoya 77mm HD UV Filter 77 mm Digital High Definition Lens Protector    US $69.00

Rokinon 62mm High Definition CPL Circular Polarizing Filter New    US $7.49

Rokinon 72mm High Definition UV Protective Filter    US $4.29

Rokinon 67mm High Definition CPL Circular Polarizing Filter New    US $7.99

Rokinon 62mm High Definition UV Protective Filter    US $3.99

Hoya 77mm HD Digital UV Filter 77 mm High Definition ePacket to US Brand NEW    US $66.99

High Definition 52mm Multi Coated MC UV MCUV Filter for Nikon Canon Olympus    US $6.95

Rokinon 52mm High Definition UV Protective Filter for Nikon D5100 D3100 D5000    US $3.79

Hoya 77mm High Definition HD Protector Digital Filter    US $63.00

Hoya HD High Definition Digital Protector Filter 82mm USA Authorized Dealer    US $74.95

Hoya 55mm HD Heavy Duty High Definition Protective Filter XHD55PROTEC    US $19.90

Genuine Hoya 77mm HD CPL High Definition Circular PL Filter    US $99.00

HOYA HD UV 58mm High Definition Filter NEW for Canon 50mm f14 Nikon 55 300mm    US $54.00

Hoya HD High Definition Digital UV Lens Filter 67mm Check Listing for Best Price    US $79.88

105mm Pro High Definition UV Filter for Sigma 120 300mm F28 EX DG OS APO HSM    US $29.95

Hoya HD High Definition Digital Protector Filter 52mm USA Authorized Dealer    US $33.50

HOYA UV HD 67mm Digital High Definition Filter for Nikon Canon Pentax Olympus    US $60.07

HOYA UV HD 72mm Digital High Definition Filter New for Nikon Canon Pentax Olymp    US $75.89

Hoya 82mm High Definition HD Protector Digital Filter    US $82.00

Hoya 82mm HD Digital UV Filter 82 mm High Definition ePacket to US Brand NEW    US $72.99

Rokinon 58mm High Definition UV Protective Filter for Canon T3i T3 T2i T1i XSi    US $3.99

Hoya 77mm HD Duty High Definition Protective Filter XHD77PROTEC    US $62.00

52mm Professional High Definition Glass UV Filter    US $7.99

High Definition 3PC Filter Kit For Kodak Z650 Z710 Z740    US $29.99

Rokinon 43mm High Definition UV Protective Filter    US $4.99

High Definition 67mm Multi Coated MC UV MCUV Filter for Nikon Canon EOS Olympus    US $8.95

Hoya 62mm HD Digital UV Filter 62 mm High Definition    US $45.99

Hoya HD High Definition Digital UV Lens Filter 58mm USA Authorized Dealer    US $40.50

High Definition 3PC Filter Kit For Nikon Coolpix 8800    US $28.99

Rokinon 37mm High Definition UV Protective Filter    US $4.99

Rokinon 305mm High Definition UV Protective Filter    US $4.99

Rokinon 30mm High Definition UV Protective Filter    US $4.99

Hoya 67mm High Definition HD Protector Digital Filter    US $53.00

Hoya 62mm High Definition HD Protector Digital Filter    US $48.00

Hoya 55mm High Definition HD Protector Digital Filter    US $37.80

Opteka Platinum Series 58mm High Definition Filter Kit Canon    US $12.96

HOYA HD UV 55mm High Definition Filter NEW for Sony 35mm f14G DT 18 55mm SAM    US $42.00

Hoya HD High Definition Digital UV Lens Filter 52mm USA Authorized Dealer    US $37.50

HOYA 58mm UV HD High Definition Lens Filter 58 mm UK    US $42.33

Hoya HD High Definition Digital UV Lens Filter 55mm Check Listing for Best Price    US $57.38

Hoya HD High Definition Digital UV Lens Filter 58mm Check Listing for Best Price    US $66.13

Hoya HD High Definition Digital UV Lens Filter 52mm Check Listing for Best Price    US $57.38

Hoya HD High Definition Digital UV Lens Filter 62mm Check Listing for Best Price    US $79.88

62mm 62 Multi Coated UV Protection Filter High Definition    US $4.99

67mm 67 Multi Coated High Definition UV Protection Filter    US $5.99

High Definition 3PC Filter Kit For Canon HF S11 HFS11    US $27.99

HOYA HD UV 52mm High Definition Filter NEW for Canon Nikon 50mm 35mm 14 45mm    US $42.00

Hoya 52mm HD Digital UV Filter 52 mm High Definition    US $35.99

Hoya 58mm High Definition HD Protector Digital Filter    US $40.90

HOYA 77mm HD Digital UV Filter High Definition Japan 77    US $67.98

HOYA 72mm HD Digital UV Filter High Definition Japan 72    US $60.86

HOYA 67mm HD Digital UV Filter High Definition Japan 67    US $53.27

HOYA 52mm HD Digital UV Filter High Definition Japan 52    US $37.14

Hoya HD 55mm 55 mm High Definition UV Filter R067    US $41.50

Hoya HD 62mm 62 mm High Definition Protector Filter NEW    US $60.07

82mm High Definition Multi Coated MC UV MCUV Filter for Canon EOS EF Sigma NEW    US $11.95

Hoya HD 72mm High Definition UV Filter New 4508    US $69.00

Hoya 52mm HD UV Filter High Definition 52    US $39.99

Hoya 62mm HD UV Filter High Definition 62    US $53.99

Hoya 67mm HD UV Filter High Definition 67    US $62.99

Hoya 72mm HD UV Filter High Definition 72    US $66.99

Hoya 77mm HD UV Filter High Definition 77    US $82.99

Hoya 82mm HD UV Filter High Definition 82    US $87.99

NEW HOYA 52mm HD High Definition Digital CIR POL Filter    US $49.99

3 Piece High Definition Lens Filter Kits UV CPL FLD 67mm    US $10.00

HOYA HD UV 62mm High Definition Filter NEW for Sony 70 300mm 18 270mm VC PZD    US $59.00

GSI Super Quality High Definition 55mm Ultra Violet Clear Lens Filter    US $11.38

HOYA 72mm HD CPL High Definition Circular Polarizer Multi Coated Filter 72 mm    US $102.99

Genuine Hoya 72mm HD UV Filter 72 mm Digital High Definition Lens Protector    US $61.00

67MM 67 ND8 NEUTRAL DENSITY HD HIGH DEFINITION FILTER DOUBLE THREADED    US $9.99

62mm 62 ND ND8 Neutral Density hd Hi Definition filter black new    US $9.99

Opteka 58mm High Definition II Pro Filter UV FD never used    US $13.95

58mm NEUTRAL DENSITY High Definition HD Lens Filter ND8 by Vivitar    US $9.99

72mm Multi Coated UV Filter Fits 72 mm Lens High Definition Camerea Olympus LF34    US $5.49

Hoya HD 52mm Protector High Definition Filter 52 mm UK    US $42.70

67mm Pro High Definition 3PC Filter Kit for FUJI S100fs    US $29.99

	Avia II List Price: $49.99 Sale Price: $32.99 You save: $17.00 (34%)

	Panasonic TH-50PH9UK 50" Plasma Display Sale Price: $800.00

	Samsung SPS4243 42-Inch Plasma EDTV List Price: $1,899.99

	Pioneer PDP-42A3HD 42-Inch High Definition Plasma Television List Price: $2,299.99

	Disney WOW: World of Wonder [Blu-ray] List Price: $39.99 Sale Price: $21.99 You save: $18.00 (45%)

	Spears & Munsil High-Definition Benchmark Blu-ray Disc Edition [Blu-ray] Sale Price: $23.50

	Digital Video Essentials: HD Basics [Blu-ray] List Price: $29.95 Sale Price: $18.95 You save: $11.00 (37%)

	Hootoo U19-A Night Vision Webcam 12.0MP, Microphone Built In List Price: $19.99 Sale Price: $1.83 You save: $18.16 (91%)

	ViewSonic PRO8200 1080p DLP Home Theatre Projector List Price: $1,499.00 Sale Price: $769.99 You save: $729.01 (49%)

	ZyXEL PLA407 HomePlug AV 200 Mbps Powerline Wall-Plug Adapter (Starter Kit - 2 Units) List Price: $154.99 Sale Price: $98.99 You save: $56.00 (36%)