WebJul 31, 2012 · Re: Ektar 12-inch F4.5. The 12" Kodak Ektar f4.5 is a Tessar copy of high quality. Should have a very nice look wide open at 4.5 and would be a nice portrait lens on 5x7-4x5 and at closer distances on 8x10. The Commercial Ektar is more like the Tessar IIb f6.3. While not as fast as the Ic the Tessar IIb was preferred by commercial … WebMar 3, 2024 · F4 Paper Size in mm, cm, inch: F4 Size in mm is 210 × 330 millimeter. F4 Size in cm is 21 × 33 centimeter. F4 Size in inch is 8.27 × 13 inches. F4 Alternative Size in mm …
Dallmeyer lenses – Toby Marshall
WebMy 13 inch f/3.0 RFT uses the same diagonal size as Coulter's original 13 inch f/4.5. An 18 inch scope calls for a diagonal to eyepiece distance of 12 inches, and if the mirror happens to be a f/4, then a 3 inch diagonal will work fine. This is a diagonal to primary ratio of 6:1. At this ratio, image degradation due to the diagonal obstruction ... WebNov 5, 2005 · It may just be that high powers brings out the CA. The 6 inch F4 as far as I can tell has excellent optics. Comparing the views between the two on nebulas with night … flannel for flannel washcloths
GSO 6" Imaging Newtonian - f/4, looking for opinions
WebAperture: 10-inches Focal Ratio: f/4 Focal Length: 1016 mm White rolled steel exterior, flat black interior for higher contrast Cooling Fan included Dual hinged rings with Vixen-style dovetail Product Details Description … WebNov 15, 2024 · The Altair 8-inch F4 Photo Newtonian is a reflecting telescope made to be used primarily with a camera for astrophotography. Advertisement Its construction … WebDec 18, 2016 · Ross 1 inch f1.9 cine lens; Ross Wide Xpres 5 inch f4 aerial reconnaissance lens (British Air Ministry) STL Elgeet 86mm f1.2 lens; Tamron SP 70-150mm f2.8 model 51a Soft Focus Zoom lens; Taylor & Hobson 25mm f1.4 Ivotal C-mount cine lens; Taylor & Hobson 3 inch f1.8 projection lens; Ultra Micro Nikkor 165mm f4 lens; Varo 75mm f1.6 lens flannel for shoe polish