FROM: Donn Cave SUBJECT: Re: Long Lenses DATE: 27 May 2000 02:51:40 GMT NEWSGROUPS: rec.photo.marketplace.large-format Quoth "Ron Klein" : | Im interested in purchasing a long lens for use with my 4x5 field. I shoot | mostly landscapes and presently use a 90 and 180 mm lens. Im not sure if I | should be looking at tele lenses or not. Im looking for something equivalent | to 135 in 35mm format. I assume that puts me somewhere about350-400.Any | advice would be appreciated Long lenses in the 35mm sense are uncommon in LF. You need telephoto optics if the focal length (at your intended subject distance) exceeds the draw between the front and rear standard; it's an optical miracle that costs you in every other respect, so if you don't need it, I think you don't want it. I guess I'd suggest any medium long lens you can find in a small shutter, usually 240-300mm, and see if that doesn't do it. When they say Copal 3 or Ilex 5, you won't believe how big those critters are (Copal 3 is 4 inches across and massive, Ilex 5 is wider.) Donn FROM: Ian Dodd SUBJECT: Re: Long Lenses DATE: Thu, 01 Jun 2000 17:44:36 GMT ORGANIZATION: Road Runner NEWSGROUPS: rec.photo.marketplace.large-format Ron Klein wrote: > Im interested in purchasing a long lens for use with my 4x5 field. I shoot > mostly landscapes and presently use a 90 and 180 mm lens. Im not sure if I > should be looking at tele lenses or not. Im looking for something equivalent > to 135 in 35mm format. I assume that puts me somewhere about350-400.Any > advice would be appreciated Ron, I'd look into the 355 G-Claron by Schneider or, for a little longer, the Fujinon 450, a great little lightweight lens. Ian FROM: zloi SUBJECT: Re: Long Lenses DATE: Fri, 02 Jun 2000 17:26:17 -0700 ORGANIZATION: Eskimo North www.eskimo.com (800) 246-6874 NEWSGROUPS: rec.photo.marketplace.large-format I am in exactly the message writer's position: have a Tachihara 4x5 field, and am looking for a more powerful, but as light as possible, lens to use for distant landscape work. I am a little discouraged by my research so far. Telephoto lenses seem extraordinarily large and heavy (in the 360-400mm range, at least). I wish someone would address their other disadvantages--it has been hard for me to get info on this. (I assume their image circle may be too small to allow use of the camera's movements.) Of regular lenses, I have read that anything larger than ~240mm does not permit close focusing with the field camera's usual 12" or so of bellows' draw. But ARE there good, fairly lightweight 240mm lenses? What could folks recommend and in what shutters? Thanks. -Tom FROM: "Kerry L. Thalmann" SUBJECT: Re: Long Lenses DATE: Sat, 03 Jun 2000 05:02:32 GMT ORGANIZATION: Kerry L. Thalmann Photography NEWSGROUPS: rec.photo.marketplace.large-format zloi wrote: > > I am in exactly the message writer's position: have a Tachihara 4x5 field, and > am looking for a more powerful, but as light as possible, lens to use for > distant landscape work. I am a little discouraged by my research so far. > Telephoto lenses seem extraordinarily large and heavy (in the 360-400mm range, > at least). I wish someone would address their other disadvantages--it has been > hard for me to get info on this. (I assume their image circle may be too small > to allow use of the camera's movements.) You should have enough bellows to use the 360mm Nikkor T-ED or the 400mm Fujinon T. These lenses are rather big and heavy with comparitively small image circles (but probably still useable for most landscape applications). Fuji also makes a little 300mm f8 T that is in a Copal #0 shutter and weighs less (415g) than a typical 210mm f5.6 plasmat. It has a 213mm image circle and requires less than 8" (195mm) to focus at infinity. > Of regular lenses, I have read that > anything larger than ~240mm does not permit close focusing with the field > camera's usual 12" or so of bellows' draw. I know several people who use a 300mm Nikkor M with a Tachihara (or similar). This lens needs 290mm to focus at infinity. Many people use it with an extender board to get another inch or two of extension. At 270g, it is very light and compact (Copal #1, 52mm filter size). It also has tons of coverage for 4x5 (325mm image circle). Fuji makes a 300mm Fujinon C that is similar in size and weight with even greater speced coverage. > But ARE there good, fairly > lightweight 240mm lenses? What could folks recommend and in what shutters? There is at least one GREAT little lens in this focal length, the 240mm f9 Fujinon A. It comes in a Copal #0 shutter, weighs 245g, takes 52mm filters and has an image circle of 336mm. This is a fantastic little lens. It was officially discontinued in August 1998, but there might be a few new ones still in existing dealer stock (or look for a used one). I have a section on lightweight lenses on my large format homepage at: http://largeformat.homepage.com/lightwei.htm You can find more info on the 240 Fujinon A and the 300mm Nikkor M (and others) by following the appropriate links. Hope that helps, Kerry -- Kerry L. Thalmann Large Format Images of Nature A Few of My Images Online at: http://www.thalmann.com/ FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Long Lenses DATE: Sat, 03 Jun 00 09:15:55 GMT ORGANIZATION: A1 Internet news-server NEWSGROUPS: rec.photo.marketplace.large-format In article <39389072.6E83@worldnet.att.net>, "Kerry L. Thalmann" wrote: >zloi wrote: > >> Of regular lenses, I have read that >> anything larger than ~240mm does not permit close focusing with the field >> camera's usual 12" or so of bellows' draw. > >I know several people who use a 300mm Nikkor M with a Tachihara (or >similar). This lens needs 290mm to focus at infinity. Many people use >it with an extender board to get another inch or two of extension. At >270g, it is very light and compact (Copal #1, 52mm filter size). It >also has tons of coverage for 4x5 (325mm image circle). Fuji makes a >300mm Fujinon C that is similar in size and weight with even greater >speced coverage. Are there any longer 'telephoto' lenses available? (less infinity-extension than their focal length, unlike 'telefocus'(?) lenses with extension=focal-length) In particular for a Speed Graflex 4x5"? That's a bit over 30cm max extension.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: bgurfinkel@aol.com (BGurfinkel) SUBJECT: Re: Long Lenses DATE: 03 Jun 2000 14:16:17 GMT ORGANIZATION: AOL http://www.aol.com NEWSGROUPS: rec.photo.marketplace.large-format >Are there any longer 'telephoto' lenses available? >(less infinity-extension than their focal length, unlike 'telefocus'(?) >lenses with extension=focal-length) ---------------------------------------------------------- Have a 600mm f12 Fujinon-T Copal 1 for sale. Covers 260mm, needs approx 15 inches of bellows at infinity. A wonderful lens. Bob Gurfinkel FROM: "Kerry L. Thalmann" SUBJECT: Re: Long Lenses DATE: Sat, 03 Jun 2000 15:25:06 GMT ORGANIZATION: Kerry L. Thalmann Photography NEWSGROUPS: rec.photo.marketplace.large-format Willem-Jan Markerink wrote: > > Are there any longer 'telephoto' lenses available? > (less infinity-extension than their focal length, unlike 'telefocus'(?) > lenses with extension=focal-length) > > In particular for a Speed Graflex 4x5"? > That's a bit over 30cm max extension.... As I mentioned above the 360mm Nikkor T-ED and the 400mm Fujinon T both require about 10" (261mm for the Nikkor and 252.4mm for the Fujinon) of extension to focus at infinity. Both are heavy (800g for the Nikkor, 600g for the Fuji), but should work fine on a Speed Graphic The Nikkor T-ED has interchangeable rear elements that allow it to be converted to 500mm and 720mm. In the 500mm configuration, it requires 349.9mm for infinity focus. Too long for a Speed Graphic without additional extension. Congo also makes a 400mm telephoto with a ftf for infinity focus of 239mm and a 500mm telephoto with an ftf of 287mm. The Congo lenses are not in the same league as the Nikon or Fuji telephotos. Congo has a web site with complete lens specs at: http://www.cosmonet.org/~congo/index_e.html Kerry -- Kerry L. Thalmann Large Format Images of Nature A Few of My Images Online at: http://www.thalmann.com/ FROM: "Michael C. Daily" SUBJECT: Re: Long Lenses DATE: Sat, 03 Jun 2000 07:51:50 -0500 NEWSGROUPS: rec.photo.marketplace.large-format I use a Schneider G-Claron 240mm f9 in a Copal 0 shutter specs are similar to the Fuji and it is still in production. It covers 8x10 quite nicely, even though Schneider recommends it for only 5x7. Michael Daily FROM: "Kerry L. Thalmann" SUBJECT: Re: Long Lenses DATE: Sat, 03 Jun 2000 15:25:05 GMT ORGANIZATION: Kerry L. Thalmann Photography NEWSGROUPS: rec.photo.marketplace.large-format Michael C. Daily wrote: > > I use a Schneider G-Claron 240mm f9 in a Copal 0 shutter specs are similar to the > Fuji and it is still in production. It covers 8x10 quite nicely, even though > Schneider recommends it for only 5x7. > Michael Daily Hi Michael, According to the Schneider web site, the 240mm G Claron is in a Copal #1 shutter and weighs 330g. The 240mm Fujinon A is in a Copal #0 and weighs 245g (actual weight of my sample - published weight 225g). Also, all G Clarons, even current production models are single coated. The 240 A is multicoated. I haven't shot with the 240 G Claron, but I have shot with it's little brother (the 150 GC). They are indeed fine lenses, but I prefer the 240 A for it's even smaller size, lighter weight and multicoating. If only Fuji wouldn't have discontinued them. Rodenstock also makes a 240mm f9 that is multicoated, but with considerably less coverage (212mm image circle - still enough for most 4x5 field applications). It is in a Copal #1 shutter and weighs 260g. Not sure if this lens is still available new, but it is no longer listed in the B&H ad, nor can I find it on their web site. I also seem to recall that it was quite a bit more expensive than the G Claron or Fujinon A. Kerry -- Kerry L. Thalmann Large Format Images of Nature A Few of My Images Online at: http://www.thalmann.com/ FROM: "Rupunzel_B" SUBJECT: Re: Contriving your own long, long lens DATE: Sat, 5 Aug 2000 08:35:55 -0700 ORGANIZATION: Prodigy http://www.prodigy.com NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format John Stafford wrote in message > > The shot required a 600mm non-reflex lens on 35mm which was no problem with > 35mm. (Used a Nikon F, 300mm ED and TC301 extender. I lucked out on this > combo and got one that is just outstanding. *This is one area where 35 mm does work better than MF or LF. The really long and expensive telephoto lenses made for 35 mm are kind of special. Like the Canon 300 mm f2.8, it is a classic and possibly one of the very best telephoto lenses made. It is the original long Tele made with a artificially grown Fluroite front element that solves much of the color dispersion innate to telephoto lenses. Other manufactures use ultra low dispersion glass to achieve similar results. *The other problem you have is just plain focal length, a 600 mm lens on a 35 mm format is aprox equal to 1200 mm on 6x9 and 2000 mm on 4x5. The longest focal length process lenses I know of are the ~2000 mm APO Ronar, 1778 mm (70 inch) APO Artar and I suspect there are others. These were made for room sized process cameras of another era. Every so often one of these show up on the used market, but they are rare. Then you need to consider mounting it and what to do for a shutter..and shutter speed.. Oh, don't forget the working apertures, typically f22- f32 or smaller and this limits resolution. *I once tried a 47 inch APO Artar on 8x10, I did not like the results and the set up was clumsy to use. > Input, advice? Or have I hit The Wall? *If it works, why fix it??? *I would stick to the 35 mm format and use what you did (Nikon 300 f2.8 + 2X converter) or rent a real 600 mm lens and use really, really fine grain film. *Generally, long Tele images work better on smaller formats, wide angle images work better on larger formats (try a 150 mm HMXL on a 8x10 Camera, it's amazing the amount of information that is recorded on film). Bernice FROM: rmonagha@smu.edu (Robert Monaghan) SUBJECT: easy long lenses tips Re: Contriving your own long, long lens DATE: 5 Aug 2000 13:03:38 -0500 ORGANIZATION: Southern Methodist University NEWSGROUPS: rec.photo.equipment.medium-format q: how to get 1200mm long lens for medium format? this is pretty easy if you have a focal plane shutter medium format rig, assuming you don't need lots of speed, you have lots of options. The easiest solution is a 2X teleconverter too on the MF rig, plus a long lens of 500 or 600mm, yielding 1000-1200mm range. see http://www.smu.edu/~rmonagha/bronhb.html Homebrew MF Lenses see also http://www.smu.edu/~rmonagha/bronscopes.html (my Astronomy mag article on cheapy homebrew optics telescope and bellows lenses etc. "lens hacking" ideas from May 1987 Astronomy magazine..)... The $100 ($129 multicoated recommended) korean 500mm f/8-f/32 lenses cover 6x6 nicely, more contrasty than mirror lenses, better DOF control etc. Easy to adapt to 6x6 etc. focal plane bodies as the rear of the lens has no glass, and just screws off, so an adapter is easy to make (esp if you have an extension tube handy. Lots of other tele lenses have excess coverage from 35mm and can be used on 6x6cm; I just bought a 320mm APO and a 400mm lens (800mm with 2X) adapted for bronica S2/EC from Don (see his page of homebrew lens at http://www.tituscollectibles.com/cameragear.html) for $75-100 US with the adapters, it is hard to beat such optics (esp for an APO long lens on 6x6! ;-) similarly, you can use large format long barrel lenses with lens iris in mounts to get cheapy setups. Big advantage here is that the lenses have lots of coverage ;-) Not as good or contrasty as the APOs, but something beats nothing... I have a 450 f/9 Nikkor LF lens out on loan doing astrophotography - handy as it covers 8x10 (too long for my 4x5" bellows, drat!) ;-) If you have a 2X teleconverter and a bellows or similar setup on a leaf shutter camera, you might be able to use such a lens with its own leaf shutter assuming you have mirror lockup or other tricks? Of course, it is easy with a focal plane camera such as the Bronica S2/EC; just a piece of PVC pipe, some removable household cement, and flat black paint plus an extension tube to PVC adapter to mount onto camera... check www.surplusshed.com and astromart for telescope achromatic objectives; long tele lenses are usually just 2 element " " - even Leitz! Unfortunately, most telescopes are optimized for 7 mm exit pupil of the eye, and don't do well on MF (35mm dime shaped images) - exception is pricey Takahashi (sp?) comet chaser's special - $5,000+; you may find a 1000mm or so focal length which would probably work at modest cost, if you don't want a lot of speed, and if setup with right baffling would probably cover 6x6; if not, a teleconverter would probably work to expand coverage as it widens field of coverage obviously, if positioned right... another option is direct projection (afocal) via eyepiece to camera mounted on bracket; circular image, vignettes a lot on most setups, but might work depending on your setup? I have a 1200mm f/4.5 - 2400mm f/9 wide field fast mirror 'scope - 1 1/2" or 2" eyepieces instead of the mini-guys, but again this is a pricey toy for a one time shoot, and being a mirror is fixed DOF, Dobsonian style mount, but it is five feet tall and I can barely get my arms around it to pick it up. But you can read signs downtown from 9 miles out ;-) [upside down, that is ;-)] Unfortunately, lead time on ordering such scopes is now in the 12 to 18 month region, so that's probably not an option unless you have a really patient client ;-) another option, depending on quality needs, is stacked teleconverters; these work better than most folks expect, if you use really good 7 element converters instead of the ones with 2 to 4 elements; see links at http://www.smu.edu/~rmonagha/mf/links.html etc. If you can't get a 500mm or 600mm lens to use with a 2X Teleconverter, try renting two teleconverters (again, assuming light loss is acceptable) with a 250mm or 300mm lens. Works much better than I'd expected based on all the "don't do it" advice I've seen, but with all the telescopes and other stuff I've accumulated not exactly an approach I need - but it might work with a leaf shutter setup is you can't find anything longer than 250mm or 300mm for rent easily, but can get the 2 TCs?... if you are using a leaf shutter and want to homebrew some long tele-lenses, you had better have a shutter lens (glassless lens for use as a shutter with mountings for other optics) or maybe microscope adapter (mostly too small opening for telephotos to not vignette?. see notes at http://www.smu.edu/~rmonagha/mf/kowapg.html bottom and ~rmonagha/bronhb.html on leaf shutter options... finally, you might be able to track down the 10000mm f/11 zeiss lens for the rollei SLX/6xxx - there is only one in USA ;-0) - priced at new car prices $10,000+ but it comes with an assistant to carry it around ;-) grins bobm -- * Robert Monaghan POB752182 Dallas Tx 75275-2182 rmonagha@post.cis.smu.edu * * Third Party 35mm Lenses: http://www.smu.edu/~rmonagha/third/index.html * * Medium Format Cameras: http://www.smu.edu/~rmonagha/mf/index.html megasite* FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: easy long lenses tips Re: Contriving your own long, long lens DATE: Sat, 05 Aug 00 18:34:27 GMT ORGANIZATION: A1 Internet news-server NEWSGROUPS: rec.photo.equipment.medium-format In article <8mhktq$3uu$1@post.cis.smu.edu>, rmonagha@smu.edu (Robert Monaghan) wrote: >finally, you might be able to track down the 10000mm f/11 zeiss lens for >the rollei SLX/6xxx - there is only one in USA ;-0) - priced at new car >prices $10,000+ but it comes with an assistant to carry it around ;-) You are too generous with zero's....it's only 1m focal length....;-)) But f5.6 in case of the mirror, f8 in case of the glass version....can be adapted to 35mm 300x SLR Rollei's too I believe....:-)) Zeiss-Jena also had a 1000/5.6 mirror....sometimes show up for US$2-3k used....most of these ended up in East-German government departments....;-)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "Rupunzel_B" SUBJECT: Re: Contriving your own long, long lens DATE: Sat, 5 Aug 2000 11:28:47 -0700 ORGANIZATION: Prodigy http://www.prodigy.com NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format > Oh no, I sense a religious war in the making. :) *Don't include me in this religious war... > But to carry to the extreme, Canon or Nikon did make a limited run of one > 300mm F2 lens design. *It was Nikon... now very collectable, very expensive. Many were converted to Arriflex lens mounts for film work. > > longest focal length process lenses I know of are the ~2000 mm APO Ronar, > > 1778 mm (70 inch) APO Artar [...] > > Thanks for that. I've just added your suggestion to my long-term wish list. > Regarding shutters - no problem at all. I have large Packards for LF (and > one can order about anything one might need) *You can find 24" f5.6 or 36" f8 areo photo lenses mounted in a Fairchild K-38 leaf shutter. These were made by Perkin Elmer, Pacific Optical, Kodak (Aero Ektar) on the used/surplus market. *I would go to the Astromart want ads or hobby telescope builders resources to find these whoppers, this is where I found the ones I have. > or can mount odd lens to a > Pentax67 or my Hassey 500c/m using - ah, something like industrial PVC pipe > laid across a sawhorse for an extension? *The Pentax has an internal shutter, so does the Hassy "F" bodies. If you chose one of these your shutter problem is solved. *You still need to make some kind of focusing mechanism, helical, rail and bellows, sliding tubes, etc... *You can also consider the paper tubes used for pouring concrete pillars (Sono Tubes). Many home built telescopes are made this way. *You will have a vibration and set up support problem. Saw horses are not the most stable thing for this project. Ideal would be a long slab of flat granite on a optical air table..This is expensive and not very portable. >Damn. The tiny apertures are a > requisite and no problem with these cameras - in fact, the longer exposures > are a good thing to overcome camera shutter vibration of the Pentax, and > exposure differences in general when using a wristwatch to time. (This is a > shot that accommodates easily to very long exposures.) *Why not just use a lens cap as the shutter??? > > *I would stick to the 35 mm format and use what you did (Nikon 300 f2.8 +2X > > converter) or rent a real 600 mm lens and use really, really fine grain film. > > For the most part, I agree with you. For this picture the results from my > Nikon-F with 300mm ED and a TC301 tele-extender are adequate in terms of > sharpness from 35mm and modest enlargement. Clearly for this shot, I'll have > to stick to 35mm, and if the buyer doesn't like it, then I'm out of luck. So > be it. I will probably revert to Plux-X Arecon film. Once you get over the > processing problem, expose and then process in a reasonable time and keep > the film cool, it's great, albeit inconvenient stuff if you go by the book. *Would you consider making a dupe of the 35mm neg on to a larger sheet of film? I'm wondering why your client is so driven to have a larger sized negative?? *IMO, I would stick to what you already have. > The long, long LF and MF alternatives are going on the 'maybe someday' > shelf. *If you start looking at the various places I mentioned, eventually you will find these really long focal length aero photo lenses. Once you have the optics, you can make your dream tele come true. Bernice FROM: jbh@magicnet.net (John Hicks) SUBJECT: Re: Contriving your own long, long lens DATE: Sun, 06 Aug 2000 02:14:40 GMT ORGANIZATION: Verio NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format You might look into using some sort of astronomical telescope and a T-mount onto a camera body (at least one dealer advertises big T-mounts for MF cameras) or eyepiece projection. I have _no idea_ of specifics; perhaps Michael G. could help here. --- John Hicks FROM: Bruce McLaughlin SUBJECT: Re: Contriving your own long, long lens DATE: Sun, 06 Aug 2000 01:13:17 -0400 ORGANIZATION: Frontier GlobalCenter Inc. NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format I don't think you will find a telephoto lens near to the 2000 mm you would need to duplicate the 35 mm shot. You can find regular lenses in the 1800 - 2000 range. I recall an old "Technique of the Master"s show in which a German photographer was using an 1800 mm Apo Ronar on an 8X10 Sinar. It required six feet of bellows." So you might be better off contriving a bellows extender for your camera rather than trying to do something about the lens. Perhaps if you camera offers removable bellows and an extendable base (monorail) you could make a temporary "bellows" out of cardboard and rent one of those long Apo Ronars from someone like Lens & Repro in New York. Even if you could find a telephoto of around 2000 mm focal length, the bellows draw required would still be very long. So you would have to work on the bellows extension issue regardless. FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Contriving your own long, long lens DATE: Sun, 06 Aug 00 12:52:26 GMT ORGANIZATION: A1 Internet news-server NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format In article <398cc996.1208882@fl.news.verio.net>, jbh@magicnet.net (John Hicks) wrote: > You might look into using some sort of astronomical telescope and a >T-mount onto a camera body (at least one dealer advertises big >T-mounts for MF cameras) or eyepiece projection. > I have _no idea_ of specifics; perhaps Michael G. could help here. > I'd be interested to learn more about this 'big T-mount' adapter....I know there are telescopes which can adapt to Pentax 6x7 (which can be modified for Bulb/Time exposure without current draw)....does this suggest a rather proprietary mount, by one manufacturer? Any brands, pointers or URL's? FROM: John R Pierce SUBJECT: Re: Pentax 67 & afocal astrophotography DATE: Sat, 05 Aug 2000 17:21:32 -0700 NEWSGROUPS: rec.photo.equipment.medium-format On 05 Aug 2000 23:02:39 GMT, dcolucci@aol.comspam (DColucci) wrote: >ok, I own a 67 and would like to start by shotting afocal images....hints, >thoughts, suggestions as to telescope/eyepiece combo ? > >thanks - experienced 67 user, beginner astro man have you already tried piggyback astro photography using the 6x7's own lenses? I'd get good at piggyback before venturing into prime focus photography (telescope + camera with no lens or eyepiece). Eyepiece projection photography is the hardest to get good results on (due to the much higher effective f/stop combined with extreme magnifications created). To do prime focus work will need a telescope with a large useful final aperture (ideally a oversized focuser to utilize 6x7 film, astro-physics uses up to 4" focus tube assemblies. See... http://www.astro-physics.com/products/telescopes/155edf/155edf.htm A-P has camera adapters specifically for the pentax 6x7 along with field flatteners (required for shorter focal length scopes). I'm not familiar with any other telescope makers (outside of Pentax telescopes which are only available in Japan*) who have 6x7 adapters of any kind. You could always take an old extender tube and start hacking in the machine shop :-D I'm not aware of ANY adapters for eyepiece projection with the 6x7. such would be HUGE, worse, the massive 6x7 camera body would be greatly offset from the telescope, causing rather major balance problems. -jrp * if you can read japanese, try http://www.pentax.co.jp/japan/product/sougan/index6.html and http://www.pentax.co.jp/japan/product/sougan/index4.html and wonder... FROM: Joe SUBJECT: Pentax 6X7 - ASTROPHOTOGRAPHY info DATE: Sat, 05 Aug 2000 22:42:36 -0400 ORGANIZATION: x NEWSGROUPS: rec.photo.equipment.medium-format Found this info at: http://www.company7.com/library/ptxshtr.html Company Seven's Modified Pentax 6x7 Cameras This Pentax 6x7 camera body has been selected and modified to better meet the performance criteria for successful astrophotography. Be assured the factory warranty continues in full force. Also, none of these modifications precludes the use of any optional Pentax 6x7 accessories, nor does it preclude the use of this Pentax 6x7 camera for conventional photography. However, there are certain operational differences between a standard Pentax 6x7 camera and those which are modified to meet Company Seven's criteria. Not all of these features are mentioned in the standard Pentax 6x7 owners manual or listed here, but the most obvious differences to the user will be: Clear Screen: The standard focusing screen has been replaced with another in order to facilitate focusing at relatively high f ratios (such as encountered in macro photography, or with long lenses and telescopes), or when photographing objects in low light environments. The focusing screen has been precisely fitted to assure the screen is parallel to the film plane. The bayonet mount alignment to the film plane may have also been adjusted as necessary to assure pinpoint imaging across the film plane. Shutter Power Bypass: The standard factory issue Pentax 6x7 camera is an electronic body. The focal plane shutter mechanism draws power from an internal 6 volt battery or from an optional external source to activate. The shutter requires power to maintain an open condition whether the shutter speed is set to 1/500th of a second or for a long exposure of many hours. The power requirements drain the battery such that the battery becomes exhausted after a matter of several hour long exposures. Also the ambient temperature will affect battery output; this takes on a more important dimension in a cold environment. In order to allow long time exposures at the "B" mode without draining the battery, this body has been modified to allow the bypass of the battery. The procedure to activate the shutter is as follows: Perform a battery condition test: press the white plastic button at the rear of the camera near the shutter speed dial. If the L.E.D. (at the inboard side of the shutter speed adjustment dial) lights then you may continue, otherwise replace the battery. Insure the camera is loaded with film, then advance the film crank to the first frame. Optional: If the film is to be commercially processed, we suggest the first frame of film be exposed to light so that commercial laboratory film cutters may have an indexing point of reference. Attach a lens to the camera, or the camera to a telescope. Frame and focus the object or the area to be photographed. Insure that any focus lock (such as a drawtube lock screw on a telescope focuser) is set. Thread a primary camera cable release into the small socket at the front panel on the camera body, (below the manual shutter release button). When installed onto the camera, the primary cable release should be unlocked (or relaxed) before it is thread into place. Set the primary cable release selector to "lock"; this will hold the shutter open when the primary cable release button is depressed. Set the camera shutter speed adjustment dial to indicate "B". Suggested option: Activate the mirror lock up by sliding the momentary switch (located to the right of the bayonet mount) up. You will hear a "click", then the focus screen will go black. Depress the primary camera cable release button. It should lock in the depressed position. Trigger the camera shutter by gently pressing the shutter release button. A secondary cable release may be employed to further reduce any possibility of vibrating the system; if so the secondary cable release selector should be set at the momentary (as opposed to lock) position. To preserve battery life, now remove the battery or disconnect the optional cold weather battery pack. As long as the primary cable release is set, the shutter will remain open and the mirror will remain up. To end an exposure, gently grasp and then unlock the primary shutter cable release. Thank you, and we wish you a lifetime of enjoyment with your camera. For information about other accessories for your telescope please call us. Contents Copyright 1994-98 Company Seven All Rights Reserved FROM: "Todd E. Maurer" SUBJECT: Re: Ultimate Long Lens (was Re: Contriving your own long, long lens) DATE: Mon, 07 Aug 2000 15:38:54 -0400 ORGANIZATION: Self NEWSGROUPS: rec.photo.equipment.large-format > John Stafford wrote in message > news:8ml45g$hn$1@Urvile.MSUS.EDU... > > > > Michael Briggs wrote in message > > news:398D8F0D.FFDBD32B@EarthLink.net... > > > > > The equivalent focal length on 4x5 would be about 1800 mm, which would > > > be very hard to find and require very long bellows. [...] > > > > My wife came up with an idea to park an Airstream trailer at the site, > > black-out the windows, put a lens in one end of the body, tape 20x24 film > to > > a board at the other end. Cool. 8^} Does anyone make a 34' (10,360mm) > lens? > > I could even develop the film "in camera". I'll bet it's been done > already. > > If not, then can anyone recommend photo accessories for my new Airstream > > camera? Accessories - a carrying strap? Can we get one in black finish > > (boy, that would really smart the Airstream fanatics.They are as bas as > > Leica mavens.) > > > > I digress. Sorry. > > Well John... > > There are plenty of LARGE process cameras that are being scrapped, I suspect > you can easily get the front standard from one of these and the vacuum film > back complete with flip up ground glass. You can mount the focusing rails > and gear rack inside your Airstream to focus the whole thing.. > > As for the lens... all it would take is $$$ to get one. Just Imagine if you > ordered a 10,360 mm f 0.95 whopper for your mobile camera ( the front > element would be over 10,360 mm in diameter, great for night shots) > > Oh, don't forget to get your Airstream mobile camera black anodized, less > reflections.. The leather camera strap must be extra sturdy as it would be > carrying a full load... The filter suppliers for this camera will just love > your bank account, so will everyone else involved with your "black box". > > I know this was totally off topic but, I just could not pass up the > opportunity to talk about the traveling ultra large format camera.. > > Bernice The digressions are endless... Perhaps Wisner would make a pocket version... What would be a good reserve price for my 4x5 (feet not inch) Airstream at my Ebay auction? This would create a new market for old water towers. LF hacks could file off the tank and they'd have a handy support for they Airstream... Arca Swiss introduces the mega ball head with counter weights. Press release says, "Position you Airstream with your pinkie." Quick release extra... A bus manufacturer announced today they would introduce a product to compete with the Airstream camera. They manufacture realized that the accordion connection between the main cab and the trailer would allow for tilts and shifts not available on the Airstream. Driving with the trailer shifted is NOT recommended... Wisner announces a deal with environmentalists to discontinue its popular Cherry Pocket Airstream as Cherry tree populations plummet... Wisner has announced its found a way to may attractive Airstreams out of boards of laminated Poison Ivy stems... Outdoor Photographers reviews the camera everyone has been itching to use.... Outdoor Photographer pans the Airstream Camera. Say, "This is really a camera for indoor photographers as the photographer is in this case, well, indoors!" Dow Chemical announces it is discontinuing research in Poison Ivy herbicides. Poison Ivy is placed on the endangered species list. Airstream lobbyists pull off major coup when Congress enacts new MPG and emission standards for all Bus Cameras. FA: one slightly used Hubble. Sure the format isn't as large as an Airstream but those don't has the history this one does. Difficult access. Allstate Insurance company refuses to insure 4x5 cameras. "They're just too small. Thieves can walk away with them and hide them easily." In a related announcement Airstream announces it is buying a 38% stake in Allstate... Traditional Airstream Camera prices skyrocket as Aluminum reserves dwindle. Airsream's goal of a camera in every driveway at risk. Police reports growing incidents of Traditional Airstreams being vandalized in ghetto neighborhoods. Seems junkies are able to sell the aluminum on the black market... As aluminum prices continue on the rise Airstream offers a newer model made of cheaper titanium. They cite that the newer model is also stiffer, lighter and dampens more vibrations than the aluminum model. Traditionalists aren't impressed. They say the titanium model is unattractive and more dangerous. They point to the lower electrical conductive abilities of titanium to protect photographers during lightening storms. Bogen introduces a new tripod line called Storm. It includes an integrated lightening suppression systems. Grounding rods extra. National Park Service closes trails to photographers. 35mm to 4x5 shooters cry foul. They claim most of the trail damage blamed on photographers is really being done by bus camera and Airstream camera users. Meanwhile complaints of bad odors and "odd lumps" prompted the National Park Service to require all photographers to stop at a waste dumping site twice daily. Again 35mm and 4x5 photographers say the regulations should be excluded them as these cameras don't have bathrooms. Airstream, Adobe, Microsoft, General Motors and Intel announce what they claim is the most complete digital camera package ever... Why by anything else? Microsoft asks, "Where do you want to go today?" Meanwhile BCI (Bus Camera, Inc.) is rumored to be talking to Compaq (alpha chip and VMS operating system), Ford (Expedition), and IBM (Corel software division). Meanwhile the GNU has posted instructions for conversion of old school buses into cameras that run on Linux. Todd Rupunzel_B wrote: FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Ultimate Long Lens (was Re: Contriving your own long, long lens) DATE: Mon, 07 Aug 00 23:43:23 GMT ORGANIZATION: A1 Internet news-server NEWSGROUPS: rec.photo.equipment.large-format In article <398F104E.214C42D@apk.net>, "Todd E. Maurer" wrote: >The digressions are endless... > >Perhaps Wisner would make a pocket version... > >What would be a good reserve price for my 4x5 (feet not inch) Airstream at my >Ebay auction? In Germany, a crew from an educational photography institute fabricated a sea-container as a pin-hole camera. Exposure was measured in hours. No tripod needed btw....:)) FROM: reynolds@panix.com (Brian Reynolds) SUBJECT: Re: Contriving your own long, long lens DATE: 8 Aug 2000 17:06:04 -0400 ORGANIZATION: Panix NEWSGROUPS: rec.photo.equipment.large-format,rec.photo.equipment.medium-format In article <8mjn05$pjj$5@news.a1.nl>, Willem-Jan Markerink wrote: >I'd be interested to learn more about this 'big T-mount' adapter....I >know there are telescopes which can adapt to Pentax 6x7 (which can be >modified for Bulb/Time exposure without current draw)....does this >suggest a rather proprietary mount, by one manufacturer? > >Any brands, pointers or URL's? > An excellent introductory book is Michael Covington's "Astrophotography for the Amateur, 2nd edition". His web site (with pointers to various astrophoto resources) is at: Brad Wallis and Robert Provin are the authors "A Manual of Advanced Celestial Photography" (out of print) and have a web site at: I believe that they used a Pentax 67 for some of their work, but based on their web site it looks like they've moved on to 4x5 sheet film and CCD imaging. You can check over in sci.astro.amateur for more information on USENET. -- Brian Reynolds | "Dee Dee! Don't touch that button!" reynolds@panix.com | "Oooh!" http://www.panix.com/~reynolds | -- Dexter and Dee Dee NAR# 54438 | "Dexter's Laboratory" FROM: dickburk@ix.netcom.com (Richard Knoppow) SUBJECT: Re: wtb telephoto lens for 8x10 DATE: Mon, 13 Nov 2000 23:21:20 GMT ORGANIZATION: MindSpring Enterprises NEWSGROUPS: rec.photo.equipment.large-format "Arnold Dubnick" wrote: >want to buy telephoto lens for 8x10 camera. >Arnold Dubnick >11409 Pelton Place Golf River, CA 95670 >phone (916) 635-3407 >email: adubnick@earthlink.net > > Do you mean a true telephoto lens or just a long focal length lens? A telephoto lens is made so that the back focal distance (distance from the back of the lens to the film) is shorter than its focal length so that it can be used on cameras without enough bellows draw for a normal lens of the same focal length. Since 8x10 cameras generally have generous bellows draw they are used with conventional lenses. I am not sure any telephoto lenses have ever been made for the format. There are a lot of process lenses avaiable on the used marked now, many of which have very long focal lengths. You may find one of these suitable for your application. There are enough of them so that the price is quite low. Be careful of the coverage of true telephoto type lenses, its very narrow compared to a conventional lens of the same focal length. A 12" or 15" telephoto lens will not cover 8x10 (they are usually intended for 4x5) where a conventional lens would without trouble. --- Richard Knoppow Los Angeles, Ca. dickburk@ix.netcom.com FROM: ncongdon@jhmi.edu SUBJECT: Re: wtb telephoto lens for 8x10 DATE: Tue, 14 Nov 2000 21:16:44 GMT ORGANIZATION: Deja.com - Before you buy. NEWSGROUPS: rec.photo.equipment.large-format Actually, there are a few true telephotos in 8 X 10. Nikon has the 600/800/1200 series, Schneider a new 800 offering. Although 8 X 10 cameras have long bellows, to get a true long lens effect in the format, you need some pretty impressive draw. The 1200 is only the equiv of 175 in 35 mm terms, and it's hard enough to use with the focus at infinity being 750+ mm. If it were truly 1200, forget it! Another great long lens (not telephoto) is the Fuji 600 12.5 C. Very light with a huge 600 mm image circle, quite sharp to my eye. Nathan FROM: dickburk@ix.netcom.com (Richard Knoppow) SUBJECT: Re: lens question... DATE: Thu, 30 Nov 2000 01:07:18 GMT ORGANIZATION: MindSpring Enterprises NEWSGROUPS: rec.photo.equipment.large-format sfeigh@aol.com (Scoot) wrote: >what would the difference in the look be between a 360 Nikkor Telepho lens, >and, say, a 360 "standard" lense by Caltar. Is there a visual differene >between a telephoto & standard lens, or is it just a matter of convenience to >use a T-lens that doesn't require as long a bellows draw? > >I hope I asked the question right..if not, and you think you know what I really >mean, your help would be appreciated. > >Thanks > >Scoot > >p.s......It costs you nothing to laugh.... > In general, Telephoto lenses have much narrower coverage than standard lenses of the same focal length. The idea is for the lens to be compact so that a longer than normal lens can be used on a camera with limited bellows draw. Telephoto lenses have some inherant problems; they are hard to correct for geometrical distortion and the complete lack of symmetry makes them harder to correct for coma and some other aberration. Nonetheless, there are some very fine telephoto lenses on the market. My guess as to the two above is that the image quality may be very similar but the Caltar will cover an image circle somewhat larger in diameter than its focal length (at infinity focus) where the Nikon is likely designed for 4x5 although it may cover a somewhat larger format. --- Richard Knoppow Los Angeles, Ca. dickburk@ix.netcom.com