Questions on 8x10 Still Life Close upsgreenspun.com : LUSENET : Large format photography : One Thread
I recently made the mistake of purchasing a 19" Red Dot Artar thinking that it would help with close up work. I learned the hard way. Apparently, you need shorter focal length lenses to get closer when doing LF work. Right?
Anyway, I currently have a wonderful 14" Red Dot Artar in a barrel, but want to be able to get in even closer on my subjects. (My passion is still lifes of fruits, flowers, etc. quite close. For example, I like the bud of a rose to fill the format.)
I shoot 8x10 format and have a Calumet C-1/C-3, which has approximately 31" of bellows draw. With this camera, would I want to go down to a 200mm/8" lens to get in really close? I know that to get 1:1, you need twice the bellows extension of the infinity focal length of the lens, correct? So, if I wanted to go above 1:1 (would twice the object size be written 2:1 or 1:2?), would I need 4x the focal length of the lens when focused at infinity? If I need 4x to get the object to fill the format, the 200mm/8" lens would be the correct focal length that I'd need, correct?
I really like the Dagors/Red Dot Artars. Are they made in the 200mm focal length? Also, would a lens that short be too wide angle, or would I still be able to get in close on the subject?
Thanks for your help as always!!
-- Ron Whitaker (email@example.com), November 07, 2000
Sorry, the question I meant to ask at the end of the third paragraph is would I need 4X THE BELLOWS DRAW of the focal length of the lens. (For example, to get the image to fill the sheet of film with a 200mm/8" lens, would I need 32" of bellows draw?)
-- Ron Whitaker (firstname.lastname@example.org), November 07, 2000.
I've made some very satisfying close ups with exactly that camera using an old Ektar 203mm f7.7 lens. A couple of things to keep in mind (and please forgive the obvious as I have no idea of your level of experience in this area) is that at such close distances and with such a large format, depth of field becomes a challenge. The temptation is to close the lens down to f64 or smaller to try to gain some valuable DOF. The problem is that when you start adding exposure to compensate for bellows extension, you are effectively (from the standpoint of diffraction artifacts) already reducing the aperture size. I've learned this the hard way and wherever possible try to select an aperture that when "adjusted" for the bellows multiplier, works out to no smaller than f64 when doing 8x10. I just did some shots in 4x5 of some seed pods with a bellows factor 4, in which I selected an aperture of f16. The results were very pleasing. When focusing, I played around with the aperture and could actually see the image degrade when I closed down to f45! That was on a pretty grainy ground glass too, I might add. In answer to you question about Dagors in 8", yes, they are available and great. The Ektar I use is a real sleeper, I feel, although it doesn't have the coverage of a Dagor. But, it can be had almost on any given day on ebay for a couple hundred bucks. One other hint I've heard on more than one occasion is that wide lenses that are of a symetrical design work real well in close up situations. This might include some optics that otherwise don't cover 8x10 at infinity. If you have some 4x5 or 5x7 lenses, you might give them a try close up on the 8x10! Hope this helps in some way.
-- Robert A. Zeichner (email@example.com), November 07, 2000.
The ratio of focal length to bellows draw varies with the reproduction ratio only. I worked through the formulas and can give you a "quick and easy" formula for this application.
Bellows Draw = (1 + R) x focal length.
R is the ratio of image size to object size. Thus if you want a 1 inch object to appear as 2 inches on the film, R = 2. The focal length can be in mm or inches or anything. The bellows draw will be in whatever units you use for the focal length.
The same formula gives the following:
((Bellows Draw)/(focal length))- 1 = R.
From this, you can quickly calculate the maximum reproduction ratio given a specific focal length and a specific bellows draw.
For a 200 mm lens, 31 inches of draw, you get a maximum ratio of (30/7.87 - 1) = 2.93. A 1 inch object would show as 2.93 inches on the film.
The node of the lens may not be in the same plane as the lensboard. Spec sheets on modern lenses (at least for Fuji) gave this info. The above formulas are based on the node, not the lensboard. You can measure the difference by focusing on infinity and measuring the distance from the lensboard to the image, and adding/subtracting the difference. Note that lens focal lengths are off from their marked length, but usually by an insignificant amount.
I hope this helps.
-- Charlie Strack (firstname.lastname@example.org), November 07, 2000.
Ron. If you want to do lifesize or above, then you should really be thinking about getting a macro lens, a copying lens or, do what I do, and use an enlarging lens for close-up work. True macro lenses are expensive. Copying lenses, like the G-Claron, can be got 2nd hand quite cheaply, but enlarging lenses are practically given away 2nd hand these days.
A 150mm Schneider Componon-s in mint condition fetches the Stirling eqivalent of about $140, and it'll easily cover 10x8 at 1:1.
-- Pete Andrews (email@example.com), November 08, 2000.
Ron: Pete has some good advice about using enlarging lenses for closeups. If you aren't used to doing closeups with a view camera, it can get tricky. Use the front standard to size the image and the back standard to focus. You may find yourself moving the tripod back and forth a bit unless you have a sliding tripod mount. You can even use a 50mm enlarging lens on your 8x10 for extreme closeups. Use a lens cap for a shutter. It works well.
-- Doug Paramore (firstname.lastname@example.org), November 08, 2000.
I think i is easier to do close using short lens. E.W talk of a 210 lens for hiw pepper still life.
When I shoot close up I prefer to use short lens As it is easier to control . For this I use a 210 or an 120 mm lens . With the 120 mm I can get great ratio factor using all my 8*10 deardorff bellows.
you can take a look of what I am talking to on my web page in still life section, all are 8*10 shoot with an 120 mm perigraphe berthiot
hope it help
-- nze christian (email@example.com), November 09, 2000.
Nze: What is your website address? The link on the LF Photographers' page doesn't work.
-- David Goldfarb (firstname.lastname@example.org), November 09, 2000.
Pete, you mentioned getting a 150mm Schneider Componon-S in mint condition for about $140. Where might I find this lens at this price? This is not a rhetorical question nor am I being sarcastic - I'm looking for a 4x5 enlarger lens and this would be my first choice.
-- Mark Parsons (Polar@thegrid.net), November 11, 2000.