Longest lens on 300mm bellows

[SMBooth]

What would be the longest lens practical to use on a 4x5 field camera that only has 300mm bellows draw. Sure I could put a 300mm on most things are closer then infinity..

Cheers

Shane

 

[Nick Zentena]

What are you doing with it?

There is going to be a difference between macro,portrait or landscape.

Plus you can always consider the telephotos. Or the tophat lensboards if your camera offers them.

 

[nemo999]

What would be the longest lens practical to use on a 4x5 field camera that only has 300mm bellows draw. Sure I could put a 300mm on most things are closer then infinity..

Cheers

Shane

The formula is 1/u + 1/v = 1/f

where u = Subject distance, v = Image distance (from lens) and f = Focal length. With 300 mm bellows, you can of course focus a 300 mm lens at infinity, a 150 mm lens for a same-size close-up, etc.

 

[SMBooth]

Landscape, I wouldn't expect to be able to do macro with anything over 150mm with my camera, and i don't do portrait images. I have a 135mm and surprisingly I think I would like something longer, not wider as I thought I would first up.

Cheer
Shane

 

[Pinholemaster]

Telephoto lenses need shorter bellows length then their focal length is indicated.

A 300 mm long lens needs 300 mm of bellows draw for infinity, if I remember correctly what my college professor explained 33 years ago. A 300 mm telephoto style lens sees infinity at a shorter bellows draw, but gives the same magnification of a 300 mm long lens. Did I get that correct?

 

[John Kasaian]

Conventional lens? I think 240mm would be stretching things for most purposes but even a 270mm would be at least a wee bit more useful than a 300mm on your camera.
Your best bet I think would be a 210 or 215mm. Roman Loranc and John Sexton use 210 for much of their work.

Telephotos are a whole different ball game, and if you need movements---ugh---everything gets cattywompus!

 

[Martin Aislabie]

The Schneider 400/5.6 APO Tele has a flange length of 285mm (distance from lens board to film plane when focused at infinity) - uses a Copal3 - so no room for a Top Hat or similar

The Fuji 400/8 Tele has a flange length of 252mm - this lens only uses a Copal1 shutter - so Top Hats can still be used to give you even more extension - http://www.badgergraphic.com/store/cart.php?m=product_detail&p=1146

For a non Tele lens you could go to a 300mm and use one or more Top Hats to give you more extension.

Almost all the non Tele lenses in the 300mm range have a slightly shorter flange length than focal length (generally 20mm or so)

The other thing to consider is how far can you rack out the front and rear standards on your LF without them getting too wobbly

With mine the last 10mm at both the front and rear make a big difference to the stability –so although you might have 300mm of available length you probably have closer to 280mm of usable length in real world conditions shooting Landscapes.

However, the real question is - with a lens of XXX focal length how near do I want to focus :confused:

I too am pondering the pretty much the same question but have a friend who has a couple of lenses he is loaning me to help me try and answer it.

Only I know the answer to my own question of how near do I want to focus with a particular lens?

Even with the help of the loaned lenses I expect it to be at best an educated guess.

Do you know anyone with some longer LF Lenses for you to try ?

Alternatively some places do a Lens Hire service – Calumet are one

Good luck

Martin

 

[John Kasaian]

Of course, if you lens standard is macho enough, you can make a "high hat" lensboard to goose another 30 or so mms of extension

 

[SMBooth]

OK now learning that there are 2 types of long lens "normal" and Tele" i did some reading (http://www.largeformatphotography.info/lenses-primer/) and learnt the basic differences. The question which Martin asks is properly the best , so what is the movement required for a 300mm to focus from infinity down to 20M and does a 250mm need more or less bellows movement to do the same range. I don't have any contacts with LF user in Australia to try lens although hopefully in a few month I will do a weekend LF course and hopefully get to answer these questions myself.

Cheers
Shane

 

[nemo999]

OK now learning that there are 2 types of long lens "normal" and Tele" i did some reading (http://www.largeformatphotography.info/lenses-primer/) and learnt the basic differences. The question which Martin asks is properly the best , so what is the movement required for a 300mm to focus from infinity down to 20M and does a 250mm need more or less bellows movement to do the same range. I don't have any contacts with LF user in Australia to try lens although hopefully in a few month I will do a weekend LF course and hopefully get to answer these questions myself.

Cheers
Shane

You can have the answers right now - no need to be scared of simple algebra!

Taking

1/u + 1/v = 1/f

and solving this for a 210 lens and 300 bellows we get

1/u + 1/300 = 1/210

Multiplying both sides by the lowest common multiple 2100:

2100/u + 7 = 10

Minus 7 from each side:

2100/u = 3

Multiplying both sides by u:

2100 = 3u

Therefore 700 = u

Answer: With a 300 mm bellows, a 210 lens will focus to 700 mm.

Similarly, the formula indicates that a 300 mm lens needs 304.5mm extension to focus at 20 metres. The formula also works for telephoto lenses, just take the actual back focus (distance from lens board to film at infinity) instead of the focal length. Typically, an older telephoto lens will have a back focus half its focal length (because it was designed to use on a press camera with a short bellows), while a more modern one will have a back focus 2/3 of its focal length.