Image Circle How Big do I need?

[sruddy]

Hi All, I’m just starting with 4x5 and am wondering about image circle specs. I have no idea what I need and is it apparent when looking at the viewfinder if the lens is to small in that regard? So far I have a 150mm Fujinon and a 205mm Ektar. The Fuji IC is 224mm not sure about the Ektar. My next lens will be wider and I haven’t picked one out yet. Fuji seems to have two 90mm with different specs.

[mhayashi]

Maybe you should start from here.
https://www.largeformatphotography.i...s/LF4x5in.html

[Bernice Loui]

Image circle required depends on your image making goals. If the image to be made is direct on to film with no significant camera movements, image circle of 165mm will cover 4x5 sheet film. Once significant swing/tilt/rise-fall/shift is required, that is when a larger image circle is needed. An overly large image circle is not always desirable or an advantage as the over sized image circle can/will project excessive light inside the bellows causing flare resulting in lowered contrast on film. Typically for 4x5 sheet film an image circle of a bit more than 200mm is plenty. Once past 300mm of image circle, most 4x5 cameras can begin to run into camera movement limitations and the excessive image circle light possibly causing internal bellows flare resulting in lower image contrast.

As for the 203mm f7.7 Ektar, it has a reported image circle of 216mm, easily covers 5x7, been there done this and it is a Very Good lens in many ways.
http://www.bnphoto.org/bnphoto/KodakEktarsDB1.htm

As for a 90mm wide angle lens, basic differences are full aperture -vs- image circle. Typically, the 90mm lenses with a full aperture of f4.5 (Nikkor, Rodenstock) or f5.6 (Schneider, Fujinon) have larger image circles then their f8 variants with the exception of the 90mm f8 sw Nikkor which has about the same image circle as the 90mm f4.5 sw Nikkor difference being physical size and image brightness on the GG.

Know there are no "hobbyist" grade view camera lenses of this variety, Rodenstock, Nikkor, Schneider, Fujinon are more similar then different as they are all designed, intended and marketed for Foto folks trying to make a living with these image making tools.

Lens choice is driven by image making goals followed by what camera is needed to meet the needs of the lens choices and image goals. Keep in mind, a view camera is basically a light tight box that is flexi in the middle with the ends of this box adjustable and able to support lens on one end and ground glass for viewing an a sheet film holder.


Bernice

Hi All, I’m just starting with 4x5 and am wondering about image circle specs. I have no idea what I need and is it apparent when looking at the viewfinder if the lens is to small in that regard? So far I have a 150mm Fujinon and a 205mm Ektar. The Fuji IC is 224mm not sure about the Ektar. My next lens will be wider and I haven’t picked one out yet. Fuji seems to have two 90mm with different specs.

[paulbarden]

I assume you mean the 203mm Ektar, f7.7
It covers 4x5 with quite a bit of room to spare. I regularly use my 203 Ektar on 5x7 and it covers well enough.
It is, as Bernice has suggested, an excellent lens. It is my go-to choice for 5x7 and 4x5 in many instances. If you never own another lens, it would be easy to be very happy with one of these.

[Tin Can]

Bernice,

Would you advise against T00 big an image circle?

why

or not

[maltfalc]

absolute bare minimum, your image circle needs to be wider than the diagonal of the image on the film (152mm for 4x5). the closer it is to that minimum the worse your image quality and vignetting will be at the edges and the more your camera movements will be restricted. stopping down the lens will give a cleaner edge to the image circle with less vignetting and better image quality. focusing on closer subjects increases the image circle so you can get away using lenses for portraits or macro shots that wouldn't have a large enough image circle for landscape photography. if your ground glass has cut corners, you can peep through them to make sure the edges of the lens aren't obstructing the aperture. the larger the image circle is the more you'll benefit from using a lens hood to keep light off the inside of your bellows, and to keep the sun from setting them on fire.

[John Layton]

spontaneous combustion of bellows...would be spectacular!

[sruddy]

Thanks for all the great info everyone!

[Doremus Scudder]

If you are only concerned with making sure the lens(es) you get will cover 4x5, then look for a minimum of about 170mm of image circle. Some Plasmat lenses (the common f/5.6 design) in shorter focal lengths like 105mm and shorter will not cover 4x5 (they were intended for smaller film formats.

Just about any lens of 150mm and upwards will cover just fine and give you plenty of room for movements.

The 135mm Plasmats (the f/5.6 design and very common) cover 4x5 adequately as well, but the image circle is a bit small for using extreme movements such as lots of front rise common in architectural work (or front tilts/swings).

Where you really need to be sure you have enough image circle for your needs is with lenses in the 90mm and shorter area. Lenses for 4x5 in this category are usually "wide-angle" designs and have designations like "SW" (Super Wide - Nikkor and Fuji) or "Super Angulon" (Schneider) or "Grandagon" (Rodenstock). There are also a few 90mm lenses that just barely cover 4x5 and allow not much (if any) movements like the 90mm (not "Super") Angulon.

As a general rule for shorter lenses, less coverage = smaller, lighter and cheaper. Lenses with more generous image circles are larger and more expensive.

So, take some time figuring out what your need for movements may be and weigh that against size and price.

BTW, your 203mm Ektar and your 150mm Fuji have lots of coverage; you should be able to deal with all but the most demanding situations with them. Your next lens should probably be a 90mm of some kind. I'm partial to the f/8 "SW" lenses (or f/6.8 Grandagon) for the compromise between size, weight, portability and image circle. If you want the lens in this category with the largest image circle, it is the Nikkor SW f/8 90mm.

Best,

Doremus

[Maris Rusis]

spontaneous combustion of bellows...would be spectacular!

I've done it! Focussing up a back lit scene with the sun just out of the field of view on my 8x10 fitted with a Fujinon-W 300mm f5.6 the sun's image fell on a bellows pleat and burned a neat round 3mm hole. I wondered why I couldn't get clear focus until I realised the camera was full of smoke.