Lens flare and large format lenses

Is there any reason why large format lenses should be more

susceptible to lens flare than smaller formats?

 

I have noticed that I am encountering lens flare more frequently

than I would expect when shooting large format. In all instances,

this is from sunlight directly hitting the front lens element

(though the sun is well out of shot). The lenses are multi-coated

Schneiders (90mm & 150mm) and I have been relying on the (sort of)

limited built in lens hoods on these lens. This seems to have been

a bit of a mistake on my behalf and it now looks as if I start using

a separate lens hood on a more routine basis (as if I didn't have

enough kit to carry!).

 

Or am I missing something??

 

S.

I dislike carrying a lot of gear on a field shoot, too. Here's a little trick I use to avoid

carrying a lens hood in my kit:

 

I almost always carry with me a grey card to assist in determining correct exposure. When I

am ready to trip the shutter, I use my free hand to hold the card between the sun and the

lens while making the exposure. I have to make sure that the card is out of the range of

the scene when using a wide angle lens. I also have to make sure that the card is casting a

shadow on the lens. Maybe I'm just lucky, but this little trick always seems to work for me

to avoid lens flare.

 

Try it to see if it works for you. YMMV.

Stephan, not sure I understand what you mean by "built in lens hoods." There are no

modern multicoated Schneider lenses that I know of that hae anything remotely resembling a

built in lens hood .... nothing more than a filter ring. Can you tell us which specific lenses

you are referring to.

Sometimes, when there is no point light source hitting the lens, the flare is coming from reflections inside the bellows. Just sometimes, but it is something worth considering when all else is in order.

I am using a multicoated Super Angulon 90mm and a 150mm Symmar-S. And yes, you are right, it's not really a built-in lens hood, more of an enlarged filter ring. It's just the standard SA 90mm.

 

I use the trick with the grey card a lot of the time with medium format and it works well. You can even see the effect in the viewfinder. But with large format, I find it much more difficult to pick up on the ground glass and the effect seems more subtle, particularly where the contrast has been reduced through the lens flare. It shows up on the print and, sure enough, when you look at the neg, you can see it.

 

Using a lens hood, means more kit to carry and also can introduce it's own problems (e.g. vignetting etc). So ideally, I would like to avoid it. But given the duff shots I have had recently, it seems like using a lens hood is the best approach.

 

I have an extendable bellows hood, but I might investigate a cheap fixed alternative that fits on the front of the filter holder. It would be a much lighter approach. Any thoughts appreciated.

I use a broad-rimmed hat to shade the lens and keep any direct sunlight from hitting the front element; this works well enough maybe 80% of the time. If you are trying to squeeze every bit of contrast out of the shot, or are shooting so near the sun that using the hat risks vignetting, then there is no choice but to use a lens hood. To check for vignetting when using the hood, just look through the front of the lens and make sure you can see all four corners of the ground glass.

If anything LF lenses should be less prone to flare than smaller format lenses, at least zoom lenses, because they have fewer air-to-glass surfaces than zoom lenses. You don't have to carry a lens shade if you're only concerned with direct sunlight striking the lens. You can use your hand or a dark slide to deal with that. Lens shades are better because if they're properly designed and used they minimize both direct and indirect light striking the lens. But for direct light alone you can use your hand, you just need to make sure your hand doesn't appear in the image.

LF lenses are usually more prone to the flare problem because they have usually a bigger entrance lens diameter. Flare is not only what you see as such on a picture but also all the lost contrast that you only see if you compare pictures taken with and without a proper lens shade.

Stephen,

 

I hate to belabor the point but IF the lenses are single as opposed to multi coated then that

could be part or most of the answer. Do they actually say Multicoated on the rim of the lens

or MC? If not, then they are single coated. Schneider has written multicoated on the side of

the lens rim since they started the pracrtice. You can check the actual dates and serial

number by going to their website www.schneideroptics.com and under the info menu

searching on vintage lens data. Both of these lenses could be either single or multi coated.

Ted, both the 90mm and 150mm are multicoated ("multicoating" engraved on the rim) and date from around 1980. I have a couple of older Symmars (180mm & 210mm) that I suspect are not coated at all. These are mid 60s lenses. Still, very sharp although getting a little old.

 

I would not be surprised by flare on the older uncoated Symmars, but I was a little bit taken back by the flare on the 90mm Super Angulon in particular. I have not seen lens flare this pronounced before (unless deliberately shooting for it), especially the impact on the contrast of the affected area.

 

I guess I will just need to be a bit more careful in the future and watch out for potential situations that are going to cause me probelms. Thanks for all the input.

Stephen, your Symmars from the 1960s will be single coated. Schneider began single coating lenses shortly after WWII -- I am not sure what delay there was, if any. For a short while, single coating was marketed by Schneider with a triangle symbol on the lenses, but soon single coating was so universal on quality lenses of all manufacturers that the symbol was dropped.

 

I have not had problems with overall flare from my Schneider lenses, including a single-coated G-Claron. Only once have I had a related problem, when an image of the aperture appeared on the photo. Have you examined the interior of your camera? Perhaps there is a shiny surface, e.g., where some paint has worn off? Or maybe the bellows lining isn't flat enough.

Stephen, Now I am baffled. Like Michael I never have trouble with flare when using any of

my modern lenses. I do generally pay some attentionto shading the lens when I am

shooting directly or nearly directly into the sun. This shading can range anywhere from a

full blown Lee Comepndium shade to just holding a hat or my hand in a way to shade the

lens. I was just looking at some which were shot directly into the sun with the sun half

behind a stone tower ... purposely getting the sun in the image and the usual flare around

the rays but otherwise all is well.

 

Some bright spot inside the camera as mentioned or perhaps an advanced case of

Schneideritis could cause the flare but not likely and it sounds like you would hve noticed.

 

Could you post one of your images for us to look at?

You said that direct sunlight was striking the lens. That's the source of your problem. It isn't a question of coating. Coating or no coating, you're almost certain to see the effects of flare if direct sunlight strikes the lens. Multicoating is nice but its principal benefit is in allowing the design and use of modern zoom lenses with their many air to glass surfaces. Without multicoasting those kinds of zoom lenses wouldn't be made. But because of the relatively simple design of most LF lenses flare isn't usually a major issue and multicoating isn't a necessity. For example, all Schneider G Claron lenses were single coated but that line of lenses was around for decades and they remain popular lenses today on the used market. 159mm Wollensak lenses remain popular as wide angle lenses for 8x10 and many of them are uncoated (including the two I owned). But with any lens, multicoated, single coated, or uncoated, you do need to prevent direct sunlight from striking the lens. You can use your hand to do that if you don't want to invest in a good compendium shade.

Ted, Here's an example. As Brian suggested, I am convinced that most, if not all, of the lens flare problems I have are due to sunlight directly hitting the front element.

 

This is a really bad example, I have others that are more subtle. This is the middle 1/3 of a much larger print. I managed to knock the camera out of position when changing DDS, so I ended up pointing more towards the sunlight than I expected. Still, the sun is not directly in shot, although sunlight is directly hitting the front element of the lens.

 

I can see 3 effects of lens flare here: 1. the streak of stray light; 2. the reflection of the edge of the diaphragm (the pentagon just on the "t" of temperate); and 3. reduced contrast in this area.

 

Having read the input in this thread, I am pretty convinced that it is due to sunlight hitting the front element of the lens. A lens hood would have avoided this problem and I intend to carry one with me more frequently moving forward.

 

Thanks to everyone for their input.<div></div>

There are two separate factors involved. ONE: direct sun hitting your front element can cause

light to bounce around within the lens itself between the elements. TWO: The sun, which is

outside the "frame" of your composed photograph, is still well within the image circle

projection of your lens, and is resolved with full detail and brightness inside your camera on

your bellows, which is right next to your film and fogs or flares it - this is called BELLOWS

FLARE. Bellows flare caused way more problems for me than lens flare ever did. Then I got a

really good rectangular shade and that was that. No non-image forming light gets into the

camera.

It's the duty of the photography to prevent it unless you think the flare can create special tone to your pic. Before pulling off the dark slide, observe if there is any direct sunlight falling on the front elements, plan to shade it high above the lens and make sure it won't block the image. Pull out the dark slide and use the slide as shade. It's effective even more than lens shade sometime, no investment, no weight and space occupied your backpack, but need practice. Good Luck.

I shoot with a lens shade and also use the darkslide if the sun is close. You will notice a drop off is degradation using a lens shade all the time because your also getting slight flaring from reflections from below the lens (i.e. sun hitting the ground just below the camera...) and it is noticeable once you see it!

This thread is a great example of how a newsgroup can really work for everyone. The problem was clearly stated, and it went back forth for a bit, with a good example for all of us to see, and good contributions with NO egos involved. I learned quite a bit from this thread. Thanks guys!