Fujinon cmw 105 5.6 Center Filter?

<p>Hello all, long time lurker and brand new member here.<br>

I just ordered the CM-W 105 5.6, which I intend to use to photograph art inside a church. I got this wide-ish angle lens because of the large artworks and short camera to subject distances that the church imposes. I need even exposure from edge to edge. Do I need a center filter with this lens? Any recommendations? Or am I going about this all wrong? Using a ShenHao 4x5.</p>

It has the same, typical, fall off as the other modern wide angles. So, if you need the most even coverage from edge to

edge you will need a center filter.

 

However, if you are doing art works and plan on capturing the brush strokes then you will also need polarized lighting as

well as a polarizer on the lens, all adjusted for the same polarizing plane. If you will be doing this then the polarizer on the

lens has to fit the front of your center filter.

<p>Thanks Bob! They're huge pieces, so I was thinking to use huge diffusers and forgo the polarization. I'll have to see whether that approach ends up being workable. Otherwise, it seems I'll need many more lights than I now have.<br>

Any thoughts on how to choose a center filter? There doesn't seem to be one dedicated to this lens.</p>

If you want the brush stroke details then it is polarized lighting only. Diffused will not do it.

<p>Interesting. Whether to use a center filter has been discussed extensively on http://www.largeformatphotography.info/forum/ To the extent that there's a consensus it is that center filters aren't necessary on 4x5 for lenses longer than 90 mm and that they're optional on 90s. </p>

<p>If you look at Schneider's current list of center filters (see https://www.schneideroptics.com/ecommerce/CatalogSubCategoryDisplay.aspx?CID=182) you'll see that although they offer CFs for focal lengths longer than 90 mm these CFs are for lenses that cover vastly more than 4x5.</p>

<p>Strong suggestion. Try y'r Fuji lens out at the film-subject distances you'll encounter in the church and see how it does.</p>

On using polarizers: They are used to cut out reflections, with the filters over the light(s) and the one over the lens 'crossed', i.e. set at a 90 degree angle between their polarization planes.<br>To make or keep the 3D structure of the brush strokes visible, you do not want to remove the reflections. You could keep those reflections, obviously, by not using a reflection eliminating polarizer setup. Setting the polarizers up - as suggested - for the same polarizing plane will achieve that. Not using polarizers at all will do that too.<br>You only need polarizers if you want to hide brush strokes. Not when you want to capture the brush strokes.<br><br>I agree with Dan that using a centre filter on a 105 mm lens on 4x5" (this thread appears in the "5x7: cameras and lenses" subcategory, but it is a 4x5" camera you are using, right?) is only a necessity if it is an absolute must that there is no fall off at all. Fall off is present without centre filter, but not to such a degree that you would really notice.

<p>I agree with Dan and Q.G. Try and judge for yourself if you really need a center filter.</p>

<p>Reading your post, another thought came into my mind: The image circle of the Fuji CMW 105/5.6 is rather small (174mm at f22), so if you're standing close to the subject you want to photograph and if your subject includes vertical lines you want to keep vertical you'll be running out of image circle quite soon, depending on how far your subject is located above the ground.<br>

I too like to photograph in churches. I own a Nikon 90/f8 and found its image circle (236mm at f22) perfect for my needs. However, since it has noticable fall off at the edges of the image circle, my Schneider Centerfilter IIIb (1.5 f-stops) works very well on this lens to achive even illumination from corner to corner ("even" to my eyes...).</p>

<p> </p>

<p>I keep hearing this myth of needing polarisers to copy artwork, and it just isn't so. What you need is controlled and <strong>hard</strong> lighting - no diffusers. Reflections are controlled by altering the angle of your lights and making sure the camera and surroundings reflect as little light as possible. Flash being ideal for this since any ambient light then has little effect. Even paintings behind glass don't need polarisers if you light them right. (i.e. Standard 45 degree copy lighting with control of any shiny or bright surfaces in front of the artwork.) Polarisers don't work on bright metal or direct glass reflections anyway, and matt surfaces will just de-polarise any light hitting them.</p>

<p>If you do use polarised light to remove all reflection from the brushstrokes of an oil-painting, then it loses its character and no longer resembles the original.</p>

<p>WRT the centre-filter: If you're going to scan the film then vignetting correction can be applied in software. </p>

Joe,

 

Go visit some museums or art photographers for a lesson on polarized copy work. Obviously if you are copying oils,

especially, the medium is not perfectly flat and using unpolarized technique will not allow you to control all spectral so and

record all the brush strokes. If they used a pallet knife it gets even more difficult to control. No myth. Just proper

technique.

<p>Wow, thanks for the responses!<br>

At this point I will actually be able to mess around with both the Fuji 105 AND the Nikon 90 f8 with and without the 3b. So, I'm pretty pumped. One of those lenses is going to get returned or sold, though -- I can't keep both of them.<br>

As to lighting, it seems clear that I should use polarizers. Or not. Or diffusers. Or not. :-) <br>

Truthfully this project can sacrifice brush strokes in favor of reducing glare, so we’ll see what turns out to be optimal. These are newly created Byzantine style icons in an Orthodox church. The 3-D aspects of the work (brush strokes etc.) are of lesser importance. <br>

My own preliminary attempts last year with my DSLR came out best just using two bare tungsten bulbs placed to rake across the surface of the painting. I felt my 24x36 softboxes were too small for the job, but I thought the bare bulbs might bounce the light around enough to cover the whole area.<br>

This approach worked pretty well for details but not for shots of the whole work, which is probably 12' x 12' and extends up the wall and into the curve of the vaulted ceiling. The camera will be across the church, which is only about 20’ wide. There are four of these large frescoes, and the rest of the church interior is covered with others of varying sizes and curvatures. I expect the project to take a month or so, using both 4x5 film and the DSLR.<br>

I'm thinking I need more bare bulbs to just fill the space with as much light as possible. Or set up a half dozen speedlights without any modifiers.) What do you all think?<br>

On another note: I have used my DSLR as a pseudo-light-meter to determine 35mm film exposures, but I’ve never done it with large format. Any pitfalls here for the unwary? <br>

I have to tell you I’m very grateful for all of your responses so far.</p>

Bob, the brush strokes stand out just because they are three dimensional and thus have reflecting sides/edges. Using crossed polarizers will hide them. So to -record- brush strokes, do -not- use polarizers.<br><br>Using polarizers can also alter the colour appearance, increasing saturation. Which may or may not be a welcome departure from the visual impact of the works. But then, using any kind of light other than the light the work is seen in normally also creates a different impression already. For us to decide which is 'correct'.

<p>Bob, my first photographic job was in a copy studio where we had to copy all kinds of artwork. No polariser was ever needed, because we had a dedicated black painted copy booth. The only time I naively used polarised lighting (believing the myth that it was needed) was to record an oil-painting collection on a client's site for insurance purposes. The results looked flat and ugly, but for insurance records they were adequate.</p>

<p>I've also operated a LittleJohn 20"x24" vacuum-backed copy camera that took up two rooms. So I don't need any lessons in copying techniques, thank you.</p>

<p>And Bob, I find your tone to be very patronising for a mere salesman. How much copy work have you actually done?</p>

<p>Ian, go with the un-modified speedlights. They may be a bit tricky to position correctly, since you'll have no modelling light for guidance, but they'll easily overpower any ambient light and give a consistent colour-temperature. Fresco is fairly matt in character and so shouldn't give any specular reflection. However the curvature might present some shading issues. Just keep in mind the old physics rule - angle of reflection = angle of incidence - and you should be able to position the lights "blind" without getting any surface glare. Remember you can light from top and bottom as well as side-to-side, and more distance means less fall-off.</p>

<p>You can also stitch DSLR images together easily for more coverage/higher detail. To be honest I don't see much need for film of any size these days. Although the movements of an LF camera do make "perspective" correction a lot easier.</p>

<p>If the church is only 20' wide and the frescoes are 12', that leaves you 4' side-to-side for lights maximum. That's a bit close. You might need two banks of lights set at different angles to get even coverage, plus shoot some light up from underneath in the middle. Top lighting would be good too, but might be problematic.</p>

I did lots of copywork. Mostly with a Robertson and then with Sinars, Linhof's, Hasselblads and Rolleis. We were taught

polarized lighting and used Kodaks lighting polarizer soft copy lights. Have you used them?

Joe,

Good strobes do have modeling lights as well as interchangeable reflectors and other accessories to control the light.

They also, today, are UV corrected so they eliminate excess blue which many "speed light"aren't. Additionally, should one

be using film, their flash durations are long enough to prevent reciprocity failure.

In any case, with the advent of good LED lighting, the use of flash may be solved providing there is a way to control the

light from the LEDs.

I said that the planes of polarization are all adjusted so that they are the same. Not crossed. You put the polarizer, a

really, really good one, on the lens and one on one light. You rotate the one on the lens to maximum polarizing effect. You

turn that light off and turn the second one on, without moving the one on the lens. You rotate the one on the second light

to maximum polarization, as viewed through the camera. Now all three are properly adjusted.

Do not use this with precious metals as they will reproduce as black metal. Do use it for all art work not using precious

metals. Good quality polarizer so will not have a blue effect and if you are using lesser ones a simple white balance will

correct for the shift.

One of the big problems that could occur using lenses that short is foreshortening, things closer to the lens will reproduce

larger then things further from the lens. When doing the icons the center of the frame will be closer then the edges.

Maybe look at using a longer lens with the digital, do multiple shots, overlapping about 30% with the lens adjusted to

swing around its nodal point and then simply stitch the shots together. Easy to do in Photoshop and other processing

software. Especially with even lighting. These lenses would also be free of fall off.

Bob, the method you describe (most definitely if it can produce black metal) sets the polarizers at an angle relative to each other. Crossed, not parallel. Not crossed and they will only cut overal light levels.<br>The more important bit however is that you use polarizers to cut reflections. Reflections (and shadows) are the thing that make a 3d structure, like brush strokes, stand out. So if you want to capture brush strokes, do not (!) use polarizers.<br>You of course can, and set the polarizers so that they do not eliminate those important reflections. But then they will only be an expensive way to reduce the amount of available light.

Try this

 

http://www.betterlight.com/downloads/conference10_speakers/guyer_Polarization.pdf

 

http://www.inkjetbuzz.com/blog/index.php/site/comments/copying_artwork_a_polarization_tutorial/

Good links, Bob:<br><i>"<b>CROSS</b> POLARIZATION"</i> and <i>"[...] how to set up proper Polarized lighting and achieve a technique called '<b>cross</b> Polarization'."</i> respectively.<br><br>That removes reflections, including those of raised brush strokes. To quote the first link: <i>"Polarization "eliminates" highlights and shadows of texture [...]"</i><br>;-)