Sigma SD Quattro for IR + B/W (removing IR filter)

Two minor notes:

Revo-ring from H+Y is an adjustable step-ring they crowdfunded not long ago There is a 77mm and an 82mm option which should suit Sigma SLR lenses, and adjust down for smaller lenses.

From the lists I’ve seen, hotspots are less likely to appear for lenses used wide-open. Perhaps the light is too diffuse.

dogpigbird said:

Included a couple of shoots from the Oly that are not your style but just for fun

All the best,

Eirik



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Beautifully haunting work, Erik!

Hi again John, and thank you.....

Not sure if this link might be helpful to you?


Just to see the Sigma lenses and hotspots.

BR

Eirik

Those are blacks and white ones on the kolari website are Nice. Kind of like Paul Caprnegro. Is it had to get a little more contrast out of them? ?

N/t?

They look nice , which filter were you using or recommend?

Terrence5050 said:

N/t?

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I started to reply to your post but then I realized that I didn't understand it so I deleted what I had written.

Terrence5050 said:

1. Ok . Thanks I was asking if I need to buy a ir cut filter to screw on the front or if just removing the filter is enough to start experimenting.

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Just removing the filter is enough to start experimenting.

Terrence5050 said:

1. Ok . Thanks I was Asking I need to buy a ir cut filter to screw on the front or if just removing the filter is enough to start experimenting.

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The Sigma "IR cut filter" is the "dust protector" that is between the sensor and the lens mount. You do not need to buy another one to put in front of the lens.

The Sigma "dust protector" is quite fragile. The sdQ/H cameras have been discontinued by Sigma, and while I have purchased a couple of extras of these "dust protectors", I do not know if they continue to be available.

Once this is removed, you are in "full spectrum" mode.

I would suggest setting the review screen/monitor to monochrome/B&W. This will make the "extra red" on the screen in color mode go away.

I can save you some pain and maybe some money.

The Quattro sensor is not so good for IR work due to the design of it (much fewer pixels in the "red" range). Suitable for purpose is my opinion, the reduced number of pixels in the lower layer(s) is fact.

So far, the sdQ seems to respond favorably with a 580nm filter, this knocks out a bunch of red before it hits the sensor. I am noticing a difference between images taken in plain full spectrum vs adding the 580nm filter.

Aftermarket "hot mirror" filters do NOT work well at all on any Sigma Foveon/Merrill/Quattro camera. The Sigma camera is essentially useless for color pictures without the OEM "dust protector". These do NOT come up on eBay often. Did I mention that these are quite fragile?

The sdQ is fantastic (again, IMO) for color to monochrome conversions within SPP.