The Colour Purple, by Epson

[ZorkiKat]

I had been shooting an actor's profile this afternoon with a Canon 350 DSLR and an Epson R-D1s. Lighting was with studio strobes. Both cameras were
set at ISO 200, and both had vintage, adapted screw-mount 50mm lenses: an M42 Meyer Oreston on the Canon and a late, coated LTM39 Industar 10 on the Epson.

The shoot went smoothly, "chimping" with both cameras revealed what looked to be similar-looking pictures. The exposure settings were the same on both cameras.

Viewing the same on a computer monitor seemed to confirm what the camera LCDs were saying all along. It was hard to tell which camera made which pictures- until the model noticed something different in the Epson set. He noticed that his tanktop looked purple. Checking the same set of photos shot with the Canon revealed that the shirt (as well as his jeans) were indeed black.

In another set, the subject wore a black pin-striped shirt with matching striped hat. The shirt also turned purple, but the had remained black. A black gobo (with skin of black synthetic silk) seen on the background also recorded as purple in the Epson shots. The Jupiter-8 lens used in this photo was from 1977.

The tanktop and the shirt which the subject wore, as well as the studio flat were definitely synthetics- rayon or similar. The hat and the jeans were likely naturals and recorded as black or neutral grey.

Jay

 

[Joe Mondello]

This is a sensitivity to IR. This has caused a huge ruckus for Leica M8 owners.

Check out this web page . . .

http://www.underexposure.com/index.php?page=irtest

It may have to do with RF camera design parameters and how thick the IR filter can be in them.

 

[jlw]

Congratulations, you've discovered one way in which the R-D is nearly a match for the Leica M8!

We've discussed previously that the R-D occasionally falls prey to a milder form of the M8's infrared transmission color casting, but you've produced a clearer example than most. Looks like an IR-blocking filter would be a good investment for you.

I've sometimes wondered whether "vintage" lenses in general and/or FSU lenses in particular might have more infrared transmission than more-current designs; if so, this could help explain why some R-D 1 users have seen this effect more than others. Your strobes and studio flat seem to provide a nice, controllable situation for evoking this effect; maybe if you get a chance to shoot it with some later lenses on the R-D, you could post the results...?

 

[JonasYip]

I've sometimes wondered whether "vintage" lenses in general and/or FSU lenses in particular might have more infrared transmission than more-current designs; if so, this could help explain why some R-D 1 users have seen this effect more than others.

When I did my IR test (i.e. the link given in Joe's post) I was using the latest pre-ASPH 50 'lux, which I assume is fairly recent, or at least not 'vintage'. I did not test different lenses... that could be interesting. I could compare it with a Summitar and J-8.

Like ZorkiKat, however, I was also using studio lighting (Dynalite).... maybe these are particularly IR heavy? In general usage the IR sensitivity hasn't really been a problem, certainly not like what I've seen from the M8...

j

 

[lZr]

I am not convinced. Industar and J-8 lens are coated for film exposures and not for digital sensor. Before going so far, need to check the coatings more carefully.
Not fair comparison, but with your knowledge about, the problem exist. I also understand that Leica will not accuse us for using those Russian lenses.

 

[rvaubel]

When I did my IR test (i.e. the link given in Joe's post) I was using the latest pre-ASPH 50 'lux, which I assume is fairly recent, or at least not 'vintage'. I did not test different lenses... that could be interesting. I could compare it with a Summitar and J-8.

Like ZorkiKat, however, I was also using studio lighting (Dynalite).... maybe these are particularly IR heavy? In general usage the IR sensitivity hasn't really been a problem, certainly not like what I've seen from the M8...

j

It's not the lens coating. It's the lights + the RD1 . There is nothing wrong with the Dynalites but a studio condition with the fabrics you are using highlights the Epson RD1 problem. It is a lot harder to see this in mixed lighting conditions or daylight but it IS there. I use a Heliopan UV/IR filter when required which isn't often with the RD1. But it looks like the m8 will require the filters just about always. Darn.

Rex

 

[Ben Z]

30 seconds only half-trying. Another minute and I'd of had it perfect. No IR filters needed.

 

[Sailor Ted]

Ben,
Please do share your 30 second work around for this issue.

Thanks,
Ted

 

[JonasYip]

It's not the lens coating. It's the lights + the RD1 . There is nothing wrong with the Dynalites but a studio condition with the fabrics you are using highlights the Epson RD1 problem.

Well yeah, i specifically chose those conditions for my test to highlight the effect. I actually never use the R-D1 in studio conditions like that.

But someone was wondering about lenses of different vintage, which could be an interesting test, even if the end result is that it *doesn't* make a difference. I'm not actually planning on performing said test, however...

j

 

[rvaubel]

..............Well yeah, i specifically chose those conditions for my test to highlight the effect. I actually never use the R-D1 in studio conditions like that.

quote]

I kinda figured you did. The shoot was just too perfect to be an accident.

But I'm g;ad you did because I've never took the time to document the condition as well as you. I've known it was there but it was so subtle in average conditions that I stopped using the IR filters that I had been using. Anyway, as Ben Z has shown, a little PP takes care of the problem when required.

To bad the M8's problem isn't as docile.

Rex

 

[jlw]

Ben,
Please do share your 30 second work around for this issue.

Thanks,
Ted

I'm not sure how Ben is doing his, but my quick fix (see attachment) involves the following Photoshop steps:

-- Use Select > Color Range to select just the problem area with as little surrounding area as possible.

-- Create a Hue adjustment layer and, using the color range pop-up, reduce the saturation and lightness of the Reds and Magentas ranges until the area looks neutral. One advantage of using an adjustment layer instead of the regular Image > Adjustments > Hue/Saturation dialog is that you can then go back and paint on the layer mask to remove any "spill" adjustment that may have gotten into areas that legitimately have a magenta cast (such as the shadow side of the model's face.)

One problem with this approach is that if you don't have a comparison image from another camera, as we do here, it can be hard to know how much adjustment to apply. Also, if there are objects in the scene that are supposed to be dark magenta in color, it may be hard to know which objects need correction and which not! Plus, of course, the problem that if you've got 250 shots in your "take," even a 30-second fix is going to take upwards of two hours to apply to every shot! So, in some cases, that IR-cut filter might be a better option...

 

[nemjo]

I'm affraid, all that IR issue doesn't belong to DRFs only.
It's rather a sensor than camera problem. The picture attached is made by an Oly300, and believe me, the background was intended to be black. The lightning was the window...
AFAIK the Oly uses Kodak sensor, just like Epson and Leica.
As I have a Nikon dSLR, I plan to remake this installation - but only next year.

Despite all the colorshifts, Happy New Year,

nemjo

 

[ampguy]

you're correct

you're correct

a few weeks ago I reviewed an IR wedding photography book in my photoblog, where the author mentions this issue with his dedicated (modified) IR digital cameras which he uses for wedding photography (75% of his clients order IR prints from him). For him, it was a simple photoshop fix for the synthetic tux wearers.

I'm affraid, all that IR issue doesn't belong to DRFs only.
It's rather a sensor than camera problem. The picture attached is made by an Oly300, and believe me, the background was intended to be black. The lightning was the window...
AFAIK the Oly uses Kodak sensor, just like Epson and Leica.
As I have a Nikon dSLR, I plan to remake this installation - but only next year.

Despite all the colorshifts, Happy New Year,

nemjo

 

[ZorkiKat]

One of digital's attractions for me was its ability to shoot IR painlessly. In fact I was fairly disappointed to discover that my first digicam (a Canon G3 4 years ago) had lower IR response than its elder brethren. The camera built into my Nokia phone does better in IR photography if an IR filter is held over its lens.

Each newer generation of digicam- P&S or DSLRs appears to have less and less of IR sensitivity than the previous batch. My Fuji pro S2 can shoot IR better than my Canon 300D or 350D. I have heard that the older Canon DSLRs (eg D30 or D60) have more sensitivity to IR compared to the current crop. In contrast, the 350D is almost blind to IR. Even when set at ISO 1600, it will only expose through an R72 filter if exposure is around 1 to 2 secs under bright sunlight.

The RD-1 sensor seems to share the IR characteristics of sensors from around 2002-2003. Leica's sensor, though new, did not follow the trend of using higher IR-cut filters.

Jay

 

[Ben Z]

Ben,
Please do share your 30 second work around for this issue.

Thanks,
Ted

Well I'm a novice Photoshopper but what I do is to right-click the lasso tool which lets me select one called "magnetic lasso", and with a little practice it makes it easy to outline whatever area you want. Then I either play with the sliders in color balance or else desaturate and adjust contrast to taste and whatever was inside the lassod area turns black.

For a shot where there was a lot of different non-contiguous areas that need correcting it would have to be done separately for each one

Honestly I think an IR filter would be my preference if I knew I was going to shoot something that would go magenta, but that might entail buying one filter in the largest size I need and a couple of stepdown adaptors, not putting one on every lens. And even if someone will put one on every lens it's good to have a Photoshop routine--no matter how kludgy--so that the filter could be removed in a situation where it was likely to cause flare. I'd rather have to try and deal with magenta in Photoshop than flare

 

[Gabriel M.A.]

I am not convinced.

Ah, the skeptic.

OK, I'll play Devil's Avocado too:

Are you human, Jay? How can we be sure you're not some highly clever Lisa-style program which has the latest advances in Artificial Intelligence?

After all, it's magenta that I see and not purple. You must not be human. I'd check your algorithm more carefully.

:angel:

-------------------------

Seriously: you could deal with this with some proper color profiling, and not having to invest in hundreds of dollars in filters. I just don't know if anybody's worked out a proper RD-1 color profile just like one for the M8 already has.

 

[ZorkiKat]

Are you human, Jay? How can we be sure you're not some highly clever Lisa-style program which has the latest advances in Artificial Intelligence?

After all, it's magenta that I see and not purple. You must not be human. I'd check your algorithm more carefully.
QUOTE]


As far as I know, I'm human People who met me during the EB of the RFfers here in Manila would probably say the same too...

 

[Didier]

30 seconds only half-trying. Another minute and I'd of had it perfect. No IR filters needed.

I guess in the RAW converter it could be done even faster...
Didier