Adapters rms to 42x1mm

Tesselator · Post by **Tesselator** » Sat Jun 12, 2010 11:04 pm

So, umm, Hmmm, Why not just spay the inside of that cone (and the back of the flat adaptor) with just some flat black primer (rough cheap spray paint)? What will the differences be in terms of actual image quality? Anything humanly detectable?

Planapo · Post by **Planapo** » Sun Jun 13, 2010 2:22 am

Tesselator,

I think the answer is that most of us simply haven't found a matte black paint that is as non-reflective as these velvety flocking materials.
So yes, a difference can already be perceived by human eye when looking through the tubes and bellows of one's set-up from the position where the camera would be attached.

--Betty

ChrisLilley · Post by **ChrisLilley** » Sun Jun 13, 2010 3:13 am

Tesselator wrote:So, umm, Hmmm, Why not just spay the inside of that cone (and the back of the flat adaptor) with just some flat black primer (rough cheap spray paint)? What will the differences be in terms of actual image quality? Anything humanly detectable?

I spent yesterday applying light trap flocking to the inside of my lens hoods. I wish now that I had taken a photo of a half-completed one, as it would illustrate this perfectly.

The insides are very noticeably blacker, at all light angles; matt black paint looks between dark grey and light grey depending on the light angle, under the same conditions.

Craig Gerard · Post by **Craig Gerard** » Sun Jun 13, 2010 4:12 am

There is a good comparison of Protostar Flocked Light Trap and flat, black paint on the Protostar website (top of page):
http://www.fpi-protostar.com/flock.htm

Craig

rjlittlefield · Post by **rjlittlefield** » Sun Jun 13, 2010 9:50 am

One of the standard treatments for telescope tubes used to be coat with glue, then with sawdust, then when dry, spray with a thin coat of flat black paint.

The purpose of the sawdust was to create a bunch of small baffles that would only reflect off their tops, which comprise a small fraction of the area.

This Protostar material does the same thing with fibers. I suspect that for grazing light it's not a lot better than sawdust and black paint, or certainly than well machined baffles with knife edges. But it sure is a lot easier to work with!

--Rik

Tesselator · Post by **Tesselator** » Sun Jun 13, 2010 10:24 am

Hehe,

Well, I'm the cheap guy so I would probably use the sawdust.

But that's not really my question. I mean sure, I SEE the difference in the tubes and all. My question is more n00bish than that however. How much does this tube light difference actually affect the photograph? The final result... including everything we know how to do in PH and ACR, etc. Are the differences actually noticeable? Or is it more of an anal thing where the thinking is: "Every little bit helps"?

elf · Post by **elf** » Sun Jun 13, 2010 10:45 am

It's actually rather easy to test the effectiveness, just remove the camera from the bellows and peer inside the bellows. Any light hitting the adaptor(s) or the bellows material needs to be blocked or contrast will be diminished. My JML lens was unusable until covering the adaptor with ProtoStar flocking.

rjlittlefield · Post by **rjlittlefield** » Sun Jun 13, 2010 10:53 am

Yes, the differences are noticeable, and they are not always fixable in post-processing. To a zeroeth approximation, the effect of flare is simply to add light to every pixel. That cuts contrast but leaves noise intact, so while in theory you could restore contrast by curves adjustment, doing that enhances noise in the shadows. The more severe problem is that when flare comes from reflections in tubes, it is usually non-uniform across the frame so you can't back it out with a simple adjustment. The problem is intractable even in theory because the pattern of added light depends mostly on environment that is outside the frame and thus unknown.

Far better to just kill the reflections than try to get rid of their effects in post.

--Rik

Tesselator · Post by **Tesselator** » Sun Jun 13, 2010 11:59 am

Well having just purchased a new camera for myself (The GH1) I'm certainly familiar with the differences between the relative low contrast of my old Minolta A2 as compared to the new one. <hopes no one notices how blatantly the boast was executed> As well as what that means in terms of both processing steps and image detail. Noise actually works out being about the same by the end but difference in image detail is fairly dramatic, yes. OK, so I think I understand. Thanks guys!

Another question. In my retirement I've recently taken to repairing lenses for extra cash. I've got six done so far out of 8 total orders (in the first 12 days YAY!) and just about all of them have a black matt finish on the seats an tubes. Does anyone think it might be worth while offering a service or developing a technique that darkens the finish and/or reduces it's reflectivity? Most of the surfaces wouldn't be that hard as mostly I find I must remove all of the elements and completely disassemble the lens anyway.

Any opinions?

OzRay · Post by **OzRay** » Mon Jun 14, 2010 1:40 am

I can honestly say that the Protostar material makes an enormous difference; it's almost like turning a light off in the tube. It's also an absolute mongrel to install, but once done, you simply don't regret doing so.

Cheers

Ray

Tesselator · Post by **Tesselator** » Wed Jul 07, 2010 10:47 pm

OK, ordered and received mine. Seems to be fairly OK on the construction grade end of things. I took a few sample shots hand-held of things just sitting around on my desktop. I got both of the adapters. Both are full frame on an M43 camera with the 8 or 10 objectives I've tried so far. That's cool... I thought for sure the flat one at least wouldn't be.

Next up is to do some flocking I guess.

Anyone know if other materials can be used? How about valuer or felt? Or even either part of velcro magic tape?

.

Tesselator · Post by **Tesselator** » Tue Jul 27, 2010 4:12 am

Thanks OzRay! I'm having fun with mine... just handheld:

http://tesselator.gpmod.com/Images/_Ima ... Objective/

No flocking yet though. Honestly, I don't see the need. Maybe at higher magnifications?

More (posted) here: http://www.photomacrography.net/forum/v ... hp?p=64323

.

OzRay · Post by **OzRay** » Tue Jul 27, 2010 1:58 pm

Looks good. Hard to say when the flocking is at its the most effective, but it's probably all incremental improvements to image quality. The flocking just takes out one negative element.

Cheers

Ray

Tesselator · Post by **Tesselator** » Tue Jul 27, 2010 2:10 pm

OzRay wrote:Looks good. Hard to say when the flocking is at its the most effective, but it's probably all incremental improvements to image quality. The flocking just takes out one negative element.

Cheers

Ray

Thanks! Here's a butterfly wing hand-held with a Nikon 20:

It actually starts to become a little difficult to hand-hold at 20.

Craig Gerard · Post by **Craig Gerard** » Thu Jul 29, 2010 1:07 am

It actually starts to become a little difficult to hand-hold at 20.

Yeah; but worth it!

I particularly like the wing@20x and image #2.

Looking at this set, there does not appear to be much of a need for flocking; but if you do decide to flock, probably best if you go with a material designed for use with optical gear - like ProtoStar. Alternatives may shed particles, collect dust, etc.

Craig