Review: How to use the amazing 14 5/8 oz Globus 4"x5" Camera shell for today's photography!

Hi, Bart,

Bart_van_der_Wolf said:

Yes, that's correct. The filter is specifically matched to the lens to compensate for the vignetting / fall-off characteristics of the lens. The filter is darker in the center, and more transparent towards the corners, thus ensuring that the sensor/film gets more uniformly exposed. This prevents underexposed corners, which may otherwise get more noisy in digital systems due to a relatively low photon count.

Of course the amount of vignetting varies with aperture, whereas the fall-off is more constant due to the corner rays striking at a more oblique angle. So it is only a partial (vignetting) solution, but better than nothing.

Click to expand...

Thanks. Makes sense. I'm embarrassed I never heard of it.

On a matter of terminology, when I said "natural vignetting" I meant what is more often called "fall-off". Natural vignetting (such as the infamous cos^4 falloff) is contrasted with mechanical vignetting, optical vignetting, and sensor angle-of-incidence vignetting.

Thanks again.

Best regards,

Doug

scott bye said:

Well instead of doing all of this I would rather buy the center filter, any recommendations?

Click to expand...

Scott,

I'm not sure we're going to need a center filter. It's most important if one is stitching. Otherwise I'd first shoot and see if there's a problem. I personally like some vignetting as it gets attention to where it matters. I'll look into the choice of center filter after I see some prints.

For the folk that intend to use the camera for the Betterlight Scanning backs, one is only using ~ 65 x 85 mm or so of the film plane and the issue of vignetting is decreased. If one is using the scanning back for a panorama by rotating, (locked, the centrally placed), scanning sensor, the effect of vignetting is reported to be minimal.

Asher

How to use the amazing 14 5/8 oz Globus 4"x5" Camera shell for today's photography! R

Lets see if

Grant Kernan said:

Lets see if

Click to expand...

Let's see if... what?

CF

Lets see if this works meant I would edit my response but I timed out

BTW There is one more Globus with a JML lens available for $900. please tell the folks.

To address Scotts queries:

"To centre filter or Not to centre filter" that is the question;
I don't see a need for using a CF [centre filter] with negative material and it is not recommended with the Betterlight. This all involves the slow JML 65mm F:8 aperture.
First the large element is inside the camera and with film stopping down to F;22-32 evens out light fall off. The Betterlight is so light hungry that the filter would be counter productive.
Only 50 lenses were ever made in one batch and a CF was never specifically designed for the Globuscope4X5. Schneider makes at least three-#1 #2 #3. Various lenses use these so
if you are shooting chrome then look for something designed for this focal length & f stop. Be forewarned that this is a very different design. It will take some trial and error.
Perhaps folks have filters that you could try? Use a larger filter and a step up ring so that you don't introduce mechanical vignetting.

Next;
The GG isn't all that great. 26 years ago I threw mine out and replaced it with a plastic fresnel from Calumet. It is still going strong. Calumets is a one piece GG and Fresnel. Works perfect.
Bob Solomon talks about the Linhof problems with their plastic fresnels warping so Globus is in good company.

I used the Globus with colour neg and B&W film. I filtered with gels. My 72mm Gel holder does vignette slightly. Note the top corner of the TEE PEE.
The rest of the pics would actually look better with some darkening in the corners The 72 X 96 mm throat or scanning area of the Betterlight means that 645
Medium format lenses can be used. I have the first Globuscope sold and one of the last bodies as well. The earlier version is 26 years old and now outfitted with a Bronica ETR Bayonet mount.
My later body will be out fitted with a Mamyia 645 bayonet for use with a 1 lb 10 0z 50mm f:4 shift lens. In Pano mode the sweet spot of the lens will be used and I don't expect to see any
chromatic aberration at all. And I can use a slit lens cap to provide an excellent lens hood.


How does one post photos here?

Grant Kernan said:

How does one post photos here?

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Well Grant, it's simple. We place the pictures somewhere online. Flickr or any other online server.

Then one gets the address of that picture, (in case you have a problem, simply drag that image to a new browser window or use the command with the mouse, "open in new window" which is the same thing.

Now insert that URL between and [IMG]

So here are your 3 pictures Globuscope using a negative film and the JML lens, 160 NC.

[CENTER][IMG]http://openphotographyforums.com/2007_OPF_AK/Grant_Kernan/Andy 1.jpeg








Grant Kernan: 3 Examples of Interior Architecture Images

These are all taken with film.

Grant also has another Globuscope camera adapted to use Bronica 6 x4.5 lenses and a
BetterLight Scanning Back inserted under the ground glass for a regular 4x5 film holder.
The camera can use any standard Bronica 6x4.5 camera lens without further adaption.[/CENTER]

Grant adds that these pictures were all from a box of "rejects" from years back that he just rediscovered! The images pictures are taken with the standard JML lens and there's no retouching. The second one is a contact print. The last picture has some vignetting in the upper left corner due to the placement of a 72mm filter over the lens. So vignetting does not seem to be an issue with the JML lens.

Asher

I have no part in the sale of the Globuscope cameras. I bought two and one is a shell to add a lens with a helical lens cone and the other has the JML 65mm lens. There's one more of these available on the entire planet. Well my son and my wife recognized that that I had a new camera, (it didn't work to say, "What this? I got this from Will Thompson for $60 2 years ago, don't you remember"). They wanted to know, "Where's the rest of the camera?. That's because this is the lightest 4x5 camera ever and so small.

So if you have $900 to spare, this would be a great investment as well as a fun camera. The last one on eBay, sold for ~$1500, I believe.

It's ready to use the minute you get it.

Just need some 4x5 film holders.

Asher

A Panorama With the lightweight Globuscope and A Scanning Back!

Well, some are lucky and have scanning back for the Globuscope. Grant kindly provided this Pano: You may need to scroll to the right!







Look at the Zoomify picture here with more pictures of the regata and a related Zoomify picture here.

Asher

Hi, Asher, Grant,

Beautiful shot.

The cyan/sepia duotone is unique but effective.

Best regards,

Doug

What's very satisfying to me is that there's no stitching required and no corrections for vignetting or anything else. The stitching back is controlled by software on a mac laptop and it has the capability to really be precise in focus. The back records 43 line pair/mm!

My set up is more modest. Just the film camera and one fixed lens.

Asher

Thanks Doug,
It is actually similar to false colour science of several decades ago.

The Betterlight Scan Back usually uses an IR filter in the optical path. Here I did not use it and I did not [colour balance] to a grey before I scanned. I merely balanced afterwards to achieve the cross processed look or Duotone.

What I am trying to accomplish is to show the different possibilities with the Fearther-weight Globuscope4X5, the scan Back and film.

In the next few days I will upload some spinouts, rollouts and dragouts.

BTW I had some info wrong. Betterlight has only sold 83 panoadapters so it is a very rare piece of hardware. Betterlight will most likely make another batch, but safe to say less than 100 will eventually make there way into the world...

Grant

Grant Kernan said:

Thanks Doug,
It is actually a false colour scenario.

The Betterlight Scan Back usually uses an IR filter in the optical path. Here I did not use it and I did not [colour balance] to a grey before I scanned. I merely balanced afterwards to achieve the cross processed look or Duotone.

Click to expand...

Grant,

That's neat that the filter can be removed so easily. Now does it alter the focus, or that does not matter since you adjust on the laptop screen anyway? Also how does it change the ISO?

Asher

When one removes the IR filter, the light sensitivity jumps substantially. Flarr uses a Betterlight to shoot in caves. Fascinating!! Our eyes can't see a thing but the back can!

The focus is altered;
Although I can't see a thing...
Focus verification easily sees...works in the dark.

Daylight is similar but exposures are very short.

Grant Kernan said:

When one removes the IR filter, the light sensitivity jumps substantially. Flarr uses a Betterlight to shoot in caves. Fascinating!! Our eyes can't see a thing but the back can!

The focus is altered;
Although I can't see a thing...
Focus verification easily sees...works in the dark.

Daylight is similar but exposures are very short.

Click to expand...

It would be interesting to test it some time and find a rough numerical value by which sensitivity is increased. I guess it might make a difference indoors and outdoors and on the temperature.

Asher

Asher Kelman said:

It would be interesting to test it some time and find a rough numerical value by which sensitivity is increased. I guess it might make a difference indoors and outdoors and on the temperature.

Click to expand...

Hi Asher,

Not so much the temperature, which is usually a few hundred degrees K too low for any meaningful IR exposure contribution, but moreso the reflectivity of IR by various subject matter. Chlorophyl in green leaves reflects a lot of IR, and human skin does a good job as well, but other subject matter is transparent to IR or absorbs it very well. That's why IR exposure can be a bit of a guess and may require a few test shots and a good interpretation of the resulting histogram. Using an incandescent lightsource (a Planckian radiator) like the sun, or traditional lightbulbs, helps a lot.

Cheers,
Bart

Bart_van_der_Wolf said:

Hi Asher,

Not so much the temperature, which is usually a few hundred degrees K too low for any meaningful IR exposure contribution, but moreso the reflectivity of IR by various subject matter. Chlorophyl in green leaves reflects a lot of IR, and human skin does a good job as well, but other subject matter is transparent to IR or absorbs it very well. That's why IR exposure can be a bit of a guess and may require a few test shots and a good interpretation of the resulting histogram. Using an incandescent lightsource (a Planckian radiator) like the sun, or traditional lightbulbs, helps a lot.

Click to expand...

Bart,

What about lower energy infra red coming from our bodies. That's been toted as an entertainment but isn't that also what allows folk to be scanned to see though clothes for hidden weapons or contraband?

Asher

Asher Kelman said:

Bart,

What about lower energy infra red coming from our bodies. That's been toted as an entertainment but isn't that also what allows folk to be scanned to see though clothes for hidden weapons or contraband?

Asher

Click to expand...

Asher,

and used to show up bruising in the skin !

*

If a DSLR has the IR filter removed it would behave quite differently than just using a R72 filter on a camera set up for normal photos.
The Betterlight does not have a permanent filter built in. Instead, a 2 or 3mm IR filter is added either inside the camera behind the lens or outside on the lens-for normal photography.

Exposure is based on IR reflectance or rather how much IR is being reflected in the scene. So exposure will vary quite a lot. Also the difference in exposure from a traditional and the IR shot will also vary quite a lot.
So you can't really say 2 stops or 7 stops. At least with the scanning back the preview image is available as large as your laptop and immediately. So within a minute you can adjust several times until you are happy with the result.

Talk later
G

This really is a fascinating project!

Ben Rubinstein said:

This really is a fascinating project!

Click to expand...

Ben,

But I'm the poor one. Just film for me, at the moment It's equivalent to using a 19mm lens approx, in 35 mm terms.

Asher

Asher Kelman said:

Bart,

What about lower energy infra red coming from our bodies. That's been toted as an entertainment but isn't that also what allows folk to be scanned to see though clothes for hidden weapons or contraband?

Click to expand...

Hi Asher,

Not really. It shows the transparency of certain clothing items to IR, and the reflectivity of skin. Blood (vessels, arteries, bruises) absorbs IR more than the skin reflects (and IR penetrates the skin more than visible light), so it can be used to show superficial arteries and such in better contrast than in the spectral band visible to the unaided eye. It's all about reflection/absorption at these temperatures.

Every object with a temperature above the absolute minimum of -273.16 Kelvin does emit ('heat') radiation, but the levels are often too low for the sensitivity of common detectors (IR sensitized film (I used to sell the stuff to the scientific community some 30 years ago) and Silicon based photovoltaic sensors). It requires super cooled sensors and amplification to detect 'normal' outdoor and human body temperatures. When things heat up, let's say to that of a hot iron for clothes, then it will probably start to register as exposure at normal (fractions of a second) exposure times.

http://hyperphysics.phy-astr.gsu.edu/hbase/bbrc.html#c4 shows how little energy falls into the 350 - 1000nm wavelength band at human body temperatures, and the "Red hot" link shows that it takes an additional 600 K to start encroaching into the visible spectrum. So it takes a few hundred K above human body temperature to start registering in the 700 - 1000nm IR sensitivity band part of silicon.

BTW, the Bayer CFA is transparent to IR, so one only needs to remove the IR absorption/reflection filter to get interesting (mostly) reflected Near IR effects (as Leica with their earlier digital range finder camera found out, the hard way).

Cheers,
Bart

Hi, Bart,

Bart_van_der_Wolf said:

Every object with a temperature above the absolute minimum of -273.16 Kelvin. . .

Click to expand...

Perhaps you mean 0 K (-273.15° C).

Best regards,

Doug

Doug Kerr said:

Perhaps you mean 0 K (-273.15° C).

Click to expand...

Hi Doug,

Bingo! I shouldn't be posting this late/early. Thanks for paying attention.

BTW, I'm slightly worried about the different sources mentioning -273.15 C or -273.16 C as being equivalent to 0 K. It can't be both ... ;-)

Cheers,
Bart

Bart_van_der_Wolf said:

It requires super cooled sensors and amplification to detect 'normal' outdoor and human body temperatures. When things heat up, let's say to that of a hot iron for clothes, then it will probably start to register as exposure at normal (fractions of a second) exposure times.

Click to expand...

Thermal imagery in the human temperature range can be made with hand-held device. Here a manufacturer (there are others): http://www.raz-ir.com/. Count a few thousands dollars for one of these cameras.

Hi, Bart,

Bart_van_der_Wolf said:

Bingo! I shouldn't be posting this late/early. Thanks for paying attention.

BTW, I'm slightly worried about the different sources mentioning -273.15 C or -273.16 C as being equivalent to 0 K. It can't be both ... ;-)

Click to expand...

As near as I can tell, the current official equivalence is 0 K = -273.15 ° C, but the story is complicated, and I don't think I understand all of it.

It seems to be related to the fact that the triple point of water is +273.16 K (+0.01 ° C) but the ice point is +273.15 K (0 ° C).

I think the premise of the definition was changed in 1968.

Best regards,

Doug

This addresses Ashers calling the Betterlight a stitching back...I don't want any confusion. Especially since there are 2 shot....and .... and 16 shot Sinar stitching backs.

If the Betterlight Super 6K HS USB2 is a stitching back, then it stitched 21,598 lines together in 93.35 seconds, or in a little over a minute and a half and on the fly... then all flatbed scanners stitch on the fly too.

Actually I can take two separate images of say a painting [with the Betteright scan back] by either moving the art or moving the camera; and then I can stitch those tiled images together.

What I am saying is that the pano scans are automatic and almost immediate-requires no photoshop intervention...

Grant Kernan said:

.......

What I am saying is that the pano scans are automatic and almost immediate-requires no photoshop intervention...

Click to expand...

The sweet spot of the lens is used for each thing slice of the rotating and focused image plane that the sensor sequentially records, so there's essentially far less need for all the mathematics of blending within the Betterlight software. Pretty impressive, as long as things don't move when they shouldnt!

Asher

Hi, Asher,

Asher Kelman said:

The sweet spot of the lens is used for each thing [thin?] slice of the rotating and focused image plane that the sensor sequentially records

Click to expand...

I'm not able to visualize what operation is being spoken of here. Perhaps it was discussed earlier in the thread and I was just to lazy to find it.

Could you elucidate or give a reference to where this is described?

Thanks.

Best regards,

Doug

Hi, Grant,

Grant Kernan said:

Especially since there are 2 shot....and .... and 16 shot Sinar stitching backs.

Click to expand...

What do those do, and how?

Thanks.

Best regards,

Doug

Sinar originally (now historically) made a 6 megapixel digital back and a controlled mechanical stitching mechanism to shoot a number of overlapping images. These were tiled and made into a much larger file. So they imaged 2 shot / 4 shot / 9 shot - you get the picture?

They are ancient now...