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View Full Version : "Sky Bow" -- Chinese 4x5 rangefinder



aly324
26-Jun-2019, 06:57
There was a brief thread (https://www.largeformatphotography.info/forum/archive/index.php/t-126276.html) here about the pinhole successor to the Sky Bow (or Celestial Bow...) that mentions the latter. The Sky Bow was distributed by Kangrinpoche but is now discontinued. Otherwise there's also not much on the camera aside from one thread (https://forum.xitek.com/thread-859660-1-1-1.html) on Xitek.

I recently picked up a used copy of this camera with an Apo-Symmar 120mm attached, and wanted to share some photos and a preliminary impression of it. First, I must admit I am brand-new to LF and haven't used or even held any view camera. So if anything below sounds naive or inexperienced please correct me.

I previously used several medium format roll film rangefinders (Mamiya 6/7, GF670, etc.) and was looking to replicate that experience in a larger format. With a Grafmatic 6-sheet back, the Sky Bow works surprisingly well for this purpose. The body itself weighs about 670 grams, so the whole set-up (with lens and Grafmatic back) is a quite manageable 1.4 kg. The previous user must have tuned the cam for the lens, because as far as I can tell it is very accurate (judging from my slides and the ground glass). I also bought a cam for 135mm and intend to switch in my Planar 135/3.5 later. We'll see how well that works, but Kangrinpoche tells me they are willing to help me fine-tune RF next time I am in Guangzhou. They still sell cams for 90, 127, 135, and 150mm.

I don't have a Chamonix Saber to compare it to, but I have handled the Polaroid camera that the Saber is based on. It's certainly smaller and lighter, but the focusing mechanism is not as smooth. With the Sky Bow you can cock, focus, and release all with your left hand in one fluid motion, and indeed the camera is intended to be used this way. (I have removed the a pictured release cable, custom-installed by the previous user.) The tensions in the hinges can be adjusted with hex keys simply if focusing is too tight or becomes too loose over time.

There's also the possibility to switch lenses and cams, which is not possible on the Saber, although switching cams requires a hex tool and infinity alignment and may be impractical on the fly. With the bellows fully retracted, you can lock the base arms solidly by pushing the sides forward. In this mode it may be possible to zone-focus a wide angle lens with a helicoid reasonably accurately. Or one can use the bellows and focus using your own markings on the pie-shaped cam. I have a 75mm on the way to experiment with.

Construction is decent, with a few points of weakness and some unavoidably primitive and skimpy parts. The front standard has a bit of play both front-back and left-right rotationally, but only if you force it. Used with care it doesn't seem to affect focus accuracy appreciably. The RF patch is bright and clear, but is covered by cheap uncoated plastic. RF coupling is done with an engraved pie-shaped cam that rotates with an arm connected to the front standard. The arm is probably a weak point. We'll see how it holds up.

The bellows extend to approximately 18cm. The cam as it is now is coupled with the 120mm lens down to 1.2m or so, but the RF patch can focus closer--if one had to patience and means to grind the cam accordingly.

The camera body and especially the "bow" are curious looking and attention-grabbing for street photography, but overall I think it's rather pleasing. It is quite an impressive product, considering (from what I gather) it was essentially designed and produced by a single individual (though distributed by Kangrinpoche).

Tin Can
26-Jun-2019, 07:33
Needs to be put back in production.

I want one!

aly324
26-Jun-2019, 07:43
There was even an 8x10 version (2.2kg body only) planned but never produced.

I suspect if people write enough emails to Kangrinpoche this can be revived. As far as I can tell few people outside China even knew about the Sky Bow.

Tin Can
26-Jun-2019, 07:50
Will do. I have a number of their products I like.

I also notice some things are shipping very quickly from China.

aly324
26-Jun-2019, 08:00
Also I should note that it was priced only at CNY 4380 or so when it came out, about USD 640 at current exchange rates.

EdSawyer
26-Jun-2019, 08:16
How do you focus? just push the front standard in and out?

I have a Saber, it's a nice camera no doubt. the lack of changing lenses/cams is a minor drawback. It's too bad both of these are out of production now. What's the RF baselength on the Skybow?

-Ed

aly324
26-Jun-2019, 08:21
How do you focus? just push the front standard in and out?

I have a Saber, it's a nice camera no doubt. the lack of changing lenses/cams is a minor drawback. It's too bad both of these are out of production now. What's the RF baselength on the Skybow?

-Ed

Hi Ed, I am not sure about the base length. How do you measure it?

Focusing indeed is done by directly pushing and pulling the front standard. Once in focus you release with your left index finger. One single fluid motion.

I was in touch with Chamonix recently and they said they will do another batch of the Saber if they get enough demand (and deposits).

fuegocito
26-Jun-2019, 14:44
From what I understand, both the Chamonix Sabre and the Sky Bow are sort of on based on the Polaroid 250, but with the finder fixed in place, instead of folding down to fit into its clamp shell. So essentially about the same RF base length and framing like the 250.

aly324
27-Jun-2019, 02:22
The Saber recycles the Polaroid 250's (and other similar models') rangefinder (reputedly made with Zeiss optics) and frame and folding mechanism.

The Sky Bow is entirely a new construction except for the rangefinder, which Kangrinpoche tells me uses a part purchased from a Chinese rangefinder camera called the Phoenix, with a base length of 120mm (this is the figure a Kangrinpoche rep gave me... but does 120mm seem too long?). From what I remember from the 250 I had, the Sky Bow's RF is clearer and with a larger and brighter focus patch. As it is implemented on the Sky Bow, the rangefinder is moved by a rotating pie-shaped cam, so you get another dimension of movement and more precise control than the linear movement of the Polaroid 250's RF. The latter requires shimming lenses that aren't close to the focal lengths it's designed for and at any rate cannot go below 120 and above 150.

europanorama
27-Jun-2019, 08:28
i am in contact with 3s-krpc on ebay. they are currently designing new cameras but we must have patience he told.the cosmic circle e.g will have 58-65mm options. pinhole seems 62mm. he will confirm. NEW: pinhole shutter is now universal-removable 18-20mm plates possible-80 usd. i will get a cam soon. will order 65mm helicoid if not that expensive.
Some aspects i see here and on the second thread are new to me. i have save all data some years ago from ebay.
Pls check: when seeing one of his products do you have also difficulties to see his items. it seems CN-authorities have blocked that. only available by googling. other HK-sellers also affected. i am in europe- CH.
NB: we have some new ideas for a special 4x5-cam. If he allows we will discuss it here.
They have multiple brands.

aly324
27-Jun-2019, 08:50
i am in contact with 3s-krpc on ebay. they are currently designing new cameras but we must have patience he told.the cosmic circle e.g will have 58-65mm options. pinhole seems 62mm. he will confirm. NEW: pinhole shutter is now universal-removable 18-20mm plates possible-80 usd. i will get a cam soon. will order 65mm helicoid if not that expensive.
Some aspects i see here and on the second thread are new to me. i have save all data some years ago from ebay.
Pls check: when seeing one of his products do you have also difficulties to see his items. it seems CN-authorities have blocked that. only available by googling. other HK-sellers also affected. i am in europe- CH.
NB: we have some new ideas for a special 4x5-cam. If he allows we will discuss it here.
They have multiple brands.

I think the "Cosmic Circle" options you're referring to (the subject of this thread (https://www.largeformatphotography.info/forum/showthread.php?126276-New-compact-4x5-camera-from-China/page5)) have been available on Taobao in China for a while. 58mm and 65mm go straight on. Above 65mm you use a helicoid.

Or do you mean there're newer designs than these?

The taobao link for the body is here: https://item.taobao.com/item.htm?spm=a1z10.5-c.w4002-12620324511.33.14276cd8Px2Qj2&id=545342957570

I don't believe Taobao is censored by the Chinese government but I'm not sure what you mean by "blocking."

Tin Can
27-Jun-2019, 08:59
I just looked at every item offered by Kangrinpoche on USA eBay. 152 items. Only 2 products interested me at this moment and I already have both.

On other eBays they offer more variety.