Chroma - Lasercut Acrylic 4x5 Field Camera

[stevelmx5]

Kind of cool to have a matching cloth but since most people who have a LF will own a cloth and newbies are generally advised to start with a t-shirt I think its probably just additional cost for the user and much more work for you.

Wise words :0) I might make myself one as I don't have anything else but I have also been working on my dark cloth hoody in the background so that might make an appearance eventually!

 

[StephenM]

Since I've not ever used a LF camera - are they always necessary? Maybe have them as an optional extra you can buy with the camera?

Are they always necessary - no. Are they sometimes and with some cameras - YES. My first LF camera had a screen so dim that even indoors pointing to the outside a cloth was necessary to see the image.

Remember that LF lenses are generally slow (in 1960s 35mm terms, when f/2.8 was a slow standard lens) at f/5.6 and less. That makes for a dimmer screen. If you want to stop down and check depth of field, it will be dimmer still, but you'll generally test that with a lupe on the glass and that acts as a hood. I'll pop back and see if I can post a photo of my Wista's screen outdoors.

Focusing cloths are usually black on the inside to absorb the light, and white on the outside to reflect the heat. On a warm summer's day with the sun beating down, white is good!

See below for what the camera was pointing at.

 

[35millimetre]

Ohhh, check that out! I see what you mean now. I like the idea of a dark cloth hoodie - I'm sure some of my own hoodies are large enough for this

 

[Terrywoodenpic]

View attachment 107343

Are they always necessary - no. Are they sometimes and with some cameras - YES. My first LF camera had a screen so dim that even indoors pointing to the outside a cloth was necessary to see the image.

Remember that LF lenses are generally slow (in 1960s 35mm terms, when f/2.8 was a slow standard lens) at f/5.6 and less. That makes for a dimmer screen. If you want to stop down and check depth of field, it will be dimmer still, but you'll generally test that with a lupe on the glass and that acts as a hood. I'll pop back and see if I can post a photo of my Wista's screen outdoors.

Focusing cloths are usually black on the inside to absorb the light, and white on the outside to reflect the heat. On a warm summer's day with the sun beating down, white is good!

See below for what the camera was pointing at.

Traditional dark cloths were red and black. at least up to the 70's

 

[stevelmx5]

I haven't had any updates for the last week but I've been working on an improved design for the front standard movements and bellows. The previous version I built looked good but was a little too stiff to move and was also quite time intensive to assemble. As a result, I've re-designed the parts so that they can be layered and bolted together using M3 bolts with embedded threads. As well as simplifying/standardising the assembly, it also means that parts can be replaced easily by simply unbolting the units. The camera is essentially built out of 5 main components;

Camera bed - incorporates focusing mechanism and brackets for rear standard
Front standard - Includes lens board/pinhole lens
Rear standard
Film/Ground Glass Surround
Bellows



There's an online 360 view here if anyone wants a closer look;

http://a360.co/2wE39tX

There are various light seals and baffles built in to the front/rear standards, these will also be laser cut at the same time as the rest of the materials. Having the front standard and main camera bed assembled using bolts means that in the event of any damage, individual components can be replaced or even individual layers of those components which means repairs are quick and seamless. Intrepid offer a comprehensive warranty with their 4x5 which I think is a good model to follow. The assembled unit is strong but if someone drops it off a tripod or throws it down a cliff, it's not going to survive because building a camera that's light, bulletproof and cost effective is a tall order! By having individual parts, the actual cost of the repair will come down to the price of a sheet of acrylic and a few minutes cutting time. I'm not planning on holding repair parts to stock so having a quick turnaround on repairs is crucial.

I've got all of my materials except for the M3 thread inserts which I'm waiting for. Once they arrive I'll be assembling the new design and I reckon it's going to look even more different to traditional cameras than my Purple/Orange one does...

 

[35millimetre]

Great progress Steve!

 

[stevelmx5]

I forgot to ask, would there be any benefit in offering two different front standards for the campaign? My original design used a more traditional/simple standard which basically relies on a pair of locking bolts to both hold the lens in position and provide the pivot points for rise/fall and tilt adjustments (like an Intrepid). However, my evolved design is a technical standard so each of the movements are individually controlled and locked. For me, I wanted the most control possible and a traditional simplified standard offers more chance of the photographer adjusting the tilt when changing rise/fall and vice versa as the same two bolts locks both sets of movements.

The simplified standard is considerably more simple to manufacture and assemble so would mean less material and my time. Any thoughts/preferences on whether I should offer both options or just focus on the technical standard?

 

[stevelmx5]

Traditional/Simplified Standard

First assembly by Steve Lloyd, on Flickr

 

[stevelmx5]

Technical Standard

 

[Andysnap]

Technical Standard

View attachment 107905

Bloody Hell Steve, that looks amazing.

 

[stevelmx5]

Bloody Hell Steve, that looks amazing.

Thanks Andy [emoji1303]

 

[Steve Smith]

Are you willing to share your files for those of us who might have a laser cutter?


Steve.

 

[StephenM]

It depends a lot on your target market. Leaving cost and complexity out of it, the advantage of having two independent locks is that it's simpler to adjust, and less to go wrong when setting up. This could be of help to a beginner, who might not realise immediately why the focus isn't "square" when using rise and fall. One lock is rather like a ball and socket tripod head - total freedom to unset everything when making a small adjustment. Some people swear by ball and socket heads, and others (like me) hate them, preferring three way or geared heads. I suspect that this depends a lot on what they photograph. The advantage of a single lock is that it could be quicker to set up - in theory. In practice, adjusting tilt is simpler if it's the only thing that's being adjusted. It could be frustrating under the dark cloth to find that painstakingly getting the tilt right has adjusted the rise/fall, and readjusting that puts the tilt out. Iterate ad infinitum...

 

[Woodsy]

That's looking awesome mate, really impressed with this. While I've not posted much, I've learnt quite a bit from this process!

 

[stevelmx5]

Are you willing to share your files for those of us who might have a laser cutter?

Steve.

Hi Steve. Sorry, but at the moment I'm going to keep the files just for myself until I get the Kickstarter campaign up and running.

It depends a lot on your target market. Leaving cost and complexity out of it, the advantage of having two independent locks is that it's simpler to adjust, and less to go wrong when setting up. This could be of help to a beginner, who might not realise immediately why the focus isn't "square" when using rise and fall. One lock is rather like a ball and socket tripod head - total freedom to unset everything when making a small adjustment. Some people swear by ball and socket heads, and others (like me) hate them, preferring three way or geared heads. I suspect that this depends a lot on what they photograph. The advantage of a single lock is that it could be quicker to set up - in theory. In practice, adjusting tilt is simpler if it's the only thing that's being adjusted. It could be frustrating under the dark cloth to find that painstakingly getting the tilt right has adjusted the rise/fall, and readjusting that puts the tilt out. Iterate ad infinitum...

Thanks Stephen. Those were my thoughts too. LF photography can be enough of a step up in frustration and complexity without the hardware adding it's own problems! I think I'm going to continue to focus on the technical standard only and maybe look to add the option for a simplified standard down the line. The camera is completely modular anyway so the front/rear standards can be swapped easily so I may look to add rear movements one day too.

That's looking awesome mate, really impressed with this. While I've not posted much, I've learnt quite a bit from this process!

Cheers bud. My Chroma is the opposite end of the scale to your Ebony in cost/materials so it's good to see that you like the look of it :0) I'm learning new things every day (good and bad!) throughout the process too.

 

[stevelmx5]

I've just picked up my shutter from the Post Office. Miles Whitehead has managed to get it up and running again so I've now got a functioning Angulon 90/6.8 ready to go :0)

 

[stevelmx5]

I can't wait to....see....the next version assembled ;0)

If I can make this version light tight, anything else will be simple!

 

[RaglanSurf]

For the launch version I'd be inclined to go for the simplified version, once you've got it up and running maybe you could offer a technical standard as a model option or even as an optional extra if that's possible.

Forgive me if this is already the case as it's a little hard to tell from the photos but I'd like the ability to swap lenses without moving the position of the front standard, so separate locking mechanism for the lens board and the front standard. .

 

[stevelmx5]

For the launch version I'd be inclined to go for the simplified version, once you've got it up and running maybe you could offer a technical standard as a model option or even as an optional extra if that's possible.

Forgive me if this is already the case as it's a little hard to tell from the photos but I'd like the ability to swap lenses without moving the position of the front standard, so separate locking mechanism for the lens board and the front standard. .

Thanks for the advice Nick. I've drawn up the simplified standard as a separate piece for now (at the moment, the entire camera is cut from 1 sheet of 3mm and 1 sheet of 5mm Acrylic along with seals etc) and will look at the cost difference.

The lens board is locked in place using a separate magnetic catch so the front standard will stay locked in place when swapping.

 

[stevelmx5]

Sorry about the poor joke in my last post about "seeing" my new build..



I figured that the best test for my various light seals would be to build a transparent camera ;0)

I'm also going for black bellows this time



(One of the card ribs sections had a problem when I was cutting it last night so had to be substituted for a thinner material that we had to hand)



I'm going to have to build a former for my next set so I look less like an angry octopus trying to line everything up when it's got spray adhesive so wants to stick together everywhere but the right place!

Now I'm waiting for the adhesive to dry before I fold this one. I've redrawn the ribs from scratch using a different design so I'm hoping it will give me more flexibility.

 

[stevelmx5]

Yay....another set of bellows that don't work how I want them to

Annoyingly, I think the first set I made were the correct design, just a little too short. The biggest difference is the material so I'm trying to find a supplier for the material used to make changing bags (which is what my first set was made from). I'm waiting to hear back from a couple of Chinese suppliers so fingers' crossed.

 

[trevorbray]

I'm sure every genius has been thwarted at some point. Head down, press on.

 

[stevelmx5]

I'm sure every genius has been thwarted at some point. Head down, press on.

Thanks for the reassurance Trevor. I seem to get one part that I'm happy with then another one winds me up! I'm not overly impressed with the quality of the cuts on my clear acrylic though either. If I hadn't cut other piece ok I'd have blamed the laser cutter but I think the acrylic is just a lower quality than the purple I've used before.

 

[Nod]

Could it be that the clear acrylic simply doesn't absorb enough of the laser energy to cut as cleanly as the tinted stuff?

 

[robhooley167]

Could it be that the clear acrylic simply doesn't absorb enough of the laser energy to cut as cleanly as the tinted stuff?

Certainly equally likely

 

[stevelmx5]

Whatever the reason, I'm not going to be offering a translucent option going forwards ;0)

 

[Steve Smith]

Whatever the reason, I'm not going to be offering a translucent option going forwards ;0)

I have also found that our white and black acrylic cuts better than clear. It cuts cleanly, whereas clear leaves a bit of a liquid residue.

Could it be that the clear acrylic simply doesn't absorb enough of the laser energy to cut as cleanly as the tinted stuff?

It seems to need the same power and speed settings, so marginal at best.


If you want to make a clear camera, you can use my transparent test bellows!

http://stevesmithphoto.webs.com/bellows.html (last picture).


Steve.

 

[stevelmx5]

I have also found that our white and black acrylic cuts better than clear. It cuts cleanly, whereas clear laves a bit of a liquid residue.

If you want to make a clear camera, you can use my transparent test bellows!

http://stevesmithphoto.webs.com/bellows.html (last picture).


Steve.

Thanks, I'm glad it's not just me imagining that the clear didn't cut as well.

I like the clear bellows, not sure even my light seals could help there though ;0)

 

[Nod]

Whatever the reason, I'm not going to be offering a translucent option going forwards ;0)

But as a sales tool to show the innards... ;0

 

[stevelmx5]

But as a sales tool to show the innards... ;0

You read my mind :0)

 

[Nod]

You have one? !!!!!

 

[stevelmx5]

You have one? !!!!!

I didn't say it was a complete and sane mind...

 

[stevelmx5]

Ok, after building another set of bellows to add to my growing pile of tests, I 'think' I've nailed the issue I had and have re-drawn the ribs again. The front face of the bellows I've built previously was slightly too long in one direction for the plate that mounts to the back of the front standard so I was never happy. Having got my head around the effect of various shaped ribs, I've settled on a simpler style which should give more flexibility and look neater too.

This is the latest test run. Not light tight but the ripstop nylon was what I had to hand and I was more interested in the design than function...although this one is in the bin now!



I've also come up with an idea for the internal blackout layer which should add pretty much no additional thickness or weight to the external ripstop. I need to speak to a friend of mine about the idea tomorrow but could be on to something...fingers' crossed!

 

[stevelmx5]

Oh, I've also started the assembly on my transparent parts. Apart from having to tidy up some of the holes I think it will look pretty awesome :0)

 

[stevelmx5]

As a sneak preview, this is the inner face of the rotating back, looking backwards from the lens, showing the various closed cell foam light seals and 2mm black Acrylic mounting plates that secure the back in place. There is also an adhesive vinyl seal that is fitted to the inner faces of the rectangular film gate to block any stray light from the side. The black surround is the rear bellows plate that will be bonded to the bellows then secured to the rear standard of the camera.



This is how the transparent ground glass holder will look too. I still need to embed the magnets (and the glass of course!) but I like how the logo stands out with the black background.

 

[RaglanSurf]

Personally Steve I don't think you should be putting these trials in the bin, they should be stored carefully and form part of the Chroma museum.

 

[stevelmx5]

Personally Steve I don't think you should be putting these trials in the bin, they should be stored carefully and form part of the Chroma museum.

Thanks Nick, I'll keep them numbered and boxed for future generations :0) To be fair, it was only that one that I've binned because I assembled/glued it then separated part of it again when I realised the better shape for the ribs so cut those and stuck it back together again so it already looked rough. After that, I started thinking about the blackout layer and separated it again so I could try spraying a coat of Plastidip onto the back (rubberised paint) to see if it went through the nylon outer...it did. I don't reckon anyone would want to see that one in the museum :0)

 

[35millimetre]

Plastidip - it covers all mistakes! Funnily enough, I was talking to a colleague yesterday about just that - dipping motorbike panels in it. Shame it peels off so easily, as it gives an interesting matte finish.

 

[stevelmx5]

Plastidip - it covers all mistakes! Funnily enough, I was talking to a colleague yesterday about just that - dipping motorbike panels in it. Shame it peels off so easily, as it gives an interesting matte finish.

It only peels off if you actively try to lift it. It even works on custom turntables..



https://flickr.com/photos/8476499@N02/sets/72157676042545045

 

[35millimetre]

That looks good! I suppose with bikes, there's a bit more danger of a knock or scratch.