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Messages - Sael

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I'm not going to share the STL because it doesn't have all the features for the safe use of a lens (like it locking..) but I have mounted a Sony-E to Nikon F tilt adapter to my 1.8 with a 3D printed mount. there isn't a lot of clearance but there is enough to mount as long as the lens doesn't extend too far beyond the mount.

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Chronos User Discussion / Re: Home made accessories
« on: August 05, 2019, 04:58:31 PM »
A few of the more successful home made bits. My first grip was made with some 1/16" aluminum, bent at a right angle with a few holes and a bit of cord tied on the grip. This worked well but I noticed the paint began to chip off the edges as it wasn't sturdy enough to hold the camera's weight and would flex. My second addon was a simple 3d printed picatinny rail that bolted to the two 4mm holes on top of the camera. A case of "it looks stupid but it works." It's good for following fast moving objects such as birds, as being able to track without the delay to the screen or a restricted field of view makes things much more easy. Simply set your focus, with as small an aperture as light allows for a wider field of focus, and put the dot on the thing you want to follow. Lastly an upgraded grip made from 1/4" aluminum bar and a bit of 9mm rod. much more sturdy, and included a cutout to access the backfocus screw.

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Chronos User Discussion / Re: Filming welding arc - filter necessary?
« on: October 30, 2018, 03:39:38 PM »
The green tint can be removed with some colour correction, there are plenty of articles around describing how:

https://www.diyphotography.net/use-welding-glass-as-10-stops-nd-filter/

I might look into if it's possible to do it with the in-camera white balance...

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Chronos User Discussion / Re: Filming welding arc - filter necessary?
« on: October 28, 2018, 04:26:03 PM »
A nice short article on the dangers of photographing bright objects over on PetaPixel: https://petapixel.com/2017/09/01/photos-cameras-lenses-got-destroyed-solar-eclipse/

If the light source you are directly filming is bright enough to burn things with just a magnifying glass it's best to look into protection, especially if you're expecting to be looking at it for a long period of time. I'd also think the near infrared radiation would be more of a hazard to the lens and camera than UV. Modern lenses usually have UV blocking coatings, as well as the glass itself being not very transmissive to UV. Near infrared on the otherhand will pass through and while the bandpass filter in front of the sensor will reflect most of it, it will heat anything it shines on.

Regular photographic ND filters are not designed to block near infrared, and as such are not suitable for solar photography. For this reason I wouldn't recommend using them for photographing welding either. A solar filter might work if you want more true colours, but I can't say how well they would work. Welding lenses are made for looking at welding arcs and are thus probably the best choice protection wise.

Welding shades are cheap insurance against lens and sensor damage, and not terrible to have extra of if you've got welding equipment already. A no.7 or 8 shade should be fine, it's about a 9-10 stop reduction and thus is approximately equivalent of going from F/2 to F/45 - F/64, or going from 1000μs to 2μs - 1μs exposure. If this is too dark for your needs a no.6 lens is a whole 3 stops faster, or 1000μs down to ~20μs.

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The external battery I bought is this one off of amazon:
https://www.amazon.ca/gp/product/B01BLXY3B6/

It's handled things fairly well thus far, surviving being tossed around in my work bag and multiple coffee spills.. though it appears to have gone up in price by ~100CAD since I bought it..

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Chronos User Discussion / Re: Moonlit stills, Chronos suitable?
« on: October 17, 2018, 06:36:57 PM »
@Nikon1 6 or 12dB, I don't remember... I did abuse levels correction to hide noise however, because it's a black background with a bright object you can crush the shadows and hide a lot of the lower intensity noise. Attached is an example without the crushed blacks. Nikon to c adapters and Canon to c adapters are available on ebay for ~$40-$60CAD.

@NiNeff 600mm on a ~4x crop makes for ~2400mm 35mm equivalent. "magnification" doesn't really make much sense in the photography world unless you have a reference point. Some camera lines use a times zoom, but that's relative to the widest view of the camera. The field of view of a lens is mainly dependent on the focal length and the sensor size. A 50mm lens on a 35mm "Full Frame" sensor (arguably the most common lens and format in the film days) has about a 40 degree FOV, 600mm on a full frame is about 3.4 degrees, and with the size of the sensor on the Chronos it would be about 0.85 degrees. I guess that would be 47x then? Or 4x compared to the widest the lens goes... (150mm)

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Chronos User Discussion / Re: Moonlit stills, Chronos suitable?
« on: October 17, 2018, 03:15:15 AM »
While not suitable for it, decent results can be gotten from the Chronos. Because the noise gets worse as you below 60FPS that's the lowest I went. The lens is a Tamron 150-600mm F/5-6.3. Video recorded at 600mm F/6.3, Moon at 60FPS, and mars at 500FPS.

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