Some park pics on a cloudy day

[Nate]

I've been making a new filter arrangement that has my Antilia venus 1.25in.  inside the helicoid, with a ZWB1 2mm in front of the EL Nikkor 80 while it's been raining for a week. Decided I needed a 3inch tube hood with black felt on the inside for this setup because without it looked like there was a hotspot in the center without it. 

 

I tested for IR and visible leaks the only means I have. For IR, I did various torches and needed at least 15 sec to see a faint LED glow, also plopped a 590nm on it with a brighter day and at 13sec saw a little bit, but couldn't make out the scene. For visible, well just looked through my windshield from inside car and needed at least 15 sec to start to see a purple sky.

Very unprofessional and probably not accurate.

 

These shots were done at 5.6 and iso400, Canon 77D FS, El Nikkor 80mm. All shots were about 1 sec, I believe because how cloudy it was.

All comments always welcome

 

This one shows some old farm equipment, too bad the park was closed, had to shoot from top

 

A little covered eating area

 

Trees off in the distance further up from above pics, noticing the haze starting

 

This shows a farmland with Kamiak Butte 8 miles/12.8Km away, loving the haze. It was perfectly clear visual

 

This was leaving the area and wondered what signs look like in UV. Stop sign and Watch for ice

 

Thanks for checking these out,

I am curious where the peak and cutoff is for this stack, couldn't find any info on stacking different UV filters together.

                                                                                                                                                                                                Thanks

 

 

 

[colinbm]

Thanks for sharing Nate, looks like you are having fun with UV.

[Nate]

@colinbmI am for sure,  thanks.

[Andrea B.]

I always like the ones which show the "layers" becoming lighter as distance & scattering increase. 

 

Curious about the purpose of stacking the ZBW1 with the Antlia?  I don't think we have any info about the Antlia. (Also I don't see a transmission chart on their product page.)

[Nate]

1 hour ago, Andrea B. said:

Curious about the purpose of stacking the ZBW1 with the Antlia?

I wanted to experiment thinking I might peak a little further down around 340 and not as close to 400nm. I tried an S8612/Zwb1 but my s8612 wasn't performing as expected in the sharpness category. The only graph I found was from the site I purchased from. I know it's probably not accurate, and the Antlia alone probably leaks IR as it's only OD3, but stacked with a ZWB1, I'm not seeing any except exposures over 13-15 sec.

Here's where I got it https://agenaastro.com/antlia-venus-ultraviolet-venus-u-filter-1-25.html

I just got back from taking some more pics with it and bright Sun was behind me for this one. 

 

I don't think there's any?, but not a pro at seeing leaks

No color editing, just Clarity and detail refinement in Affinity. WB on plumbers tape card

[Doug A]

Looks excellent @Nate. I'm also partial to the layers in your UV landscape. Your two filter stack is unique and interesting. 

 

I haven't had flare problems with the old metal El-Nikkor 80. It has been used with a hood from the beginning. The old metal El-Nikkor 135 with same lens hood has been difficult. I have finally narrowed the problem down to the M42 adapter and the longer 35-90 helicoid. The 135 does fine on the bellows. So I will try flocking or painting the helicoid interior. 

 

Thanks,

Doug A

[Nate]

Thanks @Doug A  Having fun experimenting with the purchase fails I made in the past, Shoulda bought the baader first

 

I'm using a 25-59mm helicoid that might leak too, but for outside long shots, it never extends more than 5mm about so haven't noticed yet, I'll keep that in mind, Thanks.

[Andrea B.]

Nate, thank you for the link to the Antlia chart. This unusual filter has an interesting width, bottom, top and FWHM.

Trying to eyeball this chart, I get:

• 295 - 408 nm, approximately, at the bottom.
• 330 - 370 nm, approximately, at the top with 80%+ transmission peak.
• That makes for an approximate FWHM between 310-390 nm with 40% transmission.
  That's a WIDE half-max, man!!

I'm not sure about the violet passage just past 400 nm. Looks rather high? I've never thought that a little bit of violet was anything to worry about. But for this Antlia, I'd need to test further. 

 

Yes, OD 3 is a bit too much IR. But I'd like to see that part of the chart to see where the IR passage is happening. This is a filter I would not want to squelch by putting an IR-blocker over it, but that's probably unavoidable.

 

Quite pricey as these things go given that it is (US)$199.00 for the small 1.25" version !! I should be used to this by now, but UVP members have re-sensitized me to the price issues. I'm debating buying it because it might give some interesting false color?  But I'd have to gather some parts to rear mount it.

 

I will add this chart to the Transmission Charts topic.

 

[Nate]

Your welcome @Andrea B.

I've never used just the Antila with the Nikkor 80, just with a very high UVA pass lens Canon 50mm 1.8. before I knew what I was looking at. I'll definitely do some shots with it when I have more time.

I have it mounted inside the helicoid with a rubber eyepiece part and some rubber washers, with the Nikkor screwed on holding it down. I knew I'd need those parts some day.

[OlDoinyo]

I noticed the UV guard pane on the sign in the first image.

[Nate]

@OlDoinyo That's right, I didn't even think about that my first time out there with a different UV stack.

 

Looks like one side is less blocking

[colinbm]

The left side maybe Lexan & the right side might be Perspex ?

[ulf]

4 hours ago, colinbm said:

The left side maybe Lexan & the right side might be Perspex ?

My thought too.

(Lexan is Polycarbonate (PC) by GE, Perspex is Plexiglas (PMMA).

The mechanical and optical properties of both those materials can vary depending on how they are manufactured and processed.

I encountered both when I was into the optical media. PC is used for the discs (CD, DVD BD), PMMA was often used in the transparent boxes.