Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
OP
nkistrup
•
Senior Member
•
Posts: 2,497
Re: Hot spots: Function of DoF? Or fstop value?
robgendreau wrote:
nkistrup wrote:
Only occurred to me this morning. For a given lens on a 1.5x crop, it has same DoF as a full frame camera, a full stop higher. Example: f5.6 on a 1.5x crop is the same DoF as f8 on full frame. So if a hot spot shows at f16 on full frame testing, it will show up at f11 on a 1.5 crop?
Or are hot spots a function of the aperture blades of the lens, which are constant for a given fstop value? Curious.
Tough question. See https://kolarivision.com/the-science-of-infrared-hotspots/ eg.
Thanks robgendreau! Didn't answer my question, but learned three things:
- Sensor DO MAKE a difference. Really big take away, since I always ASSUMED that hot spots were strictly a lens issue.
- Testing is dependent on the focus point.
- Gave my Zeiss 50mm f2 a failing grade, when I tested it for hot spots. Wondering if my test procedures were suspect?
Olympus XZ-1
Nikon D7100
Sony a7 III
Sony a6400
Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF
+10 more
Post
(hide subjects)
|
Posted by
|
When
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
1 |
|
|
3 months ago
|
|
|
|
3 months ago
|
1 |
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
1 |
|
|
3 months ago
|
|
|
|
3 months ago
|
2 |
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
1 |
|
|
3 months ago
|
|
|
|
3 months ago
|
2 |
|
|
3 months ago
|
|
|
|
3 months ago
|
|
|
|
3 months ago
|
3 |
|
|
3 months ago
|
|
Keyboard shortcuts:
FForum
PPrevious
NNext
WNext unread
UUpvote
SSubscribe
RReply
QQuote
BBookmark
MMy threads
Color scheme?
Blue /
Yellow
Fujifilm's 30mm F3.5 R WR is a super sharp 24mm-equivalent lens for the company's GFX lineup of digital medium-format cameras. Is it good enough to warrant a place in your camera bag? Find out in our field review.
The Insta360 One R is a unique action camera: it has interchangeable camera modules, including one with a large 1"-type sensor and a Leica lens. We show you how it works and ask, 'who's it for'?
Exposure X6 is the latest Adobe Lightroom competitor from Exposure Software. With great image quality, impressive speed and powerful features, it's a compelling option that doesn't require a monthly subscription.
Sigma's 35mm F2 DG DN designed specifically for mirrorless cameras is a compact, well-built lens that produces lovely images. Is it a good fit for you? Find out in our field review.
US manufacturer Really Right Stuff just released a new lightweight travel tripod, aimed at active and weight-conscious photographers that don't want to compromise on quality. Does its performance justify its high price? Find out in our initial review.
Whether you make a living out of taking professional portraits, or are the weekend warrior who knows their way around flashes and reflectors, you'll want a camera with high resolution, exceptional autofocus and a good selection of portrait prime lenses. Click through to see our picks.
What's the best camera for shooting landscapes? High resolution, weather-sealed bodies and wide dynamic range are all important. In this buying guide we've rounded-up several great cameras for shooting landscapes, and recommended the best.
What’s the best camera costing over $2500? The best high-end camera costing more than $2000 should have plenty of resolution, exceptional build quality, good 4K video capture and top-notch autofocus for advanced and professional users. In this buying guide we’ve rounded up all the current interchangeable lens cameras costing over $2500 and recommended the best.
What's the best camera for travel? Good travel cameras should be small, versatile, and offer good image quality. In this buying guide we've rounded-up several great cameras for travel and recommended the best.
There are a lot of photo/video cameras that have found a role as B-cameras on professional productions or A-camera for amateur and independent productions. We've combed through the options and selected our two favorite cameras in this class.