Taking Flats on a Petal Shaped Lens Hood

[MarkAR]

Hi All, I have a Samyang 14mm F2.4 lens that has a fixed petal shaped lens hood.

My initial idea to take flats is to get  some opal plastic disks, maybe a couple of 3mm think and a 5mm thick one and shooting at my laptop screen set to white.

https://www.cutplasticsheeting.co.uk/frosted-acrylic-perspex-sheeting/opal-frost-acrylic-sheeting

Trouble it on how to attach the disks to the lens hood, some sort of rubber slip on boot ???

Anyone any other Ideas on a set up to take flats with this lens?

Edited February 11, 2020 by MarkAR

[vlaiv]

Do you remember old cameras, like very old cameras?

They had accordion type shroud on them like this:

You could fashion some sort of shroud like that and have simple plastic ring on one side that you would put over your lens hood - that might be a piece of plastic canister or whatever. That way you can put light source (laptop + diffuser) some distance away from your mount and lens - maybe on a small table or even on a photo tripod (if you use tabled instead of laptop).

Although - you don' really need laptop - two pieces of diffuser glass + led strip glued to one will do the trick.

[MarkAR]

That could work, although I've just found that Samyang do a filter holder.

https://www.ebay.co.uk/itm/Samyang-SFH-14-Filter-Holder-for-Samyang-14mm-F2-8-ED-AS-IF-UMC-MF-New-UK/223852374043?hash=item341ea4281b:g:KHIAAOSwsFZeHcWS

Add 2 sheets of 3mm opal and hopefully that might be enough. Can always dim the laptop screen or sandwich on another sheet.

I'm presuming that the lens hood on the 14mm F2.4 is the same as the F2.8, can't find anything more specific.

[ollypenrice]

Could you not just stand the light source at right angles to the lens and a small distance away from it? Do you really need to attach it?

Olly

[MarkAR]

1 hour ago, ollypenrice said:

Could you not just stand the light source at right angles to the lens and a small distance away from it? Do you really need to attach it?

Olly

Hi Olly, that's pretty much what I was planning to do, hold the laptop up to the lens. It's finding something suitable to hold the opal plastic disks to the lens hood that's the problem. Saying that I have an idea which might work.

How about putting 4 pins or 2 curved pieces to hold the opal sheets on the front, the pins or curved pieces would sit over the larger petals top and bottom and not get into the field of view. Might try that as I don't think the Samyang hood will fit.

[PeterCPC]

I can't see why you want the plastic disks at all. Why not just do as Olly suggested.

Peter

[MarkAR]

1 hour ago, PeterCPC said:

I can't see why you want the plastic disks at all. Why not just do as Olly suggested.

Peter

I think without the disks, the white screen would be too harsh and needs some diffusing. Will take a couple of test shots later.

[ollypenrice]

10 minutes ago, MarkAR said:

I think without the disks, the white screen would be too harsh and needs some diffusing. Will take a couple of test shots later.

You could just put typing paper in front of it. Many of us do that.

Olly

[MarkAR]

Heres what it looks like with nothing to diffuse the screen.

[MarkAR]

Well I managed to get hold of a sheet of 3mm 40% perspex, cut a piece and taped on foam blocks.

 

If anyone wants a piece of the perspex for a filter holder let me know the size and I'll cut a piece.

Edited February 22, 2020 by MarkAR

[MarkAR]

Here's a few screenshots of the flats with details on Canon DPP4